JP6671453B2 - Mobile communication system, CSG base station and mobile terminal - Google Patents

Description

  The present invention relates to wireless communication technology.

  Among the communication systems called the third generation, the W-CDMA (Wideband Code Division Multiple Access) system has been commercialized in Japan since 2001. Further, by adding a packet transmission channel (HS-DSCH: High Speed-Downlink Shared Channel) to the downlink (individual data channel, individual control channel), it is possible to further speed up data transmission using the downlink. An HSDPA (High Speed Down Link Packet Access) service to be realized has been started. Furthermore, in order to further speed up data transmission in the uplink direction, a service has also been started for the HSUPA (High Speed Up Link Packet Access) system. W-CDMA is a communication system defined by 3GPP (3rd Generation Partnership Project), which is a standardization organization for mobile communication systems, and has been compiled for Release 8 edition.

  In 3GPP, as a communication system different from W-CDMA, “Long Term Evolution LTE” is used for a wireless section, and “System” is referred to as “System” for an entire system configuration including a core network (also simply referred to as a network). A new communication scheme called "System Architecture Evolution SAE" is being studied. In LTE, the access method, wireless channel configuration and protocol are completely different from those of the current W-CDMA (HSDPA / HSUPA). For example, in the access scheme, W-CDMA uses Code Division Multiple Access, whereas LTE uses OFDM (Orthogonal Frequency Division Multiplexing) in the downlink and SC-FDMA (Single) in the uplink. Career Frequency Division Multiple Access) is used. The bandwidth is 5 MHz in W-CDMA, while 1.4 / 3/5/10/15/20 MHz in LTE is selectable for each base station. Further, LTE does not include circuit switching unlike W-CDMA, and uses only a packet communication method.

  In LTE, since a communication system is configured using a new core network different from the W-CDMA core network (GPRS), it is defined as an independent radio access network separate from the W-CDMA network. Therefore, in order to distinguish from a W-CDMA communication system, in an LTE communication system, a base station (Base station) that communicates with a mobile terminal (UE: User Equipment) is an eNB (E-UTRAN NodeB), and a plurality of base stations. A base station controller (Radio Network Controller) for exchanging control data and user data with an EPC (Evolved Packet Core) (also referred to as an aGW: Access Gateway). In the LTE communication system, a unicast service (Unicast) service and an E-MBMS service (Evolved Multimedia Broadcast Multicast Service) are provided. The E-MBMS service is a broadcast-type multimedia service, and may be simply referred to as MBMS. News, weather forecasts, and large-capacity broadcast contents such as mobile broadcasts are transmitted to a plurality of mobile terminals. This is also called a point-to-multipoint service.

  Non-Patent Literature 1 describes current decisions regarding the overall architecture (Architecture) in the LTE system in 3GPP. The overall architecture (Chapter 4 of Non-Patent Document 14) will be described with reference to FIG. FIG. 1 is an explanatory diagram illustrating a configuration of an LTE communication system. In FIG. 1, a control protocol (for example, RRC (Radio Resource Management)) and a user plane (for example, PDCP: Packet Data Convergence Protocol, RLC: Radio Link Control, MAC: Medium Access Control, PHY: Physical layer) for the mobile terminal 101 are a base. If terminating at the station 102, E-UTRAN (Evolved Universal Terrestrial Radio Access) is configured by one or more base stations 102. The base station 102 performs scheduling (Scheduling) and transmission of a paging signal (Paging Signaling, also referred to as paging messages) notified from an MME 103 (Mobility Management Entity). The base stations 102 are connected to each other by an X2 interface. The base station 102 is connected to an EPC (Evolved Packet Core) by an S1 interface, more specifically, to an MME 103 (Mobility Management Entity) by an S1_MME interface, and to an S-GW 104 (Serving Gateway) by an S1_U interface. You. The MME 103 distributes a paging signal to a plurality or a single base station 102. Also, the MME 103 performs mobility control (Mobility control) in a standby state (Idle State). The MME 103 manages a tracking area list when the mobile terminal is in a standby state or an active state (Active State). The S-GW 104 transmits / receives user data to / from one or more base stations 102. The S-GW 104 becomes a local mobility anchor point (Mobility Anchor Point) at the time of handover between base stations. Furthermore, a P-GW (PDN Gateway) exists, and performs packet filtering and UE-ID address assignment for each user.

  Non-Patent Document 1 (Chapter 5) describes the current decision items regarding the frame configuration in the LTE system in 3GPP. This will be described with reference to FIG. FIG. 2 is an explanatory diagram showing a configuration of a radio frame used in the LTE communication system. In FIG. 2, one radio frame (Radio frame) is 10 ms. A radio frame is divided into ten equal-sized sub-frames (Sub-frames). A subframe is divided into two equally sized slots. The first (# 0) and sixth (# 5) subframes for each frame include a Downlink Synchronization Signal (SS). The synchronization signal includes a first synchronization signal (Primary Synchronization Signal: P-SS) and a second synchronization signal (Secondary Synchronization Signal: S-SS). Multiplexing of channels other than MBSFN and for MBSFN (Multimedia Broadcast multicast service Single Frequency Network) is performed in subframe units. Hereinafter, a subframe for MBSFN transmission is referred to as an MBSFN sub-frame. Non-Patent Document 2 describes an example of signaling at the time of MBSFN subframe allocation. FIG. 3 is an explanatory diagram showing the configuration of the MBSFN frame. In FIG. 3, an MBSFN subframe is allocated for each MBSFN frame. A set of MBSFN frames (MBSFN frame Cluster) is scheduled. A repetition period (Repetition Period) of a set of MBSFN frames is assigned.

  Non-Patent Document 1 describes the current decision items regarding the channel configuration in the LTE system in 3GPP. It is assumed that the same channel configuration as that of a non-CSG cell is used in a closed subscriber group cell (CSG) cell. A physical channel (Physical channel) (Chapter 5 of Non-Patent Document 15) will be described with reference to FIG. FIG. 4 is an explanatory diagram illustrating a physical channel used in the LTE communication system. In FIG. 4, a physical broadcast channel 401 (Physical Broadcast channel: PBCH) is a downlink channel transmitted from the base station 102 to the mobile terminal 101. A BCH transport block is mapped to four subframes in a 40 ms interval. There is no apparent signaling at 40 ms timing. Physical control format indicator channel 402 (Physical Control format indicator channel: PCFICH) is transmitted from base station 102 to mobile terminal 101. PCFICH notifies base station 102 to mobile terminal 101 about the number of OFDM symbols used for PDCCHs. PCFICH is transmitted for each subframe. The physical downlink control channel 403 (Physical downlink control channel: PDCCH) is a downlink channel transmitted from the base station 102 to the mobile terminal 101. The PDCCH includes resource allocation (allocation), HARQ information on DL-SCH (a downlink shared channel that is one of the transport channels shown in FIG. 5), and PCH (paging that is one of the transport channels shown in FIG. 5). Channel). The PDCCH carries an Uplink Scheduling Grant. PDCCH carries ACK / Nack which is a response signal to uplink transmission. PDCCH is also called L1 / L2 control signal. The physical downlink shared channel 404 (Physical downlink shared channel: PDSCH) is a downlink channel transmitted from the base station 102 to the mobile terminal 101. On the PDSCH, a DL-SCH (downlink shared channel) as a transport channel and a PCH as a transport channel are mapped. The physical multicast channel 405 (Physical multicast channel: PMCH) is a downlink channel transmitted from the base station 102 to the mobile terminal 101. The PMCH is mapped with an MCH (multicast channel) as a transport channel.

  A physical uplink control channel 406 (Physical Uplink control channel: PUCCH) is an uplink channel transmitted from the mobile terminal 101 to the base station 102. PUCCH carries ACK / Nack which is a response signal (response) to downlink transmission. PUCCH carries a CQI (Channel Quality indicator) report. The CQI is quality information indicating the quality of received data or the quality of a communication channel. PUCCH also carries a scheduling request (Scheduling Request: SR). The physical uplink shared channel 407 (Physical Uplink shared channel: PUSCH) is an uplink channel transmitted from the mobile terminal 101 to the base station 102. The PUSCH is mapped with the UL-SCH (uplink shared channel which is one of the transport channels shown in FIG. 5). The physical HARQ indicator channel 408 (Physical Hybrid ARQ indicator channel: PHICH) is a downlink channel transmitted from the base station 102 to the mobile terminal 101. PHICH carries ACK / Nack which is a response to uplink transmission. Physical random access channel 409 (Physical random access channel: PRACH) is an uplink channel transmitted from mobile terminal 101 to base station 102. The PRACH carries a random access preamble.

  As a downlink reference signal (Reference signal), a symbol known as a mobile communication system is inserted into the first, third, and last OFDM symbols of each slot. As a measurement of the physical layer of the mobile terminal, there is a reference symbol received power (RSRP) of a reference symbol.

  The transport channel (Transport channel) will be described with reference to FIG. FIG. 5 is an explanatory diagram illustrating transport channels used in the LTE communication system. FIG. 5A shows mapping between a downlink transport channel and a downlink physical channel. FIG. 5B shows mapping between an uplink transport channel and an uplink physical channel. For a downlink transport channel, a broadcast channel (Broadcast channel: BCH) is broadcast to the entire base station (cell). The BCH is mapped to a physical broadcast channel (PBCH). Retransmission control by HARQ (Hybrid ARQ) is applied to a downlink shared channel (Downlink Shared channel: DL-SCH). Broadcasting to the entire base station (cell) is possible. Supports dynamic or semi-static resource allocation. Semi-static resource allocation is also called persistent scheduling (Persistent Scheduling). The mobile terminal supports DRX (Discontinuous reception) to reduce power consumption of the mobile terminal. DL-SCH is mapped to a physical downlink shared channel (PDSCH). A paging channel (Paging channel: PCH) supports DRX of a mobile terminal to enable low power consumption of the mobile terminal. Broadcasting to the entire base station (cell) is required. It is dynamically mapped to a physical resource such as a physical downlink shared channel (PDSCH) that can be used for traffic or a physical resource such as a physical downlink control channel (PDCCH) of another control channel. A multicast channel (Multicast channel: MCH) is used for broadcasting to the entire base station (cell). Supports SFN combining of MBMS services (MTCH and MCCH) in multi-cell transmission. Support semi-static resource allocation. MCH is mapped to PMCH.

  Retransmission control by HARQ (Hybrid ARQ) is applied to an uplink shared channel (Uplink Shared channel: UL-SCH). Supports dynamic or semi-static resource allocation. UL-SCH is mapped to a physical uplink shared channel (PUSCH). The random access channel (Random access channel: RACH) shown in FIG. 5B is limited to control information. There is a risk of collision. The RACH is mapped to a physical random access channel (PRACH). HARQ will be described.

  HARQ is a technology for improving the communication quality of a transmission path by combining automatic retransmission (Automatic Repeat reQuest) and error correction (Forward Error Correction). There is an advantage that error correction functions effectively by retransmission even on a transmission line whose communication quality changes. In particular, it is possible to further improve the quality by combining the reception result of the initial transmission and the reception result of the retransmission for retransmission. An example of a retransmission method will be described. If the receiving side fails to decode the received data correctly (when a CRC Cyclic Redundancy Check error occurs (CRC = NG)), the receiving side transmits "Nack" to the transmitting side. The transmitting side that has received "Nack" retransmits the data. When the receiving side successfully decodes the received data (when no CRC error occurs (CRC = OK)), the receiving side transmits “Ack” to the transmitting side. The transmitting side that has received “Ack” transmits the next data. One example of the HARQ scheme is “chase combining”. Chase combining transmits the same data sequence for initial transmission and retransmission, and is a method of improving the gain by combining the initial transmission data sequence and the retransmission data sequence in retransmission. This is a concept that even if there is an error in the initial transmission data, some data is partially accurate, and the data can be transmitted with higher precision by combining the accurate data of the initial transmission data and the retransmission data. Based on Another example of the HARQ scheme is IR (Incremental Redundancy). The IR increases the redundancy, and increases the redundancy in combination with the initial transmission by transmitting a parity bit in retransmission, and improves the quality by an error correction function.

  A logical channel will be described with reference to FIG. FIG. 6 is an explanatory diagram illustrating logical channels used in the LTE communication system. FIG. 6A shows mapping between a downlink logical channel and a downlink transport channel. FIG. 6B shows mapping between an uplink logical channel and an uplink transport channel. A broadcast control channel (Broadcast control channel: BCCH) is a downlink channel for broadcast system control information. The BCCH that is a logical channel is mapped to a broadcast channel (BCH) that is a transport channel or a downlink shared channel (DL-SCH). The paging control channel (Paging control channel: PCCH) is a downlink channel for transmitting a paging signal. The PCCH is used when the network does not know the cell location of the mobile terminal. The PCCH that is a logical channel is mapped to a paging channel (PCH) that is a transport channel. The common control channel (Common control channel: CCCH) is a channel for transmission control information between the mobile terminal and the base station. The CCCH is used when the mobile terminal has no RRC connection with the network. In the downlink method, the CCCH is mapped to a downlink shared channel (DL-SCH) which is a transport channel. In the uplink direction, the CCCH is mapped to an uplink shared channel (UL-SCH), which is a transport channel.

  The multicast control channel (Multicast control channel: MCCH) is a downlink channel for one-to-many transmission. This is a channel used for transmission of MBMS control information for one or several MTCHs from the network to the mobile terminal. The MCCH is a channel used only for a mobile terminal receiving MBMS. The MCCH is mapped to a downlink shared channel (DL-SCH) or a multicast channel (MCH) which is a transport channel. A dedicated control channel (Dedicated control channel: DCCH) is a channel for transmitting dedicated control information between a mobile terminal and a network. The DCCH is mapped to the uplink shared channel (UL-SCH) in the uplink, and is mapped to the downlink shared channel (DL-SCH) in the downlink. The dedicated traffic channel (DTCH) is a channel for one-to-one communication to a dedicated mobile terminal for transmitting user information. The DTCH exists for both uplink and downlink. The DTCH is mapped to the uplink shared channel (UL-SCH) in the uplink, and is mapped to the downlink shared channel (DL-SCH) in the downlink. A multicast traffic channel (Multicast Traffic channel: MTCH) is a downlink channel for transmitting traffic data from a network to a mobile terminal. MTCH is a channel used only for a mobile terminal receiving MBMS. The MTCH is mapped to a downlink shared channel (DL-SCH) or a multicast channel (MCH).

  GCI is a Global Cell Identity. A CSG cell (Closed Subscriber Group cell) is introduced in LTE and UMTS (Universal Mobile Telecommunication System). The CSG will be described below (Non-Patent Document 7 Chapter 3.1). A CSG (Closed Subscriber Group) is a cell in which an operator specifies an available subscriber (cell for a specific subscriber). The specified subscriber is allowed to access one or more E-UTRAN cells of the PLMN (Public Land Mobile Network). One or more E-UTRAN cells to which the specified subscriber is permitted to access are called “CSG cell (s)”. However, PLMN has access restrictions. The CSG cell is a part of the PLMN that broadcasts a unique CSG identity (CSG identity: CSG ID, CSG-ID). Members of the subscriber group who have been registered in advance and permitted to access the CSG cell using the CSG-ID which is access permission information. The CSG-ID is broadcast by a CSG cell or a cell. There are a plurality of CSG-IDs in a mobile communication system. The CSG-ID is used by a terminal (UE) to facilitate access of CSG-related members. The use of a CSG cell or information broadcasted by the cell as a tracking area code (Tracking Area Code TAC) instead of the CSG-ID is being discussed at the 3GPP meeting. The location tracking of a mobile terminal is performed in units of an area including one or more cells. The position tracking is for tracking the position of the mobile terminal even when communication is not being performed (standby state) and making it possible to call the mobile terminal (the mobile terminal receives a call). The area for tracking the position of the mobile terminal is called a tracking area. The CSG White List is a list stored in USIM in which all CSG IDs of CSG cells to which the subscriber belongs are recorded. The whitelist in the mobile terminal is given by higher layers. As a result, the base station of the CSG cell allocates radio resources to mobile terminals.

  The “suitable cell” (Suitable cell) will be described below (Non-Patent Document 7, Chapter 4.3). The "suitable cell" (Suitable cell) is a cell on which the UE camps on (Camp ON) to receive a normal service. Such cells may be (1) that the cell is part of a selected or registered PLMN, or a PLMN of an "Equivalent PLMN list", and (2) provided by a non-access stratum (NAS). The latest information must further satisfy the following conditions: (1) The cell is not a barred cell. (2) The cell is not part of the “LAs prohibited for roaming” list, but part of at least one tracking area (TA). In that case, the cell needs to satisfy the above (1), (3) that the cell satisfies the cell selection evaluation criterion, and (4) that the cell is a system information (SI) as a CSG cell. ), The CSG-ID is a part of the “CSG WhiteList” (CSG WhiteList) of the UE (contained in the CSG WhiteList of the UE).

  An “acceptable cell” (Acceptable cell) will be described below (Non-Patent Document 7 Chapter 4.3). This is a cell where the UE camps on to receive a limited service (emergency call). Such a cell shall fulfill all the following requirements: That is, a minimum set of requirements for initiating an emergency call in an E-UTRAN network is shown below. (1) The cell is not a barred cell. (2) The cell satisfies the cell selection evaluation criteria.

  Camping on a cell means that the UE has completed cell selection / reselection processing and the UE has selected a cell for monitoring system information and paging information.

3GPP TS36.300 V8.6.0 3GPP R1-072963 3GPP TR R3.020 V0.6.0 3GPP R2-082899 3GPP R2-083494 3GPP TS36.331 V8.3.0 3GPP TS36.304 V8.3.0 3GPP R2-08346 3GPP S1-083461 3GPP R2-093950 3GPP R2-093864 3GPP R2-093138 3GPP TS36.213 3GPP TS36.101

  Many CSG (Closed Subscriber Group cell) cells are required to be installed in condominiums, schools, companies, and the like. For example, there is a demand for a usage method in which a CSG cell is installed for each room in a condominium, for each classroom in a school, and for each section in a company, and only a user registered in each CSG cell can use the CSG cell. Furthermore, CSG cells are assumed to have a portable size and weight, and installation and removal of these CSG cells are required to be performed frequently and flexibly. Considering such requirements, radio waves from many CSG cells are transmitted at a certain point at the same time. That is, in an apartment, a school, a company, or the like, a situation occurs in which a mobile terminal is located at a position where radio waves from many CSG cells can reach.

  In addition, the CSG cell is installed in a place where radio waves from the non-CSG cell do not reach, and it is required to enable communication with a mobile terminal via the CSG cell. For example, at present, there are many situations in which apartment rooms do not receive radio waves from non-CSG cells. In such a case, a CSG cell is installed for each room of the condominium, and a CSG is configured with the CSG cell for each room and a CSG-ID is given. For example, a mobile terminal owned by a resident of each room may perform user access registration to a CSG cell of each room. In such a situation, the mobile terminal does not reach the radio waves from the non-CSG cells, but exists in a place where radio waves from many CSG cells can reach. In such a case, depending on the radio wave propagation environment, radio waves from a CSG cell registered for user access may not reach the mobile terminal, or even if it does, the received power may be weaker than other CSG cells. I do.

  As described above, in the case of a mobile terminal located at a position where radio waves from a large number of CSG cells reach, a situation in which search and cell selection are repeated endlessly for many inaccessible CSG cells (that is, CSG cells for which user access is not registered). Occurs. In such a case, the system causes a control delay, a reduction in radio resource use efficiency, and a decrease in signaling efficiency. In addition, there is a problem that power consumption of a mobile terminal that repeats cell search increases. These problems become important when the future arrangement of CSG cells is assumed as described above. The present invention has been made to solve these problems.

  The mobile communication system according to the present invention is provided from a CSG base station, which is a base station provided in a CSG cell belonging to a CSG of a closed subscriber group, to a base station provided in another cell, or provided in another cell. In the mobile communication system in which the mobile terminal performs handover from the base station to the CSG base station, the mobile terminal performing the handover is a CSG terminal belonging to the CSG and a non-CSG terminal not belonging to the CSG, It is characterized in that the procedure of handover is made different.

  A CSG base station according to the present invention is a base station provided in a CSG cell belonging to a CSG of a closed subscriber group, and a mobile terminal performs handover to a base station provided in another cell, or to another cell. A handover procedure is performed depending on whether the mobile terminal is a CSG base station to which the mobile terminal performs handover from the provided base station and the mobile terminal to perform the handover is a CSG terminal belonging to the CSG or a non-CSG terminal not belonging to the CSG. Are characterized by differentiating from each other.

  A mobile terminal according to the present invention is a base station provided in another cell from a CSG base station which is a base station provided in a CSG cell belonging to a CSG of a closed subscriber group, or a base provided in another cell. Differentiating the handover procedure between a mobile terminal that performs handover from a station to a CSG base station and the handover mobile terminal is a CSG terminal belonging to the CSG and a non-CSG terminal not belonging to the CSG It is characterized by.

  According to the present invention, a mobile terminal can obtain a list of cells for a specific subscriber to which access is permitted.

FIG. 2 is an explanatory diagram illustrating a configuration of an LTE communication system. FIG. 2 is an explanatory diagram illustrating a configuration of an LTE communication system. FIG. 2 is an explanatory diagram illustrating a configuration of a radio frame used in the LTE communication system. FIG. 3 is an explanatory diagram illustrating a configuration of an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) frame. FIG. 2 is an explanatory diagram illustrating a physical channel used in an LTE communication system. FIG. 2 is an explanatory diagram illustrating transport channels used in an LTE communication system. FIG. 3 is an explanatory diagram illustrating logical channels used in an LTE communication system. FIG. 1 is a block diagram illustrating an overall configuration of a mobile communication system currently being discussed in 3GPP. It is a block diagram showing composition of mobile terminal 311 concerning the present invention. FIG. 14 is a block diagram illustrating a configuration of a base station 312 according to the present invention. FIG. 3 is a block diagram illustrating a configuration of an MME according to the present invention. FIG. 2 is a block diagram illustrating a configuration of a HeNBGW according to the present invention. 3 is a flowchart illustrating an outline of a cell search performed by a mobile terminal (UE) in an LTE communication system. It is a cell conceptual diagram in case there exist many CSG cells. It is a flowchart of the cell search of the mobile terminal located in the position where the radio wave from many Home-eNB reaches. FIG. 4 is a sequence diagram for reporting PCI split information according to the first embodiment. 6 is a flowchart of a cell search of a mobile terminal according to Embodiment 1. FIG. 7 shows a sequence diagram for reporting PCI split information according to a first modification of the first embodiment. It is a sequence diagram which alert | reports the PCI split information of another frequency layer. It is a figure which shows the case where Home-eNB exists in the area of eNB. FIG. 9 is a sequence diagram of a method of notifying a whitelist via a non-CSG cell, which is discussed in 3GPP. It is a figure which shows the case where Home-eNB (CSG cell) which the mobile terminal registered is outside the area of non-CSG cell. FIG. 17 is a sequence diagram in a case where a mobile terminal having no whitelist according to Embodiment 3 starts manual search. It is a figure which shows the case where a mobile terminal is under the umbrella of many CSG cells, not the umbrella of a non-CSG cell. FIG. 17 is a sequence diagram when a manual search is performed in the fourth embodiment. FIG. 9 is a sequence diagram of a method for transmitting a whitelist message before transmitting a TAU reject. FIG. 25 is a sequence diagram in a method disclosed in a first modification of the fifth embodiment. FIG. 13 is a sequence diagram of a method for prohibiting a mobile terminal from establishing an RRC connection to a cell when a TAU reject message is received once from the same cell. FIG. 9 is a diagram illustrating processing in a mobile terminal when a timer is provided. FIG. 39 is a sequence diagram of a method for transmitting a whitelist registration message before transmitting an n-th TAU reject message in the seventh embodiment. FIG. 13 is a sequence diagram of a method in which a mobile terminal prohibits an RRC connection request to the cell when receiving an RRC connection reject message once from the same cell. FIG. 11 is a sequence diagram of a method of transmitting a whitelist registration message before a CSG cell belonging to a CSG-ID for which the mobile terminal has not performed user access registration transmits an RRC connection reject message. 146 is a sequence diagram of a method of returning Ack / Nack of reception success / failure of a whitelist (update) message in Embodiment 11. [FIG. 9 is a flowchart illustrating a process of a mobile terminal for reestablishing an RRC connection. It is a flowchart which shows the process of the mobile terminal concerning RRC connection re-establishment when introducing a CSG cell. It is a flowchart which shows the process of the mobile terminal concerning RRC connection re-establishment when the timer of the permissible time until the cell in E-UTRA is selected is provided separately for whitelist useful and whitelist unnecessary. It is a flowchart which shows the process of the mobile terminal which concerns on RRC connection reset when notifying the timer of a whitelist useful from a CSG cell. It is a flowchart which shows the process of the mobile terminal which concerns on RRC connection reset when notifying the timer of a whitelist useful from a CSG cell. 6 is a flowchart illustrating processing of a mobile terminal related to priorities according to the related art. It is a flowchart which shows a process of the mobile terminal when the priority order whitelist useful and whitelist unnecessary are separately provided. It is a flowchart which shows the process of the mobile terminal when the effective time of a priority order is provided with whitelist useful and whitelist non-use separately. 9 is a flowchart illustrating a process of a mobile terminal in a cell reselection procedure of the related art. 10 is a flowchart illustrating a process of a mobile terminal in a cell reselection procedure using a cycle of performing measurement for cell reselection even when a mobile terminal having a CSG-ID in a whitelist has a good serving cell state. A flowchart showing processing of a mobile terminal in a cell reselection procedure using a cycle and an offset value in which a mobile terminal having a CSG-ID in a whitelist performs measurement for cell reselection even when the state of a serving cell is good. It is. The mobile terminal having the CSG-ID in the whitelist cancels the period for performing measurement for cell reselection and the period for performing measurement when cell reselection cannot be performed even when the serving cell is in good condition. 9 is a flowchart illustrating processing of a mobile terminal in a cell reselection procedure. 11 is a flowchart illustrating processing of a mobile terminal in a cell reselection procedure using a metric for starting a cell reselection for a mobile terminal having a CSG-ID in the whitelist by the mobile terminal having the CSG-ID in the whitelist. It is. It is a flowchart which shows the process of the mobile terminal when the offset is separately provided for the UE which has a CSG-ID in a whitelist and the UE which does not have it, and the reselection procedure to a hybrid cell is made different. 26 is a flowchart illustrating a cell reselection procedure process of a mobile terminal in a case where Embodiment 15 and a method of separately providing an offset are combined. It is a flowchart which shows the cell reselection procedure process of the mobile terminal at the time of providing an offset separately in order to make it difficult to reselect a cell from a hybrid cell. It is a conceptual diagram in case UE of a CSG member stays longer than UE of a non-CSG member in a hybrid cell. It is a procedure example until PRACH initial transmission in a hybrid cell. It is a procedure outline until PRACH initial transmission in a hybrid cell when the difference of a cell reselection threshold is used.

Embodiment 1 FIG.
FIG. 7 is a block diagram showing an overall configuration of an LTE mobile communication system currently under discussion in 3GPP. Currently, in 3GPP, CSG (Closed Subscriber Group) cells (e-UTRAN Home-eNodeB (Home-eNB, HeNB), UTRAN Home-NB (HNB)) and non-CSG cells (e-UTRAN eNodeB (eNB ), Node B (NB) of UTRAN, BSS of GERAN), and the overall configuration of the system including e-UTRAN is as shown in FIG. 7 (a) or (b). It has been proposed (Non-Patent Documents 1 and 3). FIG. 7A will be described. A mobile terminal (UE) 71 performs transmission and reception with a base station 72. The base station 72 is classified into an eNB (non-CSG cell) 72-1 and a Home-eNB (CSG cell) 72-2. The eNB 72-1 is connected to the MME 73 via the interface S1, and control information is communicated between the eNB and the MME. A plurality of MMEs are connected to one eNB. The Home-eNB 72-2 is connected to the MME 73 by the interface S1, and control information is communicated between the Home-eNB and the MME. A plurality of Home-eNBs are connected to one MME.

  Next, FIG. 7B will be described. A mobile terminal (UE) 71 performs transmission and reception with a base station 72. The base station 72 is classified into an eNB (non-CSG cell) 72-1 and a Home-eNB (CSG cell) 72-2. As in FIG. 7A, the eNB 72-1 is connected to the MME 73 via the interface S1, and control information is communicated between the eNB and the MME. A plurality of MMEs are connected to one eNB. On the other hand, the Home-eNB 72-2 is connected to the MME 73 via a HeNBGW (Home-eNB GateWay) 74. Home-eNB and HeGW are connected by interface S1, and HeNBGW74 and MME73 are connected via interface S1_flex. One or more Home-eNBs 72-2 are connected to one HeNBGW 74, and information is communicated through S1. HeNBGW74 is connected to one or more MME73, and information is communicated through S1_flex.

  By connecting one HeNBGW 74 to a Home-eNB belonging to the same CSG-ID using the configuration of FIG. 7B, a plurality of pieces of information belonging to the same CSG-ID belonging to the same When transmitting to the Home-eNB 72-2, the signal is transmitted to the HeNBGW 74 once, and then transmitted to a plurality of Home-eNBs 72-2, so that the signaling efficiency is improved compared to the case where the signal is directly transmitted to the plurality of Home-eNBs 72-2. Can be enhanced. On the other hand, when each Home-eNB 72-2 communicates individual information with the MME 73, the Home-eNB 72-2 passes through the HeNBGW 74 but only passes (transmits) the information without processing it. And the MME 73 can be communicated as if they were directly connected.

  FIG. 8 is a block diagram showing the configuration of the mobile terminal (terminal 71 in FIG. 7) according to the present invention. The transmission process of the mobile terminal shown in FIG. 8 will be described. First, control data from the protocol processing unit 801 and user data from the application unit 802 are stored in the transmission data buffer unit 803. The data stored in the transmission data buffer unit 803 is passed to the encoder unit 804, where the data is subjected to encoding processing such as error correction. Data directly output from the transmission data buffer unit 803 to the modulation unit 805 without performing the encoding process may exist. The data encoded by the encoder unit 804 is subjected to modulation processing by the modulation unit 805. After the modulated data is converted to a baseband signal, it is output to frequency conversion section 806 and converted to a radio transmission frequency. After that, a transmission signal is transmitted from the antenna 807 to the base station 312. The receiving process of the mobile terminal 311 is executed as follows. A wireless signal from the base station 312 is received by the antenna 807. The received signal is converted from a radio reception frequency to a baseband signal by frequency conversion section 806, and demodulation processing is performed by demodulation section 808. The demodulated data is passed to a decoder unit 809, where decoding processing such as error correction is performed. Of the decoded data, control data is passed to the protocol processing unit 801, and user data is passed to the application unit 802. A series of processing of the mobile terminal is controlled by the control unit 810. Therefore, the control unit 810 is connected to each unit (801 to 809), although not shown in the drawing.

  FIG. 9 is a block diagram showing a configuration of the base station (base station 72 in FIG. 7) according to the present invention. The transmission process of the base station shown in FIG. 9 will be described. EPC communication section 901 transmits and receives data between base station 72 and EPC (MME 73, HeNBGW 74, etc.). The other base station communication unit 902 transmits and receives data to and from another base station. The EPC communication unit 901 and the other base station communication unit 902 exchange information with the protocol processing unit 903, respectively. Control data from the protocol processing unit 903 and user data and control data from the EPC communication unit 901 and the other base station communication unit 902 are stored in the transmission data buffer unit 904. The data stored in the transmission data buffer unit 904 is passed to an encoder unit 905, where the data is subjected to encoding processing such as error correction. Data directly output from the transmission data buffer unit 904 to the modulation unit 906 without performing the encoding process may exist. The encoded data is subjected to a modulation process in a modulation unit 906. After the modulated data is converted to a baseband signal, it is output to frequency conversion section 907 and converted to a radio transmission frequency. After that, a transmission signal is transmitted from the antenna 908 to one or more mobile terminals 71. The receiving process of the base station 72 is executed as follows. Radio signals from one or more mobile terminals 311 are received by the antenna 908. The received signal is converted from a radio reception frequency to a baseband signal by a frequency conversion section 907, and demodulation processing is performed by a demodulation section 909. The demodulated data is passed to the decoder unit 910, where decoding processing such as error correction is performed. Among the decoded data, control data is passed to the protocol processing unit 903 or the EPC communication unit 901 and the other base station communication unit 902, and user data is passed to the EPC communication unit 901 and the other base station communication unit 902. A series of processes of the base station 72 is controlled by the control unit 911. Accordingly, the control unit 911 is connected to each unit (901 to 910) although not shown in the drawing.

  FIG. 10 is a block diagram illustrating a configuration of an MME (Mobility Management Entity) according to the present invention. The PDN GW communication unit 1001 transmits and receives data between the MME 73 and the PDN GW. The base station communication unit 1002 transmits and receives data between the MME 73 and the base station 72 using the S1 interface. If the data received from the PDN GW is user data, the user data is passed from the PDN GW communication unit 1001 to the base station communication unit 1002 via the user plane processing unit 1003, and is transmitted to one or a plurality of base stations 72. You. If the data received from the base station 72 is user data, the user data is passed from the base station communication unit 1002 to the PDN GW communication unit 1001 via the user plane processing unit 1003, and transmitted to the PDN GW.

  If the data received from the PDN GW is control data, the control data is passed from the PDN GW communication unit 1001 to the control plane control unit 1005. If the data received from the base station 72 is control data, the control data is passed from the base station communication unit 1002 to the control plane control unit 1005. The HeNBGW communication unit 1004 is provided when the HeNBGW 74 is present, and performs data transmission and reception between the MME 73 and the HeNBGW 74 by an interface (IF) depending on the information type. The control data received from the HeNBGW communication unit 1004 is passed from the HeNBGW communication unit 1004 to the control plane control unit 1005. The result of the process in the control plane control unit 1005 is transmitted to the PDN GW via the PDN GW communication unit 1001. The result processed by the control plane control unit 1005 is transmitted to one or more base stations 72 via the S1 interface via the base station communication unit 1002, and to one or a plurality of HeNBGW 74 via the HeNBGW communication unit 1004. Sent.

