JP5098676B2 - Mobile communication system - Google Patents

Description

  The present invention relates to a mobile communication system in which a base station performs radio communication with a plurality of mobile terminals, and in particular, mobile communication capable of providing a broadcast type multimedia service (MBMS: Multimedia Broadcast Multicast Service) to mobile terminals. It is about the system.

  Among the communication systems called the third generation, the W-CDMA (Wideband Code division Multiple Access) system has been commercialized in Japan since 2001. Also, by adding a packet transmission channel (HS-DSCH: High Speed-Downlink Shared Channel) to the downlink (dedicated data channel, dedicated control channel), further speeding up data transmission using the downlink Realized HSDPA (High Speed Down Link Packet Access) service has been started. Furthermore, the HSUPA (High Speed Up Link Packet Access) method is also standardized in order to further increase the speed of data transmission in the uplink direction. W-CDMA is a communication method defined by 3GPP (3rd Generation Partnership Project), which is a standardization organization for mobile communication systems, and standardized release 7 editions are compiled.

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

  LTE is defined as an independent radio access network different from the W-CDMA network because the communication system is configured using a new core network different from the W-CDMA core network (GPRS). 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) that exchanges control data and user data with each other is called an EPC (Evolved Packet Core) (sometimes called an aGW: Access Gateway). In the LTE communication system, a 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. Mass broadcast contents such as news, weather forecasts, and mobile broadcasts are transmitted to a plurality of mobile terminals. This is also called a point-to-multipoint service.

  Non-Patent Document 1 describes the current decisions regarding the overall architecture of the LTE system in 3GPP. The overall architecture (Chapter 4 of Non-Patent Document 1) 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 based. If terminated at station 102, Evolved Universal Terrestrial Radio Access (E-UTRAN) is composed of one or more base stations 102. The base station 102 performs scheduling (Scheduling) and transmission of a paging signal (also referred to as a paging message or paging message) notified from the MME 103 (Mobility Management Entity). Base stations 102 are connected to each other via an X2 interface. The base station 102 is connected to the EPC (Evolved Packet Core) via the S1 interface. More specifically, the base station 102 is connected to the MME 103 (Mobility Management Entity) via the S1_MME interface, and is connected to the S-GW 104 (Serving Gateway) via the S1_U interface. The The MME 103 distributes the paging signal to a plurality or a single base station 102. Further, the MME 103 performs mobility control (Mobility control) in an idle state. The S-GW 104 transmits / receives user data to / from one or a plurality of base stations 102.

  Non-Patent Document 1 (Chapter 5) describes the current decisions 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 is 10 ms. The radio frame is divided into 10 equally sized sub-frames. The subframe is divided into two equally sized slots. A downlink synchronization channel (SCH) is included in the first (# 0) and sixth (# 5) subframes for each frame. The synchronization signal includes a first synchronization channel (Primary Synchronization Channel: P-SCH) and a second synchronization channel (Secondary Synchronization Channel: S-SCH). Channels other than MBSFN (Multimedia Broadcast multicast service Single Frequency Network) and channels other than MBSFN are multiplexed on a subframe basis. Hereinafter, a subframe for MBSFN transmission is referred to as an MBSFN sub-frame. Non-Patent Document 2 describes a signaling example 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 (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 decisions regarding the channel configuration in the LTE system in 3GPP. A physical channel (Chapter 5 of Non-Patent Document 1) will be described with reference to FIG. FIG. 4 is an explanatory diagram illustrating physical channels 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 obvious signaling of 40ms timing. A physical control format indicator channel 402 (Physical Control format indicator channel: PCFICH) is transmitted from the base station 102 to the 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. A 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, HARQ information related to 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. The PDCCH carries ACK / Nack that is a response signal for uplink transmission. A physical downlink shared channel 404 (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) that is a transport channel is mapped. A physical multicast channel 405 (Physical multicast channel: PMCH) is a downlink channel transmitted from the base station 102 to the mobile terminal 101. PMCH is mapped with MCH (multicast channel) which is 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. The PUCCH carries ACK / Nack which is a response signal (response) to downlink transmission. PUCCH carries a CQI (Channel Quality Indicator) report. CQI is quality information indicating the quality of received data or channel quality. A 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. PUSCH is mapped with UL-SCH (uplink shared channel which is one of the transport channels shown in FIG. 5). A 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. The PHICH carries ACK / Nack that is a response to uplink transmission. A physical random access channel 409 (Physical random access channel: PRACH) is an uplink channel transmitted from the mobile terminal 101 to the base station 102. The PRACH carries a random access preamble.