  The control plane control unit 1005 includes a NAS security unit 1005-1, an SAE bearer control unit 1005-2, an idle state (Idle State) mobility management unit 1005-3, and performs overall processing for the control plane. The NAS security unit 1005-1 performs security of a NAS (Non-Access Stratum) message. The SAE bearer control unit 1005-2 performs management of a bearer of SAE (System Architecture Evolution) and the like. The idle state mobility management unit 1005-3 performs mobility management in a standby (LTE-IDLE state, also simply referred to as idle) state, generation and control of a paging signal in a standby state, one or more mobile terminals 71 being served thereby. Adds, deletes, updates, and searches the tracking area (TA), and manages the tracking area list (TA list). The MME initiates a paging protocol by transmitting a paging message to a cell belonging to a tracking area (tracking area: TA) in which the UE is registered. The management of the CSG of the Home-eNB 72-2 connected to the MME, the management of the CSG-ID, and the management of the whitelist may be performed by the idle state mobility management unit 1005-3. In the management of the CSG-ID, the relationship between the mobile terminal corresponding to the CSG-ID and the CSG cell is managed (addition, deletion, update, search). For example, the relationship may be one or more mobile terminals registered for user access to a certain CSG-ID and CSG cells belonging to the CSG-ID. In the whitelist management, the relationship between the mobile terminal and the CSG-ID is managed (addition, deletion, update, search). For example, one or a plurality of CSG-IDs registered by a certain mobile terminal as a user may be stored in the whitelist. Although the management regarding these CSGs may be performed in other parts in the MME 73, by performing them in the idle state mobility management unit 1005-3, tracking instead of the CSG-ID, which is currently being discussed at the 3GPP meeting, is performed. A method using an area code (Tracking Area Code) can be performed efficiently. A series of processes of the MME 313 is controlled by the control unit 1006. Therefore, the control unit 1006 is connected to each unit (1001 to 1005) although omitted in the drawing.

  FIG. 11 is a block diagram showing a configuration of the HeNBGW according to the present invention. The EPC communication unit 1101 transmits and receives data between the HeNBGW 74 and the MME 73 using the S1_flex interface. The base station communication unit 1102 transmits and receives data between the HeNBGW 74 and the Home-eNB 72-2 by using the S1 interface. The location processing unit 1103 performs a process of transmitting registration information and other information to a plurality of Home-eNBs from data from the MME 73 passed via the EPC communication unit 1101. The data processed by the location processing unit 1103 is passed to the base station communication unit 1102 and transmitted to one or a plurality of Home-eNBs 72-2 via the S1 interface. Data that is passed (transmitted) without requiring processing in the location processing unit 1103 is passed from the EPC communication unit 1101 to the base station communication unit 1102, and is transmitted to one or a plurality of Home-eNBs 72-2 via the S1 interface. Sent. A series of processes of the HeNBGW 74 is controlled by the control unit 1104. Therefore, the control unit 1104 is connected to each unit (1101 to 1103) although omitted in the drawing.

  Next, an example of a general cell search method in a mobile communication system will be described. FIG. 12 is a flowchart showing an outline from a cell search to a standby operation performed by a mobile terminal (UE) in an LTE communication system. When the mobile terminal starts cell search, a slot timing and a frame timing are determined using a first synchronization signal (P-SS) and a second synchronization signal (S-SS) transmitted from a peripheral base station in step ST1201. Synchronize. In addition to the P-SS and the S-SS, the synchronization signal (SS) is assigned a synchronization code corresponding to a physical cell identity (PCI) assigned to each cell on a one-to-one basis. Currently, 504 types of PCIs are under study, and synchronization is performed using the 504 types of PCIs, and the PCIs of the synchronized cells are detected (identified). Next, for a synchronized cell, in step ST1202, a reference signal RS (Reference Signal) transmitted from the base station for each cell is detected and the received power is measured. The reference signal RS uses a code that has a one-to-one correspondence with PCI, and can be separated from other cells by correlating with the code. By deriving the RS code of the cell from the PCI identified in ST1201, it is possible to detect the RS and measure the RS received power. Next, in ST1203, a cell having the best RS reception quality (for example, a cell having the highest RS reception power, the best cell) is selected from one or more cells detected up to ST1202. Next, in ST1204, PBCH of the best cell is received, and BCCH as broadcast information is obtained. The BCCH on the PBCH carries an MIB (Master Information Block) containing cell configuration information. The MIB information includes, for example, a DL (downlink) system bandwidth, the number of transmitting antennas, and an SFN (System Frame Number).

  Next, in 1205, the DL-SCH of the cell is received based on the cell configuration information of the MIB, and an SIB (System Information Block) 1 in the broadcast information BCCH is obtained. The SIB1 includes information on access to the cell, information on cell selection, and scheduling information of another SIB (SIBk; k ≧ 2). The SIB1 includes a TAC (Tracking Area Code). In addition, the CSG-ID may be included in the SIB1. Next, in ST1206, the mobile terminal compares the TAC received in ST1205 with the TAC already held by the mobile terminal. As a result of comparison, if they are the same, the cell enters a standby operation. If the mobile terminals are different from each other, the mobile terminal requests a change of the TA to perform a TAU (Tracking Area Update) to a core network (EPC) (including an MME) through the cell. The core network updates the TA based on the identification number (eg, UE-ID) of the mobile terminal transmitted from the mobile terminal together with the TAU request signal. After updating the TA, the core network sends a TAU acknowledgment signal to the mobile terminal. The mobile terminal rewrites (updates) the TAC (or TAC list) held by the mobile terminal with the TAC of the cell. Thereafter, the mobile terminal enters a standby operation in the cell.

  In LTE and UMTS (Universal Mobile Telecommunication System), introduction of a CSG (Closed Subscriber Group) cell is under study. As described above, access is allowed only to one or a plurality of mobile terminals registered in the CSG cell. One or more mobile terminals registered with the CSG cell make up one CSG. A unique identification number called CSG-ID is assigned to the CSG configured as described above. Note that one CSG may include a plurality of CSG cells. If a mobile terminal registers in any one CSG cell, it can access another CSG cell to which the CSG cell belongs. In addition, a Home-NB in LTE or a Home-NB in UMTS may be used as a CSG cell. One or more CSG cells included in one CSG-ID belong to the same TA. For this reason, one or a plurality of CSG cells included in one CSG-ID broadcast the same TAC on the broadcast information to the mobile terminals being served thereby. A mobile terminal registered in a CSG cell has a whitelist. Specifically, the whitelist is stored in the SIM / USIM. The CSG information of the CSG cell registered by the mobile terminal is placed in the whitelist. Specific examples of the CSG information include CSG-ID, TAI (Tracking Area Identity), and TAC. As long as the CSG-ID and the TAC are associated with each other, one of them is sufficient. GCI may be used as long as CSG-ID or TAC is associated with GCI (Global Cell Identity). As described above, a mobile terminal having no whitelist (including the case where the whitelist is empty in the present invention) cannot access the CSG cell, and accesses only the non-CSG cell. Can not. On the other hand, the mobile terminal having the whitelist can access both the CSG cell of the registered CSG-ID and the non-CSG cell.

  A problem arises when a mobile terminal performs a cell search in a place where many CSG cells exist. FIG. 13 shows a conceptual diagram of a cell in the case where many CSG cells exist. In the figure, reference numeral 1301 denotes a non-CSG cell by eNB, and 1302 denotes a CSG cell by Home-eNB. 1303 is a mobile terminal. Many CSG cells are required to be installed in condominiums, schools, companies, and the like. In a condominium, a CSG cell is installed for each room in a school, for each classroom in a school, and for each section in a company, and a usage method is required in which only users registered in each CSG cell can use the CSG cell. . Furthermore, CSG cells are assumed to have a portable size and weight, and installation and removal of these CSG cells are required to be performed frequently and flexibly. Considering such requirements, radio waves from many CSG cells are transmitted at a certain point at the same time. That is, in an apartment, a school, a company, or the like, a situation occurs in which the mobile terminal 1303 is at a position where radio waves from many CSG cells can reach, as shown in FIG. In such a situation, there are mobile terminals having a whitelist and mobile terminals not having a whitelist. In this situation, consider a case where the mobile terminal has performed a cell search.

  FIG. 14 shows an example of a cell search flowchart of a mobile terminal located at a position where radio waves from many CSG cells can reach. When the mobile terminal starts cell search, it performs the operation described as a general case in FIG. In ST1401, synchronization is performed with the first synchronization signal P-SS and the second synchronization signal S-SS, and detection (identification) of PCI (Physical Cell Identity) is performed. In ST1402, RS detection detects RS reception power. A best cell is selected in ST1403, and PBCH reception and MIB information of the cell selected in ST1404 are obtained. ST-1405 receives DL-SCH to obtain information on SIB1. If the TAC information of SIB1 is the same as the TAC owned by the mobile terminal, the operation shifts to a standby operation. However, if they are not the same, the operation differs from that shown in the general case. As described above, in such a situation, there are mobile terminals having a whitelist and mobile terminals not having a whitelist. In ST1407, it is determined whether or not the mobile terminal has a whitelist. If the mobile terminal has a whitelist, it is determined whether or not the TAC of SIB1 is the same as the CSG-ID (TAC) in the whitelist in ST1408. This is because if the CSG-IDs (TACs) are not the same, access to the cell is prohibited because there is no registration. If they are the same, they have already been registered, so that access to the cell is permitted and the operation shifts to a standby operation. If they are different, the cell cannot be accessed because it has not been registered, and the UE moves to ST1409. In ST1409, the UE determines whether the cell is a CSG cell. In LTE, the SIB1 of the broadcast information of each cell includes a CSG indicator indicating whether or not the own cell is a CSG cell. Therefore, the determination in ST1409 can be made using the CSG indicator included in the information of SIB1 obtained in ST1405. If the CSG indicator indicates a CSG cell, the mobile terminal makes a transition to ST1410. In ST1410, the mobile terminal stores the PCI of the cell and makes a setting so as to exclude the PCI of the cell at the time of subsequent cell search and selection of the best cell. This is because the cell is a CSG-ID (TAC) cell that is not on the whitelist of the mobile terminal even if the cell is a CSG cell. In order to store the PCI of the inaccessible CSG cell for which the mobile terminal has once performed the cell search or the best cell selection, an inaccessible PCI list may be provided and written in the list. The PCI of the inaccessible CSG cell may be reset or deleted when a timer is provided and the timer period ends and / or when a new CSG-ID is registered. If it is determined in ST1409 that the cell is not a CSG cell, the cell shifts to a standby operation after TAU because it is a non-CSG cell.

  On the other hand, if the mobile terminal does not have a whitelist in ST1407, the mobile terminal shifts to ST1409. If it is determined in ST1409 that the cell is not a CSG cell, the mobile terminal shifts to a standby operation after TAU. However, if the cell is a CSG cell, the same process in ST1410 is performed, and a cell search and a best cell selection operation are performed again. Do. If the cell search and the best cell selection operation are performed again and a CSG cell is found, ST1407, ST1409, and ST1410 are performed again, and the cell search and the best cell selection operation are performed again. In this way, a mobile terminal having no whitelist in particular performs cell search and selection of the best cell for all cells even if it is known that the mobile terminal can never access the CSG cell. In the case of a mobile terminal located at a position where radio waves from many Home-eNBs reach, it is highly likely that many CSG cells will be searched and the best cell will be selected, and ST1401, ST1402, ST1403, ST1404, ST1405, ST1406, Since the operations of ST1407, ST1409, and ST1410 are repeated many times, it takes a long time before the standby operation is started, which causes a problem that a large control delay occurs as a system. In addition, there is a problem that the power consumption becomes huge in a mobile terminal that has to repeat the cell search. This problem occurs even if, in ST1410, the process of storing the PCI of the CSG cell to which the mobile terminal cannot access and performing the subsequent cell search and setting to exclude the PCI of the cell when selecting the best cell is performed. . This problem is a serious problem assuming the future arrangement of CSG cells as described above.

  In order to solve such a problem, in 3GPP, it has been discussed to divide all PCI (Physical Cell Identity) into CSG cells and non-CSG cells (referred to as PCI split) (Non-Patent Document). 4). By dividing all PCIs for CSG cells and non-CSG cells, a mobile terminal that does not have a whitelist at the time of cell search performs P-SCH and S-SCH synchronization using PCIs for non-CSG cells. Then, since it is sufficient to specify the PCI, the CSG cell is not searched. However, the mobile terminal must always recognize the PCI split information before performing the cell search. For this reason, it has been proposed in 3GPP to fix the PCI split range, that is, determine in advance the range of the PCI to be allocated to the CSG cell and the range of the PCI to be allocated to the non-CSG cell. For example, PCI # 0 to # 49 are assigned to CSG cells, and PCI # 50 to # 503 are assigned to non-CSG cells in advance and described in the standard. By doing so, the mobile terminal can always recognize this value before performing a cell search, and it is possible to prevent a mobile terminal without a whitelist from unnecessarily searching for a CSG cell during a cell search. It becomes possible.

  However, as described above, the method of determining in advance the range of the PCI to be allocated to the CSG cell and the range of the PCI to be allocated to the non-CSG cell cannot satisfy the above-described request to the Home-eNB. That is, the Home-eNB is assumed to have a portable size and weight, and it is required that the installation and removal of the Home-eNB be performed frequently and flexibly. Considering this requirement, the number of CSG cells will vary depending on various situations such as the operator, frequency layer, installation location, time, and the like. Therefore, if the PCI split information is determined in advance, a problem arises in that the number of CSG cells that cannot be changed due to flexible and frequent installation or removal of Home-eNBs cannot be handled.

  In order to solve this problem, a method is disclosed in which PCI split information is broadcasted to a mobile terminal being served by the broadcast information that is received as a minimum required for an operation of waiting from a cell search. FIG. 15 shows a sequence diagram for broadcasting PCI split information in the LTE communication system. For example, in an LTE communication system, there is SIB1 as broadcast information to be received at a minimum necessary for an operation of waiting from a cell search. All base stations (Home-eNB (CSG cell) and eNB (non-CSG cell)) put PCI split information in SIB1, and map BCCH including SIB1 to DL-SCH. Then, each of the base stations transmits the DL-SCH to the mobile terminal (UE) being served thereby and broadcasts the PCI split information put in the SIB1. Here, the PCI split information transmitted by all base stations is the PCI split information of the frequency layer to which the own cell belongs. Next, FIG. 16 shows a flowchart of the cell search of the mobile terminal in the present method. The mobile terminal starts cell search. First, in ST1601, the mobile terminal determines whether or not it has PCI split information. For example, when the power is turned on, if there is no PCI split information yet, the mobile terminal shifts to ST1602. The mobile terminal that has proceeded to ST1602 performs the method described in the flowchart shown in FIG. 14, and performs the processing of ST1602 to ST1611. Here, the point different from the flowchart shown in FIG. 14 is that a process of receiving the PCI split information contained in SIB1 transmitted on DL-SCH in ST1606 is performed. The mobile terminal that has received the PCI split information stores the PCI split information. A PCI split information list may be provided and stored in the list together with the PLMN and the frequency layer. The PCI split information stored in the list is rewritten when the broadcast information is corrected.

  The PCI split information stored in the list may be reset or erased when power is turned off / on, when reselection between frequency layers is performed, or when reselection is performed between other systems. If the mobile terminal that has obtained the PCI split information in ST1606 proceeds to ST1611, the mobile terminal can use the PCI split information in ST1601 at the time of the next cell search and selection of the best cell. The mobile terminal determines that the mobile terminal has the PCI split information in ST1601, and moves to ST1612. The mobile terminal, having shifted to ST1612, determines whether or not it has a whitelist. If the mobile terminal has a whitelist, the mobile terminal shifts to ST1602, and performs the operations of ST1602 to ST1611 again. However, the mobile terminal that does not have a whitelist moves to ST1613 and performs P-SS and S-SS synchronization using the PCI of the non-CSG cell according to the PCI split information obtained in ST1606 of the first cell search. PCI is detected (specified). The mobile terminal that has identified the PCI moves to ST1614, and performs the processing of ST1614 to ST1618. This processing is the same as the processing in a general cell search. What is important here is that the CSG cell is not searched because the P-SS and the S-SS are synchronized using the PCI of the non-CSG cell to detect (specify) the PCI. For this reason, even if it is known that a mobile terminal having no whitelist, which is generated by the method described in the flowchart shown in FIG. 14, cannot access the CSG cell, the mobile terminal repeatedly performs the operations of ST1602 to ST1611 (excluding ST1609). The problem of repetition is eliminated.

  Further, for example, when a mobile terminal having no whitelist and having obtained PCI split information at the first cell search after power-on performs a cell search again thereafter, since the mobile terminal has PCI split information, the mobile terminal has the PCI split information. Yes ", and it moves to ST1612. The mobile terminal that has proceeded to ST1612 performs the processing of ST1613 to ST1618. Therefore, even in this case, even if it is known that a mobile terminal having no whitelist, which is generated by the method described in the flowchart shown in FIG. 14, cannot access the CSG cell, the operation of ST1602 to ST1611 (excluding ST1609) is performed. The problem of repeating step many times is solved.

  There are many types of notification information blocks. When the PCI split information is put in another SIB of SIB1, it is not received in a waiting operation from a general cell search. In order to receive another broadcast information block (SIBk; an integer of k ≧ 2) of MIB and SIB1, it is necessary to receive scheduling information (assignment information) of another SIB over SIB1, so that it takes more time. This delay causes a delay and further increases the power consumption of the mobile terminal. The mobile terminal does not need to obtain another broadcast information block and obtains the PCI split information with low power consumption in a short time by including the PCI split information in the broadcast information to be received at a minimum necessary for the operation of waiting from the cell search. Becomes possible. As a system, it is possible to construct a good system with a small control delay. For example, in an LTE communication system, MIB or SIB1 is broadcast information to be received as a minimum required for an operation of waiting from a cell search.

  By using the method disclosed in the present embodiment to broadcast the PCI split information to SIB1 of the broadcast information to the mobile terminals being served thereby, the mobile terminal having no whitelist can perform the second or subsequent cell search. It is possible to eliminate useless CSG cell search. For this reason, it takes a long time from the cell search to the start of the standby operation, which can solve the problem that a large control delay occurs as a system and the problem that the power consumption of the mobile terminal becomes enormous. Therefore, it is possible to respond to a request for installing a large number of Home-eNBs in the future and a request for a flexible change in the number of CSG cells caused by frequent and flexible installation and removal of Home-eNBs. It is possible to construct a mobile communication system.

  All the cells (non-CSG cells and CSG cells) disclosed in the present embodiment broadcast the PCI split information to the mobile terminals being served by the broadcast information, which is received as a minimum required for the operation of waiting from the cell search. By using the method, even a mobile terminal having a whitelist can selectively search for a CSG cell or a non-CSG cell. For example, when a mobile terminal having a whitelist preferentially accesses a CSG cell instead of a non-CSG cell, a CSG cell is preferentially used by using PCI split information obtained by receiving SIB1. Can be cell searched. In this case, the operation after ST1612 shown in FIG. 16 may be performed as follows. If it is determined that the mobile terminal has the whitelist in ST1612, the first synchronization signal P-SS and the second synchronization signal S-SS are synchronized using the PCI of the CSG cell, and the PCI is detected (specified). . The reference signal (RS) is detected using the specified PCI, and the received power is measured. Then, the best cell is selected by comparing the measured received power. The PBCH of the selected cell is received, the MIB is received, the DL-SCH is received, and the SIB1 is received. If the tracking area code (Tracking Area Code TAC) on the SIB1 is the same as the one held by the mobile terminal, the operation shifts to the standby operation. If the tracking area code TAC is different, the tracking area code TAC of the SIB1 is stored in the whitelist held by the mobile terminal. It is compared whether it is the same as CSG-ID (TAC). If they are the same, the operation shifts to a standby operation. If not, the cell search is performed again. Then, a cell search is performed using the PCI of the CSG cell, and when there is no cell to be selected, an operation of performing a cell search using the PCI of the non-CSG cell is started. By doing so, it is possible to preferentially search for CSG cells, and to perform cell search and cell selection for non-CSG cells when there are no more selectable CSG cells. Become.

  In the above description, a case has been described in which a mobile terminal having a whitelist preferentially accesses a CSG cell instead of a non-CSG cell, but conversely, an access to a non-CSG cell instead of a CSG cell Can be performed preferentially. If the mobile terminal determines in ST1612 that it has a whitelist, it performs P-SS and S-SS synchronization using the PCI of the non-CSG cell, and detects (specifies) the PCI. The RS is detected using the specified PCI, and the RS received power is measured. The best cell is selected by comparing the measured RS received power. The PBCH of the selected cell is received, the MIB is received, the DL-SCH is received, and the SIB1 is received. If the TAC on the SIB1 is the same as the TAC owned by the mobile terminal, the process proceeds to a standby operation, and if different, the process proceeds to a post-TAU standby operation. Then, a cell search is performed using the PCI of the non-CSG cell, and when there is no cell to be selected, an operation of performing a cell search using the PCI of the CSG cell is started. By doing so, it is possible to preferentially search for a non-CSG cell, and perform cell search and cell selection for a CSG cell when there are no more selectable non-CSG cells. It becomes possible.

  Therefore, even in a mobile terminal having a whitelist, it is possible to eliminate a useless cell search when performing the second and subsequent cell searches, and it takes a long time from the cell search to the standby operation. In addition to solving the problem of large control delay as a system and the problem of enormous power consumption in mobile terminals, it is possible to selectively search for CSG cells or non-CSG cells. Becomes Thereby, a request for installation of a large number of Home-eNBs in the future, a request for flexible change of the number of CSG cells caused by frequent and flexible installation and removal of Home-eNBs, For example, it is possible to construct a mobile communication system that can respond to a mobile terminal that wants to access a CSG cell registered more preferentially than a non-CSG cell, a request for a system that the user wants to access, and the like.

  In the above-described method, a method is disclosed in which the PCI split information is broadcast to the mobile terminal being served on the SIB1 of the broadcast information. However, a method of broadcasting the PCI split information to the mobile terminal being served on the MIB of the broadcast information is disclosed. It is good. FIG. 15 is applicable to the sequence diagram in the case of this method. All base stations (eNB and Home-eNB) put the PCI split information in the MIB and map the BCCH including the MIB to the PBCH. Then, all the base stations transmit the PBCH to the mobile terminals (UEs) being served thereby and broadcast the PCI split information included in the MIB. Here, the PCI split information transmitted by all base stations is the PCI split information of the frequency layer to which the own cell belongs. The flowchart of the cell search of the mobile terminal in this method may be modified as follows from ST1605 and ST1606 in FIG. Since the base station broadcasts the PCI split information in the MIB, the mobile terminal performs a process of receiving the PCI split information in ST1605. On the other hand, in ST1606, PCI split information is not received. Such a change can be realized. The above-described effect can be obtained in the same manner by using a method in which the PCI split information is broadcast to the mobile terminals being served by the MIB in the broadcast information.

  A modification of the first embodiment will be described. Embodiment 1 discloses a method of notifying a mobile terminal being affiliated with the broadcast information to receive PCI split information from all cells (a CSG cell and a non-CSG cell on a minimum necessary basis for an operation of waiting from a cell search). In the first modification, a method is disclosed in which the PCI split information is broadcast to the mobile terminal being served by the mobile terminal on the basis of the broadcast information that is received from the CSG cell only as a minimum necessary for the operation of waiting from the cell search. 3 is a sequence diagram for broadcasting PCI split information in the LTE communication scheme, in which the Home-eNB puts the PCI split information into SIB1, maps a BCCH including SIB1 to a DL-SCH, and all Home-eNB base stations are under the umbrella. A DL-SCH is transmitted to a mobile terminal (UE) and PCI split information put in SIB1 Here, the Home-eNB transmits the PCI split information as the PCI split information of the frequency layer to which the own cell belongs, while the eNB broadcasts the PCI split information to a mobile terminal (UE) being served thereby. In the case of this modification, the mobile terminal can obtain the PCI split information only when the cell selected by the cell search and the best cell selection is a CSG cell, but even in this case, the mobile terminal does not have a whitelist. The terminal repeatedly performs the operations of ST1602 to ST1611 (except ST1609) in FIG. 16 such as cell search for a CSG cell that cannot be accessed thereafter and selection of the best cell by selecting the CSG cell as the best cell once. The problem of repetition can be solved.

  Only the effect described in the first embodiment can be obtained by using a method in which the PCI split information is broadcast on the SIB1 or the MIB of the broadcast information and broadcast to the mobile terminal being served by only the Home-eNB disclosed in the first modification. In addition, new information (PCI split information) for CSG need not be transmitted to the broadcast information from the non-CSG cell. This eliminates the need for changes in the existing LTE system (eUTRA / eUTRAN) that does not include CSG, and improves compatibility.

Embodiment 2 FIG.
In the first embodiment, all the cells (non-CSG cells and CSG cells) transmit the PCI (Physical Cell Identity) split information to the mobile terminal being served by the subordinate mobile terminal by using broadcast information that is received from the cell search as a minimum necessary for a standby operation. A method of notifying has been disclosed. The PCI split information is PCI split information of a frequency layer to which the own cell belongs. Embodiment 2 discloses a method in which all base stations (eNB and Home-eNB) broadcast PCI split information of another frequency layer as broadcast information to mobile terminals being served thereby. FIG. 18 shows a sequence diagram for broadcasting PCI split information of another frequency layer in the LTE communication system. All base stations (Home-eNB and eNB) include, in the broadcast information (BCCH), PCI split information of another frequency layer different from the frequency layer to which the own cell belongs. Then, all the base stations report the broadcast information to the mobile terminals (UEs) being served thereby. Therefore, the mobile terminal being served thereby can obtain the PCI split information of another frequency layer from the broadcast information from the serving cell. For this reason, the mobile terminal may use the PCI split information of the other frequency layer when it needs a process related to another frequency layer, such as a process of cell search, cell selection, cell reselection, handover, or the like. It becomes possible. Since the PCI split information of another frequency layer can be used, for example, when performing cell search and cell selection between frequency layers, PCI split information of a desired frequency layer is used from the first cell search and cell selection of the operation. It becomes possible. It is possible to prevent a mobile terminal having no whitelist from searching for a CSG cell that cannot be accessed when performing a cell search. Therefore, it takes a long time from the cell search to the other frequency layer to the start of the standby operation, which causes a large control delay as a system and an enormous power consumption in the mobile terminal. Eliminate problems. Therefore, it is possible to respond to a request for installing a large number of Home-eNBs in the future and a request for a flexible change in the number of CSG cells caused by frequent and flexible installation and removal of Home-eNBs. It is possible to construct a mobile communication system. The number of other frequency layers may be one, or one or more. In this case, the mobile terminal may store the PCI split information, the priority of the frequency, and the like as a pair (for example, it may be stored as a list).

  In the second embodiment, it is assumed that the broadcast information (BCCH) includes PCI split information of another frequency layer different from the frequency layer to which the own cell belongs. Specifically, it may be added to SIB5, which is a broadcast information block currently under discussion of 3GPP and broadcast information of a frequency layer different from the own cell. The base station maps the BCCH including the SIB5 carrying the broadcast information of the frequency layer different from that of the own cell to the DL-SCH, and transmits the DL-SCH to a mobile terminal (UE) being served thereby. By receiving the SIB5, the mobile terminal uses the PCI split information of the other frequency layer in the SIB5 in the case of cell search to another frequency layer, cell selection, and the like, thereby achieving low power consumption in a short time. It becomes possible to perform cell search, cell selection, and the like for other frequency layers.

  Further, the PCI split information of another frequency layer different from the frequency layer to which the own cell belongs may be transmitted as the individual information. For example, the cell may transmit the PCI split information of another frequency layer different from the frequency layer to which the own cell belongs in the dedicated control information (DCCH) and individually transmit the mobile terminals being served thereby. Also, a mobile terminal being served by a certain cell may transmit a request message individually requesting the cell to transmit the PCI split information as individual information. Further, for example, the cell may transmit PCI split information of another frequency layer different from the frequency layer to which the own cell belongs in the paging information (PCCH) and individually transmit the mobile terminals being served thereby. By doing so, it becomes possible for each cell to transmit the PCI split information of another frequency layer different from the frequency layer to which the own cell belongs, if necessary, so that the use efficiency of radio resources can be improved. it can.

  In Embodiments 1 and 2, PCI split information is transmitted from a non-CSG cell or a CSG cell to a mobile terminal. The PCI split information may be generated in a core network and transmitted to a mobile terminal via a non-CSG cell or a CSG cell. In this case, the same effect as described above can be obtained.

  In the first and second embodiments, the communication system of the LTE (Long Term Evolution) system and the UMTS (Universal Mobile Telecommunication System) using Home-eNB or Home-NB using CSG (Closed Subscriber Group Cell) have been described. The present invention is also applicable to UMTS using Home-NB in which CSG is not used. The PCI may be divided into Home-NBs and other NBs, and the PCI split information may be included in the broadcast information from all base stations (NB and Home-NB) and broadcast to the mobile terminals being served thereby. In the broadcast information, the broadcast information block necessary for cell search and cell selection may include the PCI split information and broadcast to the mobile terminals being served thereby. As a result, a mobile terminal not registered in the Home-NB does not perform useless cell search and cell selection, and it takes a long time from the cell search to the standby operation, and a large control delay as a system. And the problem that the power consumption of the mobile terminal becomes enormous can be solved. Therefore, it is possible to construct a mobile communication system that can respond to a demand for a case where a large number of Home-NBs are installed in the future or a case where the installation and removal of the Home-NBs become frequent and flexible. Become.

Embodiment 3 FIG.
In response to a request for the installation of a large number of CSG (Closed Subscriber Group) cells in the future and a request for a flexible change in the number of CSG cells caused by frequent and flexible installation and removal of CSG cells. Embodiments 1 and 2 disclose a method of transmitting and receiving PCI split information in order to construct a mobile communication system. In the present embodiment, a problem in the operation of a whitelist caused by frequent and flexible installation and removal of a large number of CSG cells and installation and removal of CSG cells is shown, and the problems are solved. The method is disclosed.

  Currently, in 3GPP, a method of obtaining a whitelist when a mobile terminal registers in a CSG cell in an LTE system is being discussed (Non-Patent Document 5). In 3GPP, a method has been agreed in which a mobile terminal is notified of a whitelist via a non-CSG cell. FIG. 19 illustrates a case where a Home-eNB (CSG cell) exists in an area of an eNB (non-CSG cell). A mobile terminal (UE) is in the area of a CSG cell. In the figure, one CSG cell is included in a non-CSG cell, but a plurality of CSG cells may exist. A method for obtaining a whitelist in such a situation will be described. First, the Home-eNB owner notifies the network operator that the mobile terminal (UE) owned by the user has been registered for user access. After that, the network operator notifies the mobile terminal (UE) of the whitelist from the upper layer. The notification of the white list is performed via an eNB (non-CSG cell).

  FIG. 20 shows a sequence diagram of a method of notifying a whitelist via a non-CSG cell, which is being discussed in 3GPP. The figure shows a case of an LTE communication system. In the figure, “Owner” is the owner of the Home-eNB, and “CN” is the core network (MME, base station controller). The core network includes an MME and the like. When the user performs user access registration of the mobile terminal to the Home-eNB, in ST2001, the owner of the Home-eNB notifies the network operator that the mobile terminal (UE) owned by the user has been registered for user access to the Home-eNB. For example, an identification number of the mobile terminal (UE-ID, IMSI identification information such as IMSI) is transmitted to the core network. In ST2002, the network operator having received the identification number (UE-ID, IMSI, etc.) of the mobile terminal transmitted from the owner, transmits the Home-eNB from the core network so that the mobile terminal can access the Home-eNB. -Send an access permission setting request to the eNB. The Home-eNB that has received the access permission setting request performs a setting to permit access from the mobile terminal in ST2003. Next, in ST2004, the network operator transmits a whitelist from the core network to the eNB of the non-CSG cell where the Home-eNB exists. The eNB that has received the whitelist in ST2005 notifies the mobile terminal of the whitelist. The mobile terminal notified of the whitelist in ST2006 stores the whitelist in its own mobile terminal. Specifically, it is proposed that the data be stored in a SIM / USIM (which may be a storage device such as a memory or a CPU).

  A mobile terminal having no whitelist cannot access a CSG cell, and can access only a non-CSG cell. On the other hand, the mobile terminal having the whitelist can access both the CSG cell of the registered CSG-ID and the non-CSG cell.

  The method of obtaining a whitelist when a mobile terminal registers in a CSG cell, which has been discussed in 3GPP, has been described above. However, in this method, the mobile terminal receives the whitelist via the eNB (non-CSG cell). This is a necessary condition that the mobile terminal is under the umbrella of the non-CSG cell. That is, when the mobile terminal is not under the control of the non-CSG cell, there is a problem that it is impossible to obtain the whitelist.

  FIG. 21 illustrates a case where a Home-eNB (CSG cell) registered by a mobile terminal is out of the area of a non-CSG cell. Since the mobile terminal is not under the umbrella of the non-CSG cell, it cannot communicate with the non-CSG cell. For this reason, even if a mobile terminal registers in a CSG cell, it cannot obtain a whitelist. Since a mobile terminal having no whitelist is not allowed to access the CSG cell, it cannot access the registered CSG cell. Therefore, even though a mobile terminal having no whitelist is under the umbrella of a CSG cell for which user access has been registered, it is impossible to perform cell search or cell selection for the CSG cell. In order to solve this problem, 3GPP proposes that a mobile terminal outside the area of a non-CSG cell that has performed user access registration to a CSG cell activates a manual search (Non-Patent Document 5). According to Non-Patent Document 5, a mobile terminal that is outside the area of a non-CSG cell that has performed user access registration with a CSG cell does not yet have a whitelist and is within the area of a CSG cell that has performed user access registration. In this case, it is described that, by activating a manual search, a TAU is transmitted to the core network via the CSG cell that has performed user access registration to obtain a whitelist.

  However, the 3GPP proposal does not show a specific method of the manual search. It does not describe how to enable the transmission of TAU to the core network via the CSG cell. Here, by disclosing the specific method, it is possible to obtain a whitelist from a CSG cell when a user equipment having no whitelist has performed user access registration to the CSG cell. FIG. 22 discloses a specific sequence diagram in a case where a mobile terminal having no whitelist activates manual search in, for example, an LTE communication system. When the user performs user access registration of the mobile terminal to the CSG cell (here, Home-eNB), in ST2201, the owner of the CSG cell is registered in the network operator by the mobile terminal (UE) owned by the user for user access to the CSG cell. For example, an identification number (UE-ID, IMSI, or the like) of the mobile terminal is transmitted to the core network to notify that the mobile terminal has been notified. In ST2202, the network operator having received the identification number of the mobile terminal (UE-ID, IMSI, etc.) transmitted from the owner, transmits the CSG cell from the core network so that the mobile terminal can access the CSG cell. Send an access permission setting request to. The CSG cell that has received the access permission setting request makes a setting to permit access from the mobile terminal in ST2203.

  Next, in ST2204, the mobile terminal that has performed user access registration to the CSG cell activates manual search for the CSG cell. In the manual search for the CSG cell, a mobile terminal having no whitelist is permitted to access the CSG cell for which the user access is registered. By doing so, a mobile terminal being served by a CSG cell for which user access registration has been performed can perform a cell search for the CSG cell and perform cell selection. The mobile terminal that has selected the CSG cell receives the TAC (Tracking Area Code) transmitted from the CSG cell and compares the TAC with the TAC stored in the mobile terminal. Since the mobile terminal does not have a whitelist, the TAC held in the mobile terminal is different from the TAC transmitted from the CSG cell. Conventionally, when the TACs are different, the mobile terminal is not allowed to establish an RRC connection to the CSG cell. Then, access to the CSG cell becomes impossible, and it becomes impossible to transmit a TAU to the core network via the CSG cell. Therefore, a whitelist cannot be obtained. However, in the method disclosed in the present embodiment, even when the TAC is different at the time of starting the manual search for obtaining the whitelist, even when the TAC is different, the mobile terminal requests the RSG connection to the CSG cell to which the user access has been registered. , TAU (Tracking Area Update) request can be made. The mobile terminal, which has started the manual search in ST2204 and selected the CSG cell, transmits an RRC connection request to the CSG cell. The CSG cell that has received the RRC connection request from the mobile terminal permits establishment of an RRC connection because the mobile terminal has been set to permit access in ST2203. The mobile terminal permitted to establish the RRC connection transmits a TAU request to the CSG cell in ST2205. A number (UE-ID, IMSI, etc.) for identifying the mobile terminal may be sent together with the TAU request message. The CSG cell that has received the TAU request transmits a TAU request to the core network together with a number for identifying the mobile terminal in ST2206 because the mobile terminal is also set to have access permission. In ST2207, the core network checks whether the mobile terminal that has transmitted the TAU is a mobile terminal registered in the CSG cell. Specifically, the core network has a list of mobile terminal identification numbers to which user access is permitted for each TAC or CSG-ID, and includes in the list the mobile terminal identification numbers registered for user access in ST2201. Is rewritten (or may be deleted or added). The process of ST2207 is performed by, for example, MME73. For example, the process is performed by the idle state mobility management unit 1005-3 of the MME 73 illustrated in FIG.

  By using the list in ST2207, the core network can determine whether the mobile terminal that has transmitted a TAU (Tracking Area Update) is a mobile terminal registered in the CSG cell. The core network, which has determined in ST2207 that the mobile terminal that transmitted the TAU is a mobile terminal registered in the CSG cell, transmits a TAU accept message to the CSG cell in ST2208. The CSG cell that has received the TAU accept message transmits a TAU accept message to the mobile terminal in ST2209. Further, in ST2210, the core network transmits a whitelist to the CSG cell, and the CSG cell that has received it transmits a whitelist to the mobile terminal in ST2211. The mobile terminal notified of the whitelist in ST2212 stores the whitelist in its own mobile terminal. Specifically, it is proposed that the information be stored in the SIM / USIM. Although the whitelist is described here as being transmitted, the whitelist may not be the whitelist itself, but may be the CSG information of the CSG cell registered in the whitelist for user access by the mobile terminal. Specifically, CSG-ID, TAI, TAC, and the like can be considered as the CSG information. Any one may be used as long as the CSG-ID and TAI or TAC are associated with each other.

  GCI may be used as long as CSG-ID, TAI, or TAC is associated with GCI (Global Cell Identity). Instead of the whitelist itself, a message requesting that the mobile terminal write the TAC or CSG-ID information on the BCCH received in the series of cell search and cell selection processing into the whitelist. The mobile terminal notified of the whitelist in ST2211 stores (registers) the whitelist in its own mobile terminal in ST2212. If not the whitelist but the CSG-ID is notified in ST2211, the CSG-ID is stored in the whitelist. If it is requested to write the TAC or CSG-ID information on the BCCH to the whitelist, the TAC or CSG-ID information is stored in the whitelist. The mobile terminal that has registered the whitelist in ST2212 can access the CSG cell, not only when the manual search is activated. Note that the CSG cell described here may be any CSG cell as long as it belongs to the same CSG-ID. The method disclosed in the present embodiment can also be applied to a case where a mobile terminal that already has a whitelist changes (erases or adds) the whitelist.

  By performing the manual search method in the case where a mobile terminal having no whitelist has performed user access registration to a CSG cell as shown in the sequence of FIG. 22, even if the mobile terminal is under the umbrella of a non-CSG cell Even when the CSG cell does not exist, a whitelist can be obtained from the CSG cell. In the Home-eNB manual search proposed in 3GPP, as shown in FIG. 21, a mobile terminal having no whitelist is under the umbrella of a CSG cell registered for user access and can select the CSG cell at the time of manual search. Is assumed. For this reason, the mobile terminal can establish an RRC connection, which cannot be performed conventionally, and can request a TAU (Tracking Area Update) only for a CSG cell belonging to the CSG-ID of the CSG cell for which user access registration has been performed. If this is done, the mobile terminal can access the CSG cell by manual search, and can obtain a whitelist.

Embodiment 4 FIG.
In the future, when a large number of CSG cells are installed or when the installation or removal of the CSG cells is performed frequently and flexibly, the method disclosed in the third embodiment alone may not be able to obtain a whitelist. Will happen. FIG. 23 shows a case where the mobile terminal is not under the control of a non-CSG cell but under the control of a large number of CSG cells. The situation as shown in the figure may occur when many CSG cells are installed in an apartment, a school, a company, or the like in the future. As a method of operating a CSG cell, it has been studied to promote installation in a place where radio waves from the non-CSG cell do not reach and enable communication via the CSG cell.

  For example, at present, there are many situations in which apartment rooms do not receive radio waves from non-CSG cells. In such a case, a CSG cell is installed in each room, a CSG is configured for each room, and a CSG-ID is given. For example, a mobile terminal owned by a resident of each room may register user access to the CSG of each room. In such a situation, as shown in FIG. 23, the mobile terminal does not reach the radio waves from the non-CSG cells, but exists in a place where radio waves from many CSG cells can reach. In such a case, depending on the radio wave propagation environment, radio waves from a CSG cell registered for user access may not reach the mobile terminal, or even if it does, the received power may be weaker than other CSG cells. I do. Under such a situation, it becomes impossible for the mobile terminal to select a CSG cell for which user access has been registered.

  According to the above-mentioned proposal in 3GPP (Non-Patent Document 5), when a mobile terminal that has performed user access registration in a CSG cell does not yet have a whitelist and is in the area of the CSG cell in which user access registration has been performed, Although it is described that a TAU is transmitted to the core network via the CSG cell that has performed user access registration by initiating a manual search, the mobile terminal performs a user access-registered CSG cell (the same CSG-ID). There is no description about the case where the CAU cannot be selected (including the CSG cell), and there is no description about the case where the TAU is rejected. Therefore, in a situation where the mobile terminal cannot select a CSG cell for which user access registration has been made, it is impossible to obtain a whitelist by the method proposed in 3GPP (Non-Patent Document 5). Problem.

  Further, the following problem occurs not only when a mobile terminal that does not have a whitelist registers the whitelist but also when a mobile terminal that already has a whitelist changes (erases or adds) the whitelist. . In the above-mentioned proposal in 3GPP, there is no description about a mobile terminal having a whitelist. Even in the case of a mobile terminal having a whitelist, in a situation as shown in FIG. 23, the mobile terminal selects a CSG cell (a cell that is not a suitable cell) having a different CSG-ID from the CSG cell with which the mobile terminal has performed user access registration. In some cases. Also in such a case, there is no description about a case where the mobile terminal cannot select a CSG cell (including a CSG cell of the same CSG-ID) for which user access registration has been performed, and there is no description about a case where a TAU is rejected. The method proposed in 3GPP (Non-Patent Document 5), which is not described at all, has a problem that it becomes impossible to obtain a whitelist. Discussions at the 3GPP do not suggest any of these problems, nor do they provide any solutions to these problems.

  In order to solve these problems, in the present embodiment, when a mobile terminal that has performed user access registration (hereinafter, including change (deletion, addition)) in a CSG cell performs a manual search, the presence or absence of a whitelist is determined. Regardless, not only the CSG cell belonging to the CSG-ID of the CSG cell that has performed the user access registration, but also the establishment of the RRC connection and the TAU transmission to the core network via the CSG cell to other CSG cells are enabled, and the mobile terminal Discloses a method for transmitting a TAU to a core network via a selected CSG cell regardless of which CSG cell is selected.

  FIG. 24 shows a case where the RRC connection can be established not only in the CSG cell belonging to the CSG-ID of the CSG cell that has performed user access registration but also in other CSG cells, and the TAU can be transmitted to the network via the CSG cell. Is a sequence diagram when a manual search has been performed for. The figure shows an LTE communication system using, for example, Home-eNB. The figure will be described. Here, the mobile terminal performs user access registration with Home-eNB (C), but the operations from ST2401 to ST2403 are the same as those described above, and thus description thereof will be omitted. The mobile terminal in the situation as shown in FIG. 23 starts manual search of the Home-eNB in ST2404 when registering and changing the whitelist. The mobile terminal that has activated the manual search performs cell search and cell selection in ST2405. In the situation shown in FIG. 23, the mobile terminal selects a CSG cell. Regardless of whether the cell selected CSG cell is a CSG cell that has performed user access registration, the mobile terminal can establish an RRC connection to the CSG cell and transmit a TAU to the network via the CSG cell. . Therefore, in ST2406, the mobile terminal transmits an RRC connection request to a CSG cell (here, Home-eNB (A)) that is not a CSG cell (here, Home-eNB (C)) for which user access has been registered, and this RRC The Home-eNB (A) that has received the connection establishment request transmits an establishment permission for the establishment request to the mobile terminal, thereby establishing an RRC connection between the mobile terminal and the Home-eNB (A). Next, in ST2407 and ST2408, the mobile terminal is enabled to transmit a TAU request message to the core network via a CSG cell (Home-eNB (A)) that is not a CSG cell for which user access has been registered. Here, the mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the TAU request message, may be combined with the TAU request message, or may be transmitted as another message. Also, an RRC connection request message and a TAU request message from a mobile terminal are manually added so that a CSG cell that is not a CSG cell for which user access has been registered can distinguish between activation of manual search and other cases. Information indicating that the search is activated may be included. As a result, a CSG cell that is not a CSG cell for which user access has been registered is limited to the time of manual search activation, and establishes an RRC connection with the mobile terminal, receives a TAU request message from the mobile terminal, and transmits to the core network. Transmission and reception of a series of messages such as transmission can be enabled.

  The core network that has received the TAU request message checks whether the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the mobile terminal identification number that has also been received. As the method of this check, the method described in ST2207 disclosed in FIG. 22 can be applied. Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the core network that has determined that it is inaccessible to the Home-eNB (A) in Steps ST2410 and ST2411. A TAU reject message for the TAU request is transmitted to the mobile terminal via the eNB (A). The mobile terminal that has received the TAU reject message releases the RRC connection with the Home-eNB (A) in ST2412. Then, in ST2413, the mobile terminal performs cell selection again. Here, the cell selection may be performed after performing the cell search again. When the cell is selected again after receiving the TAU reject message, the best cell may be selected again except for the Home-eNB (A) that transmitted the TAU reject message, or the Home-eNB that transmitted the TAU reject message. The best cell including (A) may be selected again. Even when the best cell is selected again including the Home-eNB (A) that has transmitted the TAU reject message, another cell selection is performed after the cell search is performed again. A cell may become the best cell and another cell may be selected.

  The mobile terminal that has selected the Home-eNB (B) in the cell selection again is permitted to establish an RRC connection to a CSG cell for which user access registration has not been performed, and to transmit a TAU to the network via the CSG cell. Therefore, an RRC connection establishment process is transmitted in ST2414, and a TAU request message is transmitted to the core network in ST2415 and ST2416. However, as in ST2409, in ST2417, since the mobile terminal identification number is not registered in the CSG-ID to which Home-eNB (B) belongs, it is determined that Home-eNB (B) cannot be accessed. In ST2418 and ST2419, the network transmits a TAU reject message for the TAU request to the mobile terminal via Home-eNB (B). The mobile terminal that has received the TAU reject message releases the RRC connection with Home-eNB (B) in ST2420. Then, in ST24121, the mobile terminal performs cell selection again as in ST2413. The mobile terminal that has selected Home-eNB (C) in the cell selection again has a request for establishing an RRC connection to a CSG cell regardless of whether user access registration has been performed or not, and a TAU to the network via the CSG cell. Since the transmission of RRC connection is permitted, ST2422 transmits an RRC connection establishment process, and ST2423 and ST2424 transmit a TAU request message to the core network. In ST2425, since the mobile terminal identification number is registered in the CSG-ID to which the Home-eNB (C) belongs, the core network determines that the Home-eNB (C) is accessible, and in ST2426 and ST2427, the home network is determined. -Send a TAU accept message for the TAU request to the mobile terminal via the eNB (C). Also, in ST2428, the core network transmits a whitelist to Home-eNB (C). Home-eNB (C) that has received the whitelist transmits the whitelist to the mobile terminal in ST2429. The mobile terminal, to which the whitelist has been transmitted in ST4730, stores the whitelist in its own mobile terminal.

  By adopting such a method, in the manual search of the mobile terminal, even if the CSG cell for which the user access is registered is not selected in the initial cell selection, the whitelist cannot be obtained, and In the cell selection for the first time, the CSG cell for which user access registration has been performed is selected, and the mobile terminal can obtain a whitelist from the core network via the CSG cell for which user access registration has been performed. .

  As disclosed in the present embodiment, when performing a manual search in a mobile terminal, regardless of the presence or absence of a whitelist, not only the CSG cell belonging to the CSG-ID of the CSG cell that has performed user access registration but also other CSG cells The cell can also establish an RRC connection and transmit TAU to the core network via the CSG cell, and can transmit the TAU to the core network via the selected CSG cell regardless of which CSG cell the mobile terminal selects. By using the method, it is possible to solve the above-described problem that it is impossible to obtain a whitelist in a situation where a mobile terminal cannot select a CSG cell for which user access registration has been performed. Become. Also, when a mobile terminal that already has a whitelist changes (erases or adds) the whitelist, the mobile terminal selects a CSG cell having a CSG-ID different from the CSG cell with which the mobile terminal has performed user access registration. Under such circumstances, it is possible to solve the problem that it is impossible to obtain a whitelist. As a result, it is possible to cope with a future demand for a system in which a large number of CSG cells are installed, and installation and removal of the CSG cells are performed frequently and flexibly.

Embodiment 5 FIG.
By performing the method disclosed in the fourth embodiment, it is possible to solve the problem that it becomes impossible to obtain a whitelist in a situation where a mobile terminal cannot select a CSG cell for which user access has been registered. It becomes possible. In the present embodiment, a method is disclosed that enables effective communication even when there are a large number of CSG cells belonging to a CSG-ID that has not been registered for user access.

  In the situation as shown in FIG. 23, when there are a large number of CSG cells belonging to a CSG-ID to which the mobile terminal has not performed user access registration, when performing a manual search in the mobile terminal, In cell selection, and again in cell search and cell selection, a situation arises in which CSG cells for which the mobile terminal has not registered for user access continue to be selected. In such a situation, the mobile terminal repeatedly establishes an RRC connection with a large number of CSG cells and repeatedly requests a TAU to the core network via the CSG cells. In the future system operation, a situation in which a large number of mobile terminals as described above are present is assumed. For example, there is a case where a CSG cell is installed in each classroom of a school, and students in each classroom individually register or change a whitelist. In such a case, from many more mobile terminals, the mobile terminal repeatedly establishes an RRC connection to a large number of CSG cells and repeatedly requests a TAU to the core network via the CSG cells. The number is expected to be enormous. In such a situation, there arises a problem that the use efficiency and the signaling efficiency of the radio resources are extremely reduced as a system. Furthermore, a large amount of time is required from the cell search to the start of the standby operation, causing a problem that a large control delay occurs in the system and a problem that the power consumption of the mobile terminal becomes enormous.

  In addition, if the whitelist of the mobile terminal is rewritten for some reason, or the whitelist sent from the core network is incorrectly received by the mobile terminal when registering or changing the whitelist The following problems also occur. For example, a case will be described in which the content of the whitelist transmitted from the core network is erroneously received by the mobile terminal when registering or changing the whitelist. As shown in FIG. 23, in a situation where a large number of CSG cells exist, a case may occur in which a CSG cell belonging to the CSG-ID of the erroneously received whitelist is selected. Even in such a case, the mobile terminal may repeatedly establish an RRC connection to the CSG cell belonging to the wrong whitelisted CSG-ID or repeatedly request the TAU to the core network via the CSG cell. Become.

  In order to solve these problems, in the present embodiment, in addition to the method of Embodiment 4, when the mobile terminal performs a manual search, the CSG-ID of the CSG cell to which the mobile terminal has performed user access registration is added. When an RRC connection is established in a CSG cell different from the CSG cell belonging to the CSG cell and a TAU request is further transmitted to the core network via the CSG cell, the core network transmits a TAU reject message to the mobile terminal via the CSG cell. Before transmitting a whitelist via the CSG cell. FIG. 25 shows a sequence diagram of a method of transmitting a whitelist before transmitting a TAU reject. The figure will be described. The figure shows an LTE system using Home-eNB, for example. Here, the mobile terminal performs user access registration with Home-eNB (C), but the operations from ST2501 to ST2503 are the same as those described above, and thus description thereof will be omitted. The mobile terminal that has started the manual search for the CSG cell (Home-eNB in this case) in ST2504 performs cell search and cell selection in ST2505.

  In the situation as shown in FIG. 23, if there are more CSG cells belonging to the CSG-ID for which the mobile terminal has not performed user access registration, the mobile terminal selects a CSG cell. As disclosed in the fourth embodiment, the mobile terminal can establish an RRC connection to the CSG cell, regardless of whether the CSG cell selected by the cell is a CSG cell that has performed user access registration or not. TAU can be transmitted to the network via the network. By this means, in ST2506, the mobile terminal transmits an RRC connection request to a CSG cell (here, Home-eNB (A)) that is not a CSG cell (here, Home-eNB (C)) for which user access has been registered. The Home-eNB (A) that has received the RRC connection establishment request transmits an establishment permission for the establishment request to the mobile terminal, thereby establishing an RRC connection between the mobile terminal and the Home-eNB (A). . Next, in ST2507 and ST2508, the mobile terminal is enabled to transmit the TAU request message to the core network via a CSG cell (Home-eNB (A)) which is not a CSG cell for which user access has been registered. Here, the mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the TAU request message, may be combined with the TAU request message, or may be transmitted as another message. Also, an RRC connection request message and a TAU request message from a mobile terminal are manually added so that a CSG cell that is not a CSG cell for which user access has been registered can distinguish between activation of manual search and other cases. Information indicating that the search is activated may be included. As a result, a CSG cell that is not a CSG cell for which user access has been registered is limited to the time of manual search activation, and establishes an RRC connection with the mobile terminal, receives a TAU request message from the mobile terminal, and transmits to the core network. Transmission and reception of a series of messages such as transmission can be enabled. The core network that has received the TAU request message checks whether the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the mobile terminal identification number that has also been received. As the method of this check, the method described in ST2207 disclosed in FIG. 22 can be applied. Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the core network determines that the mobile terminal cannot access the Home-eNB (A).

  In the method disclosed in the fifth embodiment, even when the core network determines that the mobile terminal cannot access the Home-eNB (A), before transmitting the TAU reject, the core network returns the Home-eNB (ST2510). Transmit the whitelist of the mobile terminal to A). Home-eNB (A), which has received the whitelist of the mobile terminal, transmits a whitelist to the mobile terminal in ST2511. The mobile terminal, to which the whitelist has been transmitted in ST5212, stores the whitelist in its own mobile terminal. In ST2513 and ST2514, the core network that transmitted the whitelist of the mobile terminal to Home-eNB (A) in ST2510 transmits a TAU reject message for the TAU request to the mobile terminal via Home-eNB (A) in ST2513 and ST2514. Send. The mobile terminal that has received the TAU reject message releases the RRC connection with Home-eNB (A) in ST2515.

  By adopting such a method, in the manual search for the mobile terminal, the CSG cell for which the user access registration has been performed in the cell selection endlessly does not stop being selected. In the first cell selection, the mobile terminal performs the user access. The whitelist can be obtained from the core network via the unregistered CSG cell. Further, even when only the best cell is selected in the cell selection, by using this method, a whitelist can be reliably obtained from the selected best cell.

  As a method of manual search, not only cell search, activation before cell selection, but also a cell identification number of one or more cells suitable for cell search selection criteria in cell search, or TAC, or CSG-ID or the like to the mobile terminal. The display may be performed, and the user of the mobile terminal may manually select a desired cell from the one or more cells, establish an RRC connection, and transmit a TAU request to the desired cell. If the mobile terminal manually selects a CSG cell with user access registration as a desired cell, the mobile terminal needs to perform transmission / reception for establishing an RRC connection and transmission of a TAU request message to a CSG cell with no user access registration. Disappears.

  However, it takes time to receive the cell identification number of the cell, or TAC, or CSG-ID, because it is necessary to receive broadcast information such as SIB1 from the cell as shown by ST1205 in FIG. I will. In a situation where a large number of CSG cells are installed, in cell search, it is considered that cells suitable for the cell search selection criterion become enormous, and broadcast information of all those cells is received, and a cell identification number, Alternatively, displaying a TAC, a CSG-ID, or the like on a mobile terminal also requires an enormous amount of time. Also, when the mobile terminal performs a cell search for a CSG cell suitable for the cell search selection criterion, it is required to store the resolution for separating the CSG, the broadcast information of the CSG cell in the mobile terminal, and the like. In a situation where a large number of CSG cells are installed, in cell search, cells suitable for the cell search selection criterion are considered to be enormous, and the resolution for receiving all these cells and the Storing the received broadcast information complicates the receiving unit of the mobile terminal, and requires a storage processing unit having a huge storage capacity to be provided in the mobile terminal. Therefore, the size of the mobile terminal is increased and the manufacturing cost is increased. In order to avoid such a problem, in the cell search process, a method of setting a limit on a search time or a method of setting a limit on the number of cells to be searched is used. There is a method of selecting the best cell within a certain time limit or from a certain limited number of cells.

  When such a method is used, the cell identification number of one or a plurality of cells suitable for the cell search selection criterion in cell search, or TAC, CSG-ID, or the like is displayed on the mobile terminal, and the one or more cells are displayed. In a method in which a mobile terminal manually selects a CSG cell for which a user access has been registered from among them, the CSG cell cannot be searched within a search time limit, or a cell to be searched is restricted. There is a problem that the CSG cell does not enter. In such a case, no matter how much manual search is performed, the mobile terminal cannot select a CSG cell for which user access registration has been performed, and a problem arises in that it becomes impossible to obtain a whitelist.

  Even in such a case, the above-described problem can be solved by applying the present embodiment. When the mobile terminal that has performed user access registration (hereinafter, including change (deletion, addition) includes) in the CSG cell performs a manual search, regardless of the presence or absence of the whitelist, the CSG-cell of the CSG cell that performed the user access registration is performed. Not only the CSG cell belonging to the ID but also other CSG cells can establish an RRC connection and transmit TAU to the core network via the CSG cell, and select a CSG cell even if the mobile terminal selects any CSG cell. By enabling transmission of TAU to the core network via the CSG cell, the cell search cannot search the CSG cell within the search time limit, or the cell to be searched is restricted, and the CSG cell is included in the cell. Even if it does not come, by selecting another CSG cell, the other CSG cell RRC connection establishment and TAU transmission to the core network via the CSG cell are enabled, and the core network transmits the TAU reject message to the mobile terminal via the CSG cell via the CSG cell before transmitting the TAU reject message. It is possible to transmit a whitelist, and the mobile terminal can obtain the whitelist.

  By adopting the method disclosed in the present embodiment, a case where a huge number of CSG cells belonging to a CSG-ID for which a mobile terminal has not performed user access registration or a case where a mobile terminal is in such a situation is present. If there is a large number of whitelists, or the whitelist of the mobile terminal has been rewritten for some reason, or the whitelist sent from the core network when registering or changing the whitelist is incorrectly displayed by the mobile terminal. If the mobile terminal performs a manual search when receiving it, a situation occurs in which the CSG cell is continuously selected for a long time, and the mobile terminal establishes an RRC connection to a large number of CSG cells, It is possible to solve the problem that the request of the TAU to the core network via the cell is repeated uselessly. By solving these problems, it is possible to prevent an extreme decrease in the use efficiency of the radio resources and the signaling efficiency in the future system operation. Further, the time from the cell search to the start of the standby operation can be reduced, and the problem that a large control delay occurs as a system can be solved. Furthermore, it is possible to eliminate a situation in which a CSG cell is continuously selected when a manual search is performed in a mobile terminal, so that power consumption of the mobile terminal can be reduced.

  Hereinafter, a modified example of the fifth embodiment described above will be described. In the fifth embodiment, in addition to the method of the fourth embodiment, when a mobile terminal performs a manual search, the mobile terminal performs a manual search on a CSG cell different from the CSG cell belonging to the CSG-ID of the CSG cell with which the user access registered. Even if an RRC connection is established and a TAU request is sent to the core network via the CSG cell, the core network sends the CSG cell before sending a TAU reject message to the mobile terminal via the CSG cell. A method for transmitting a whitelist via the Internet has been disclosed. This modification discloses a method in which a core network transmits a TAU reject message to the mobile terminal via the CSG cell by placing a whitelist on the TAU reject message.

  FIG. 26 shows a sequence diagram in the method disclosed in the first modification. Since this method is almost the same as the method described in FIG. 25 of the fifth embodiment, only different portions will be described here. In ST2609, based on the received mobile terminal identification number, the core network that has checked whether or not the mobile terminal belongs to the CSG-ID of Home-eNB (A), the mobile terminal determines that the mobile terminal is Home-eNB (A). It is determined that A) cannot be accessed. In ST2610, the core network transmits a TAU reject message including a whitelist notification request to Home-eNB (A). Home-eNB (A), having received this message, transmits a TAU reject message including a whitelist notification to the mobile terminal in ST2611. The mobile terminal, which has received the TAU reject message including the whitelist notification in ST2611, stores the whitelist in its own mobile terminal in ST2612. Also, in ST2613, the RRC connection between the mobile terminal and the Home-eNB (A) is released. By adopting such a method, in addition to the effect of Embodiment 5, it is possible to further reduce the signaling for whitelist transmission performed before the core network transmits the TAU reject message to the mobile terminal via the CSG cell. It becomes possible. Further, since a TAU reject message is transmitted and received in response to the TAU request message, an effect of improving compatibility with the conventional TAU request and reject method is obtained.

Embodiment 6 FIG.
In order to solve the problems described in the fifth embodiment, in the present embodiment, when a mobile terminal receives a TAU reject message from the same cell n times (n ≧ 1 integer) consecutively, the mobile terminal Discloses a method of prohibiting establishment of an RRC connection to the cell and transmission of a TAU request message.

  FIG. 27 shows a sequence diagram of a method for prohibiting the mobile terminal from establishing an RRC connection to the cell when a TAU reject message is received once from the same cell. The figure will be described. The figure shows a case of an LTE system using a Home-eNB, for example. Here, the mobile terminal performs user access registration with Home-eNB (B), but the operations from ST2701 to ST2703 are the same as those described above, and thus description thereof will be omitted. The mobile terminal that has started the manual search for the CSG cell (here, Home-eNB) in ST 2704 performs cell search and cell selection in ST 2705. In the situation as shown in FIG. 23, if there is a huge number of CSG cells belonging to a CSG-ID for which the mobile terminal has not registered for user access, the mobile terminal will be assigned to a CSG-ID for which user access has not been registered. In many cases, the CSG cell to which the cell belongs is selected. As disclosed in the fourth embodiment, the mobile terminal can establish an RRC connection to the CSG cell, regardless of whether the CSG cell selected by the cell is a CSG cell that has performed user access registration or not. TAU can be transmitted to the network via the network. Thereby, in ST2706, the mobile terminal transmits an RRC connection request to a CSG cell (here, Home-eNB (A)) which is not a CSG cell (here, Home-eNB (C)) for which user access has been registered, The Home-eNB (A) that has received the RRC connection establishment request transmits an establishment permission for the establishment request to the mobile terminal, thereby establishing an RRC connection between the mobile terminal and the Home-eNB (A).

  Next, in ST2707 and ST2708, the mobile terminal transmits a TAU request message to the core network via the Home-eNB (A). Here, the mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the TAU request message, may be combined with the TAU request message, or may be transmitted as another message. In ST2709, the core network that has received the TAU request message checks whether or not the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the received mobile terminal identification number. As the method of this check, the method described in ST2207 disclosed in FIG. 22 can be applied. Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the core network determines that the mobile terminal cannot access the Home-eNB (A). In ST2710 and ST2711, the core network transmits a TAU reject message to the mobile terminal via the Home-eNB (A). In Step ST2712, the mobile terminal that has received the TAU reject message releases the RRC connection with the Home-eNB (A). Upon receiving the TAU reject message once, the mobile terminal performs a process of prohibiting establishment of an RRC connection to the Home-eNB (A) in ST2713. Specifically, for example, an RRC connection establishment prohibited cell list is provided inside the mobile terminal, and the mobile terminal stores a cell identification number (PCI, Cell-ID, GCI, etc.) of the Home-eNB (A) in the list. I do. Then, before establishing the next RRC connection, the list is checked to determine whether or not the cell is stored in the list. In the case of a cell stored in the list, establishment of an RRC connection is prohibited. Here, the list may be a CSG-ID or TAC, and the CSG-ID or TAC may be stored in association with the cell identification number. In this way, when the Home-eNB (A) is selected again in the future by cell search and cell selection, the mobile terminal does not establish an RRC connection with the Home-eNB (A). it can. The mobile terminal, which has not been able to obtain the whitelist in ST2713, performs a new cell search and cell selection in ST2714.

  Here, when the Home-eNB (A) is selected again, since the establishment of the RRC connection is prohibited, the cell is selected from the cells excluding the Home-eNB (A). The mobile terminal that has selected Home-eNB (B) by cell selection performs an RRC connection establishment process with Home-eNB (B) in ST2715. After the establishment of the RRC connection is performed, in ST2716 and ST2717, the mobile terminal transmits a TAU request message to the core network via the Home-eNB (B). In ST2718, the core network receiving the TAU request message determines whether the mobile terminal belongs to the CSG-ID (TAC) of the Home-eNB (B) based on the mobile terminal identification number received together. Check. The method described in ST2207 disclosed in FIG. 22 can be applied to this check. Since the mobile terminal identification number is registered in the CSG-ID to which the Home-eNB (B) belongs, the core network determines that the mobile terminal can access the Home-eNB (B). In ST2719 and ST2720, the core network transmits a TAU accept message to the mobile terminal via the Home-eNB (B). In ST2721 and ST2722, the core network transmits a whitelist to the mobile terminal via Home-eNB (B). The mobile terminal notified of the whitelist in ST 2723 stores the whitelist in its own mobile terminal.

  In the example of the present embodiment, the process has been described in which the mobile terminal prohibits the establishment of the RRC connection to the cell that has received the TAU reject message, but all the mobile terminals that belong to the CSG-ID of the cell that has received the TAU reject message The establishment of the RRC connection to the cell may be prohibited. In addition, although the process of prohibiting the establishment of the RRC connection has been described, the process of prohibiting the transmission of the TAU request message or the process of prohibiting both of them may be used. Also, a process has been described in which the mobile terminal prohibits the establishment of an RRC connection to a cell that has once received a TAU reject message. It may be prohibited. The number of times a TAU reject message is continuously received from the same cell may be transmitted from the cell using broadcast information, or may be determined in advance.

  By adopting the method disclosed in the present embodiment, when there is an enormous number of CSG cells belonging to a CSG-ID for which the mobile terminal has not performed user access registration, or when there are many mobile terminals in such a situation, If there is, the whitelist of the mobile terminal is rewritten for some reason, or the whitelist sent from the core network when registering or changing the whitelist is incorrectly received by the mobile terminal. In the case where the mobile terminal performs a manual search, a situation occurs in which the CSG cell is continuously selected for a long time, and the mobile terminal establishes an RRC connection to a large number of CSG cells or sets a CSG cell. It is possible to solve the problem that the request of the TAU to the core network is repeated unnecessarily via the core network. By solving these problems, it is possible to prevent an extreme decrease in the use efficiency of the radio resources and the signaling efficiency in the future system operation. Further, the time from the cell search to the start of the standby operation can be reduced, and the problem that a large control delay occurs as a system can be solved. Furthermore, it is possible to eliminate a situation in which a CSG cell is continuously selected when a manual search is performed in a mobile terminal, so that power consumption of the mobile terminal can be reduced.

  Next, a first modification of the sixth embodiment described above will be described. The first modification discloses a method in which the core network transmits information to the mobile terminal with the information of prohibiting RRC connection establishment and prohibiting transmission of a TAU request message in a TAU reject message.

  This will be described with reference to FIG. A part of FIG. 27 may be changed as follows. The description of the same operation as in the sixth embodiment will be omitted. In ST2709, the core network that has received the TAU request message checks whether or not the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the received mobile terminal identification number. Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the core network determines that the mobile terminal cannot access the Home-eNB (A). In ST2710 and ST2711, the core network transmits a TAU reject message to the mobile terminal via the Home-eNB (A). At this time, the core network puts information on prohibition of establishment of the RRC connection to the Home-eNB (A) and prohibition of transmission of the TAU request message in the TAU reject message. Specifically, a 1-bit indicator may be provided to set "1" for prohibition and "0" for permission (of course, vice versa). Upon receiving this, the mobile terminal releases the RRC connection with the Home-eNB (A) in ST2712, and performs a process of prohibiting the establishment of the RRC connection with the Home-eNB (A) in ST2713.