  A transport channel (Chapter 5 of Non-Patent Document 1) will be described with reference to FIG. FIG. 5 is an explanatory diagram for explaining a transport channel used in an LTE communication system. FIG. 5A shows mapping between the downlink transport channel and the downlink physical channel. FIG. 5B shows mapping between the uplink transport channel and the uplink physical channel. For the downlink transport channel, a broadcast channel (BCH) is broadcast to the entire base station (cell). BCH is mapped to the physical broadcast channel (PBCH). Retransmission control by HARQ (Hybrid ARQ) is applied to the downlink shared channel (DL-SCH). Broadcasting to the entire base station (cell) is possible. Supports dynamic or semi-static resource allocation. Quasi-static resource allocation is also called Persistent Scheduling. In order to reduce power consumption of the mobile terminal, DRX (Discontinuous reception) of the mobile terminal is supported. DL-SCH is mapped to a physical downlink shared channel (PDSCH). A paging channel (Paging channel: PCH) supports DRX of the mobile terminal in order to enable low power consumption of the mobile terminal. Notification to the entire base station (cell) is required. It is mapped to a physical resource such as a physical downlink shared channel (PDSCH) that can be dynamically 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 broadcast to the entire base station (cell). Supports SFN combining of MBMS services (MTCH and MCCH) in multi-cell transmission. Supports quasi-static resource allocation. MCH is mapped to PMCH.

  Retransmission control by HARQ (Hybrid ARQ) is applied to the 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 technique for improving the communication quality of a transmission path by combining automatic repeat request and error correction (forward error correction). There is also an advantage that error correction functions effectively by retransmission even for a transmission path in which communication quality changes. In particular, further quality improvement can be obtained by combining the reception result of the initial transmission and the reception result of the retransmission upon retransmission. An example of the retransmission method will be described. When the reception data cannot be decoded correctly on the receiving side (when a CRC Cyclic Redundancy Check error occurs (CRC = NG)), “Nack” is transmitted from the receiving side to the transmitting side. The transmission side that has received “Nack” retransmits the data. When the reception data can be correctly decoded on the reception side (when no CRC error occurs (CRC = OK)), “Ack” is transmitted from the reception side to the transmission side. The transmitting side that has received “Ack” transmits the next data. An example of the HARQ method is “Chase Combining”. Chase combining is a method in which the same data sequence is transmitted for initial transmission and retransmission, and the gain is improved by combining the initial transmission data sequence and the retransmission data sequence in retransmission. The idea is that even if there is an error in the initial transmission data, it is partially accurate, and it is possible to transmit data with higher accuracy by combining the initial transmission data and the retransmission data of the correct part. Based on. Another example of the HARQ scheme is IR (Incremental Redundancy). IR is to increase the redundancy. By transmitting parity bits in retransmission, the redundancy is increased in combination with the initial transmission, and the quality is improved by the error correction function.

  The logical channel (Chapter 6 of Non-Patent Document 1) 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 the downlink logical channel and the downlink transport channel. FIG. 6B shows mapping between the uplink logical channel and the uplink transport channel. A 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). A paging control channel (Paging control channel: PCCH) is a downlink channel for transmitting a paging signal. 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 (CCCH) is a channel for transmission control information between the mobile terminal and the base station. CCCH is used when the mobile terminal does not have an RRC connection with the network. Whether the CCCH is provided downstream is not determined at this time. In the uplink direction, the CCCH is mapped to an uplink shared channel (UL-SCH) that is a transport channel.

  A 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. MCCH is a channel used only for a mobile terminal receiving MBMS. MCCH is mapped to a downlink shared channel (DL-SCH) or multicast channel (MCH) which is a transport channel. The dedicated control channel (Dedicated control channel: DCCH) is a channel for transmitting dedicated control information between the mobile terminal and the 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 (Dedicate Traffic channel: DTCH) is a channel for one-to-one communication to individual mobile terminals for transmission of user information. 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 that is receiving MBMS. The MTCH is mapped to the downlink shared channel (DL-SCH) or multicast channel (MCH).