  By doing so, the same effect as in the sixth embodiment can be obtained. Furthermore, the core network can determine whether to prohibit RRC connection establishment and prohibit transmission of a TAU request message. As a result, the core network can appropriately cause the mobile terminal to perform the prohibition process according to the situation at that time, such as the signaling load amount and the arrangement state of the CSG cell, and thus the operation of the system becomes flexible. can get.

  Next, a second modification of the sixth embodiment described above will be described. In the description of the sixth embodiment and the first modification, when the mobile terminal receives the TAU reject message, the mobile terminal prohibits the establishment of the RRC connection to the cell and the method of prohibiting the transmission of the TAU request message. Disclosed. However, if the mobile terminal newly performs user access registration (update) to the CSG cell in the above-described prohibited state, a problem may occur.

  If the mobile terminal has been prohibited from establishing an RRC connection and transmitting a TAU request message for the CSG-ID of the CSG cell before registering a new user access, Even if access registration is made, establishment of an RRC connection and transmission of a TAU request message to the CSG cell may be prohibited, and access may not be possible. In order to solve such a problem, as a second modification, it is disclosed that a timer for canceling the prohibition of the establishment of the RRC connection and the prohibition of the transmission of the TAU request message is provided. The value of the timer may be determined in advance as a value common to all cells, or may be broadcast in the broadcast information of the CSG cell.

  When broadcasted by the broadcast information of the CSG cell, the value may be different for each cell. This enables flexible operation for each cell. Also, it may be transmitted by being included in the TAU reject message shown in ST2710 and ST2711 in FIG. This may be the first TAU reject message or a TAU reject message immediately before the establishment of the RRC connection is prohibited and the transmission of the TAU request message is prohibited. In this case, it becomes possible for the core network to set the value of the timer, and further, it is possible to individually set the mobile terminal, so that the system status such as the signaling load, the remaining battery capacity of the mobile terminal, etc. It is possible to appropriately set the value of the timer according to the situation specific to the mobile terminal. The start of the timer may be, for example, transmission of a TAU request message to a certain CSG cell. The timer may be terminated when the timer expires, when a TAU accept message is received from the CSG cell, or when user access registration (update) to a new CSG cell is performed. FIG. 28 discloses an example of a process in the mobile terminal when a timer is provided.

  The mobile terminal that has started the Home-eNB (CSG cell) manual search performs cell search and cell selection in ST2801. In ST2802, the UE determines whether or not the CSG-ID (TAC) of the selected Home-eNB has a timer running for TAU prohibition. For example, specifically, the CSG-ID (TAC) and the timer set in the CSG-ID (TAC) may be placed in the prohibition list shown in the process of ST2713 in FIG. What is necessary is just to make a determination by looking at the timer in the list. If the timer is running, the CSG cell whose cell has been selected is TAU-prohibited. Therefore, a cell that is not a CSG-ID (TAC) for which TAU has been prohibited in ST2803 is cell-searched, selected, and the process proceeds to ST2804. On the other hand, if a CSG cell in which the timer is not running is selected in ST2802, the CSG cell is not in the TAU prohibition state, and thus the UE proceeds to ST2804 and transmits a TAU request to the Home-eNB that has selected the cell. In ST2805, using the transmission of the TAU request as a trigger, a timer is set for the CSG-ID (TAC) of the Home-eNB that has made the TAU request. In Step ST2806, the NAS message for the TAU request message is received from the Home-eNB.

  The mobile terminal, in ST2807, determines whether the NAS message received in ST2806 is TAU reject or TAU accept. In the case of TAU accept, the mobile terminal shifts to ST2808 to end the timer and reset the timer. Then, a whitelist registration process is performed in ST2809, and the process proceeds to a normal process. On the other hand, if TAU rejection is determined in ST2807, the mobile terminal shifts to ST2810 to determine again whether the timer period has expired. If the timer period has expired in ST2810, the mobile terminal shifts to ST2812 to permit TAU for the CSG-ID (TAC) of the Home-eNB that has requested the TAU, resets the timer in ST2813, and performs cell search and cell search again. Move to selection. If the timer period has not expired in ST2810, the mobile station shifts to cell search and cell selection again while prohibiting the TAU for the CSG-ID (TAC) of the Home-eNB having requested the TAU. Note that whether or not the timer period has ended may be included not only in the case shown in FIG. 28 but also in the process in ST2802, for example. If the timer period has expired, the mobile terminal may perform the processing of ST2812 and ST2813 and then move to ST2804. If the timer period has not expired, the mobile terminal may proceed to ST2803 after performing the process of ST2811.

  As described above, by providing the timer for canceling the prohibition of the establishment of the RRC connection and the prohibition of the transmission of the TAU request message, the same effect as that described in the sixth embodiment and the first modification can be obtained. . In addition, it is possible to solve a problem that access becomes impossible when a mobile terminal newly performs user access registration (update) to a CSG cell. This makes it possible to construct a more stable system.

  In Embodiment 6 described above, Home-eNB using CSG and LTE and UMTS using Home-NB have been described. However, the present invention is also applicable to a UMTS using a Home-NB without using a CSG. In the case of UMTS using a Home-NB in which CSG is not used, the mobile terminal accesses the Home-eNB that has performed user access registration, and if the access is successful, the Home-NB transmits the cell identification number (Cell Identity) of the Home-NB. , PCI, GCI, etc.) and register them in a whitelist (called a cell identification number whitelist in the case of UMTS) in the mobile terminal. Also in this case, when a Home-NB different from the Home-NB with which the mobile terminal has performed user access registration is continuously selected by cell search and cell selection, the mobile terminal cannot receive the cell identification number with which the user access registration has been performed. Or it takes time to receive.

  In order to solve such a problem, the method according to the sixth embodiment can be applied to a UMTS using a Home-NB in which a CSG is not used. When the mobile terminal receives the TAU reject message, the mobile terminal prohibits the establishment of the RRC connection to the cell and prohibits the transmission of the TAU request message. Since the Home-NB different from the Home-NB that has received the <RTI ID = 0.0> is </ RTI> selected, the Home-NB different from the Home-NB with which the mobile terminal has performed user access registration does not continue to be selected.

  In the case of the UMTS communication system, an RNC is provided between the base station (Home-NB, NB) and the core network, and an RRC message such as an RRC connection request is transmitted and received between the mobile terminal and the RNC. The NAS message such as a TAU request may be transmitted and received from the mobile terminal to the core network via the base station (Home-NB, NB) and the RNC. By doing so, the present invention can be applied to a UMTS communication system in which Home-NBs are used as CSG cells. Therefore, the mobile terminal does not perform useless cell search and cell selection, and a long time is required from the cell search to the start of the standby operation. In this case, the problem of enormous power consumption can be solved. In the future, it becomes possible to construct a mobile communication system that can respond to a demand for a case where a large number of Home-NBs are installed or a case where the installation and removal of the Home-NBs become frequent and flexible.

Embodiment 7 FIG.
In order to solve the problem described in the fifth embodiment, in the present embodiment, the core network continuously transmits a TAU reject message n times (an integer of n ≧ 1) to the same mobile terminal. In this case, the core network discloses a method of transmitting the whitelist before transmitting the nth TAU reject message.

  FIG. 29 is a sequence diagram of a method of transmitting a whitelist before transmitting an n-th TAU reject message when a TAU reject message is transmitted twice to the same mobile terminal continuously. Show. The figure will be described. The figure shows an LTE system using, for example, Home-eNB. Here, the mobile terminal performs user access registration with Home-eNB (B), but the operations from ST2901 to ST2903 are the same as those described above, and thus description thereof will be omitted. The mobile terminal that has started the manual search for a CSG cell (here, Home-eNB) in ST 2904 performs cell search and cell selection in ST 2905. In the situation as shown in FIG. 23, if there is a huge number of CSG cells belonging to a CSG-ID for which the mobile terminal has not registered for user access, the mobile terminal will be assigned to a CSG-ID for which user access has not been registered. In many cases, the CSG cell to which the cell belongs is selected. As disclosed in the fourth embodiment, the mobile terminal can establish an RRC connection to the CSG cell, regardless of whether the CSG cell selected by the cell is a CSG cell that has performed user access registration or not. TAU can be transmitted to the network via the network. Thereby, in ST2906, the mobile terminal transmits an RRC connection request message to a CSG cell (here, Home-eNB (A)) that is not a CSG cell (here, Home-eNB (C)) for which user access has been registered. The Home-eNB (A) that has received the RRC connection request message establishes an RRC connection between the mobile terminal and the Home-eNB (A) by transmitting permission for the request to the mobile terminal.

  Next, in ST2907 and ST2908, the mobile terminal transmits a TAU request message to the core network via the Home-eNB (A). Here, the mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the TAU request message, may be transmitted together with the TAU request message, or may be transmitted as another message. In ST2909, the core network that has received the TAU request message checks whether or not the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the received mobile terminal identification number. As the method of this check, the method described in ST2207 disclosed in FIG. 22 can be applied. Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the core network determines that the mobile terminal cannot access the Home-eNB (A). The core network that has determined that the mobile terminal cannot access the Home-eNB (A) further counts the number of rejections to the mobile terminal (n = 1). In ST2910 and ST2911, the core network transmits a TAU reject message to the mobile terminal via the Home-eNB (A). In Step ST2912, the mobile terminal that has received the TAU reject message releases the RRC connection with the Home-eNB (A). The mobile terminal, which has not been able to obtain the whitelist by ST2912, newly performs cell search and cell selection in ST2913. Here, when Home-eNB (A) is selected again, an RRC connection is established again with Home-eNB (A) in ST2914. Next, in ST2915 and ST2916, the mobile terminal transmits a TAU request message to the core network via the Home-eNB (A). Here, the mobile terminal also transmits the mobile terminal identification number.

  In ST2917, the core network that has received the TAU request message checks whether or not the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the mobile terminal identification number that has also been received. Similar to ST2909, since the mobile terminal identification number is not registered in the CSG-ID to which Home-eNB (A) belongs, the core network determines that the mobile terminal cannot access Home-eNB (A). judge. The core network that has determined that the mobile terminal cannot access the Home-eNB (A) increments the number of rejections to the mobile terminal by 1 (n = 2). Since the number of rejects to the same mobile terminal is two, the core network transmits a whitelist registration message before transmitting the second TAU reject message. In ST2918 and ST2919, the core network transmits a whitelist to the mobile terminal via Home-eNB (B). The mobile terminal notified of the whitelist in ST2920 stores the whitelist in its own mobile terminal. The core network that has transmitted the whitelist of the mobile terminal to the Home-eNB (A) in ST2918, transmits the second TAU reject message for the TAU request via the Home-eNB (A) in ST2921 and ST2922. Send to terminal. The mobile terminal that has received the TAU reject message releases the RRC connection with the Home-eNB (A) in ST2923. The number of times a TAU reject message is continuously transmitted to the same mobile terminal may be determined in advance, but the core network may flexibly determine the number of times of transmitting the TAU reject message. The flexibility of the core network allows the whitelist to be transmitted to the mobile terminal as appropriate according to the situation at that time, such as the signaling load amount and the reception quality of the mobile terminal. Is obtained.

  By adopting the method disclosed in the present embodiment, when there is an enormous number of CSG cells belonging to a CSG-ID for which the mobile terminal has not performed user access registration, or when there are many mobile terminals in such a situation, If there is, the whitelist of the mobile terminal is rewritten for some reason, or the whitelist sent from the core network when registering or changing the whitelist is incorrectly received by the mobile terminal. In the case where the mobile terminal performs a manual search, a situation occurs in which the CSG cell is continuously selected for a long time, and the mobile terminal establishes an RRC connection to a large number of CSG cells or sets a CSG cell. It is possible to solve the problem that the request of the TAU to the core network is repeated unnecessarily via the core network. By solving these problems, it is possible to prevent an extreme decrease in the use efficiency of the radio resources and the signaling efficiency in the future system operation. Further, the time from the cell search to the start of the standby operation can be reduced, and the problem that a large control delay occurs as a system can be solved. Furthermore, it is possible to eliminate a situation in which a CSG cell is continuously selected when a manual search is performed in a mobile terminal, so that power consumption of the mobile terminal can be reduced.

Embodiment 8 FIG.
In Embodiments 4 to 7 described above, the mobile terminal establishes an RRC connection with a CSG cell belonging to a CSG-ID for which user access registration has not been performed, and transmits a TAU reject message transmitted from the core network to the mobile terminal. The method used was disclosed. However, in any of these cases, it is necessary to establish an RRC connection between the mobile terminal and a CSG cell belonging to a CSG-ID for which the mobile terminal has not performed user access registration. It is necessary to send and receive a NAS message such as a TAU request to and from the server.

  Thus, a method for registering a whitelist using an RRC connection reject message for an RRC connection request message transmitted by a mobile terminal, instead of using a TAU reject message transmitted by the core network to the mobile terminal, is disclosed. As a result, it is not necessary to set up an RRC connection or transmit / receive a NAS message such as a TAU request. For example, in the method disclosed in the sixth embodiment, instead of using the TAU reject message transmitted by the core network to the mobile terminal, using the RRC connection reject message for the RRC connection request message transmitted by the mobile terminal, A method for registering a list is disclosed. When the mobile terminal receives the RRC connection reject message n times (n is an integer equal to or more than 1) continuously from the same cell, the mobile terminal prohibits the RRC connection request to the cell.

  FIG. 30 shows a sequence diagram of a method in which, when an RRC connection reject message is received once from the same cell, the mobile terminal prohibits an RRC connection request to the cell. The figure will be described. The figure shows an LTE system using, for example, Home-eNB. Here, the mobile terminal performs user access registration with Home-eNB (B), but the operations from ST3001 to ST3003 are the same as those described above, and thus description thereof will be omitted. In ST3004 and ST3005, the core network transmits information of the CGS-ID (TAC) of each Home-eNB and the identification number of the mobile terminal belonging to the CSG-ID to all CSG cells (here, Home-eNB). deep. For example, the core network transmits information of the mobile terminal identification number belonging to the CSG-ID of the Home-eNB (B) to the Home-eNB (B), and transmits the information to the Home-eNB (A). The information of the mobile terminal identification number belonging to the CSG-ID of the Home-eNB (A) is transmitted. As a specific example of such information, a list in which mobile terminal identification numbers belonging to the CSG-ID are described may be used. The list corresponding to the CSG-ID of each Home-eNB is sent from the core network to each Home-eNB.

  The mobile terminal that has started the manual search for the Home-eNB in ST3006 performs a cell search and a cell selection in ST3007. In the situation as shown in FIG. 23, if there is a huge number of CSG cells belonging to a CSG-ID for which the mobile terminal has not registered for user access, the mobile terminal will be assigned to a CSG-ID for which user access has not been registered. In many cases, the CSG cell to which the cell belongs is selected. In the present embodiment, whether or not the cell selected CSG cell is a CSG cell that has performed user access registration, the mobile terminal can transmit an RRC connection request message to the CSG cell. The mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the RRC connection request message or may be used together with the RRC connection request message. Thereby, in ST3008, the mobile terminal transmits an RRC connection request to a CSG cell (here, Home-eNB (A)) that is not a CSG cell (here, Home-eNB (B)) for which user access has been registered. In Step ST3009, the Home-eNB (A) that has received the RRC connection request determines whether the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the received mobile terminal identification number. Check if. This check determines whether or not the mobile terminal identification number list included in the CSG-ID of Home-eNB (A) transmitted from the core network in ST3008 includes the mobile terminal identification number.

  Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the Home-eNB (A) determines that the mobile terminal cannot access the Home-eNB (A). I do. In ST 3010, Home-eNB (A) transmits an RRC connection reject message to the mobile terminal. The mobile terminal that has received the RRC connection reject message once performs a process of prohibiting transmission of the RRC connection request message to the Home-eNB (A) in ST3011. Specifically, for example, an RRC connection request transmission prohibited cell list is provided inside the mobile terminal, and the mobile terminal stores the cell identification number (PCI, Cell-ID, GCI, etc.) of the Home-eNB (A) in the list. I do. Then, before transmitting the next RRC connection request, the list is checked to determine whether or not the cell is stored in the list. In the case of a cell stored in the list, transmission of an RRC connection request is prohibited. Here, what is stored in the list may be the CSG-ID or TAC of the CSG cell, and the CSG-ID or TAC may be stored in association with the CSG cell identification number. By doing so, when the Home-eNB (A) is selected again in the future by cell search and cell selection, the mobile terminal does not transmit an RRC connection request to the Home-eNB (A). I can do it.

  The mobile terminal, which has not been able to obtain the whitelist in ST3011, performs a new cell search and cell selection in ST3012. Here, when Home-eNB (A) is selected again, transmission of the RRC connection request is prohibited, and cell selection is performed from cells excluding Home-eNB (A). The mobile terminal that has selected Home-eNB (B) by cell selection transmits an RRC connection request message to Home-eNB (B) in ST3013. In Step ST3014, the Home-eNB (B), which has received the TAU request message, sets the CSG-ID (TAC) of the Home-eNB (B) based on the mobile terminal identification number received together. Check if it belongs. The above-described method can be applied to this check. Since the mobile terminal identification number is registered in the CSG-ID to which the Home-eNB (B) belongs, the Home-eNB (B) determines that the mobile terminal can access the own cell. The Home-eNB (B) that has determined that the mobile terminal can access its own cell may notify the mobile terminal of a whitelist in ST3015 before transmitting an RRC connection accept message. The mobile terminal that has received the whitelist in ST 3016 stores the whitelist in its own mobile terminal. Home-eNB (B) which transmitted the whitelist to the mobile terminal transmits an RRC connection accept message in ST3017. As a result, an RRC connection is established between the mobile terminal and the Home-eNB (B) (ST3018). Then, in ST3019 and ST3020, the mobile terminal transmits a TAU request message to the core network via Home-eNB (B). Here, the mobile terminal also transmits the mobile terminal identification number.

  The core network that has received the TAU request message checks the CSG-ID (TAC) in ST3021 based on the received mobile terminal identification number. In ST3021, the core network that has confirmed that the mobile terminal belongs to the CSG-ID (TAC) of the Home-eNB (B) transmits a TAU accept to the mobile terminal to the Home-eNB (B) in ST3022 and ST3023. To send through. In ST3004 and ST3005, the core network transmits information on the CGS-ID (TAC) of each Home-eNB and the identification number of the mobile terminal belonging to the CSG-ID to all CSG cells (here, Home-eNB). However, the information of the mobile terminal identification number belonging to each CSG-ID may be transmitted to the HeNBGW connected to the CSG cell belonging to the CSG-ID. The HeNBGW may transmit the received information on the mobile terminal identification number belonging to each CSG-ID to a CSG cell of the same CSG-ID connected to the own HeNB. In addition, the HeNBGW transmits the received information of the mobile terminal identification number belonging to each CSG-ID to the CSG cell of the same CSG-ID connected to the own HeNB. The CSG cell that has received the RRC connection request sends a message requesting information of the mobile terminal identification number belonging to the CSG-ID of the own CSG cell to the HeNBGW, and when the HeNBGW receives the message, May be done.

  In the present embodiment, the process has been described in which the mobile terminal prohibits the RRC connection request for the CSG cell that has received the RRC connection reject message. May be prohibited from requesting the RRC connection to the cell. Also, the description has been given of the processing in which the mobile terminal prohibits the request for the RRC connection to the CSG cell that has received the RRC connection reject message once. May be prohibited. The number of times that the RRC connection reject message is continuously received from the same cell may be transmitted by broadcast information from the cell, or may be determined in advance. In addition, the notification of the whitelist is performed before the Home-eNB transmits the RRC connection accept. However, after receiving the TAU accept of ST3023, the Whitelist moves from the core network via the CSG cell by the NAS message. You may make it transmit to a terminal.

  Next, for example, in the methods disclosed in Embodiments 5 and 7, instead of using the TAU reject message transmitted by the core network to the mobile terminal, the RRC connection for the RRC connection request message transmitted by the mobile terminal is performed. A method for transmitting a whitelist using a reject message is disclosed. In Embodiments 5 and 7, it is necessary to transmit a whitelist of a mobile terminal from a CSG cell belonging to a CSG-ID for which the mobile terminal has not registered for user access. For this reason, the core network transmits information on all CSG-IDs (TAC) and identification numbers of mobile terminals belonging to the CSG-ID to all CSG cells.

  FIG. 31 shows a sequence diagram of a method of transmitting a whitelist before a CSG cell belonging to a CSG-ID for which the user equipment has not performed user access registration transmits an RRC connection reject message. FIG. 31 shows a case of an LTE system using Home-eNB, for example. Here, the mobile terminal performs user access registration with Home-eNB (C), but the operations from ST3101 to ST3103 are the same as those described above, and thus description thereof will be omitted. In ST3104, the core network transmits information on all CGS-IDs (TAC) and identification numbers of mobile terminals belonging to the CSG-ID to all CSG cells (here, all Home-eNBs). As a specific example of such information, a list in which mobile terminal identification numbers belonging to the CSG-ID are described may be used. The list corresponding to all CSG-IDs is sent from the core network to all Home-eNBs. The mobile terminal that has started the manual search of the Home-eNB in ST3105 performs a cell search and a cell selection in ST3106. In the situation as shown in FIG. 23, if there is a huge number of CSG cells belonging to a CSG-ID for which the mobile terminal has not registered for user access, the mobile terminal will be assigned to a CSG-ID for which user access has not been registered. In many cases, the CSG cell to which the cell belongs is selected. In the present embodiment, whether or not the cell selected CSG cell is a CSG cell that has performed user access registration, the mobile terminal can transmit an RRC connection request message to the CSG cell. The mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the RRC connection request message or may be used together with the RRC connection request message.

  Thereby, in ST3107, the mobile terminal transmits an RRC connection request to a CSG cell (here, Home-eNB (A)) that is not a CSG cell (here, Home-eNB (C)) for which user access has been registered. In Step ST3108, the Home-eNB (A) that has received the RRC connection request checks whether the mobile terminal belongs to any CSG-ID based on the received mobile terminal identification number. This check is performed using the list of mobile terminal identification numbers belonging to all CSG-IDs transmitted from the core network in ST 3104. The Home-eNB (A) searches for and specifies the CSG-ID including the mobile terminal identification number. In ST3109, Home-eNB (A) notifies the mobile terminal of a whitelist using the specified CSG-ID. In Step ST3110, the mobile terminal that has received the whitelist stores the whitelist in its own mobile terminal. Home-eNB (A), which has notified the mobile terminal of the whitelist in ST3109, transmits an RRC connection reject message to the mobile terminal in ST3111.

  In ST3104, the core network transmits information on all CGS-IDs (TAC) and identification numbers of mobile terminals belonging to the CSG-ID to all CSG cells (here, all Home-eNBs). However, the information of the mobile terminal identification number belonging to each CSG-ID may be transmitted to all HeNBGWs. The HeNBGW may transmit information on mobile terminal identification numbers belonging to all CSG-IDs to all CSG cells connected to the own HeNB. All HeNBGWs receive the RRC connection request from the mobile terminal in ST3107 in the process of transmitting the received information of the mobile terminal identification numbers belonging to all the CSG-IDs to all the CSG cells connected to the own HeNB. The CSG cell may send a message requesting information of mobile terminal identification numbers belonging to all CSG-IDs to HeNBGW, and the message may be transmitted when HeNBGW receives the message. By adopting such a method, the whitelist of the mobile terminal can be transmitted from a CSG cell belonging to a CSG-ID for which the user does not perform user access registration.

  By adopting the method disclosed in the above description, in addition to the effects described in the fourth to seventh embodiments, it is not necessary to set up an RRC connection or transmit / receive a NAS message such as a TAU request. Further, it is possible to improve the use efficiency of the radio resources, reduce the signaling load, reduce the control delay as a system, and reduce the power consumption of the mobile terminal.

Embodiment 9 FIG.
In Embodiments 3 to 7 described above, a mobile terminal that has performed user access registration to a CSG cell transmits a TAU request to the core network in order to obtain a whitelist from the core network. It has been described that the core network that has received the TAU request from the mobile terminal checks the CSG-ID (TAC) using the identification number of the mobile terminal and transmits a whitelist to the mobile terminal. .

  The core network may transmit the whitelist according to the above method whenever the TAU request message is transmitted from the mobile terminal. However, the TAU request message may occur for other reasons, not just to obtain a whitelist from the core network. For example, when a mobile terminal already has two CSG-IDs in the whitelist and moves from a CSG cell belonging to one CSG-ID to a CSG cell belonging to another one CSG-ID, a new whitelist is obtained. It is not necessary to register (update) the list, but since the TACs of the two CSG cells are different, the mobile terminal sends a TAU request to the core network. In such a case, even though the core network does not need to transmit the whitelist to the mobile terminal, the whitelist is transmitted to the mobile terminal, and the signaling load is unnecessarily increased. Problems arise.

  Further, with the method disclosed in the first modification of the sixth embodiment and the method disclosed in the seventh embodiment, it is possible to determine that the core network prohibits the mobile terminal from establishing an RRC connection or transmitting a TAU request. However, even in such a case, it is better for the core network to know whether the TAU request message transmitted by the mobile terminal is for a whitelist request, otherwise, the core network transmits for another reason. The inefficient operation is also taken into account because the TAU request message is also taken into account. In order to solve such a problem, the present embodiment discloses that information indicating a whitelist (registration) update request or a whitelist transmission (notification) request is added to a TAU request message. .

  For example, in the case of the example illustrated in FIG. 25 described in Embodiment 5, in ST2507 and ST2508, the mobile terminal transmits a TAU request to the core network via Home-eNB (A). Information indicating that the request is for a whitelist (registration) update request is placed on the TAU request message, and the TAU request is notified to the core network that the reason is for a whitelist (registration) update request. I do. With this configuration, the core network can know that the mobile terminal is requesting a whitelist (registration) update. Conversely, if there is no information in the TAU request message indicating that the request is for a whitelist (registration) update request, the TAU request message is not a request for whitelist (registration) update. It is not necessary to send a whitelist to the mobile terminal. As a specific method of putting information indicating a whitelist (registration) update request on the TAU request message, a whitelist (registration) update request may be added to the Type information of the TAU. The Type information may be indicated by a numerical value. Also, a 1-bit indicator may be provided on the TAU request message to indicate whether the request is for a whitelist (registration) update request.

  By adopting the method described above, even though the core network does not need to transmit a whitelist to the mobile terminal, the transmission of the whitelist to the mobile terminal causes an increase in signaling load that is originally unnecessary. Can be suppressed. In addition, when the core network determines to prohibit establishment of an RRC connection or transmission of a TAU request for the mobile terminal, inefficiency due to consideration of the TAU request message transmitted for other reasons is inefficient. The problem of causing an operation can be solved.

  Next, a first modified example of the present embodiment will be described. The method of putting information used for a whitelist (registration) update request on a TAU request message is applicable to the third to seventh embodiments. Here, in order to apply to the method disclosed in the eighth embodiment, information indicating that the request is for a whitelist (registration) update request or a whitelist transmission (notification) request is added to the RRC connection request message. Disclose.

  In the eighth embodiment, a whitelist is transmitted using an RRC connection reject message for an RRC connection request message transmitted by a mobile terminal. It has been described that the CSG cell to which the RRC connection request is transmitted from the mobile terminal checks the CSG-ID (TAC) using the identification number of the mobile terminal and transmits a whitelist to the mobile terminal. . The CSG cell may transmit the whitelist according to the above method whenever the RRC connection request message is transmitted from the mobile terminal. However, in this case, as described above, the CSG cell is wastefully transmitted. This causes a problem that the use efficiency of the radio resource is reduced, and further causes an inefficient operation. In order to solve such a problem, the first modification discloses that information indicating a whitelist (registration) update request is added to an RRC connection request message.

  For example, in the case of the example shown in FIG. 31 described in Embodiment 8, in ST3107, the mobile terminal transmits an RRC connection request to Home-eNB (A). Information indicating that the request is for a whitelist (registration) update request is placed on the RRC connection request message, and Home-information indicating that the reason is for a whitelist (registration) update request is given together with the RRC connection request. Notify the eNB (A). By doing so, the Home-eNB (A) can know that the mobile terminal has requested a whitelist (registration) update. Conversely, if there is no information indicating that the request is for a whitelist (registration) update request in the RRC connection request message, the RRC connection request message requests a whitelist (registration) update. It is not necessary to transmit the whitelist to the mobile terminal.

  As a specific method of putting information indicating that the request is for a whitelist (registration) update request on the RRC connection request message, a whitelist (registration) update request is used as the cause information of the RRC connection request message. Just add. The reason information may be indicated by a numerical value. Also, a 1-bit indicator may be provided on the RRC connection request message to indicate whether the request is for a whitelist (registration) update request. Although the modification has been described with reference to the case where the method is applied to the method disclosed in the eighth embodiment, it is also possible to apply the modification to the third to seventh embodiments. It can be applied at the time of requesting an RRC connection performed at the time of a whitelist (registration) update request.

  By adopting the method disclosed in the present embodiment, in addition to the effects described in Embodiment 8, it is not necessary for the CSG cell to transmit a whitelist to the mobile terminal as described above. Regardless, a whitelist registration (update) notification message is transmitted to the mobile terminal, and the radio resources are unnecessarily reduced. Further, the CSG cell sends an RRC connection request to the mobile terminal. When it is determined that transmission is prohibited, it is possible to solve the problem of causing inefficient operation due to consideration of the RRC connection request message transmitted for other reasons. Also, by placing information indicating that the request is for a whitelist (registration) update request on a TAU request message or an RRC connection request message, the RRC to a CSG cell other than the CSG cell to which the mobile terminal has performed user access registration is performed. The establishment of the connection and the transmission of the TAU request message to the core network via the CSG cell are not limited to the time of manual search activation. By applying the method shown in the present embodiment and the modification, if the mobile terminal is for a (registration) update request of the whitelist, the mobile terminal may make a request to a CSG cell other than the CSG cell to which the user access registered. The establishment of the RRC connection and the transmission of the TAU request message to the core network via the CSG cell may be permitted, so that, for example, after the user access registration, the automatic search is not performed without starting the manual search. It is also possible to perform communication for obtaining a whitelist, and it is also possible to periodically initiate a whitelist without activating a manual search (for example, periodically at a predetermined cycle). ) It is also possible to perform communication for obtaining a whitelist. By doing so, the procedure until the mobile terminal obtains the registered (updated) whitelist can be made flexible, a large number of future CSG cells will be installed, and user access registration will be performed in various places. It is possible to cope with such a situation. By applying the method described in the present embodiment and the modification, information indicating that the mobile terminal has started the manual search as disclosed in Embodiments 4 and 5 can be transmitted to the RRC connection request or the like. There is no need to include it in the TAU request, and the amount of signaling can be reduced.

Embodiment 10 FIG.
In Embodiments 4 to 7, a mobile terminal that has performed user access registration to a CSG cell transmits a TAU request to the core network via the CSG cell in order to obtain a whitelist from the core network (CN). Will be. The core network that has received the TAU request from the mobile terminal checks the CSG-ID (TAC) using the identification number of the mobile terminal, and if it determines that access to the CSG cell is not possible, It has been described that the TAU reject message is transmitted to the mobile terminal via the CSG cell. On the other hand, a method of determining the next operation according to the TAU reject message received by the mobile terminal from the core network via the CSG cell has also been described. In such a case, it is better for the mobile terminal to know whether or not the TAU reject message received via the CSG cell is in response to a TAU request for a whitelist registration (update) request, and does not know. Then, the TAU reject message transmitted for other reasons is also taken into consideration, resulting in inefficient operation.

  On the other hand, in 3GPP, it is under study to add reason information indicating “unsuitable cells” to a TAU reject message or RRC connection reject message. However, as described above, since there are many types of definitions of “suitable cells” (suitable cells), it is not possible to specify which definition does not apply. In order to solve such a problem, in the present embodiment, the TAU reject message indicates that the reason for rejection is that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs. Disclose to put information.

  For example, in the case of the example shown in FIG. 27 described in Embodiment 6, in ST2710 and ST2711, the core network transmits a TAU request reject message to the mobile terminal via Home-eNB (A). By putting information indicating that the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs on the TAU reject message, the reason is as follows. It notifies that the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs. By doing so, the mobile terminal can know that the reason for the received TAU request reject message is that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs. Become. Conversely, if the TAU reject message contains no information indicating that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs, the TAU reject message It turns out that the message was for some other reason.

  As a specific method of putting information indicating that the reason for rejection on the TAU reject message is that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs, the TAU reject message Information indicating that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs may be added to the reason (cause) information. The reason information may be indicated by a numerical value. Also, a 1-bit indicator indicating whether or not the mobile terminal identification number is not registered may be provided in the CSG-ID to which the CSG cell belongs on the TAU request reject message.

  By adopting the method disclosed in the present embodiment, in addition to the effects described in Embodiments 4 to 7, in addition, as described above, the mobile terminal may perform RRC rejection on the TAU reject message transmitted from the core network. To solve the problem of causing inefficient operation due to taking into account the TAU reject message sent for other reasons when determining to prohibit the establishment of a connection or the transmission of a TAU request. It becomes possible.

  Next, a first modification of the tenth embodiment described above will be described. Here, in order to apply to the method disclosed in Embodiment 8, information indicating that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs is included in the RRC connection reject message on the RRC connection reject message. Disclose to put on. In the eighth embodiment, it has been described that the mobile terminal performs the process of prohibiting the transmission of the RRC connection request message by using the RRC connection reject message for the RRC connection request message transmitted by the mobile terminal. The mobile terminal may prohibit the transmission of the RRC connection request message to the CSG cell whenever the RRC connection reject message is transmitted from the CSG cell. Similarly, it causes inefficient operation.

  In order to solve such a problem, in the first modification, the RRC connection reject message indicates that the reason for rejection is that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs. Disclose to put information. For example, in the case of the example illustrated in FIG. 31 described in Embodiment 8, in ST3110, the mobile terminal receives an RRC connection reject from Home-eNB (A). Home-eNB (A) indicates in the RRC connection reject message that the reason for rejection is that the mobile terminal identification number is not registered in the CSG-ID to which Home-eNB (A) belongs. And notifies the mobile terminal that the reason for the rejection is that the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs. By doing so, the mobile terminal can know that the received RRC connection reject message is because the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs. . Conversely, if there is no information on the RRC connection reject message indicating that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs, the rejection is performed. It is possible to know that the reason is not because the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs.