  Non-Patent Document 1 describes the current decisions regarding the E-MBMS service in 3GPP. The definition of words related to E-MBMS (Chapter 15 of Non-Patent Document 1) will be described with reference to FIG. FIG. 7 is an explanatory diagram illustrating the relationship between the MBSFN synchronization area and the MBSFN area. In FIG. 7, an MBSFN synchronization area 701 (Multimedia Broadcast multicast service Single Frequency Network Synchronization Area) is an area of a network in which all base stations can synchronize and execute MBSFN (Multimedia Broadcast Multicast Service Single Frequency Network) transmission. That is. The MBSFN synchronization area includes one or more MBSFN areas (MBSFN Areas) 702. In one frequency layer, a base station can belong to only one MBSFN synchronization area. The MBSFN area 702 (MBSFN Area) includes a group of base stations (cells) included in the MBSFN synchronization area of the network. A base station (cell) in the MBSFN synchronization area may constitute a plurality of MBSFN areas.

  The logical structure (Logical Architecture) of E-MBMS will be described with reference to FIG. 8 (Chapter 15 of Non-Patent Document 1). FIG. 8 is an explanatory diagram illustrating a logical structure (Logical Architecture) of E-MBMS. In FIG. 8, a multi-cell / multicast coordination entity (MCE) is a logical entity. The MCE 801 allocates radio resources to all base stations in the MBSFN area in order to perform multi-cell MBMS transmission. In addition to time and / or frequency radio resource allocation, the MCE 801 makes decisions about radio structure details (eg, modulation scheme, code, etc.). The E-MBMS gateway 802 (MBMS GW) is a logical entity. The E-MBMS gateway 802 is located between the eBMSC and the base station, and the main function is to transmit / broadcast the MBMS service to each base station using the SYNC protocol. The M3 interface is a control plane interface between the MCE 801 and the E-MBMS gateway 802. The M2 interface is a control interface between the MCE 801 and the eNB 102. The M1 interface is a user data interface (User Plane Interface) between the E-MBMS gateway 802 and the eNB 102.

  The architecture (Architecture) of E-MBMS (Chapter 15 of Non-Patent Document 1) will be described. FIG. 9 is an explanatory diagram illustrating the architecture (Architecture) of E-MBMS. Two E-MBMS architectures are considered as shown in FIGS. 9A and 9B. The MBMS cell will be described (Non-Patent Document 115). The LTE system includes an MBMS dedicated cell (base station) (MBMS-dedicated cell) and an MBMS / Unicast-mixed cell (MBMS / Unicast-mixed cell) capable of executing both MBMS and unicast services. The MBMS dedicated cell will be described. The characteristics when the MBMS dedicated cell belongs to the frequency layer dedicated to MBMS transmission will be described below. Hereinafter, the MBMS transmission dedicated frequency layer is also referred to as the MBMS dedicated cell frequency layer. Both the downlink logical channels MTCH (multicast traffic channel) and MCCH (multicast control channel) are mapped to the downlink transport channel MCH (multicast channel) or DL-SCH (downlink shared channel) in one-to-many transmission. The There is no uplink in the MBMS dedicated cell. Also, unicast data cannot be transmitted / received within the MBMS dedicated cell. Also, no counting mechanism is set. It is undecided whether to provide paging signals (Paging messages) in the frequency layer dedicated to MBMS transmission.

  Next, the MBMS / unicast mixed cell will be described. The characteristics when the MBMS / unicast mixed cell does not belong to the frequency layer dedicated to MBMS transmission will be described below. A frequency layer other than the MBMS transmission-dedicated frequency layer is referred to as a “unicast / mixed frequency layer”. Both MTCH and MCCH, which are downlink logical channels, are mapped to MCH or DL-SCH, which is a downlink logical channel, in one-to-many transmission. In an MBMS / unicast mixed cell, both unicast data and MBMS data can be transmitted.

  MBMS transmission (Chapter 15 of Non-Patent Document 1) will be described. MBMS transmission in the LTE system supports single-cell transmission (SC transmission) and multi-cell transmission (MC transmission). Single cell transmission does not support SFN (Single Frequency Network) operation. Multi-cell transmission supports SFN operation. MBMS transmission is synchronized in an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area. SFN combining (Combining) of MBMS services (MTCH and MCCH) in multi-cell transmission is supported. MTCH and MCCH are mapped to MCH by one-to-many transmission. Scheduling is performed by the MCE.