  As a specific method of putting information indicating that the reason for rejection on the RRC connection reject message is that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs, the RRC connection rejection is used. Information indicating that the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs may be added to the reason (cause) information of the message. The reason information may be indicated by a numerical value. Further, a 1-bit indicator indicating whether or not the mobile terminal identification number is not registered in the CSG-ID to which the CSG cell belongs on the RRC connection reject message may be provided.

  By adopting the method disclosed in the present embodiment, in addition to the effects described in Embodiment 8, in addition to the above-described effects, when the mobile terminal receives the RRC connection reject message from the CSG cell, It is possible to solve the problem of causing an inefficient operation due to considering the RRC connection reject message transmitted for other reasons in the case of the method of determining the prohibition of.

Embodiment 11 FIG.
A description has been given that a mobile terminal may erroneously receive whitelist contents transmitted from a core network when registering or changing a whitelist. In such a case, in a situation where a large number of CSG cells exist, a case may occur in which a CSG cell belonging to the CSG-ID of the erroneously received whitelist is selected. An RRC connection is established to the CSG cell belonging to the ID, and a request for a TAU to the core network is repeated through the CSG cell. Therefore, there arises a problem that the use efficiency and the signaling efficiency of the radio resources are extremely reduced as a system. Furthermore, a large amount of time is required from the cell search to the start of the standby operation, which causes a problem that a large control delay occurs as a system and a problem that the power consumption of the mobile terminal becomes enormous.

  In order to solve these problems, the present embodiment discloses a method in which a mobile terminal explicitly transmits whitelist reception success / failure (Ack / Nack) to a core network. FIG. 32 shows a sequence diagram of a method of explicitly transmitting success / failure (Ack / Nack, completion / incomplete, complete / incomplete) of whitelist reception in the mobile terminal to the core network at the time of whitelist registration. The figure shows a case of an LTE communication system using Home-eNB, for example. The figure will be described. Here, the mobile terminal performs user access registration with Home-eNB (C). However, since operations from ST3201 to ST3203 are the same as those described above, description thereof will be omitted. The mobile terminal that has started the manual search for the CSG cell (here, Home-eNB) in ST3204 performs cell search and cell selection in ST3205. In the situation as shown in FIG. 23, if there are more CSG cells belonging to the CSG-ID for which the mobile terminal has not performed user access registration, the mobile terminal selects a CSG cell. As disclosed in the fourth embodiment, the mobile terminal can establish an RRC connection to the CSG cell, regardless of whether the CSG cell selected by the cell is a CSG cell that has performed user access registration or not. TAU can be transmitted to the network via the network. By this means, in ST3206, the mobile terminal transmits an RRC connection request to a CSG cell (here, Home-eNB (A)) which is not a CSG cell (here, Home-eNB (C)) for which user access has been registered. The Home-eNB (A) that has received the RRC connection establishment request transmits an establishment permission for the establishment request to the mobile terminal, thereby establishing an RRC connection between the mobile terminal and the Home-eNB (A).

  Next, in ST3207 and ST3208, the mobile terminal transmits a TAU request message to the core network via the Home-eNB (A). Here, the mobile terminal also transmits the mobile terminal identification number. The mobile terminal identification number may be included in the TAU request message, may be combined with the TAU request message, or may be transmitted as another message. The core network that has received the TAU request message checks whether the mobile terminal belongs to the CSG-ID of the Home-eNB (A) based on the mobile terminal identification number that has also been received. As the method of this check, the method described in ST2207 disclosed in FIG. 22 can be applied. Since the mobile terminal identification number is not registered in the CSG-ID to which the Home-eNB (A) belongs, the core network determines that the mobile terminal cannot access the Home-eNB (A). In this embodiment, for example, the method disclosed in Embodiment 5 is used. Even if the core network determines that the mobile terminal cannot access the Home-eNB (A), before transmitting the TAU reject, the mobile terminal whitelists the mobile terminal to the Home-eNB (A) in ST3210. Send Home-eNB (A), which has received the whitelist of the mobile terminal, transmits the whitelist to the mobile terminal in ST3211.

  Here, the mobile terminal that has received the whitelist transmits an Ack indicating successful reception of the whitelist to Home-eNB (A) in ST3212. This Ack may be a NAS message. Home-eNB (A), which has received the Ack indicating successful whitelist reception from the mobile terminal, transmits an Ack indicating successful whitelist reception to the core network in ST3213. The core network that has received the Ack indicating the successful reception of the whitelist receives information for notifying Home-eNB (C) that the mobile terminal has performed user access registration in ST3215 that the mobile terminal has completed user access registration. Send On the other hand, in ST3214, the mobile terminal stores the received whitelist in its own mobile terminal. The core network that has received the Ack indicating the successful reception of the whitelist in ST3213 transmits a TAU reject message for the TAU request to the mobile terminal via the Home-eNB (A) in ST3216 and ST3217. The mobile terminal that has received the TAU reject message releases the RRC connection with Home-eNB (A) in ST3218.

  The mobile terminal that has failed in receiving the whitelist in ST 3211 transmits a Nack indicating that whitelist reception failed to Home-eNB (A) in ST 3212. This Nack may be a NAS message. Home-eNB (A), which has received the Nack of whitelist reception failure from the mobile terminal, transmits a Nack of whitelist reception failure to the core network in ST3213. The core network that has received the Nack of the whitelist reception failure transmits the whitelist to the mobile terminal via the Home-eNB (A) again in ST3210 and ST3211. Such processing is repeated until the mobile terminal successfully receives the whitelist. If the mobile terminal has successfully received, the mobile terminal performs the processing after ST3212. By adopting such a method, it is possible to greatly reduce the probability that the mobile terminal erroneously receives the contents of the whitelist transmitted from the core network. Therefore, as described above, in a situation where a large number of CSG cells exist, the mobile terminal selects a CSG cell belonging to the CSG-ID of the erroneously received whitelist, and the RSG is repeatedly transmitted to the CSG cell. It is possible to solve the problem of establishing a connection and repeatedly requesting a TAU to a core network via a CSG cell. By solving these problems, it is possible to prevent an extreme decrease in the use efficiency of the radio resources and the signaling efficiency in the future system operation.

  In the fourth to eleventh embodiments of the present invention, whitelist registration has been described. However, the present invention can be applied to not only whitelist registration but also whitelist update (including deletion and addition). In the examples of Embodiments 1 to 11 of the present invention, the communication system using the LTE system in which the Home-eNB is used as the CSG cell has been described. However, even in the case of the UMTS communication system in which the Home-NB is used as the CSG cell, Applicable. In the case of a UMTS communication system in which a Home-NB is used as a CSG cell, an RNC is provided between a base station (Home-NB, NB) and a core network, and an RRC message such as an RRC connection request is transmitted between the mobile terminal and the RNC. The NAS message such as the TAU request may be transmitted and received from the mobile terminal to the core network via the base station (Home-NB, NB) and the RNC. By doing so, the present invention can be applied to a UMTS communication system in which Home-NBs are used as CSG cells.

Embodiment 12 FIG.
Non-Patent Document 6 discloses a procedure of an RRC (Radio Resource Control) connection re-establishment as an LTE mobile communication system. FIG. 34 shows a flow of a process as a mobile terminal related to RRC connection re-establishment disclosed in FIG. 33. In Step ST3301, the mobile terminal determines whether or not a radio link failure (Radio link failure) has been detected. As a result, when a wireless link failure has been detected, the mobile terminal shifts to step ST3305; otherwise, the mobile terminal shifts to step ST3302. In Step ST3302, the mobile terminal judges whether or not handover has failed (Handover failure). As a result, when the handover has failed, the mobile terminal shifts to step ST3305; otherwise, the mobile terminal shifts to step ST3303. In Step ST3303, the mobile terminal judges whether or not there is an instruction from a layer having a lower integrity failure (Integrity failure). As a result, if there is an instruction of integrity failure, the process proceeds to step ST3305, and if there is no instruction, the process proceeds to step ST3304. In Step ST3304, the mobile terminal judges whether or not RRC connection reconfiguration failure has occurred. As a result, if the RRC connection reset has failed, the mobile terminal shifts to step ST3305; otherwise, shifts to step ST3301. The mobile terminal returning to step ST3301 repeats the processing of step ST3301, step ST3302, step ST3303, and step ST3304. Further, the order of the processes of step ST3301, step ST3302, step ST3303, and step ST3304 is arbitrary, and may be simultaneous.

  The radio link failure in which the mobile terminal determines the presence or absence of detection in step ST3301 will be described below. The time during which radio link recovery (Radio link recovery) is allowed after detecting the physical layer problem (Physical layer problem) is, for example, T310. Instead of T310, it is also possible to define a counter value of a physical layer failure from when a physical layer problem is detected until radio link recovery is permitted. Further, the time allowed to recover the radio link after receiving the random access problem indicator from the MAC is, for example, T312.

  When the timers (T310, T312) expire, the mobile terminal detects a radio link failure. Note that the timers (T310, T312) are transmitted from the base station (network side) to the mobile terminal as part of the timer and constant information element (UE-Timer And Constansts information element) of the mobile terminal. Information BlockType2: SIB2) and is notified on PDSCH (DL-SCH) using BCCH.

  The handover failure determined by the mobile terminal in step ST3302 will be described below. The mobile terminal executes the handover by receiving the RRC message that triggers the handover. When the mobility control information is included in the RRC connection reconfiguration message, the mobile terminal sets a timer (for example, T304) included in the mobility control information. When the MAC has completed the random access procedure, the mobile terminal stops the timer (T304). When the timer (T304) expires, the mobile terminal determines that the handover has failed. That is, the timer (T304) defines the allowable time required for the MAC to complete the random access procedure from the start of the handover. Note that the timer (T304) is mapped by the base station (network side) to the RRC connection reconfiguration message (RRC Connection Reconfiguration message) as a part of the mobility control information element of the mobile terminal. , NAS dedicated information (NAS (Non Access Stratum) Dedicated information).

  The RRC connection reset failure determined by the mobile terminal in step ST3304 will be described below. If the configuration that the UE cannot perform is included in the RRC connection reconfiguration message, it is determined that the RRC connection reconfiguration has failed. The base station (network side) notifies the mobile terminal of the RRC connection reset message as NAS individual information. After detecting the physical layer problem in Step ST3305, the mobile terminal stops the timer for the time (T310) during which the radio link recovery is allowed, and proceeds to Step ST3306. After receiving the random access problem indicator from the MAC in Step ST3306, the mobile terminal stops the timer for the time (T312) during which radio link recovery is permitted, and proceeds to Step ST3307. In Step ST3307, the mobile terminal detects the radio link failure, determines that the handover has failed, determines that the integrity has failed, or determines that the RRC connection reconfiguration has failed, and determines whether to allow the mobile terminal to select a cell in the E-UTRA. A time timer (for example, T311) is started, and the mobile terminal shifts to step ST3308. The timer (T311) is transmitted from the base station (network side) to the mobile terminal as part of a timer and a constant information element (UE-Timer And Constansts information element) of the mobile terminal. : SIB2), and is notified on the PDSCH using the BCCH. In Step ST3308, the mobile terminal resets the MAC (Media Access Control) and moves to Step ST3309. In Step ST3309, the mobile terminal resets the RLC (Radio Link Control) of all the set radio bearers (Radio Bearer: RB), and moves to Step ST3310.

  In Step ST3310, the mobile terminal determines whether the T311 timer has expired. As a result, if the timer has expired (timeout, timer completed, timer expired), the mobile terminal shifts to step ST3311. If not, the mobile terminal shifts to step ST3314. In Step ST3311, the mobile terminal resets the RLC reset of all the radio bearers set as the MAC, and moves to Step ST3312. In Step ST3312, the mobile terminal releases all radio resources (Radio resources), and proceeds to Step ST3313. In Step ST3313, the mobile terminal makes a transition to the RRC_IDLE state. In Step ST3314, the UE determines whether or not the E-UTRA cell is selected by a cell selection process (cell selection process) or a cell reselection process (cell reselection process). As a result, the mobile terminal shifts to step ST3315 when an E-UTRA cell is selected, and shifts to step ST3317 when an E-UTRA cell is not selected. In Step ST3315, the mobile terminal stops the timer T311 and moves to Step ST3316. In Step ST3316, the mobile terminal transmits an RRC connection reestablishment request message to the network side. In Step ST3317, the mobile terminal determines whether or not an inter-RAT (Radio Access Technology Cell) has been selected by a cell selection procedure. As a result, if an inter-RAT cell has been selected, the mobile terminal proceeds to Step ST3311. If the mobile terminal has shifted and does not select an inter-RAT cell, the mobile terminal shifts to step ST3310, and the mobile terminal that has returned to step ST3310 repeats the processing of step ST3310, step ST3314, and step ST3317.

  The problem in the twelfth embodiment will be described below. As described above, CSG cells are introduced in LTE and UMTS. However, Non-Patent Document 6 does not disclose how to introduce a CSG cell in the procedure as a mobile communication system for RRC connection reestablishment. Further, there is no suggestion about the problem pointed out in the twelfth embodiment. In order to receive a standard service in a CSG cell, the mobile terminal needs to register with the CSG cell. After completing the registration, the mobile terminal stores the CSG-ID of the registered CSG cell in the whitelist existing in the mobile terminal (USIM, SIM, memory, CPU, etc.). The CSG cell reports a CSG-ID or a tracking area code (Tracking Area Code: TAC) associated with the CSG-ID to mobile terminals under its control as system information (System information). The CSG-ID or TAC is mapped to a system information block type 1 (System Information Block Type1: SIB1), and is broadcast from the CSG cell on the PDSCH using the BCCH. The cycle at which SIB1 is notified is set to once every 20 ms. In order for the UE to select a CSG cell as a suitable cell (suitable cell) and to perform location registration or standby for obtaining a standard (normal) service, the UE selects a non-CSG cell as a suitable cell. In addition, it is necessary to additionally perform a process of determining whether the own mobile terminal is registered in the CSG cell. In order to determine whether the own mobile terminal is registered in the CSG cell, it is necessary to determine whether the CSG-ID (or TAC) broadcast by the CSG cell is the same as the CSG-ID in the whitelist in the own mobile terminal. You need to judge.

  4 shows a RRC connection re-establishment procedure when a CSG cell is introduced. The procedure is almost the same as that in FIG. 33, but FIG. 34 shows details of the characteristic step ST3314. In Step ST3401, the mobile terminal judges whether or not the whitelist includes the CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. In a case where the whitelist includes a CSG-ID, or in a case where the UE has been registered in a CSG cell, the UE proceeds to Step ST3402. In a case where the whitelist does not include the CSG-ID, or in a case where the whitelist has not been registered in the CSG cell, the UE proceeds to Step ST3410. In Step ST3402, the mobile terminal determines whether or not there is a cell that can be a serving cell in the CSG cell based on the measurement result of the reception quality of the neighboring cell (Neighboring Cell). If present, the mobile terminal makes a transition to step ST3403. If not, the mobile terminal makes a transition to step ST3410. In Step ST3403, the mobile terminal selects the best cell (best cell: also called best cell) based on the reception quality among the cells that can be the serving cell in the CSG cell from the measurement result of the reception quality of the neighboring cells, The mobile terminal moves to step ST3404.

  In Step ST3404, the mobile terminal receives a physical downlink control channel (Physical downlink control channel: PDCCH, also called an L1 / L2 signaling channel) of the cell selected in Step ST3403. For receiving the PDCCH, the mobile terminal needs to perform a blind detection (Blind Detection) process. As a result of the blind detection, the mobile station receives the allocation of the BCCH on the PDSCH, and moves to step ST3405. In Step ST3405, the mobile terminal receives PDSCH according to the allocation for BCCH received in Step ST3404, and moves to Step ST3406. In the PDSCH, the BCCH to which the SIB1 is mapped is transmitted once every 20 ms. The mobile terminal acquires SIB1 in Step ST3405. In Step ST3406, the mobile terminal obtains the CSG-ID or TAC mapped to SIB1 received in Step ST3405, and moves to Step ST3407. There is a possibility that the CSG-ID is mapped to system information different from SIB1, but even in such a case, the present embodiment can be applied.

  In Step ST3407, the mobile terminal judges whether or not the CSG-ID of the CSG cell obtained in Step ST3406 is the same as the CSG-ID of the registered CSG cell stored in the whitelist of the own mobile terminal. . Accordingly, the mobile terminal determines whether or not the CSG cell can be a “suitable cell”. That is, when the CSG-ID of the CSG cell exists in the whitelist, the cell can be a “suitable cell” as a registered CSG cell. Conversely, if the CSG-ID of the CSG cell does not exist in the whitelist, the cell cannot be a “suitable cell” as an unregistered CSG cell. If the CSG cell is a registered CSG cell, the mobile terminal shifts to step ST3315 in FIG. If the CSG cell is an unregistered CSG cell, the mobile terminal makes a transition to step ST3408.

  In Step ST3408, the mobile terminal omits the CSG cell from the E-UTRA cell selection process, and moves to Step ST3409. In Step ST3409, the mobile terminal determines whether the T311 timer has expired. As a result, if the timer has expired (timeout, timer completed, timer expired), the process proceeds to step ST3311 in FIG. 33, and if not, the process returns to step ST3402. In Step ST3410, the mobile terminal determines whether or not there is a cell that can be a serving cell in the non-CSG cell based on the measurement result of the reception quality of the neighboring cell (Neighboring Cell). If present, the mobile terminal makes a transition to step ST3411. If not, the mobile terminal shifts to step ST3317 in FIG. In Step ST3411, the mobile terminal selects the best cell based on the reception quality among the cells that can be the serving cell among the non-CSG cells based on the measurement result of the reception quality of the neighboring cells, and proceeds to Step ST3315 in FIG. I do.

  As is clear from the above and FIG. 34, the time required for the mobile terminal including the CSG-ID in the whitelist, that is, the mobile terminal registered in any one of the CSG cells, to select the E-UTRA cell is represented by the CSG-ID in the whitelist. It can be understood that there is a possibility that a mobile terminal that does not include, that is, a mobile terminal that is not registered in any CSG cell becomes longer than the time required for E-UTRA cell selection. This phenomenon appears more remarkably than when the own mobile terminal has registered in a CSG cell (assuming CSG-ID = 10), but there is no CSG cell (CSG-ID = 10) in the vicinity. In this case, the mobile terminal determines that the cell is an “unregistered CSG cell” in step ST3407 of FIG. Furthermore, when a mobile terminal exists in a place where there are many CSG cells that are not registered by the own mobile terminal and the reception quality of many unregistered CSG cells is good and the cell can be a serving cell, the above-described problem occurs. Appears more prominently. In this case, the process from step ST3402 to step ST3409 in FIG. 34 is repeated until there is no cell that can be a serving cell among the CSG cells.

  The following problem arises due to the difference in time required for cell selection between a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist. As described above, the allowable time from the detection of a radio link failure, the determination of a handover failure, the determination of an integrity failure, or the determination of an RRC connection reconfiguration failure to selection of a cell in E-UTRA. (For example, T311). In the case where the above-mentioned timer is one type as it is now, consider a case where the timer value is adapted to a mobile terminal having a CSG-ID in a whitelist. In this case, since there is no CSG-ID in the whitelist, the timer does not time out even though the time required for cell selection is relatively short. That is, in step ST3310 of FIG. 33, the determination that "timer has ended" is unnecessarily delayed. This means that release of all radio resources (radio resources) performed in step ST3312 of FIG. 33 is unnecessarily delayed. Therefore, a problem of securing unnecessary radio resources occurs. Conversely, consider a case where the timer value is adapted to a mobile terminal that does not have a CSG-ID in the whitelist. In this case, since the whitelist has the CSG-ID, the time required for cell selection is long, and therefore, the timer is set during cell selection. May time out.

  That is, it is conceivable that the determination of “timer end” in step ST3310 of FIG. 33 or the determination of “timer end” in step ST3409 of FIG. 34 is too early. This causes a problem that the MAC of the mobile terminal having the CSG-ID in the whitelist is reset, but the possibility of re-establishing the RRC connection in a state where the radio bearer, that is, the radio resource is secured, occurs. This causes a problem that a mobile terminal having a CSG-ID in the whitelist transits to the RRC_IDLE state and a control delay occurs even though there are cells having good reception quality in the vicinity. Note that Non-Patent Document 6 does not suggest this problem. FIG. 34 illustrates a case where the selection of the CSG cell is performed with a higher priority than the selection of the non-CSG cell. However, even without this priority, the above problem occurs. Further, this problem occurs both in introducing a CSG cell in an LTE (E-UTRAN) system and in introducing a CSG cell in a W-CDMA (UTRAN, UMTS) system.

  A solution to the problem of the twelfth embodiment will be described below. The solution is applicable to both LTE and W-CDMA systems. In a twelfth embodiment, in order to solve the above-described problem, it is disclosed that a different timer is separately provided depending on whether or not a whitelist has a CSG-ID and reflected on a mobile terminal. More specifically, the detection of radio link failure, the determination of handover failure, the determination of integrity failure, or the determination of RRC connection reconfiguration failure by determining whether or not the whitelist has a CSG-ID, -Discloses that a timer (for example, T311) for an allowable time until a cell in UTRA is selected is separately provided (for example, T311_whitelist is present and T311_whitelist is not present) and reflected on a mobile terminal.

  A specific operation example will be described with reference to FIG. In FIG. 35, description of the same step numbers as in FIG. 33 will be omitted. 34 can be used also in FIG. In Step ST3501, the mobile terminal determines whether or not the whitelist includes a CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. In a case where the whitelist includes the CSG-ID, or in a case where the whitelist has been registered in the CSG cell, the UE proceeds to Step ST3502. In a case where the whitelist does not include the CSG-ID, or in a case where the UE has not been registered in the CSG cell, the UE proceeds to Step ST3503. In Step ST3502, the mobile terminal detects the radio link failure, determines that the handover has failed, determines that the integrity has failed, or determines from the determination that the RRC connection reconfiguration has failed, and determines whether to allow the mobile terminal to select a cell in E-UTRA. Detection of a radio link failure for a case where a time timer (for example, T311) includes a CSG-ID in a whitelist or registration with a CSG cell, determination of a handover failure, or determination of an integrity failure Alternatively, a timer (for example, T311_whitelist is present) of an allowable time from the determination that the RRC connection reconfiguration has failed to the selection of a cell in the E-UTRA is set, and the UE proceeds to Step ST3307.

  In Step ST3503, the mobile terminal detects the radio link failure, determines that the handover has failed, determines that the integrity has failed, or determines that the RRC connection reconfiguration has failed, and determines whether to allow the mobile terminal to select a cell in the E-UTRA. Detection of a radio link failure for a case where the CSG-ID is not included in the whitelist in the time timer (for example, T311), or a case where the CSG cell is not registered in the CSG cell, a determination of a handover failure, or a determination of an integrity failure Alternatively, a timer (for example, no T311_whitelist) for an allowable time from the determination that the RRC connection reconfiguration has failed to the selection of a cell in the E-UTRA is set, and the UE proceeds to Step ST3307.

  Next, a method of notifying a timer separately provided with a different timer depending on whether or not the whitelist has a CSG-ID will be disclosed. As a first method, a timer used when a CSG-ID is included in a whitelist (for example, T311_whitelist is provided), and a timer used when a CSG-ID is not provided in a whitelist (for example, no T311_whitelist is provided) In both cases, the serving cell (network side) notifies the mobile terminal. More specifically, notification is made using a dedicated control channel (DCCH) or a broadcast control channel (BCCH). When the dedicated control channel is used, it is an excellent method in that control according to the communication state of the mobile terminal is possible. When the BCCH is used, it is possible to notify all the mobile terminals being served thereby, which is an excellent method in terms of effective use of radio resources. As a specific example of the case of using the BCCH for notification, mapping to MIB or SIB can be considered. When the MIB is used, since the MIB is mapped to the PBCH, this is an excellent method in that the mobile terminal can receive the signal with a small control delay. When SIB is used, notification is made using SIB1. MIB or SIB1 is an excellent method in reducing control delay of a mobile terminal in that it is broadcast information to be received at a minimum required for an operation of waiting from a cell search. In addition, as a part of a UE and a constant information element (UE-Timer And Constansts information element) of the mobile terminal, it is mapped to a system information block type 2 (System Information Block Type2: SIB2), and is notified on the PDSCH using the BCCH. . Furthermore, regardless of whether the serving cell is a CSG cell or a non-CSG cell, a timer (for example, with T311_whitelist) used when the CSG-ID is included in the whitelist, and a timer used when the CSG-ID is not included in the whitelist. The serving cell (network side) as well as the timer to be used (for example, T311_no white list) is used by the serving cell (network side) as a part of the UE's timer and constant information element (UE-Timer and Constansts information element). (BlockType2: SIB2), and is notified on PDSCH using BCCH. When SIB2 is used, similar (same type) parameters can be notified at the same time from the viewpoint of a timer, which is an excellent method in that processing of the received mobile terminal is easy. Furthermore, even if a method of notifying with system information other than SIB1 and SIB2 is broadcast information, it can be notified to all mobile terminals under its control, and is an excellent method in terms of effective use of radio resources. According to the first method, the mobile terminal can obtain a different timer only by receiving the BCCH or DCCH of the serving cell, so that the effect of preventing control delay can be obtained.

  As a second method, a timer (for example, no T311_whitelist) used when a CSG-ID is not included in a whitelist is transmitted from a serving cell (network side) to a mobile terminal by a timer of the mobile terminal and a constant information element ( As a part of UE-Timer and Constansts information element), it is mapped to system information block type 2 and notified on PDSCH using BCCH. Further, regardless of whether the serving cell is a CSG cell or a non-CSG cell, the serving cell (network side) uses a timer (for example, T311_no whitelist) used when the CSG-ID is not included in the whitelist as the mobile terminal. Are mapped to the system information block type 2 as part of the timer and constant information elements, and are notified on the PDSCH using the BCCH. A timer (for example, T311_with whitelist) used when the CSG-ID is included in the whitelist is mapped by the CSG cell to the mobile terminal in the system information, and is notified on the PDSCH using the BCCH.

  A specific operation example will be described with reference to FIGS. 36 and 37. In FIG. 36, the description of the same step numbers as in FIGS. 33 and 35 and the description of the same step numbers in FIG. 37 as in FIG. 34 will be omitted. In Step ST3601 of FIG. 36, the mobile terminal determines whether the serving cell is a CSG cell. If the serving cell is a CSG cell, the mobile terminal makes a transition to step ST3502. When the serving cell is not a CSG cell, the mobile terminal makes a transition to step ST3503. In Step ST3502 in FIG. 36, the mobile terminal sets T311_with a whitelist (T311 received from a CSG cell (serving cell)) in T311. In Step ST3503 of FIG. 36, the mobile terminal sets T311_no whitelist (T311 received from a non-CSG cell (serving cell)) in T311. In Step ST3701 of FIG. 37, the mobile terminal determines whether or not a timer (for example, T311_with whitelist) used when a CSG-ID is included in the whitelist is set in T311. If T311_whitelist is set, the mobile terminal shifts to step ST3407. If T311_whitelist is not set, the mobile terminal shifts to step ST3702.

  In Step ST3702 of FIG. 37, the mobile terminal obtains T311_whitelist from the system information mapped to the BCCH on the PDSCH received in Step ST3405, and proceeds to Step ST3703. In Step ST3703 of FIG. 37, the mobile terminal selects a cell in E-UTRA based on detection of radio link failure, determination of handover failure, determination of integrity failure, or determination of RRC connection reconfiguration failure. Detection of a radio link failure for a case where the timer (for example, T311) of the permissible time up to and including a CSG-ID in a whitelist or registration with a CSG cell, judgment of handover failure, or integrity failure , Or a timer (for example, T311_whitelist is present) of an allowable time from the determination that the RRC connection reconfiguration has failed until the selection of a cell in E-UTRA is set, and the UE proceeds to Step ST3407. According to the second method, it is possible to obtain an effect that it is not necessary to change the system information of the non-CSG cell due to the introduction of CSG. This eliminates the need for changes in the existing LTE system (eUTRA / eUTRAN) that does not include CSG, and improves compatibility. In the above second method, a method of notifying a timer (for example, T311_with a whitelist) used when a CSG-ID is included in a whitelist in system information mapped to a BCCH on a PDSCH has been specifically described. Also in the case of the second notification method, a specific example can use an individual control channel and a broadcast control channel (MIB, SIB) similarly to the first notification method.

  The effects of the twelfth embodiment will be described below. Under the umbrella of the base station, there is a possibility that a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist are present together. For a mobile terminal having a CSG-ID in a whitelist and a mobile terminal not having a CSG-ID in a whitelist, radio link failure detection is separately performed, or handover failure is determined, or integrity is determined, Alternatively, it is possible to set a timer (for example, T311) of an allowable time from the determination that the RRC connection reconfiguration has failed to the selection of a cell in the E-UTRA. This makes it possible to appropriately set the timer value both for a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist. Accordingly, it is possible to avoid securing unnecessary radio resources due to the long setting of the timer, and it is possible to obtain an effect of effectively utilizing the radio resources. Further, it is possible to obtain an effect of avoiding an increase in control delay as a mobile communication system due to the short setting of the timer. Prevention of control delay can also be obtained with the effect of reducing power consumption of the mobile terminal.

  The solution of the twelfth embodiment is superior in that the effect is obtained even if the network side (such as a base station) does not know whether the corresponding mobile terminal has a CSG-ID in the whitelist or not. . This eliminates the need for the mobile terminal to notify the base station of the presence / absence of a CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, there is no need for the base station to manage the presence / absence of a CSG-ID in the whitelist of the mobile terminals being served thereby, and the effect of reducing the processing load on the base station can be obtained.

Embodiment 13 FIG.
Non-Patent Document 7 discloses that priority of different E-UTARAN frequencies or Inter-RAT frequencies in an LTE mobile communication system is provided from a network side to a UE in system information and an RRC message. ing. When priorities are assigned from the network side to the mobile terminal via dedicated signaling, the mobile terminal ignores all priorities provided by the system information. Non-Patent Document 6 describes the following. The RRC Connection Release message includes the idle mode mobility control information, and the idle mode mobility control information includes a cell reselection priority expiry timer. If (for example, T320) is included, the following operation is performed as the mobile communication system. 39 shows a flow of a process as a mobile terminal disclosed in FIG. 38. In Step ST3801, the mobile terminal receives different E-UTRAN frequencies or Inter-RAT frequency priorities in the system information transmitted from the base station, and moves to Step ST3802. In Step ST3802, the mobile terminal judges whether or not different priorities of different E-UTRAN frequencies or Inter-RAT frequencies have been received in the individual signal transmitted from the base station. If received, the mobile terminal makes a transition to step ST3803. If not, the mobile terminal makes a transition to step ST3804. In Step ST3803, the mobile terminal reselects a cell according to the priority received in the system information.

  In Step ST3804, the mobile terminal performs cell reselection according to the priority received in the individual signal, and moves to Step ST3805. In Step ST3805, the mobile terminal determines whether or not it has left the PLMN for which the priority is set by the dedicated signal. In the case of separation, the mobile terminal makes a transition to step ST3808. If not, the mobile terminal makes a transition to step ST3806. In Step ST3806, the mobile terminal determines whether or not the mobile terminal has transitioned to the RRC connection state. In the case of transition, the UE proceeds to Step ST3808. If not, the mobile terminal makes a transition to step ST3807. In Step ST3807, the mobile terminal determines whether or not the timer T320 has expired. If the processing has been completed, the processing transits to Step 3808. If not finished, the process returns to step ST3804 and repeats the processing from step ST3804 to step ST3807. In addition, the order of processing from step ST3804 to step ST3807 is arbitrary, and may be simultaneous.

  The problem in the thirteenth embodiment will be described below. As described above, CSG cells are introduced in LTE and UMTS. A mobile terminal that has not been registered in any CSG cell, that is, a mobile terminal that does not have a CSG-ID in the whitelist, targets only the non-CSG cell for cell reselection. A mobile terminal registered in any one of the CSG cells, that is, a mobile terminal having a CSG-ID in the whitelist, sets not only the non-CSG cells but also the CSG cells as targets for reselection. Further, studies on a frequency (frequency layer) dedicated to the CSG in which only the CSG cell exists are also progressing. Therefore, a mobile terminal that has not been registered in a CSG cell (a mobile terminal that does not have a CSG-ID in a whitelist) and a mobile terminal that has been registered in any CSG cell (a mobile terminal that has a CSG-ID in a whitelist) , The same priority (priority of different E-UTRAN frequencies or Inter-RAT frequencies) is set as the mobile communication system, which causes a problem such as an increase in control delay. Further, this problem occurs both when introducing a CSG cell into an LTE (E-UTRAN) system and when introducing a CSG cell into a W-CDMA (UTRAN, UMTS) system.

  A solution to the problem of the thirteenth embodiment will be described below. The solution is applicable to both LTE and W-CDMA systems. In the thirteenth embodiment, in order to solve the above-described problem, different priorities (different E-UTARAN frequencies or inter-RAT frequency priorities) are separately provided depending on whether or not a whitelist has a CSG-ID. , Is disclosed to be reflected on the mobile terminal. A specific operation example will be described with reference to FIG. In FIG. 39, description of the same step numbers as in FIG. 38 will be omitted. In Step ST3901, the mobile terminal assigns a priority (for different E-UTRAN frequencies) for mobile terminals having a CSG-ID in the whitelist transmitted from the base station in the system information (for mobile terminals registered in the CSG cell). , Or the priority of the Inter-RAT frequency) and the priority of the mobile terminal having no CSG-ID in the whitelist (for the mobile terminal not registered in the CSG cell), and the mobile terminal makes a transition to step ST3802. In Step ST3902, the mobile terminal judges whether or not the whitelist includes the CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. In a case where the whitelist includes the CSG-ID, or in a case where the UE has been registered in the CSG cell, the UE proceeds to Step ST3903. When the whitelist does not include the CSG-ID, or when not registered in the CSG cell, the mobile terminal makes a transition to step ST3904. In Step ST3903, the mobile terminal reselects a cell according to the priority order for the mobile terminal having the CSG-ID in the whitelist received in the system information (for the mobile terminal registered in the CSG cell). In Step ST3904, the mobile terminal reselects a cell according to the priority order for mobile terminals that do not have a CSG-ID in the whitelist received in the system information (for mobile terminals that are not registered in CSG cells).

  In Step ST3905, the mobile terminal judges whether or not the whitelist includes the CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. In a case where the whitelist includes a CSG-ID, or in a case where the UE has been registered in a CSG cell, the UE proceeds to Step ST3906. In a case where the whitelist does not include the CSG-ID, or in a case where the whitelist has not been registered in the CSG cell, the UE proceeds to Step ST3907. In Step ST3906, the mobile terminal reselects a cell according to the priority order for the mobile terminal having the CSG-ID in the whitelist received by the dedicated signal (for the mobile terminal registered in the CSG cell), and in Step ST3805. Move to. In Step ST3907, the mobile terminal performs cell reselection according to the priority order for mobile terminals that do not have a CSG-ID in the whitelist received as the dedicated signal (for mobile terminals that are not registered in the CSG cell), The mobile terminal moves to step ST3805. Here, the priority order which differs depending on whether or not the whitelist includes the CSG-ID may be either the priority order notified by the system information or the priority order notified by the individual signal.

  Next, a method of notifying different priorities depending on whether or not a whitelist has a CSG-ID as system information (step ST3901) will be disclosed. As a first method, both the priority used when the CSG-ID is included in the whitelist and the priority used when the CSG-ID is not included in the whitelist, the serving cell (network side) transmits the system information to the mobile terminal. Is notified on the PDSCH using the BCCH. Furthermore, regardless of whether the serving cell is a CSG cell or a non-CSG cell, the serving cell (network side) uses the BCCH as system information for the mobile terminal, when the whitelist does not have a CSG-ID. Notify by PDSCH. According to the first method, since the mobile terminal can obtain different priorities only by receiving the BCCH of the serving cell, it is possible to obtain an effect of preventing control delay. As a second method, the serving cell (on the network side) notifies the mobile terminal of the priority to be used when there is no CSG-ID in the whitelist on the PDSCH using the BCCH as system information. Furthermore, regardless of whether the serving cell is a CSG cell or a non-CSG cell, the priority used when the CSG-ID is included in the whitelist, and the priority used when the CSG-ID is not included in the whitelist are both serving cells. (Network side) notifies the mobile terminal to the PDSCH using the BCCH as system information. The priority order used when the CSG-ID is included in the whitelist is reported by the CSG cell mapping the mobile terminal to the system information and using the BCCH on the PDSCH. It is possible to obtain the effect that it is not necessary to change the system information of the non-CSG cell due to the introduction of CSG. This eliminates the need for changes in the existing LTE system (eUTRA / eUTRAN) that does not include CSG, and improves compatibility.

  Next, when the whitelist notified to the mobile terminal from the base station (on the network side) by an individual signal includes a CSG-ID, or when the mobile station is registered in a CSG cell, the priority order is used, and the whitelist includes CSG-ID. An RRC message can be considered as a method of notifying the priority order when the ID is not included or when the terminal is not registered in the CSG cell.

  The effects of the thirteenth embodiment will be described below. Under the umbrella of the base station, there is a possibility that a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist are present together. Separate priorities (eg, different E-UTARAN frequencies or Inter-RAT frequency priorities) for mobile terminals having a CSG-ID in the whitelist and mobile terminals having no CSG-ID in the whitelist Configurable. Thereby, an effect of preventing an increase in control delay as a mobile communication system is obtained. The solution of the thirteenth embodiment is superior in that the above-described effect is obtained even if the network side (such as a base station) does not know whether the corresponding mobile terminal has a CSG-ID in the whitelist. . This eliminates the need for the mobile terminal to notify the base station of the presence / absence of a CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, there is no need for the base station to manage the presence / absence of a CSG-ID in the whitelist of the mobile terminals being served thereby, and the effect of reducing the processing load on the base station can be obtained.

Embodiment 14 FIG.
The problem in the fourteenth embodiment will be described below. As described in the thirteenth embodiment, in the related art, the priority (different E-UTRAN frequency or Inter-RAT frequency priority) notified from the network side (base station) to the mobile terminal by an individual signal is effective. The time was one type. As described above, CSG cells are introduced in LTE and UMTS. A mobile terminal that has not been registered in any CSG cell, that is, a mobile terminal that does not have a CSG-ID in the whitelist, targets only the non-CSG cell for cell reselection. Therefore, it is considered that there is little change in the priority order. A mobile terminal registered in any one of the CSG cells, that is, a mobile terminal having a CSG-ID in the whitelist, is subjected to reselection not only of the non-CSG cells but also of the CSG cells. Therefore, the priority change is considered to be frequent. In a situation where the frequency of priority change is different as described above, if there is only one kind of effective time of priority, it is impossible to set an effective time suitable for each situation change, and control delay increases. The task of doing so occurs. Further, this problem occurs both in introducing a CSG cell into an LTE (E-UTRAN) system and in introducing a CSG cell into a W-CDMA (UTRAN, UMTS) system.

  A solution to the problem of the fourteenth embodiment will be described below. The solution is applicable to both LTE and W-CDMA systems. In the fourteenth embodiment, in order to solve the above-described problem, the effective time of different priorities (priorities of different E-UTRAN frequencies or Inter-RAT frequencies) depends on whether or not the whitelist has a CSG-ID (for example, T320) is separately provided, and this is reflected on the mobile terminal. A specific operation example will be described with reference to FIG. In FIG. 40, description of portions having the same step numbers as in FIG. 38 will be omitted. In Step ST4001, the mobile terminal determines whether or not the whitelist includes a CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. When the whitelist includes the CSG-ID, or when the whitelist includes the CSG-ID, the mobile terminal makes a transition to step ST4002. In a case where the whitelist does not include the CSG-ID, or in a case where the UE has not been registered in the CSG cell, the UE proceeds to Step ST4003. In Step ST4002, the mobile terminal determines whether the CSG-ID is included in the whitelist in the effective time (for example, T320) of the priority (priority of different E-UTRAN frequencies or Inter-RAT frequencies) An effective time (for example, T320_whitelist is present) of a priority (priority of a different E-UTRAN frequency or Inter-RAT frequency) for a registered case is set, and the mobile terminal shifts to step ST3807.

  In Step ST4003, the mobile terminal does not include the CSG-ID in the whitelist during the effective time (for example, T320) of the priority order (priority order of different E-UTRAN frequencies or Inter-RAT frequencies), or An effective time (for example, no T320_whitelist) of a priority order (priority order of different E-UTRAN frequencies or Inter-RAT frequencies) for a case where it is not registered is set, and the mobile terminal shifts to step ST3807. When the CSG-ID is included in the whitelist, or the validity time of the priority order when registered in the CSG cell, and when the CSG-ID is not included in the whitelist, or not registered in the CSG cell An RRC message and a broadcast control channel can be considered as a method of notifying the validity time of the priority for the case. When the dedicated control channel is used, it is an excellent method in that control according to the communication state of the mobile terminal is possible. When the notification is made on the broadcast control channel, the notification can be made to all the mobile terminals being served thereby, which is an excellent method in terms of effective use of radio resources. Embodiment 14 can be used together with Embodiment 13. When the CSG-ID is included in the whitelist in that case, or the validity time of the priority order when registered in the CSG cell, and when the CSG-ID is not included in the whitelist, or registered in the CSG cell As a method of notifying the validity time of the priority order when it is not performed, an RRC message and a broadcast control channel can be considered. When the notification is made by the RRC message, the notification may be further made together with the priority notified by the individual signal. When the notification is made by the RRC message, the priority and the effective time of the priority can be notified by the same notification method, which is excellent in avoiding the complexity of the mobile communication system. Further, it is excellent in that control delay of the mobile communication system can be reduced by notifying both the priority and the effective time of the priority. When the notification is made on the broadcast control channel, the notification can be made to all the mobile terminals being served thereby, which is an excellent method in terms of effective use of radio resources.

  The effects of the fourteenth embodiment will be described below. Under the umbrella of the base station, there is a possibility that a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist are present together. For mobile terminals having the CSG-ID in the whitelist and mobile terminals not having the CSG-ID in the whitelist, priority (such as priority of different E-UTARAN frequencies or Inter-RAT frequencies) is separately set. Valid time can be set. This makes it possible to set the effective time of the priority according to the frequency of the change of the priority. Thereby, an effect of preventing an increase in control delay as a mobile communication system is obtained. The solution of the fourteenth embodiment is superior in that the above-described effect is obtained even if the network side (such as a base station) does not know whether the corresponding mobile terminal has a CSG-ID in the whitelist. . This eliminates the need for the mobile terminal to notify the base station of the presence / absence of a CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, there is no need for the base station to manage the presence / absence of a CSG-ID in the whitelist of the mobile terminals being served thereby, and the effect of reducing the processing load on the base station can be obtained. By using Embodiment 14 and Embodiment 13 together, a flexible, priority suitable for a mobile terminal having a CSG-ID in a whitelist and a mobile terminal having no CSG-ID in a whitelist The ranking can be set. Thereby, an effect of preventing an increase in control delay as a mobile communication system is obtained.

Embodiment 15 FIG.
Non-Patent Document 6 (Chapter 10.1.1.2) and Non-Patent Document 7 (Chapter 5.2.4.2) disclose procedures for cell reselection (Cell Reselection) as an LTE mobile communication system. The matters disclosed are described below. A mobile terminal in the RRC_IDLE state performs cell reselection. The mobile terminal measures a serving cell and a neighboring cell (Neighbor cell) in order to perform reselection. There is no need to indicate neighboring cells in the serving cell system information (for the purpose of the mobile terminal searching and measuring cells). If the characteristics of the serving cell satisfy the search or measurement criteria, the measurement is omitted. Cell reselection authenticates a cell to be camped on by a mobile terminal. It is based on cell reselection criteria for serving cell measurements. Reselection between same frequencies is based on cell ranking. Reselection between different frequencies is based on the absolute priority of the mobile terminal attempting to camp on the highest available frequency. The absolute priority for reselection is provided only by the previously registered PLMN, the RPLMN, and is valid only within the RPLMN. The priority is provided by the system information and is valid for all mobile terminals in the cell (mobile terminals belonging to the cell). The special priority for each mobile terminal can be notified in an RRC Connection Release message. The effective time can be linked with the priority of each mobile terminal. It is possible to indicate layer-specific cell reselection parameters (eg, layer-specific offsets, etc.) for inter-frequency adjacent cells. These parameters are common to all neighboring cells on frequency. Neighbor Cell List (NCL) can be provided for serving cells to handle special cases between same frequency and between different frequencies. The neighbor cell list includes cell-specific cell reselection parameters (eg, cell-specific offset) for specific neighbor cells. A blacklist can be provided so that the mobile terminal does not reselect specific neighboring cells between the same frequency and different frequencies. Cell reselection is speed dependent (can be speed dependent). Speed detection is based on the UTRAN solution. Although the cell reselection parameter can be applied to all mobile terminals in one cell, a specific reselection parameter can be set for each mobile terminal group and each mobile terminal.

  42 shows a flow of a process as a mobile terminal disclosed in FIG. 41. In Step ST4101, the mobile terminal selects a cell or reselects a cell, and proceeds to Step ST4102. In Step ST4102, the mobile terminal determines whether or not a measurement criterion for starting cell reselection is satisfied. Specifically, it is determined whether or not the reception quality of the serving cell is equal to or less than a threshold. More specifically, it is determined whether S_ServingCell is equal to or less than S_intrasearch (or S_ServingCell is equal to or less than S_non intrasearch). If the measurement criterion is satisfied, the mobile terminal shifts to step ST4103. If not, the process of step ST4102 is repeated. In Step ST4103, the UE performs measurement for cell reselection, and proceeds to Step ST4104. In Step ST4104, the mobile terminal determines whether to perform cell reselection based on the result of the measurement performed in Step ST4103. When performing cell reselection, the mobile terminal returns to step ST4101. When cell reselection is not performed, the mobile terminal returns to step ST4102.

  CSG cells are introduced in LTE and UMTS. It has been considered that a cheaper charging system is set in the CSG cell than in the non-CSG cell. Therefore, it is expected that the user desires to camp on the CSG cell in a place where the CSG cell can be selected. Also, in a situation where a CSG cell exists within the coverage of a non-CSG cell as a mobile communication system, as the number of mobile terminals in charge of scheduling and the like increases, the processing load of the non-CSG cell increases accordingly. Is reduced. Therefore, it is expected that a mobile terminal in a location where a CSG cell can be selected desires to camp on the CSG cell also for the mobile communication system.

  In the cell reselection procedure described in Non-Patent Documents 6 and 7, the following problem occurs. Consider a case where a CSG cell is installed in a non-CSG cell. Also, consider a case in which a mobile terminal whose serving cell is a non-CSG cell is within the coverage of the CSG cell. In this situation, if the measurement criterion of the mobile terminal is not satisfied, if the reception quality of the serving cell (non-CSG cell) is larger than a threshold, or if S_ServingCell> S_intrasearch, the mobile terminal does not perform measurement for cell reselection. Will be. It is determined in step ST4102 of FIG. 41 that the measurement criterion is not satisfied, and step ST4102 is repeated without performing the process of step ST4103. This means that the mobile terminal is not provided with an opportunity to reselect the CSG cell while being within the coverage of the CSG cell. This causes a problem that the user cannot benefit from the charging plan of the CSG cell. Further, also in the mobile communication system, there is a problem that the load of the non-CSG cell cannot be reduced.

  The above problem is also disclosed in Non-Patent Document 8. Non-Patent Document 8 is a document for UTRA. Non-Patent Document 8 discloses the following method as a solution to the above problem. The mobile terminal should be able to search for the HNB even when the state of the serving cell is good (Sx> S_intrasearch, Sx> S_intersearch). The HNB search cycle in that case is expected to be longer than the search cycle normally used. By not performing a search in a place where the HNB is not arranged, low power consumption of the mobile terminal is supported. This method uses a search cycle longer than the above-described normal search cycle only when the presence of the HNB is indicated in the neighboring cell list of the non-CSG cell.

  The problem in the fifteenth embodiment will be described below. Since Non-Patent Document 8 is a document for UTRA, Non-Patent Document 8 does not disclose a solution to the problem in EUTRAN (LTE system). Furthermore, Non-Patent Document 8 uses a peripheral cell list to support low power consumption of a mobile terminal. However, in the LTE system, as described above, it is not necessary for a mobile terminal to indicate a neighboring cell in serving cell system information in order to search and measure a cell. Therefore, it is impossible to directly apply the method for supporting low power consumption of a mobile terminal using a neighboring cell list described in Non-Patent Document 8 to an LTE system. Further, as a new problem with respect to the technology disclosed in Non-Patent Document 8, even when a CSG cell exists in a peripheral cell of a serving cell (non-CSG cell), a CSG cell is included in a whitelist of the mobile terminal. If not registered, the mobile terminal has no possibility of selecting the CSG cell as a suitable cell. Therefore, a mobile terminal that is not registered in the CSG cell uses the technique of Non-Patent Document 8 and the state of the serving cell is good just because a CSG cell exists in a peripheral cell of the serving cell (non-CSG cell) (Sx> (S_intrasearch, Sx> S_intersearch) Even when the search is started, consider the case. In this case, since it is impossible for the mobile terminal (not registered in the CSG cell) to select a CSG cell, useless measurement occurs, and a problem of increasing power consumption of the mobile terminal occurs.

  The solution to the problem of the fifteenth embodiment is described below. In the fifteenth embodiment, in order to solve the above-mentioned problem, the present invention is applied to a case where the whitelist has a CSG-ID, and the cell reselection is performed even when the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch). To provide a measurement period (may be a timer) for the measurement to be reflected on the mobile terminal. Alternatively, a period (or a timer) for performing measurement for cell reselection is provided even when the state of the serving cell is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied when the mobile terminal is registered in the CSG cell. , Is disclosed to be reflected on the mobile terminal. A specific operation example will be described with reference to FIG. In FIG. 42, description of portions having the same step numbers as in FIG. 41 will be omitted. In Step ST4201, the mobile terminal determines whether or not the whitelist includes a CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. In a case where the whitelist includes the CSG-ID, or in a case where the UE has been registered in the CSG cell, the UE proceeds to Step ST4202. In a case where the whitelist does not include the CSG-ID, or in a case where the whitelist has not been registered in the CSG cell, the UE proceeds to Step ST4207. In Step ST4202, the mobile terminal starts a measurement cycle for cell reselection or a timer (for example, T_reselectCSG) applied when a CSG-ID is included in the whitelist, and proceeds to Step ST4203. Alternatively, the mobile station starts a measurement cycle for cell reselection or a timer (for example, T_reselectCSG) applied when the mobile terminal is registered in a CSG cell, and proceeds to step ST4203.

  In Step ST4203, the mobile terminal judges whether or not it is a measurement cycle for cell reselection (for example, T_reselectCSG) to be applied when the whitelist has a CSG-ID. Alternatively, the mobile terminal determines whether a timer for cell reselection (for example, T_reselectCSG) applied when the CSG-ID is included in the whitelist has timed out (or timed out). If it is the measurement cycle or if the timer times out, the mobile terminal shifts to step ST4205. If it is not the measurement cycle or if the timer has not timed out, the mobile terminal shifts to step ST4204. In Step ST4204, the mobile terminal determines whether or not a measurement criterion for starting cell reselection is satisfied. Specifically, it is determined whether or not the reception quality of the serving cell is equal to or less than a threshold. More specifically, it is determined whether S_ServingCell is equal to or less than S_intrasearch (or S_ServingCell is equal to or less than S_non intrasearch). If the measurement criterion is satisfied (if the reception quality of the serving cell is equal to or less than the threshold, or if S_ServingCell ≦ S_intrasearch), the mobile terminal makes a transition to step ST4205. If not, the process returns to Step ST4203. In Step ST4205, the UE performs measurement for cell reselection, and proceeds to Step ST4206. In Step ST4206, the mobile terminal determines whether to perform cell reselection based on the result of the measurement performed in Step ST4205. When performing cell reselection, the mobile terminal returns to step ST4101.

  When cell reselection is not performed, the mobile terminal returns to step ST4202. In Step ST4207, the mobile terminal determines whether or not a measurement criterion for starting cell reselection is satisfied. Specifically, it is determined whether the reception quality of the serving cell is equal to or less than a threshold. More specifically, it is determined whether S_ServingCell is equal to or less than S_intrasearch (or S_ServingCell is equal to or less than S_non intrasearch). When the measurement criterion is satisfied, the mobile terminal shifts to step ST4208. If not, the process of step ST4207 is repeated. In Step ST4208, the UE performs measurement for cell reselection, and proceeds to Step ST4209. In Step ST4209, the mobile terminal determines whether to perform cell reselection based on the result of the measurement performed in Step ST4208. When performing cell reselection, the mobile terminal returns to step ST4101. When cell reselection is not performed, the mobile terminal returns to step ST4207.

  Next, a cycle for performing measurement for cell reselection (even with a timer) even when the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied when the whitelist has a CSG-ID. (For example, T_reselectCSG) is disclosed. As a first method, a serving cell (on the network side) notifies a mobile terminal to a mobile terminal on a PBCH or PDSCH using a BCCH as broadcast information.

  Further, the serving cell notifies on the PBCH using the master information (MIB) or on the PDSCH using the system information (SIB). When the MIB is used, since the MIB is mapped to the PBCH, this is an excellent method in that the mobile terminal can receive the signal with a small control delay. When SIB is used, notification is made using SIB1. MIB or SIB1 is an excellent method in reducing control delay of a mobile terminal in that it is broadcast information to be received at a minimum required for an operation of waiting from a cell search. Furthermore, even if a method of notifying with system information other than SIB1 is broadcast information, it can be notified to all mobile terminals under its control, and is an excellent method in terms of effective use of radio resources. The first method is applied when the mobile terminal only receives the BCCH of the serving cell and has a CSG-ID in the whitelist, in which case the state of the serving cell is good (Sx> S_intrasearch, Sx> S_intersearch). Since a period (timer) for performing measurement for cell reselection can be obtained, an effect of preventing control delay can be obtained. As a second method, the CSG cell notifies the mobile terminal of the PBCH or PDSCH using the BCCH as broadcast information. Furthermore, the CSG cell notifies on the PBCH using the master information (MIB) or the PDSCH using the system information (SIB). When the MIB is used, since the MIB is mapped to the PBCH, this is an excellent method in that the mobile terminal can receive the signal with a small control delay. When SIB is used, notification is made using SIB1. MIB or SIB1 is an excellent method in reducing control delay of a mobile terminal in that it is broadcast information to be received at a minimum required for an operation of waiting from a cell search. Furthermore, even if a method of notifying with system information other than SIB1 is broadcast information, it can be notified to all mobile terminals under its control, and is an excellent method in terms of effective use of radio resources. It is possible to obtain the effect that it is not necessary to change the system information of the non-CSG cell due to the introduction of CSG. This eliminates the need for changes in the existing LTE system (eUTRA / eUTRAN) that does not include CSG, and improves compatibility. As a third method, a non-CSG cell notifies a mobile terminal of PBCH or PDSCH using BCCH as broadcast information. Furthermore, the CSG cell notifies on the PBCH using the master information (MIB) or the PDSCH using the system information (SIB). When the MIB is used, since the MIB is mapped to the PBCH, this is an excellent method in that the mobile terminal can receive the signal with a small control delay. When SIB is used, notification is made using SIB1. MIB or SIB1 is an excellent method in reducing control delay of a mobile terminal in that it is broadcast information to be received at a minimum required for an operation of waiting from a cell search. Furthermore, a method of notifying with system information other than SIB1 may be used. Since system information other than SIB1 is also broadcast information, it can be notified to all mobile terminals under its control, and is an excellent method in terms of effective use of radio resources. In order to select a CSG cell when the non-CSG cell is a serving cell, it is sufficient to notify the relevant parameter from the non-CSG cell. Therefore, the third method is superior in terms of effective use of radio resources. As a fourth method, a static value is used as a mobile communication system (a value known to a mobile terminal, a base station, or the like as a mobile communication system, a value described in a standard or the like). As a result, no radio signal is generated between the base station (on the network side) and the mobile terminal. Therefore, an effect can be obtained in terms of effective use of wireless resources. Furthermore, since the value is determined statically, it is possible to obtain an effect of preventing a reception error of a radio signal from occurring.

  In the above, a period (timer) for performing measurement for cell reselection is provided even when the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied when the CSG-ID is included in the whitelist. However, the problem can be solved by providing a different period (timer) separately depending on whether or not the whitelist has the CSG-ID and reflecting the same on the mobile terminal. Further, in the above, a period (timer for performing measurement for cell reselection even when the serving cell condition is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied when the CSG-ID is included in the whitelist. ) Is provided and reflected on the mobile terminal. However, even if the mobile terminal has a CSG-ID in the whitelist, the cycle may be applied only when the serving cell is a non-CSG cell. Accordingly, the measurement for useless cell selection when the serving cell is already a CSG cell, which occurs in the above solution (there is no need to change the serving cell from a non-CSG cell to a CSG cell, Even when the reception quality is good, the measurement for selecting the CSG cell is a wasteful measurement). This has the effect of reducing the power consumption of the mobile terminal. Although LTE using HeNB using CSG has been described above, the present invention is directed to UMTS using HNB using CSG, HeNB and HNB not using CSG, and base stations with small radius (also referred to as pico cells and macro cells). ) Is also applicable.

  The effects of the fifteenth embodiment are described below. Under the umbrella of the base station, there is a possibility that a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist are present together. A period (may be a timer) for performing measurement for cell reselection is provided even when the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied when the CSG-ID is included in the whitelist. Thereby, when the reception quality of the serving cell (non-CSG cell) is good, the user may benefit from the charging plan of the CSG cell, which occurs because the measurement for reselecting the CSG cell is not performed. It is possible to solve the problem that the load cannot be reduced in a non-CSG cell even in a mobile communication system. Even if the serving cell is in a good state when the CSG-ID is included in the whitelist (when the measurement criterion is not satisfied, Sx> S_intrasearch, Sx> S_intersearch), measurement for cell reselection is performed. A mobile terminal that has not been registered in a CSG cell that does not have a CSG-ID, if the state of the serving cell is good (if the measurement criterion is not satisfied, Sx> S_intrasearch, Sx> S_intersearch), is used for measurement for cell reselection. Is not performed. This makes it possible to omit measurement for selecting a CSG cell even when the serving cell is in a useless state, which is useless for a mobile terminal that cannot reselect a CSG cell because the cell is not registered in the CSG cell. . This has the effect of reducing the power consumption of mobile terminals that are not registered in the CSG cell. This effect is an effect according to the present invention that cannot be obtained by the technique disclosed in Non-Patent Document 8. The solution of the fifteenth embodiment is also excellent in that the problem can be solved without using the neighboring cell list. Because, as described above, the CSG cell, HeNB, and HNB are assumed to have a portable size and weight, and it is assumed that the installation and removal of these CSG cells and the like are performed frequently and flexibly. Therefore, in the solution using the neighboring cell list, it is necessary to update the neighboring cell list every time a CSG cell, HeNB, HNB, or the like is installed or removed, and it is expected that the neighboring cell list is frequently updated. . Therefore, a solution using the neighboring cell list results in a complicated and complicated mobile communication system. Further, the solution of the fifteenth embodiment is excellent in that the above-mentioned effect is obtained even if the network side (such as a base station) does not know whether the corresponding mobile terminal has a CSG-ID in the whitelist. I have. This eliminates the need for the mobile terminal to notify the base station of the presence / absence of a CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, there is no need for the base station to manage the presence / absence of a CSG-ID in the whitelist of the mobile terminals being served thereby, and the effect of reducing the processing load on the base station can be obtained.

  Next, a first modification of the fifteenth embodiment will be described. In the fifteenth embodiment, a cycle for performing measurement for cell reselection applied to a case where a whitelist includes a CSG-ID even when the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch) (The timer may be used), and the problem was solved by reflecting it on the mobile terminal. However, it is unclear whether a CSG cell existing around the current serving cell can be an appropriate cell (suitable cell) just because the whitelist has a CSG-ID. If the mobile terminal has not been registered in a CSG cell existing around the current serving cell, performing measurement for cell reselection even when the serving cell is in a good state increases the power consumption of the mobile terminal. The problem occurs. This is a problem that occurs when a user registered in a CSG cell installed in a company returns home.

  A solution to the problem in the first modification of the fifteenth embodiment will be described below. In the first modification of the fifteenth embodiment, the case where the state of the serving cell is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied to a case where the whitelist includes a CSG-ID in order to solve the above-described problem. Even if the cell cannot be selected in spite of performing the measurement for cell selection at the cycle of performing the measurement for cell reselection (or a timer may be used), even if the state of the serving cell is good, Disclosed is to add an offset to a period for performing measurement for cell reselection and reflect the result to a mobile terminal. A specific operation example will be described with reference to FIG. In FIG. 43, description of portions having the same step numbers as in FIG. 42 will be omitted. In step 4301, the mobile terminal adds an offset value to a cycle (timer) (eg, T_reselectCSG) for performing measurement for cell reselection even when the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch), The mobile terminal moves to step ST4202. For example, if the offset value is a positive value, even if the serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch), measurement for cell reselection is performed, but cell reselection is not performed. In other words, if a CSG cell that is an appropriate cell (Suitable cell) for the mobile terminal is not found, the period for performing measurement for cell reselection is extended even if the state of the serving cell is good. . Therefore, by using the offset value, it is possible to reduce the power consumption of the mobile terminal when the mobile terminal has not been registered in a CSG cell existing around the current serving cell. As the method of notifying the offset value, the method of notifying the period (timer) for performing measurement for cell reselection can be used even in the case where the state of the serving cell is good in Embodiment 15. At this time, even when the offset value and the state of the serving cell are good, the notification of the cycle (timer) for performing measurement for cell reselection may be simultaneous or separate.

  Although LTE using HeNB using CSG has been described above, the present invention is directed to UMTS using HNB using CSG, HeNB and HNB not using CSG, and base stations with small radius (also referred to as pico cells and macro cells). ) Is also applicable.

  In the first modification of the fifteenth embodiment, the following effects can be obtained in addition to the effects of the fifteenth embodiment. It is possible to reduce the power consumption of the mobile terminal when the mobile terminal has not been registered in a CSG cell existing around the current serving cell. Further, in that the network side (such as a base station) has the above-mentioned effect without knowing which CSG cell the corresponding mobile terminal has registered (which CSG-ID is in the whitelist), The solution of the first modification of the fifteenth embodiment is excellent. This eliminates the need for the mobile terminal to notify the base station of the CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, in that the base station does not need to manage the CSG-ID in the whitelist of the mobile terminals being served thereby, the effect of reducing the processing load on the base station can be obtained.

  Next, a second modification of the fifteenth embodiment will be described. Regarding the problem described in the first modification of the fifteenth embodiment, a solution different from the first modification of the fifteenth embodiment will be disclosed. The second modification of the fifteenth embodiment is a case where a serving cell state is good (Sx> S_intrasearch, Sx> S_intersearch), which is applied to a case where a CSG-ID is included in a whitelist in order to solve the above problem. In the case where the cell cannot be selected in spite of performing the measurement for cell selection in a cycle for performing the measurement for cell reselection (or a timer), the state of the serving cell is good. Also discloses releasing the application of the period for performing measurement for cell reselection. A specific operation example will be described with reference to FIG. 44, the description of the same step number as in FIG. 42 is omitted. In Step ST4206, the mobile terminal judges whether or not cell reselection has been performed based on the result of the measurement performed in Step ST4205. If cell reselection has been performed, the process returns to step ST4101. If cell reselection has not been performed, the mobile terminal makes a transition to step ST4207.

  Although LTE using HeNB using CSG has been described above, the present invention is directed to UMTS using HNB using CSG, HeNB and HNB not using CSG, and base stations with small radius (also referred to as pico cells and macro cells). ) Is also applicable.

  In the second modification of the fifteenth embodiment, the following effects can be obtained in addition to the effects of the fifteenth embodiment. It is possible to reduce the power consumption of the mobile terminal when the mobile terminal has not been registered in a CSG cell existing around the current serving cell. Further, in that the network side (such as a base station) has the above-mentioned effect without knowing which CSG cell the corresponding mobile terminal has registered (which CSG-ID is in the whitelist), The solution of the second modification of the fifteenth embodiment is excellent. This eliminates the need for the mobile terminal to notify the base station of the CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, in that the base station does not need to manage the CSG-ID in the whitelist of the mobile terminals being served thereby, the effect of reducing the processing load on the base station can be obtained.

Embodiment 16 FIG.
In the sixteenth embodiment, a solution different from the fifteenth embodiment for the problem described in the fifteenth embodiment will be disclosed. Also, in the current cell reselection procedure, the following operation can be considered to enable selection of a CSG cell in a neighboring cell even when the reception quality of a serving cell that is a non-CSG cell is good. For example, S_intrasearch is set low. As a result, even when the reception quality of the serving cell is good, the measurement criterion is easily satisfied, and the measurement for cell reselection is easily performed. However, when S_intrasearch is lowered as described above, even when all mobile terminals (including mobile terminals not having a CSG-ID in the whitelist) under the serving cell are in a good reception condition of the serving cell, , Measurement criteria are easily satisfied, and measurement for cell reselection is easily performed. In this case, since it is impossible for the mobile terminal (not registered in the CSG cell) to select a CSG cell, useless measurement occurs and a problem of increasing power consumption of the mobile terminal occurs.

  In the sixteenth embodiment, in order to solve the above problem, the metric for starting cell reselection is divided into a case where the whitelist has a CSG-ID and a case where the whitelist does not have a CSG-ID. Disclosed to be provided and reflected on the mobile terminal. More specifically, the threshold for comparing with the reception quality of the serving cell, which is a metric for starting cell reselection, has a CSG-ID in the whitelist and does not have a CSG-ID in the whitelist. It discloses that it is provided in each case and reflected on the mobile terminal. A specific operation example will be described with reference to FIG. In FIG. 45, description of portions having the same step numbers as in FIGS. 41 and 42 is omitted. In Step ST4201, the mobile terminal determines whether or not the whitelist includes a CSG-ID. Alternatively, the mobile terminal determines whether or not the mobile terminal has registered with the CSG cell. When the whitelist includes the CSG-ID, or when the whitelist includes the CSG-ID, the mobile terminal makes a transition to step ST4501. In a case where the whitelist does not include the CSG-ID, or in a case where the whitelist has not been registered in the CSG cell, the UE proceeds to Step ST4502. In Step ST4501, the mobile terminal judges whether or not a criterion for cell reselection applied when a CSG-ID is included in the whitelist is satisfied. As a specific example, it is determined whether or not the reception quality (for example, Sx) of the serving cell is equal to or less than a threshold (for example, S_intrasearchCSG) applied when the CSG-ID is included in the whitelist.

  When the measurement criterion is satisfied, or as a specific example, Sx ≦ S_intrasearchCSG, the mobile terminal shifts to step ST4205. If the measurement criterion is not satisfied, as a specific example, if Sx> S_intrasearchCSG, the process returns to step ST4501. In this case, a comparison may be made not only with a threshold value that satisfies a measurement criterion between the same frequencies but also with a threshold value (eg, S_intersearchCSG) that satisfies a measurement criterion between different frequencies. In Step ST4502, the mobile terminal judges whether or not a measurement criterion for cell reselection to be applied normally (may be a case where there is no CSG-ID in the whitelist) is satisfied. As a specific example, it is determined whether the reception quality (for example, Sx) of the serving cell is equal to or less than a threshold (S_intrasearch). When the measurement criterion is satisfied, or as a specific example, when Sx ≦ S_intrasearch, the mobile terminal shifts to step ST4208. If the measurement criterion is not satisfied, as a specific example, if Sx> S_intrasearch, the process returns to step ST4502. In this case, a comparison may be made not only with a threshold value that satisfies the measurement criterion between the same frequencies but also with a threshold value (eg, S_intersearch) that satisfies the measurement criterion between different frequencies. Also, the threshold (e.g., S_intersearchCSG) to be applied when the whitelist has the CSG-ID in the whitelist disclosed above is applied to the case where the serving cell is a non-CSG cell even for a mobile terminal having the CSG-ID in the whitelist. You may apply only. Accordingly, when the serving cell that is generated in the above solution is already a CSG cell, measurement for useless cell selection (since there is no desire to change the serving cell from a non-CSG cell to a CSG cell, Even when the reception quality is good, the measurement for selecting the CSG cell is a wasteful measurement). This has the effect of reducing the power consumption of the mobile terminal.