  A multicast control channel (MCCH) structure will be described (Chapter 15 of Non-Patent Document). A broadcast control channel (BCCH) that is a downlink logical channel indicates scheduling of one or two primary multicast control channels (Primary MCCH: P-MCCH). The P-MCCH for single cell transmission is mapped to DL-SCH (downlink shared channel). Further, the P-MCCH for multi-cell transmission is mapped to MCH (multicast channel). When the secondary multicast control channel (Secondary MCCH: S-MCCH) is mapped on the MCH, the primary multicast control channel (P-MCCH) can be used to indicate the address of the secondary multicast control channel (S-MCCH). The broadcast control channel (BCCH) indicates a resource of the primary multicast control channel (P-MCCH), but does not indicate an available service.

  Non-Patent Document 1 (Chapter 10) describes the current decisions regarding paging in 3GPP. The paging group uses the L1 / L2 signaling channel (PDCCH). A clear identifier (UE-ID) of the mobile terminal can be confirmed on the paging channel (PCH).

3GPP TS36.300 V8.2.0

3GPP R1-072963

3GPP R2-0775570

3GPP R1-080073

3GPP R2-080463

  The first problem to be solved by the invention will be described. Non-Patent Document 1 discloses the presence of a frequency layer dedicated to MBMS transmission and the presence and characteristics of an MBMS dedicated cell. On the other hand, there is no disclosure of a method for moving a mobile terminal to a frequency layer dedicated to MBMS transmission or a method for selecting a desired service. It is an object of the present invention to disclose a method for selecting a desired service in a frequency layer dedicated to MBMS transmission and a mobile communication system therefor.

  The second problem to be solved by the invention will be described. From Chapter 15 of Non-Patent Document 1, it can be understood that the MBSFN area is composed of cell groups in the MBSFN synchronization area adjusted to realize MBSFN transmission. Therefore, if the MBSFN areas are different, MBSFN transmission may not be realized. Therefore, the following problems occur. In the unicast / mixed frequency layer, when a mobile terminal receiving an MBMS service transmitted in multicell from an MBMS dedicated cell or a unicast / MBMS mixed cell performs handover, the following problems occur. The unicast / MBMS mixed cell of the handover source (current serving cell) and the unicast / MBMS mixed cell of the handover destination (base station (new serving cell) to be newly selected as the serving cell) do not belong to the same MBSFN area. Think about the case. If the MBSFN area is different, the receivable MBMS service contents may be different. Therefore, there is a problem that MBMS service reception is interrupted due to handover.

  The mobile communication system according to the present invention uses an OFDM (Orthogonal Frequency Division Multiplexing) scheme as a downlink access scheme, and uses an SC-FDMA (Single Career Frequency Division Multiple Access) scheme as an uplink access scheme. In a mobile communication system capable of transmitting broadcast type data providing MBMS (Multimedia Broadcast Multicast Service), which is a one-to-many broadcast communication service to a terminal, and transmitting one-to-one type individual communication data to a mobile terminal, A unicast cell in which a mobile terminal can transmit and receive dedicated communication data, a MBMS dedicated cell in which the mobile terminal can receive broadcast-type data but cannot transmit and receive dedicated communication data, both a unicast cell and an MBMS dedicated cell Three types of unicast / MBMS mixed cells that can provide services The MBMS dedicated cell and the unicast / MBMS mixed cell constitute an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) synchronization area in which a plurality of base stations synchronize and transmit the broadcast type data. Among the cast cell, the MBMS dedicated cell, and the unicast / MBMS mixed cell, the serving cell that performs the scheduling process for allocating radio resources to the mobile terminal is an MBMS service available in the MBMS dedicated cell or the unicast / MBMS mixed cell The frequency is notified.

  An OFDM (Orthogonal Frequency Division Multiplexing) method is used as a downlink access method, and an SC-FDMA (Single Career Frequency Division Multiple Access) method is used as an uplink access method. In a mobile communication system capable of transmitting broadcast type data providing MBMS (Multimedia Broadcast Multicast Service) and transmitting one-to-one type individual communication data to the mobile terminal, the mobile terminal can transmit and receive the individual communication data. A unicast cell that is a cell, an MBMS dedicated cell that allows mobile terminals to receive broadcast-type data but cannot transmit / receive individual communication data, and a unicast / MBMS mixed cell that can provide both unicast and MBMS dedicated cell services 3 types of cells, MBMS dedicated cell and UNI The broadcast / MBMS mixed cell constitutes an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) synchronization area in which a plurality of base stations synchronize and transmit the broadcast type data, and includes a unicast cell, an MBMS dedicated cell, and a unicast cell. Among the cast / MBMS mixed cells, the serving cell that performs scheduling processing for allocating radio resources to the mobile terminal notifies the frequency of the MBMS service that can be used in the MBMS dedicated cell or the unicast / MBMS mixed cell. Can move to the frequency layer of the MBMS dedicated cell or a method until a desired service is selected.