  The notification method of the measurement reference for starting the cell reselection when the CSG-ID is included in the whitelist performs the measurement for the cell reselection even in the case where the state of the serving cell in Embodiment 15 is good. A period (timer) notification method can be used. At this time, the notification of the metric for starting the cell reselection when the CSG-ID is included in the whitelist may be simultaneous with or separate from the metric for cell reselection which is normally applied. Absent.

  Although LTE using HeNB using CSG has been described above, the present invention is directed to UMTS using HNB using CSG, HeNB and HNB not using CSG, and base stations with small radius (also referred to as pico cells and macro cells). ) Is also applicable.

  The effects of the sixteenth embodiment are described below. Under the umbrella of the base station, there is a possibility that a mobile terminal having a CSG-ID in the whitelist and a mobile terminal having no CSG-ID in the whitelist are present together. By providing a metric for starting cell reselection, which is applied when a CSG-ID is included in the whitelist, the CSG cell can be re-established when the receiving quality of the serving cell (non-CSG cell) is good. The problem that the user cannot benefit from the charging plan of the CSG cell, which occurs because the measurement for selection is not performed, and that the load of the non-CSG cell cannot be reduced even in the mobile communication system. The problem can be solved. Even if the serving cell is in a good state when the CSG-ID is included in the whitelist, the mobile terminal performs measurement for cell reselection, and the mobile terminal has not been registered in the CSG cell that does not have the CSG-ID in the whitelist. Does not perform measurement for cell reselection when the state of the serving cell is good as before. This makes it possible to omit measurement for selecting a CSG cell even when the serving cell is in a useless state, which is useless for a mobile terminal that cannot reselect a CSG cell because the cell is not registered in the CSG cell. . This has the effect of reducing the power consumption of mobile terminals that are not registered in the CSG cell. This effect is an effect according to the present invention that cannot be obtained by the technique disclosed in Non-Patent Document 8.

  The solution of the sixteenth embodiment is also excellent in that the problem can be solved without using the neighboring cell list. Because, as described above, the CSG cell, HeNB, and HNB are assumed to have a portable size and weight, and it is assumed that the installation and removal of these CSG cells and the like are performed frequently and flexibly. Therefore, in the solution using the neighboring cell list, it is necessary to update the neighboring cell list every time a CSG cell, HeNB, HNB, or the like is installed or removed, and it is expected that the neighboring cell list is frequently updated. . Therefore, a solution using the neighboring cell list results in a complicated and complicated mobile communication system. Further, the solution of the sixteenth embodiment is excellent in that the above effects can be obtained even if the network side (such as a base station) does not know whether the corresponding mobile terminal has a CSG-ID in the whitelist. I have. This eliminates the need for the mobile terminal to notify the base station of the presence / absence of a CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, there is no need for the base station to manage the presence / absence of a CSG-ID in the whitelist of the mobile terminals being served thereby, and the effect of reducing the processing load on the base station can be obtained.

  Next, a first modification of the above-described sixteenth embodiment will be described. Specifically, a solution to the problem described in the first modification of the fifteenth embodiment will be disclosed. In the first modification of the sixteenth embodiment, cell selection is performed by a metric for starting cell reselection (for example, S_intrasearchCSG), which is applied when a CSG-ID is included in a whitelist to solve the above problem. It is disclosed that, when a cell cannot be selected despite the measurement for, the application of a metric (eg, S_intrasearchCSG) for starting cell reselection is released. A specific operation example will be described with reference to FIG. In Step ST4206, the mobile terminal judges whether or not cell reselection has been performed based on the result of the measurement performed in Step ST4205. If cell reselection has been performed, the process returns to step ST4101. If cell reselection has not been performed, the mobile terminal makes a transition to step ST4502.

Embodiment 17 FIG.
In 3GPP, base stations called Home-NodeB (Home-NB, HNB) and Home-eNodeB (Home-eNB, HeNB) are being studied. HNB / HeNB is a base station in UTRAN / E-UTRAN, for example, for home, business, and commercial access services. Non-Patent Document 9 discloses three different modes of HeNB and access to the HNB. An open access mode, a closed access mode, and a hybrid access mode. Each mode has the following features. In the open access mode, the HeNB or the HNB is operated as a normal cell of a normal operator. In the closed access mode, HeNB and HNB are operated as CSG cells. A CSG cell is a cell that can be accessed only by CSG members. In the hybrid access mode, a non-CSG member is a CSG cell to which access is simultaneously permitted. A cell in the hybrid access mode is, in other words, a cell that supports both the open access mode and the closed access mode. A cell in the hybrid access mode is also called a hybrid cell.

  In 3GPP, a method of enabling cell reselection to a desired CSG cell even when receiving quality of a serving cell is good is being studied. This is considered to be necessary for the hybrid cell. For example, in Non-Patent Document 10, in a hybrid cell, the UE of the CSG member should stay longer than the UE of the non-CSG member, and therefore, a camping mechanism between the UE of the CSG member and the UE of the non-CSG member is provided. It has been proposed that it needs to be different. However, Non-Patent Document 10 does not disclose any specific method.

  Since the hybrid cell is a CSG cell, as a specific method for allowing the UE of the CSG member to stay longer than the UE of the non-CSG member in the hybrid cell, Embodiment 15, the first modification of Embodiment 15, Fifteenth Embodiment The method disclosed in the second modification, the sixteenth embodiment, and the first modification of the sixteenth embodiment can be applied. By these methods, even if the state of the serving cell is good, a UE having a CGS-ID in a whitelist (CSG-ID list, allowed CSG list) or a UE registered in a CSG cell is a UE that is not so It is possible to execute the cell reselection procedure earlier than before. For this reason, it is possible to quickly detect CSG cells including hybrid cells. Therefore, the UE having the CSG-ID of the CSG to which the hybrid cell belongs or the UE registered in the CSG can quickly perform cell reselection to the hybrid cell. The method disclosed in the above embodiment can be applied to a specific operation.

  In the sixteenth embodiment, it has been disclosed that measurement criteria for cell reselection are provided separately for a case where the whitelist has a CSG-ID and a case where the whitelist does not have a CSG-ID. As an example, the threshold for cell reselection when there is no CSG-ID in the whitelist is S_intrasearch, and the threshold for cell reselection when there is a CSG-ID in the whitelist is S_intrasearchCSG.

  In order to allow the cell reselection procedure to be performed earlier when the CSG-ID is included in the whitelist than when the CSG-ID is not included in the whitelist, S_intrasearchCSG is set lower than S_intrasearch (S_intrasearch> S_intrasearchCSG) should be set. The lower the cell reselection threshold is, the easier it is to start the cell reselection procedure. As a result, the UE of a CSG member can easily make a cell reselection to a CSG cell quickly. Therefore, also in the seventeenth embodiment, it is possible to facilitate cell reselection to a hybrid cell quickly.

Embodiment 18 FIG.
As a specific method for enabling cell reselection to a desired CSG cell even when the receiving quality of the serving cell is good, for example, Non-Patent Document 11 describes a method of giving a Qoffset to each CSG cell.

  Qoffset is an offset given to a measured reception quality value of a detected cell when performing cell ranking at the time of cell reselection, as described in Non-Patent Document 7. The Qoffset is broadcast from the serving cell together with information on the cell to which the Qoffset is given.

  For example, Non-Patent Document 12 describes a method of giving one Qoffset to a hybrid cell, in other words, a method of giving one Qoffset to all cells in a hybrid access mode. Further, there is shown a method in which two Qoffsets corresponding to the RSRP range of the macro cell are provided, and each Qoffset is applied above and below a certain threshold of the RSRP of the macro cell.

  As in these methods, simply giving Qoffset for each CSG cell or one for a hybrid cell, or corresponding to the RSRP range of a macro cell, requires only a cell or cell type or a positional relationship with a macro cell. Only the offset value can be different for each case.

  However, although a hybrid cell is a CSG cell, it supports both open access mode and closed access mode simultaneously. For this reason, for the hybrid cell, the criteria for cell reselection cannot be different between the UE of the non-CSG member and the UE of the CSG member. Therefore, these methods have a problem that the UE of the CSG member cannot stay longer than the UE of the non-CSG member in the hybrid cell.

  In order to solve this problem, in the present embodiment, an offset value (Qoffset_csg) applied to a UE having a CSG-ID in a whitelist or a UE registered in a CSG, and an offset value (Qoffset_csg) applied to a UE that is not so Qoffset_noncsg) is provided.

  As described above, by separately providing offsets for the UE having the CSG-ID in the whitelist or for the UE registered in the CSG and the UEs not having the CSG-ID, the criteria for cell reselection can be set as the UE of the non-CSG member. And CSG member UEs. Thereby, also in a hybrid cell, it becomes possible for UE of a CSG member to stay longer than UE of a non-CSG member.

  A specific operation example will be described with reference to FIG. In FIG. 46, description of portions having the same step numbers as in FIG. 41 will be omitted. In ST4103, the UE performs measurement for cell reselection and performs cell ranking. In Step ST4601, the UE determines whether or not the whitelist includes the CSG-ID. Alternatively, the UE determines whether or not the UE has registered with the CSG cell. In a case where the whitelist includes a CSG-ID or in a case where the UE has been registered in a CSG cell, the UE proceeds to ST4602. In ST4602, the UE subtracts Qoffset_csg from the measured value. In a case where the whitelist does not include the CSG-ID, or in a case where the whitelist has not been registered in the CSG cell, the UE proceeds to ST4603. In ST4603, the UE subtracts Qoffset_noncsg from the measured value. By performing a cell ranking based on the result of these subtractions, a criterion for reselecting a cell between a UE having a CSG-ID in the whitelist or a UE registered in the CSG and a UE not registered in the CSG-ID is determined. It is possible to make it different. It is also possible to set the cell ranking only in step ST4602 or step ST4603 and omit the cell ranking in step ST4103.

  Regarding the value of Qoffset_noncsg and the value of Qoffset_csg, depending on the radio wave environment of the serving cell and the neighboring cells, a UE having a CSG-ID in the whitelist or a UE registered in the CSG is reactivated earlier than a UE that does not. What is necessary is just to set so as to satisfy the selected reception quality standard.

  For example, the value of Qoffset_csg is set lower (Qoffset_noncsg> Qoffset_csg) than the value of Qoffset_noncsg. By doing so, the result calculated in consideration of these offsets for a certain cell, the UE having a CSG-ID in the whitelist or the UE registered in the CSG is less than the UE that is not so Get higher. Therefore, a UE having a CSG-ID in the whitelist or a UE registered in the CSG satisfies the reception quality criterion for cell reselection earlier than a UE not having the CSG-ID. By satisfying the reception quality criterion of cell reselection earlier, it becomes possible to perform reselection to a suitable cell earlier. Therefore, for the hybrid cell, it becomes possible for the UE of the CSG member to reselect the cell earlier than the UE of the non-CSG member, and the UE of the CSG member can be kept longer than the UE of the non-CSG member. Become.

  The following formula may be used as a criterion for cell ranking.

For UEs having a CSG-ID in the whitelist or UEs registered in the CSG,
Rn = Qmeas, n-Qoffset_csg
And for UEs that are not,
Rn = Qmeas, n-Qoffset_noncs
And

  Qmeas, n is a measured value of the reception quality of the nth cell, and Rn is a calculation result of the reception quality in consideration of the offset.

  Alternatively, the following equation may be used as a criterion for cell ranking.

For UEs having a CSG-ID in the whitelist or UEs registered in the CSG,
Rn = Qmeas, n-Qoffset-Qoffset_csg
And UEs that are not,
Rn = Qmeas, n-Qoffset-Qoffset_noncsg
And

  In consideration of the conventional Qoffset, Qoffset_noncsg and Qoffset_csg can be used only for making a difference between a UE having a CSG-ID in the whitelist or a UE registered in the CSG and a UE not having the CSG-ID.

  As the notification method of Qoffset_csg and Qoffset_noncsg, the first to fourth methods disclosed as the notification method of the period for performing measurement for cell reselection in Embodiment 15 can be applied. When these are applied, the same effect can be obtained.

  In the first method, when SIB is used, the notification may be made using SIB4. In SIB4, the conventional offset value is transmitted together with the corresponding cell information. By transmitting the offset value together with such information, it becomes possible to execute the cell ranking criteria together with the conventional offset value for each corresponding cell. As the corresponding cell information, a PCI range that can be provided for a hybrid cell may be used. By doing so, the same value can be set for a plurality of hybrid cells, and the information amount of SIB4 can be reduced.

  Further, in the second method, only the hybrid cell may notify the offset value as the broadcast information.

  In the method disclosed above, an offset value (Qoffset_csg) to be applied to a UE having a CSG-ID or a UE registered in the CSG in a whitelist, and an offset value (Qoffset_noncsg) to be applied to a UE not having the CSG-ID are provided. , And cell reselection is performed.

  As another method, a difference value (Qoffset_delta) between an offset value applied to a UE having a CSG-ID or a UE registered in the CSG and a UE not registered in the CSG-ID may be provided in a whitelist. . That is, Qoffset_noncsg and Qoffset_delta may be provided and used as criteria for cell ranking.

  For example, the following formula may be used as the criteria for cell ranking.

For UEs having a CSG-ID in the whitelist or UEs registered in the CSG,
= Qmeas, n- (Qoffset_noncsg-Qoffset_delta)
And for UEs that are not,
= Qmeas, n-Qoffset_noncsg
And

  Thereby, it is possible to obtain the same effect as the method of notifying Qoffset_noncsg and Qoffset_csg disclosed above.

  As another method, an offset value to be applied to a UE having no CSG-ID in the whitelist or a UE not registered in the CSG is set as a conventional Qoffset, and is used in combination with the difference value Qoffset_delta. Is also good.

  For example, the following formula may be used as the criteria for cell ranking.

For UEs having a CSG-ID in the whitelist or UEs registered in the CSG,
Rn = Qmeas, n- (Qoffset-Qoffset_delta)
And UEs that are not,
Rn = Qmeas, n-Qoffset
And

  As a result, not only can the same effect as the method disclosed above be obtained, but also the number of parameters to be set can be reduced by one. That is, it is not necessary to set both Qoffset_csg and Qoffset_noncsg, and it is only necessary to set Qoffset_delta. Therefore, it is possible to reduce the amount of information for parameter setting. The above-described method can be applied as the notification method. As another method, Qoffset and Qoffset_delta may be notified from different cells. For example, Qoffset is reported from the serving cell, and Qoffset_delta is reported from the hybrid cell. Since Qoffset_delta is a value used only for the hybrid cell, it is notified only from the hybrid cell, and in the cell ranking criterion, the UE having the CSG-ID in the whitelist or the UE registered in the CSG is , May be recalculated using the offset value (Qoffset_delta). Other UEs do not need to recalculate and do not need to receive the offset value of the hybrid cell, so that it is only necessary to measure the reception quality. Therefore, the measurement at the time of cell reselection can be simplified, and the effect of reducing power consumption of the UE can be obtained.

  The method disclosed in the present embodiment includes a method of giving a Qoffset for each CSG cell shown in Non-Patent Document 11, a method of giving one Qoffset to a hybrid cell shown in Non-Patent Document 12, or a method of using a macro cell. It is also possible to apply a method in which two Qoffsets corresponding to the RSRP range are provided, and each Qoffset is applied above and below a certain threshold of the RSRP of the macro cell. For example, these Qoffsets may be used as Qoffset in the criteria for cell ranking disclosed in the present embodiment or in addition to Qoffset. This makes it possible to take into account, for example, each Qoffset for each CSG cell, or for each hybrid, or corresponding to the RSRP range of a macro cell.

  As another method, the values shown in these non-patent documents are applied to UEs having a CSG-ID in a whitelist or UEs registered in the CSG, and are applied to UEs that do not. Don't do it. For example, as a criterion for cell ranking, a value indicated in these non-patent documents may be used for Qoffset_delta. By doing so, it is possible to make the criteria for cell reselection different for the hybrid cell between the UE of the non-CSG member and the UE of the CSG member.

  The method disclosed in the present embodiment is applicable to the fifteenth embodiment, the first modification of the fifteenth embodiment, the second modification of the fifteenth embodiment, the sixteenth embodiment, the first modification of the sixteenth embodiment, It is possible to use in combination with the method disclosed in the seventeenth embodiment.

  For example, FIG. 47 shows a specific operation example when combined with Embodiment 15. In FIG. 47, description of the same step numbers as in FIG. 42 will be omitted. In Step ST4201, the UE determines whether or not the whitelist includes a CSG-ID. Alternatively, the UE determines whether or not the UE has registered with the CSG cell. If the CSG-ID is included in the whitelist or if the cell is registered in the CSG cell, in ST4701, Qoffset_csg is subtracted from the measured value. If the CSG-ID is not included in the whitelist, or if the cell is not registered in the CSG cell, in ST4702, Qoffset_noncsg is subtracted from the measured value. By performing a cell ranking based on the result of these subtractions, a criterion for reselecting a cell between a UE having a CSG-ID in the whitelist or a UE registered in the CSG and a UE not registered in the CSG-ID is determined. It is possible to make it different. It is also possible to set only the cell ranking in step ST4701 or step ST4702 and omit the cell ranking in step ST4205 or ST4208.

  The other embodiments and modifications can be used in combination by performing similar operations. By combining the method disclosed in the present embodiment with these embodiments and modifications, it is possible to flexibly cope with differences in radio wave environments due to flexible arrangement of HeNB or HNB including hybrid cells. Is obtained.

  By adopting the method disclosed in the present embodiment, it is possible to make the criteria for cell reselection different between a UE of a non-CSG member and a UE of a CSG member for a hybrid cell. Thereby, also in a hybrid cell, it becomes possible for UE of a CSG member to stay longer than UE of a non-CSG member.

  This allows the CSG member to receive services such as high-speed communication and preferential billing plans for the CSG member in the hybrid cell faster and longer.

Embodiment 19 FIG.
In the eighteenth embodiment, a method in which a UE of a CSG member performs cell reselection for a hybrid cell earlier than a UE of a non-CSG member, in other words, a method of facilitating (inbound) reselection to a hybrid cell Was disclosed.

  In the present embodiment, the UE of the CSG member performs cell reselection later from the hybrid cell than the UE of the non-CSG member, in other words, it is difficult to perform (outbound) cell reselection from the hybrid cell. In the list, an offset value (Qoffset_csg) to be applied to a UE having a CSG-ID or a UE registered in the CSG and an offset value (Qoffset_noncsg) to be applied to other UEs are provided. A case is disclosed in which selection is performed, and a method of making cell reselection criteria different between a UE of a non-CSG member and a UE of a CSG member is applied.

  As a specific operation example, the criteria for cell ranking may be expressed by the following equation.

For UEs having a CSG-ID in the whitelist or UEs registered in the CSG,
Rs = Qmeas, s + Qhyst-Qoffset_csg
And for UEs that are not,
Rs = Qmeas, s + Qhyst-Qoffset_noncsg
And

  Qmeas, s is a measured value of the reception quality of the serving cell, Qhyst is an offset value for providing hysteresis, and Rs is a calculation result of the reception quality of the serving cell in consideration of the offset.

  In reselection from a hybrid cell, the hybrid cell becomes the serving cell. Therefore, in order to make cell reselection from a hybrid cell difficult, at the time of cell ranking at the time of cell reselection, a UE having a CSG-ID in the whitelist or a UE registered in the CSG in the measured value of the serving cell And UEs that are not. As a specific example, calculation is performed using Qoffset_noncsg and Qoffset_csg when Rs is derived. This makes it possible for both UEs to have different criteria for performing cell reselection from a hybrid cell.

  Regarding the value of Qoffset_noncsg and the value of Qoffset_csg, depending on the radio wave environment of the serving cell and neighboring cells, a UE having a CSG-ID in the whitelist or a UE registered in the CSG is slower than a UE not having such a cell list. What is necessary is just to set so as to satisfy the selected reception quality standard.

  For example, the value of Qoffset_csg is set to be higher (Qoffset_noncsg <Qoffset_csg) than the value of Qoffset_noncsg. In this way, the result calculated in consideration of these offsets for the serving cell that is a hybrid cell is that a UE having a CSG-ID in the whitelist or a UE registered in the CSG is better than a UE that is not. Will also be lower. Therefore, a UE having a CSG-ID in the whitelist or a UE registered in the CSG satisfies the reception quality criterion of cell reselection later than a UE not having the CSG-ID.

  By satisfying the reception quality standard for cell reselection later, it becomes possible to prevent reselection from hybrid cells until later. Therefore, in the hybrid cell, it becomes possible for the UE of the CSG member to reselect the cell later than the UE of the non-CSG member, and the UE of the CSG member can stay longer than the UE of the non-CSG member.

  FIG. 48 shows a specific operation example of cell reselection in a hybrid cell. 48, the description of the same step number as in FIG. 41 will be omitted. The UE that has entered the cell selection or cell reselection procedure in ST 4101 performs measurement of a serving cell for cell reselection, and performs a cell ranking criterion for the serving cell. In Step ST4801, the UE determines whether or not the whitelist includes a CSG-ID. Alternatively, the UE determines whether or not the UE has registered with the CSG cell. In a case where the whitelist includes a CSG-ID or in a case where the UE has been registered in a CSG cell, the UE proceeds to ST4802. In ST4802, the UE subtracts Qoffset_csg from the measured value. In a case where the whitelist does not include the CSG-ID, or in a case where the UE has not been registered in the CSG cell, the UE moves to ST4803. In ST4803, the UE subtracts Qoffset_noncsg from the measured value. Based on the result of the subtraction, it is determined whether or not a measurement criterion for cell reselection is satisfied in ST4102. By doing so, it is possible to make the determination criteria for cell reselection different between a UE having a CSG-ID in the whitelist or a UE registered in the CSG and a UE not registered in the CSG.

  When deriving the measured value of the serving cell when performing the cell ranking including the measured value of the received quality of the serving cell in ST4103, the offset value (Qoffset_csg, Qoffset_noncsg) may not be used. If not used, it is possible to increase the possibility that the UE of the CSG member selects the serving cell.

  Separately, an offset value (Qoffset_csg_r) to be applied to a UE having a CSG-ID or a UE registered in the CSG in the whitelist and an offset value (Qoffset_noncsg_r) to be applied to UEs other than those are provided. When deriving the measured values of the serving cell when performing the cell ranking including the measured values of the reception quality, the cell ranking may be performed by applying the measured values of the serving cell to the measured values of the serving cell, and the cell reselection may be performed. In this case, it is preferable to set Qoffset_noncsg_r higher than Qoffset_csg_r. In this way, the result calculated in consideration of these offsets for the serving cell that is a hybrid cell is that a UE having a CSG-ID in the whitelist or a UE registered in the CSG is better than a UE that is not. Will also be higher. Therefore, it is possible to increase the possibility that a UE having a CSG-ID in the whitelist or a UE registered in the CSG selects a serving cell than a UE not having the CSG-ID.

  By setting the cell ranking criteria as described above, in a hybrid cell, it becomes possible for the UE of the CSG member to reselect the cell later than the UE of the non-CSG member, and the UE of the CSG member is changed to the non-CSG member. Can stay in the hybrid cell longer than the UE.

  As the notification method of these parameters, the first to fourth methods disclosed as the notification method of the period for performing measurement for cell reselection in Embodiment 15 can be applied, and the same effect can be obtained. .

  By combining the present embodiment with the eighteenth embodiment, the UE of the CSG member makes it easier to reselect to the hybrid cell than the UE of the non-CSG member, and it is difficult to reselect from the hybrid cell. It is possible to do. Therefore, it is possible to make the UE of the CSG member stay in the hybrid cell longer than the UE of the non-CSG member.

  In the case where the present embodiment and the eighteenth embodiment are combined, an offset value provided for the UE of the CSG member to facilitate reselection to the hybrid cell than the UE of the non-CSG member, and a cell from the hybrid cell The offset values provided to make reselection difficult may be set to different values, or may be the same value.

  For example, offset values provided to facilitate reselection to hybrid cells are Qoffset_csg_in, Qoffset_noncsg_in, and offset values provided to make cell reselection from hybrid cells difficult are Qoffset_csg_out, Qoffset_noncsg_out, respectively. To be able to set. By doing so, it is possible to cope with more flexible HeNB and HNB installation and operation.

  As an example of setting to the same value, two offsets of Qoffset1 and Qoffset2 may be provided. In order to facilitate reselection to a hybrid cell, Qoffset_csg = Qoffset1 and Qoffset_noncsg = Qoffset2 are set to be used in deriving the cell ranking Rn of neighboring cells. On the other hand, in order to make cell reselection from the hybrid cell difficult, Qoffset_csg = Qoffset2 and Qoffset_noncsg = Qoffset1 are used to derive the cell ranking Rs of the serving cell. Qoffset1 is preferably set lower than Qoffset2. By doing so, the number of parameters can be reduced, and the amount of information transmitted to the UE can be reduced.

  As notification methods of these parameters, the notification methods disclosed in the fifteenth and eighteenth embodiments are possible, and various combinations of notification methods are also possible.

  For example, since Qoffset_csg_in and Qoffset_noncsg_in are used for deriving the cell ranking Rn of the neighboring cells, they are notified by the SIB4 from the serving cell. May be notified.

  By doing so, it is possible to reduce the amount of information to be notified from a cell that is not a hybrid cell.

  In the case where two offsets Qoffset1 and Qoffset2 are provided, the notification may be made in SIB1 of all cells. By doing so, it is possible to reduce the amount of information to be notified even in the hybrid cell.

  The method disclosed in the present embodiment is applicable to the fifteenth embodiment, the first modification of the fifteenth embodiment, the second modification of the fifteenth embodiment, the sixteenth embodiment, the first modification of the sixteenth embodiment, It is possible to use in combination with the methods disclosed in the seventeenth and eighteenth embodiments.

  By combining the method disclosed in the present embodiment with these embodiments and modifications, CSG members can be used even in various radio environments due to the flexible arrangement of HeNB or HNB including hybrid cells. UEs can be more easily reselected to a hybrid cell than non-CSG member UEs, and can be harder to reselect from a hybrid cell. Therefore, it is possible to make the UE of the CSG member stay longer than the UE of the non-CSG member in the hybrid cell.

Embodiment 20 FIG.
In the above-described embodiment, a method of reselecting a cell to / from a hybrid cell to keep a UE of a CSG member longer than a UE of a non-CSG member in the hybrid cell has been disclosed. In the present embodiment, a method of handover (inbound HO / outbound HO) to / from a hybrid cell for allowing a UE of a CSG member to stay longer than a UE of a non-CSG member in the hybrid cell is disclosed.

  In the handover to / from the hybrid cell, the procedure, rules, and criteria for the handover are different between the non-CSG member UE and the CSG member UE. As a specific method, parameters to be applied to a UE having a CSG-ID in a whitelist or UEs registered in a CSG and parameters to be applied to UEs not having the CSG-ID in a whitelist are provided for parameters used for HO to / from a hybrid cell. . By making the parameter different between the non-CSG member UE and the CSG member UE, the criteria for handover to / from the hybrid cell are different between the non-CSG member UE and the CSG member UE. Becomes possible.

  As an example of a parameter used for handover to / from the hybrid cell, there is a parameter serving as a determination index for determining whether or not an event occurs in a measurement report. Event occurrence thresholds (Thresh, Thresh1, Thresh2), serving cell offset value (Ocs) applied to the reception quality measurement result, serving cell frequency offset value (Ofs) applied to the reception quality measurement result, Neighbor cell offset value (Ocn) applied to reception quality measurement results, adjacent cell frequency offset value (Ofn) applied to reception quality measurement results, event-specific offset value (Off), event There is hysteresis (Hys) for each.

  For example, when the serving cell is a hybrid cell, Thresh_noncsg to be applied to UEs having a CSG-ID in the whitelist or UEs registered in the CSG, and Thresh_csg to be applied to UEs not having the same are provided in the event list. By setting Thresh_csg higher than Thresh_noncsg, the UE of the CSG member has a later occurrence of an event for handover than the UE of the non-CSG member, and can stay in the hybrid cell longer.

  For example, with respect to the offset value of the adjacent cell, Ocn_csg to be applied to a UE having a CSG-ID in the whitelist or UE registered in the CSG, and Ocn_noncsg to be applied to UEs not having the CSG-ID are provided. When subtracting the offset value from the reception quality measurement result, Ocn_noncsg is set higher than Ocn_csg. When the neighboring cell is a hybrid cell, the UE of the CSG member calculates the reception quality of the neighboring cell using Ocn_csg, and the UE of the non-CSG member calculates the reception quality of the neighboring cell using Ocn_noncsg. Since Ocn_noncsg is set higher than Ocn_csg, the UE of the CSG member generates an event for handover earlier than the UE of the non-CSG member, and can perform handover to the hybrid cell earlier.

  The method of notifying the parameter may be to individually notify the UE to be measured from the serving cell. For example, the notification may be made by including it in a measurement control message. As a result, each UE can be individually set and can be set according to the radio wave condition of each UE, so that the communication quality of each UE can be improved.

  In addition, in advance of the measurement at the UE, a difference between a parameter applied to a UE having a CSG-ID in a whitelist or a UE registered in the CSG and a parameter applied to a UE other than the UE is reported as broadcast information from the serving cell. You may do it. Only one of the parameters may be notified individually for each UE, and the UE may be derived using the difference value. As a result, information to be notified individually for each UE is reduced, so that a resource load for signaling can be reduced.

  Alternatively, the difference value may be statically determined in advance so that the base station and the UE can recognize the information in advance. Since there is no need to broadcast as broadcast information, it is possible to further reduce the resource availability for signaling.

  By adopting the method disclosed in the present embodiment, it becomes possible for the UE of the CSG member to perform HO earlier than the UE of the non-CSG member in the handover to the hybrid cell, and the handover to the hybrid cell In this handover, the UE of the CSG member can perform the handover later than the UE of the non-CSG member. For this reason, it becomes possible to make UE of a CSG member stay in a hybrid cell longer than UE of a non-CSG member.

  The method disclosed in the present embodiment can be applied even when the serving cell does not recognize whether the UE is accessing the open mode or accessing the closed mode, and in such a case, The same effect can be obtained.

  The method disclosed in the present embodiment is applicable to the fifteenth embodiment, the first modification of the fifteenth embodiment, the second modification of the fifteenth embodiment, the sixteenth embodiment, the first modification of the sixteenth embodiment, The present invention can be used in combination with any of the methods disclosed in the seventeenth, eighteenth, and nineteenth embodiments.

  By combining the method disclosed in the present embodiment with these embodiments and modifications, the CSG can be performed regardless of the state of the UE, that is, not only in the RRC_Idle but also in the RRC_Connected state. Member UEs can remain in the hybrid cell longer than non-CSG member UEs.

Embodiment 21 FIG.
The problems of the present embodiment are described below. For example, cells with the same CSG-ID are owned by the same owner, or cells with the same CSG-ID can receive the same preferential treatment, or cells with the same CSG-ID can receive the same treatment at the same communication speed. Service is conceivable. This may allow the user to desire to reselect a cell having the same CSG-ID.

  In order to solve this problem, in the present embodiment, an offset value (Qoffset_samecsg) adapted to a neighboring cell having the same CSG-ID as the serving cell and an offset value (Qoffset_diffcsg) adapted to a neighboring cell having a different CSG-ID from the serving cell. Is provided.

  In this way, by separately providing offsets for the peripheral cell having the same CSG-ID as the serving cell and for the peripheral cell having a different CSG-ID from the serving cell, the criteria for cell reselection have the same CSG-ID. It is possible to make the peripheral cell different from a peripheral cell having a different CSG-ID. This makes it easier to reselect a cell having the same CSG-ID than a cell having a CSG-ID different from the serving cell.

  A specific operation example will be described with reference to FIG. In FIG. 46, description of portions having the same step numbers as in FIG. 41 will be omitted. In ST4103, the UE performs measurement for cell reselection and performs cell ranking. In Step ST4601, the UE determines whether or not the measured CSG-ID of the neighboring cell is the same as the serving cell. If it is determined that they are the same CSG-ID, the UE moves to ST4602. In ST4602, the UE subtracts Qoffset_samecsg from the measured value. If it is determined that the CSG-ID is different, the mobile terminal shifts to ST4603. In ST4603, the UE subtracts Qoffset_diffcsg from the measured value. By performing the cell ranking based on the result of these subtractions, it is possible to make the judgment criteria for cell reselection different between a peripheral cell having the same CSG-ID and a peripheral cell having a different CSG-ID. Become. It is also possible to set the cell ranking only in step ST4602 or step ST4603 and omit the cell ranking in step ST4103.

  Regarding the value of Qoffset_samecsg and the value of Qoffset_diffcsg, depending on the radio wave environment of the serving cell and neighboring cells, the cell having the same CSG-ID satisfies the reception quality criterion of reselection from the cell having a different CSG-ID from the serving cell. It will be easier.

  For example, the value of Qoffset_samecsg is set lower (Qoffset_diffcsg> Qoffset_samecsg) than the value of Qoffset_diffcsg. This makes it easier for cells having the same CSG-ID to satisfy the reselection reception quality standard than cells having a CSG-ID different from the serving cell. By easily satisfying the reception quality criterion for reselection, it becomes possible to easily perform cell reselection for cells having the same CSG-ID.

  The following formula may be used as a criterion for cell ranking.

For neighboring cells having the same CSG-ID as the serving cell,
Rn = Qmeas, n-Qoffset_samecsg
And the surrounding cell having a CSG-ID different from the serving cell,
Rn = Qmeas, n-Qoffset_diffcsg
And

  Qmeas, n is a measured value of the reception quality of the nth cell, and Rn is a calculation result of the reception quality in consideration of the offset.

  Also, the Qoffset_samecsg and Qoffset_diffcsg may be adapted only for UEs having a CSG-ID in the whitelist or UEs registered in the CSG. UEs that are not registered with the CSG do not want to reselect cells having the same CSG-ID. Therefore, it is possible to reduce a useless processing load of a UE that has not been registered in the CSG, and to obtain an effect of reducing power consumption of the UE.

  Alternatively, the following equation may be used as a criterion for cell ranking.

For neighboring cells having the same CSG-ID as the serving cell,
Rn = Qmeas, n-Qoffset-Qoffset_samecsg
And for a neighboring cell having a CSG-ID different from the serving cell,
Rn = Qmeas, n-Qoffset-Qoffset_diffcsg
And

  In consideration of the conventional Qoffset, Qoffset_samecsg and Qoffset_diffcsg can be used only to differentiate between having the same CSG-ID as the serving cell or having a different CSG-ID from the serving cell.

  As the notification method of Qoffset_samecsg and Qoffset_diffcsg, the first to fourth methods disclosed as the notification method of the cycle for performing measurement for cell reselection in Embodiment 15 can be applied. When these are applied, the same effect can be obtained.

  In the first method, when SIB is used, the notification may be made using SIB4. In SIB4, the conventional offset value is transmitted together with the corresponding cell information. By transmitting the offset value together with such information, it becomes possible to execute the cell ranking criteria together with the conventional offset value for each corresponding cell.

  In the method disclosed above, an offset value (Qoffset_samecsg) to be applied to a peripheral cell having the same CSG-ID as the serving cell and an offset value (Qoffset_diffcsg) to be applied to a peripheral cell having a different CSG-ID from the serving cell are provided. And cell re-selection is performed.

  As another method, a difference value (Qoffset_delta2) between an offset value applied to a neighboring cell having the same CSG-ID as the serving cell and an offset value applied to a neighboring cell having a different CSG-ID from the serving cell may be provided. . That is, Qoffset_diffcsg and Qoffset_delta2 may be provided and used as criteria for cell ranking.

  For example, the following formula may be used as the criteria for cell ranking.

For neighboring cells having the same CSG-ID as the serving cell,
Rn = Qmeas, n- (Qoffset_diffcsg-Qoffset_delta2)
And for a neighboring cell having a CSG-ID different from the serving cell,
Rn = Qmeas, n-Qoffset_diffcsg
And

  As a result, it is possible to obtain the same effect as the method of notifying Qoffset_samecsg and Qoffset_diffcsg disclosed above.

  As another method, an offset value applied to a neighboring cell having a CSG-ID different from that of the serving cell may be set as a conventional Qoffset and used together with the difference value Qoffset_delta2.

  For example, the following formula may be used as the criteria for cell ranking.

For neighboring cells having the same CSG-ID as the serving cell,
Rn = Qmeas, n- (Qoffset-Qoffset_delta2)
And for a neighboring cell having a CSG-ID different from the serving cell,
Rn = Qmeas, n-Qoffset
And

  As a result, not only can the same effect as the method disclosed above be obtained, but also the number of parameters to be set can be reduced by one. That is, it is not necessary to set both Qoffset_samecsg and Qoffset_diffcsg, and it is only necessary to set Qoffset_delta2. Therefore, it is possible to reduce the amount of information for parameter setting. The above-described method can be applied as the notification method. As another method, Qoffset and Qoffset_delta2 may be notified from different cells. For example, Qoffset is reported from the serving cell, and Qoffset_delta2 is reported from the CSG cell. Since Qoffset_delta2 is a value used only for the CSG cell, it is notified only from the CSG cell, and in a cell ranking criterion, the offset value (Qoffset_delta2) for a neighboring cell having the same CSG-ID as the serving cell. It is sufficient to recalculate using. For non-CSG cells, there is no need to recalculate, and it is only necessary to measure the reception quality. Therefore, the measurement at the time of cell reselection can be simplified, and the effect of reducing power consumption of the UE can be obtained.

  The method disclosed in the present embodiment includes a method of giving a Qoffset for each CSG cell shown in Non-Patent Document 11, a method of giving one Qoffset to a hybrid cell shown in Non-Patent Document 12, or a method of using a macro cell. It is also possible to apply a method in which two Qoffsets corresponding to the RSRP range are provided, and each Qoffset is applied above and below a certain threshold of the RSRP of the macro cell. For example, these Qoffsets may be used as Qoffset in the criteria for cell ranking disclosed in the present embodiment or in addition to Qoffset. This makes it possible to take into account, for example, each Qoffset for each CSG cell, or for each hybrid, or corresponding to the RSRP range of a macro cell.

  The method disclosed in the present embodiment is applicable to the fifteenth embodiment, the first modification of the fifteenth embodiment, the second modification of the fifteenth embodiment, the sixteenth embodiment, the first modification of the sixteenth embodiment, It is possible to use in combination with the methods disclosed in the seventeenth, eighteenth, nineteenth, and twentieth embodiments.

  For example, a specific operation example when combined with Embodiment 15 will be described with reference to FIG. In FIG. 47, description of the same step numbers as in FIG. 42 will be omitted. In Step ST4201, the UE determines whether or not the whitelist includes a CSG-ID. Alternatively, the UE determines whether or not the UE has registered with the CSG cell. If the CSG-ID is included in the whitelist or if the cell is registered in the CSG cell, ST4701 is performed. In Step ST4701, the UE subtracts Qoffset_samecsg from the measured value when the measured CSG-ID of the neighboring cell is the same as the serving cell. On the other hand, if the UE determines in step ST4701 that the CSG-ID is different from the serving cell, the UE subtracts Qoffset_diffcsg from the measured value. The cell ranking is performed based on the result of the subtraction. When the CSG-ID is not included in the whitelist, or when the whitelist is not registered in the CSG cell, nothing is specifically performed in step ST4702. This makes it possible to make different criteria for cell reselection between a peripheral cell having the same CSG-ID and a peripheral cell having a different CSG-ID.

  The other embodiments and modifications can be used in combination by performing similar operations. By combining the method disclosed in the present embodiment with these embodiments and modified examples, it is possible to obtain an effect of being able to flexibly cope with the difference in each radio wave environment due to the flexible arrangement of HeNB or HNB.

  By adopting the method disclosed in the present embodiment, it is possible to make different criteria for cell reselection between a peripheral cell having the same CSG-ID and a peripheral cell having a different CSG-ID. This makes it easier to reselect a cell having the same CSG-ID than a cell having a CSG-ID different from the serving cell.

  This allows the user to continuously select a cell with the same CSG-ID and receive the same service with the same CSG-ID. Therefore, the effect of building a mobile communication system that is easy for the user to use can be obtained.

Embodiment 22. FIG.
The CSG member allows the CSG member UE to stay longer in the hybrid cell than the non-CSG member UE in the hybrid cell so that the CSG member can receive services such as high-speed communication and preferential charging plans for the CSG member faster and longer. Is required.

  FIG. 49 shows a conceptual diagram in a case where the UE of the CSG member is allowed to stay longer than the UE of the non-CSG member in the hybrid cell. In the figure, reference numeral 4901 denotes a non-CSG cell, which is a macro cell (eNB) here. Reference numeral 4902 denotes coverage by the non-CSG cell 4901. Reference numeral 4903 denotes a HeNB in a hybrid access mode, that is, a hybrid cell. Reference numeral 4904 denotes a coverage accessible in both the open access mode and the closed access mode in the hybrid cell 4903. Reference numeral 4905 denotes coverage that can be accessed only in the closed access mode in the hybrid cell 4903. Reference numeral 4906 denotes a UE of the same CSG member as the CSG to which the hybrid cell 4903 belongs. Reference numeral 4907 denotes a UE of a non-CSG member. UE 4906 of the CSG member communicates with non-CSG cell 4901 outside the area of coverage 4905, and UE 4906 that has moved to the area of coverage 4905 communicates with hybrid cell 4903 by cell reselection. The non-CSG member UE 4907 is still communicating with the non-CSG cell 4901 even in the area of the coverage 4905, and can communicate with the hybrid cell 4903 by cell reselection only after moving to the coverage 4904.

  In this way, when performing cell reselection to or from the hybrid cell, when the UE of the CSG member is made to stay longer than the UE of the non-CSG member, the coverage of only the closed access mode is wider than the coverage of the open access mode. It may be. In such a case, assuming that the initial transmission power of the UE when starting uplink communication in the hybrid cell is the same between the UE of the CSG member and the UE of the non-CSG member, the coverage at which the UE of the CSG member becomes accessible is better. Due to the widening, there is a high possibility that the uplink transmission of the UE of the CSG member will fail at the coverage end.

  As a procedure for starting uplink communication, there is a random access (RA) procedure. In the RA procedure, PRACH is used as a physical channel. The RACH preamble is used for the initial transmission of the PRACH. The PRACH initial transmission power Pprach is determined as follows (Non-Patent Documents 13 and 14).

Pprach = min {Pcmax, PREAMBLE_RECEIVED_TARGET_POWER + PL} _ [dBm]
Pcmax = min ｛Pemax, Pumax｝
Here, PREMBLE_RECEIVED_TARGET_POWER is the target reception power of the base station, PL is the path loss, Pemax is the maximum allowable power set for each cell, and Pumax is the maximum transmission power of the UE. Pemax is reported to the UE being served thereby as broadcast information from each cell, and is the maximum allowable power common to all UEs being served. Pumax is determined in advance according to the power class of each UE.

  As can be seen from the formula for deriving the initial transmission power Pprach of the PRACH, for example, when the PL is large, the initial transmission power is limited by Pcmax. Since Pcmax is also limited by Pemax, the initial transmission power of the PRACH is limited by Pemax. Since Pemax is common to all UEs being served by the cell, in a hybrid cell, the value is the same for both UEs of CSG members and UEs of non-CSG members. Therefore, when the PRACH initial transmission power is limited by Pemax, for example, when the PL is large, both the UE of the CSG member and the UE of the non-CSG member can transmit only up to the common Pemax. For this reason, in a hybrid cell, when the coverage of the UE of the CSG member becomes wider than that of the UE of the non-CSG member, there is a high possibility that the uplink transmission of the UE of the CSG member will fail. Would.

  This problem occurs in both the RRC_Idle state and the RRC_Connected state. For example, when the UE of the CSG member reselects to the hybrid cell in the state of RRC_Idle, or when the UE of the CSG member HOs to the hybrid cell in the state of RRC_Connected. There is no prior literature on this problem, and no discussion has been made in 3GPP.

  In the present embodiment, in order to solve this problem, a method is disclosed in which the initial transmission power of a UE when starting uplink communication can be made different between a UE of a CSG member and a UE of a non-CSG member. As a specific example, in order to make the initial transmission power of the PRACH different between the UE of the CSG member and the UE of the non-CSG member, the maximum allowable power used in deriving the PRACH initial transmission power in the hybrid cell is CSG. It is provided separately for the member UE and the non-CSG member UE. Let the maximum allowable power for CSG members be Pemax_csg and the maximum allowable power for non-CSG members be Pemax_noncsg.

  An equation for deriving the initial transmission power Pprach in the hybrid cell is as follows.

Pprach = min {Pcmax, PREAMBLE_RECEIVED_TARGET_POWER + PL} _ [dBm]
For CSG members, Pcmax = min {Pemax_csg, Pumax},
For non-CSG members, Pcmax = min {Pemax_noncsg, Pumax}.

  By doing so, even when the PL is large, the initial transmission power Pprach in the hybrid cell can have different maximum allowable powers between the UE of the CSG member and the UE of the non-CSG member. In a hybrid cell, when coverage of a UE of a CSG member is wider than that of a UE of a non-CSG member, Pemax_csg is set to be larger than Pemax_noncsg, thereby reducing uplink transmission failure of the UE of the CSG member. It is possible to do.

  Further, by providing the maximum allowable power for each cell for the UE of the CSG member and for the UE of the non-CSG member, it is possible to set different initial transmission powers for both UEs for each cell, so that the system is flexible. Hybrid cells can be arranged, and it is possible to cope with an increase in the number of operating HeNBs in the future.

  The method for deriving the initial uplink transmission power in the hybrid cell disclosed herein can be applied when starting uplink communication in the hybrid cell when the UE of a CSG member reselects a cell to the hybrid cell in the RRC_Idle state. Further, in the RRC_Connected state, the present invention can be applied to a case where a UE of a CSG member executes HO to a hybrid cell and starts uplink communication in the hybrid cell serving as a target cell.

  A method for notifying the maximum allowed power used in the hybrid cell to the UE is disclosed below.

  As a first method, a cell in which these maximum allowable powers are set is notified to a UE being served thereby by using a BCCH as broadcast information on a PBCH or a PDSCH. The notification is made on the PBCH using the master information (MIB) or on the PDSCH using the system information (SIB). Since the MIB is mapped to the PBCH, the method using the MIB is excellent in that the mobile terminal can receive with a small control delay. When SIB is used, notification is made using SIB1. MIB or SIB1 is excellent in that it reduces the control delay of the mobile terminal in that it is a necessary minimum amount of broadcast information received from the start of the cell search to the transition to the standby state (RRC-Idle state). Is the way. Furthermore, even in the method of notifying using system information other than SIB1, notification is performed using a channel for transmitting broadcast information, so that notification can be made to all mobile terminals being served thereby, and effective use of radio resources can be achieved. This is an excellent method.

  As a second method, when performing HO with a cell for which these maximum allowable power is set as a target cell, the serving cell individually notifies the UE that performs HO. The UE may be notified by including it in the information of the target cell necessary for performing the HO, or may be notified using another message. By notifying the information included in the target cell information, the number of necessary messages can be reduced, and thus the time until HO is completed can be reduced. On the other hand, when the notification is performed using another message, the message can be notified only in the case of the cell in which the setting of the maximum allowable power is necessary. In this case, it is possible to reduce the amount of information required for notification and the number of messages.

  The determination of the maximum allowable power (Pemax_csg) value for the CSG member and the maximum allowable power (Pemax_noncsg) value for the non-CSG member may be performed by the hybrid cell, or may be performed by the network side (MME, HeNBGW, etc.). . When performing on the network side, the maximum allowable power is notified from the network side to the hybrid cell in advance. This notification can be made using the hybrid cell and the interface S1 on the network side. By deciding on the network side, it is possible to set a value based on the radio wave environment and the load status (for example, the number of connected terminals, etc.) of the surrounding cells. As a system, it is possible to reduce a communication impossible state, a connection delay due to a communication error, an increase in signaling amount, a concentration of a load, and the like.

  In the method described above, the maximum allowable power for CSG members is Pemax_csg, and the maximum allowable power for non-CSG members is Pemax_noncsg. As another method, a maximum allowable power (Pemax_common) common to the CSG member and the non-CSG member may be provided, and a difference (Pemax_delta) between the maximum allowable power of the CSG member and the non-CSG member may be provided. An example of a formula for deriving the initial transmission power Pprach in the hybrid cell in this case is shown below.

Pprach = min {Pcmax, PREAMBLE_RECEIVED_TARGET_POWER + PL} _ [dBm]
For CSG members, Pcmax = min {Pemax_common + Pemax_delta, Pumax}, and for non-CSG members, Pcmax = min {Pemax_common, Pumax}. By doing so, it is possible to have different maximum allowable powers between the UE of the CSG member and the UE of the non-CSG member, so that the same effect as the above-described method can be obtained.

  Note that Pemax set as the conventional maximum allowable power may be used as the common parameter Pemax_common. As a result, the method for deriving the initial transmission power of the non-CSG member does not need to be changed from the current method. Therefore, the effect of avoiding the complexity of the mobile communication system can be obtained.

  As another method, Pumax may be provided separately for the CSG member and for the non-CSG member. Pumax is the maximum transmission power of the UE and is determined in advance according to the power class of each UE. What is necessary is just to determine in advance the CSG member (Pumax_csg) and the non-CSG member (Pumax_noncsg) according to the power class of each UE. An example of a formula for deriving the initial transmission power Pprach in the hybrid cell in this case is shown below.

Pprach = min {Pcmax, PREAMBLE_RECEIVED_TARGET_POWER + PL} _ [dBm]
For CSG members, set Pcmax = min {Pemax, Pumax_csg},
For non-CSG members, Pcmax = min {Pemax, Pumax_noncsg}. By doing so, Pemax can be set to a common setting for all UEs being served by the cell, so that the setting can be the same as the conventional setting.

  It may be a static value for the mobile communication system. The static value refers to a value known to a mobile terminal / base station as a mobile communication system, or a known value described in a standard or the like. By using a static value, no radio signal is generated between the base station (on the network side) and the mobile terminal. Therefore, an effect can be obtained in terms of effective use of wireless resources. Furthermore, since the value is determined statically, it is possible to obtain an effect of preventing a reception error of a radio signal from occurring.

  A specific operation example in the case where the maximum allowable power for a CSG member is set as Pemax_csg and the maximum allowable power for a non-CSG member is set as Pemax_noncsg in a hybrid cell will be described.

  FIG. 50 shows a procedure example up to the PRACH initial transmission in the hybrid cell.

  First, a UE of a CSG member will be described. A UE of a CSG member camps on a hybrid cell in ST5001, for example, after cell reselection. The hybrid cell transmits broadcast information in ST5004, and UEs of CSG members receive the broadcast information. The notification information includes the maximum allowable power. If uplink transmission has occurred to the UE of the CSG member in ST5005, the mobile terminal proceeds to ST5007, and derives an uplink initial transmission power using the maximum allowable power for the CSG member UE (Pemax_csg) among the received maximum allowable powers. In ST5009, the CSG member UE sets the uplink initial transmission power to the transmission power, and starts uplink transmission in ST5011.

  Next, UEs of non-CSG members will be described. The UE of the non-CSG member camps on the hybrid cell in ST50001, for example, after cell reselection. The hybrid cell transmits broadcast information in ST5004, and the UE of a non-CSG member receives the broadcast information. The notification information includes the maximum allowable power. If uplink transmission has occurred to the UE of the non-CSG member in ST5006, the mobile terminal proceeds to ST5008, and uses the maximum allowable power for the non-CSG member UE (Pemax_noncsg) among the received maximum allowable power to transmit the uplink initial transmission power. Is derived. In ST5010, the UE of a non-CSG member sets the uplink initial transmission power to the transmission power, and starts uplink transmission in ST5012.

  In addition, since the timing of the occurrence of uplink transmission differs for each UE, the timing of the initial uplink transmission also differs for each UE. Therefore, for example, ST5012 may be executed following ST5011 as shown in the figure, or ST5011 may be executed following ST5012.

  Thus, by making the maximum allowable power used for uplink initial transmission power derivation different depending on whether the UE camping on the hybrid cell is a CSG member or a non-CSG member, even if the UE of the CSG member is accessible Even in a case where the user is camped on a small area, only the UEs of the CSG members can increase the transmission power of uplink transmission, so that it is possible to secure sufficient uplink reception power for communication in the hybrid cell.

  By adopting the method disclosed in the present embodiment, in a hybrid cell, when the coverage of the CSG member UE is wider than that of the non-CSG member UE, the uplink transmission of the CSG member UE fails. Can be solved.

  In addition, it becomes possible for the UE of the CSG member to stay longer in the hybrid cell than the UE of the non-CSG member, and the CSG member provides services such as high-speed communication and preferential billing plans to the CSG member in the hybrid cell faster and longer. It is possible to receive.

  In addition, since it is possible to provide the UE of the non-CSG member with the maximum allowable power lower than that of the UE of the CSG member, when the PL is large, the transmission power of the UE of the non-CSG member becomes larger than necessary. Can be prevented and uplink interference power can be reduced.

Embodiment 23 FIG.
In the present embodiment, in order to enable the initial transmission power of the UE when starting uplink communication to be different between the UE of the CSG member and the UE of the non-CSG member, the CSG- A difference between a UE having an ID or a UE registered in the CSG and a criterion applied to a UE not having the ID is used.

  As a specific example, a threshold for cell reselection (S_intrasearch) when the CSG-ID is not included in the whitelist disclosed in the seventeenth embodiment and a CSG-ID is included in the whitelist or registered in the CSG. In this case, the difference from the cell reselection threshold (S_intrasearchCSG) is used.

  As another specific example, an offset value (Qoffset_csg_in) applied to a UE having a CSG-ID in a whitelist or a UE registered in a CSG disclosed in Embodiment 18 and an offset value applied to a UE not in the whitelist. The difference between the offset values (Qoffset_noncsg_in) is used. This difference may be a difference value (Qoffset_delta).

  Further, as another specific example, the offset value (Qoffset_csg_out) applied to a UE having a CSG-ID in a whitelist or a UE registered in a CSG disclosed in Embodiment 19, and applied to a UE that is not so. The difference between the offset values (Qoffset_noncsg_out) is used. This difference may be a difference value.

  These difference values may be used as difference values between the CSG member UE and the non-CSG member UE having the maximum allowable power used in deriving the PRACH initial transmission power in the hybrid cell.

  Cell reselection threshold (S_intrasearch) when there is no CSG-ID in the whitelist and cell reselection threshold (S_intrasearchCSG) when there is a CSG-ID in the whitelist disclosed in Embodiment 17. In this case, this difference is used. The difference value is set to S_intrasearch_delta.

S_intrasearch_delta = S_intrasearch-S_intrasearchCSG
This value is defined as Pemax_delta (= Pemax_csg-Pemax_noncsg), which is the difference between the maximum allowable power used for deriving the PRACH initial transmission power for the CSG member UE and the non-CSG member UE.

Pemax_delta = S_intrasearch_delta
Or,
Pemax_delta = | S_intrasearch_delta |
It is good.

In the case of an offset value (Qoffset_csg_in) applied to a UE having a CSG-ID in the whitelist or a UE registered in the CSG, and an offset value (Qoffset_noncsg_in) applied to a UE not registered in the eighteenth embodiment, , And the difference value as Qoffset_delta (= Qoffset_noncsg_in−Qoffset_csg_in),
Pemax_delta = Qoffset_delta
Or,
Pemax_delta = | Qoffset_delta |
It is good.

In the case of the offset value (Qoffset_csg_out) applied to the UE having the CSG-ID in the whitelist or the UE registered in the CSG, and the offset value (Qoffset_noncsg_out) applied to the UE that is not disclosed in Embodiment 19, , And the difference value as Qoffset_delta (= Qoffset_csg_out−Qoffset_noncsg_out),
Pemax_delta = Qoffset_delta
Or,
Pemax_delta = | Qoffset_delta |
It is good.

  Specific operation of a method of using a difference between a UE having a CSG-ID in a whitelist or a UE registered in a CSG and a UE applied to a UE other than the UE having a CSG-ID in a whitelist in deriving a maximum allowable power in a hybrid cell Here is an example.

  FIG. 51 shows an outline of the procedure up to the initial transmission of the PRACH in the hybrid cell when the difference of the cell reselection threshold is used.

  First, a UE of a CSG member will be described. The UE of the CSG member camps on cell A in ST5101, for example, after cell reselection. Cell A is transmitting broadcast information in ST 5104, and UEs of CSG members receive the broadcast information. The broadcast information includes a cell reselection threshold. In ST5105, the UE of the CSG member performs the cell reselection procedure using the cell reselection threshold (S_intrasearchCSG) in the case where the UE has the CSG-ID in the whitelist or is registered in the CSG among the received cell reselection thresholds. . In ST5107, it is determined whether or not the cell reselection criterion is satisfied. If the cell reselection criterion is satisfied, the process proceeds to ST5109. If the UE of the CSG member reselects to a hybrid cell according to the cell reselection criteria in ST5107, it camps on the hybrid cell in ST5109.

  The hybrid cell transmits broadcast information in ST 5112, and the UE of the CSG member receives the broadcast information. The notification information includes the maximum allowable power. However, the maximum allowable transmission power broadcast here does not include the maximum allowable transmission power set differently for CSG members and non-CSG members as disclosed in Embodiment 22 and is common to conventional cells. Only the maximum allowable power. If uplink transmission has occurred to the UE of a CSG member in ST5113, the mobile terminal proceeds to ST5115, and receives a threshold value (S_intrasearch) for cell reselection when CSG-ID is not included in the whitelist received in ST5104, and a whitelist. A difference value (S_intrasearch_delta) of a cell reselection threshold value (S_intrasearchCSG) when a CSG-ID is included therein is derived. In step ST5116, the UE of the CSG member uses the difference value (S_intrasearch_delta) as the difference (Pemax_delta) in the transmission power between the UE for the CSG member and the UE for the non-CSG member and uses the difference value (Pemax_delta) in ST5117. The initial transmission power (Pprach) is derived. In ST5119, the UE of the CSG member sets the uplink initial transmission power to the transmission power, and starts uplink transmission in ST5121.

  Next, UEs of non-CSG members will be described. Here, the UE of a non-CSG member camps on cell A in ST5102, for example, after cell reselection. Cell A transmits broadcast information in ST 5104, and the UE of a non-CSG member receives the broadcast information. The broadcast information includes a cell reselection threshold. In ST5106, the UE of the non-CSG member performs the cell reselection procedure using the cell reselection threshold (S_intrasearch) when the CSG-ID is not included in the whitelist among the received cell reselection thresholds. In ST5108, it is determined whether or not the cell reselection criterion is matched. If matched, the process proceeds to ST5110, and if not, the process returns to ST5106. If the UE of a non-CSG member reselects to a hybrid cell according to the cell reselection criteria in ST5108, it camps on the hybrid cell in ST5110.

  Even in the case of a UE that has a CSG-ID in the whitelist but is a non-CSG member of the hybrid cell, the hybrid cell must be reselected in the open access mode. -Perform a cell reselection procedure using the cell reselection threshold (S_intrasearch) when there is no ID, and determine whether or not the cell reselection criteria are met. In the case of a UE that has a CSG-ID in the whitelist but is a non-CSG member of a hybrid cell, for example, even if the cell reselection procedure is first performed using S_intrasearchCSG, the UE sets the CSG-ID of the cell to The received CSG-ID is checked, and if the CSG-ID does not match, the cell may be reselected using the cell reselection procedure ST5106 for a non-CSG member.

  The hybrid cell transmits the broadcast information in ST5112, and the UE of the non-CSG member receives the broadcast information. The notification information includes the maximum allowable power. However, the maximum allowable transmission power broadcast here does not include the maximum allowable transmission power set differently for the CSG member and the non-CSG member as disclosed in Embodiment 22 and is common to the conventional cells. Only the maximum allowable power. If uplink transmission has occurred to the UE of a CSG member in ST5114, the mobile terminal proceeds to ST5118, and uses the maximum allowable power (Pemax_common) common to the conventional cells broadcast from the hybrid cell in ST5112 to transmit the uplink initial transmission power in ST5118. (Pprach) is derived. In ST5120, the UE of a non-CSG member sets the uplink initial transmission power to the transmission power, and starts uplink transmission in ST5122.

  In addition, since the timing of the occurrence of uplink transmission differs for each UE, the timing of the initial uplink transmission also differs for each UE. Therefore, for example, ST5122 may be executed following ST5121, as shown in the figure, or ST5121 may be executed following ST5122.

  As described above, in the cell reselection, the UE that camps on the hybrid cell using the difference between the UE that has the CSG-ID in the whitelist or the UE that is registered in the CSG and the criterion applied to the UE that is not the same. Can be adopted in which the maximum allowable power used for deriving the uplink initial transmission power differs depending on whether the is a CSG member or a non-CSG member. At this time, even when the UE of the CSG member camps on an accessible area, only the UE of the CSG member can increase the transmission power of the uplink transmission, so that sufficient communication for the hybrid cell is sufficient. It is possible to secure uplink reception power.

  Not limited to the above specific examples, the methods disclosed in the seventeenth, eighteenth, nineteenth, and twentieth embodiments can be used.

  Not limited to this example, among the criteria in cell reselection, regarding the configuration parameters affecting the extent of coverage of the hybrid cell, the PRACH initial values for the CSG member UE and the non-CSG member UE are determined based on the difference. What is necessary is just to derive each transmission power.

  When a plurality of criteria for cell reselection (for example, a cell reselection threshold and an offset) are set, it is better to determine in advance which criteria to use. For example, a priority may be assigned to which one of a plurality of criteria is used. By doing so, it is possible to use another criterion in the order of priority even if any criterion is not set. As another example, it is possible to determine which criterion is to be used according to the difference value among a plurality of criterions. For example, a criterion having the largest difference value is used. As still another example, an average value of a plurality of reference difference values may be used.

  Further, as another method, the serving cell may determine which criterion to use from among a plurality of criteria, and notify the UE. As a notification method, notification may be performed as notification information. Instead of determining the serving cell, the network side (MME, HeNBGW, etc.) may determine and notify the UE via the serving cell. The interface S1 can be used for notification from the network side to the serving cell. This makes it possible to flexibly cope with the arrangement of cells including the hybrid cells. If the network side decides, it is possible to set a value based on the radio wave environment and the load situation (for example, the number of connected terminals, etc.) of the neighboring cells. As a system, it is possible to reduce a communication impossible state, a connection delay due to a communication error, an increase in signaling amount, a concentration of a load, and the like.

  The method described above uses the criteria for cell reselection. Therefore, it can be used when a hybrid cell is reselected using the criterion. In other cases, for example, when moving to a hybrid cell by HO, the method disclosed in Embodiment 22 is applied, and the setting value may be individually notified to the UE performing HO from the serving cell. Good.

  By using the method disclosed in the present embodiment, it is possible to make the initial transmission power of the UE different from the UE of the CSG member and the UE of the non-CSG member at the time of starting the uplink communication. It is possible for a CSG member UE to stay longer than a non-CSG member UE.

  Also, used to derive the PRACH initial transmission power in a hybrid cell to enable the initial transmission power of the UE when starting uplink communication to be different between the UE of the CSG member and the UE of the non-CSG member. The maximum allowable power is provided separately for the UE of the CSG member and for the UE of the non-CSG member, and these are broadcast from the hybrid cell to the UE being served thereby, but in the hybrid cell, the PRACH initial transmission power is derived. It is not necessary to separately provide the maximum allowable power used for the UE of the CSG member and the UE of the non-CSG member, and it is not necessary to notify them to UEs being served thereby. Therefore, it is possible to reduce the number of parameters that need to be broadcast in the hybrid cell and further reduce the amount of information to be signaled.

  The method disclosed in the seventeenth to twenty-third embodiments is not limited to the case where the open mode cell (non-CSG cell) and the CSG cell are mixed in the same frequency carrier (same frequency layer) (mixed carrier), The present invention can also be applied to a case where there is only a CSG cell in the same frequency carrier (same frequency layer) (a dedicated carrier). Further, if there is a hybrid cell in the same frequency layer, it can be applied.

  Further, the present invention is applicable not only to cell reselection and HO within the same frequency layer (intra-frequency), but also to frequency layers (inter-frequency) or between systems (RAT) (inter-RAT).

  Although LTE using HeNB using CSG has been described above, the present invention is directed to UMTS using HNB using CSG, HeNB and HNB not using CSG, and base stations with small radius (also referred to as pico cells and macro cells). ) Is also applicable. In the first modification of the sixteenth embodiment, the following effects can be obtained in addition to the effects of the sixteenth embodiment. It is possible to reduce the power consumption of the mobile terminal when the mobile terminal has not been registered in a CSG cell existing around the current serving cell. Further, in that the network side (such as a base station) has the above-mentioned effect without knowing which CSG cell the corresponding mobile terminal has registered (which CSG-ID is in the whitelist), The solution of the first modification of the sixteenth embodiment is excellent. This eliminates the need for the mobile terminal to notify the base station of the CSG-ID in the whitelist, thus enabling effective use of radio resources. In addition, in that the base station does not need to manage the CSG-ID in the whitelist of the mobile terminals being served thereby, the effect of reducing the processing load on the base station can be obtained.

  In the above, the case where the CSG-ID, which is information broadcasted by the CSG cell or the cell, and the tracking area code (TAC) broadcasted by the CSG cell or the cell are mainly described, the present invention is not limited to the above. Even when the CSG-ID and the TAC are not associated with each other, it is of course applicable.

  If they are not associated, for example, it may be determined separately whether or not they have already been registered in the CSG and whether or not TA update is necessary, as described below.

  At the time of cell reselection, when it is determined whether or not the own mobile terminal has been registered in the selected cell, whether or not the CSG-ID received by the broadcast information of the cell exists in the whitelist of the own mobile terminal To judge. If the CSG-ID received from the broadcast information of the cell exists in the whitelist, it is determined that the cell has been registered in the cell selected by the own mobile terminal. That is, it is determined that the cell can be an “appropriate cell” for the mobile terminal. On the other hand, if the CSG-ID received from the broadcast information of the cell does not exist in the whitelist of the own mobile terminal, it is determined that the self mobile terminal has not been registered in the selected cell. That is, it is determined that the cell cannot be an “appropriate cell” for the mobile terminal.

  When it is determined at the time of cell reselection whether or not a TA update is necessary, one or more TACs stored in the own mobile terminal (hereinafter referred to as a TA list) are stored in the TAC received from the broadcast information of the cell. It is determined based on whether or not it is included in. When the TAC received from the broadcast information of the cell is included in the TA list in the own mobile terminal, it is determined that the TA update is unnecessary and the TAU is unnecessary. On the other hand, when the TAC received from the broadcast information of the cell is not included in the TA list in the own mobile terminal, it is determined that TA update is necessary and that TAU needs to be performed.

  Specific examples correspond to steps ST1406 to ST1409 in FIG. 14, steps ST1607 to ST1610 in FIG.

  Although the present invention has been described focusing on the LTE system (E-UTRAN), the present invention is applicable to a W-CDMA system (UTRAN, UMTS) and LTE-Advanced. Further, the present invention is applicable to a mobile communication system in which a CSG (Closed Subscriber Group) is introduced, and a communication system in which an operator specifies a subscriber and access to the specified subscriber is permitted as in the case of the CSG. It is.

  101 mobile terminal, 102 base station, 103 MME (Mobility Management Entity), 104 S-GW (Serving Gateway).

Claims (4)

Mobile terminal from a CSG base station, which is a base station provided in a CSG cell belonging to a CSG of a closed subscriber group, to a base station provided in another cell, or from a base station provided in another cell to a CSG base station Is a mobile communication system for handover,
A mobile communication system characterized in that a handover procedure is different between a case where a mobile terminal performing a handover is a CSG terminal belonging to a CSG and a case where the mobile terminal is a non-CSG terminal not belonging to a CSG.   The mobile communication system according to claim 1, wherein the CSG base station is a hybrid base station accessible by a CSG terminal and accessible by a non-CSG terminal. A base station provided in a CSG cell belonging to a CSG of a closed subscriber group, in which a mobile terminal hands over to a base station provided in another cell, or a mobile terminal from a base station provided in another cell. A CSG base station for handover,
A CSG base station, wherein a handover procedure is different between a case where a mobile terminal performing a handover is a CSG terminal belonging to the CSG and a case where the mobile terminal is a non-CSG terminal not belonging to the CSG. Handover from a CSG base station, which is a base station provided in a CSG cell belonging to a CSG of a closed subscriber group, to a base station provided in another cell, or from a base station provided in another cell to a CSG base station A mobile terminal,
A mobile terminal characterized in that a handover procedure is different between a case where a mobile terminal performing a handover is a CSG terminal belonging to the CSG and a case where the mobile terminal is a non-CSG terminal not belonging to the CSG.

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