  The mobile communication system according to the present invention uses an OFDM (Orthogonal Frequency Division Multiplexing) scheme as a downlink access scheme, and uses an SC-FDMA (Single Career Frequency Division Multiple Access) scheme as an uplink access scheme. In a mobile communication system capable of transmitting broadcast type data providing MBMS (Multimedia Broadcast Multicast Service), which is a one-to-many broadcast communication service to a terminal, and transmitting one-to-one type individual communication data to a mobile terminal, A unicast cell in which a mobile terminal can transmit and receive dedicated communication data, a MBMS dedicated cell in which the mobile terminal can receive broadcast-type data but cannot transmit and receive dedicated communication data, both a unicast cell and an MBMS dedicated cell Three types of unicast / MBMS mixed cells that can provide services The MBMS dedicated cell and the unicast / MBMS mixed cell constitute an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area for transmitting broadcast-type data at one frequency, and one or more MBSFN areas include a plurality of MBSFN areas. Are further configured with an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) synchronization area in which broadcast base data is transmitted in synchronization with each other, and among unicast cells, MBMS dedicated cells, and unicast / MBMS mixed cells, A serving cell that performs a scheduling process for allocating radio resources to a mobile terminal notifies the mobile terminal of the contents of an MBMS service that can be used in an MBSFN area adjacent to the cell in which the mobile terminal is located.

  The mobile communication system according to the present invention uses an OFDM (Orthogonal Frequency Division Multiplexing) scheme as a downlink access scheme, and uses an SC-FDMA (Single Career Frequency Division Multiple Access) scheme as an uplink access scheme. In a mobile communication system capable of transmitting broadcast type data providing MBMS (Multimedia Broadcast Multicast Service), which is a one-to-many broadcast communication service to a terminal, and transmitting one-to-one type individual communication data to a mobile terminal, A unicast cell in which a mobile terminal can transmit and receive dedicated communication data, a MBMS dedicated cell in which the mobile terminal can receive broadcast-type data but cannot transmit and receive dedicated communication data, both a unicast cell and an MBMS dedicated cell Three types of unicast / MBMS mixed cells that can provide services The MBMS dedicated cell and the unicast / MBMS mixed cell constitute an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area for transmitting broadcast-type data at one frequency, and one or more MBSFN areas include a plurality of MBSFN areas. Are further configured with an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) synchronization area in which broadcast base data is transmitted in synchronization with each other, and among unicast cells, MBMS dedicated cells, and unicast / MBMS mixed cells, The serving cell that performs scheduling processing for allocating radio resources to the mobile terminal notifies the mobile terminal of the contents of the MBMS service that can be used in the MBSFN area adjacent to the cell where the mobile terminal is located. The mobile terminal The problem of interruption of MBMS service reception by the server can be prevented.

Embodiment 1 FIG.
FIG. 10 is a block diagram showing the overall configuration of the mobile communication system according to the present invention. In FIG. 10, the mobile terminal 101 transmits and receives control data (C-plane) and user data (U-plane) to and from the base station 102. The base station 102 is a unicast cell 102-1 that handles only unicast transmission / reception, a mixed cell 102-2 that handles transmission / reception of unicast and MBMS services (MTCH and MCCH), and an MBMS dedicated cell 101- that handles only transmission / reception of MBMS services. It is classified into 3. The unicast cell 102-1 that handles unicast transmission / reception and the MBMS / unicast mixed cell (mixed cell, mixed cell) 102-2 are connected by the MME 103 and the interface S1_MME. Furthermore, the unicast cell 102-1 and the mixed cell 102-2 that handle unicast transmission / reception are connected to the S-GW 104 via an interface S1_U for transmission / reception of unicast user data. The MME 103 is connected to a PDNGW (Packet Data Network Gateway) 902 through an interface S11. The MCE 801 allocates radio resources to all base stations 102 in the MBSFN area in order to perform multi-cell (MC) transmission. For example, there is an MBSFN area # 1 composed of one or a plurality of MBMS / unicast mixed cells 102-2 and a MBSFN area # 2 composed of one or a plurality of MBMS dedicated cells 101-3. Think. The MBMS / unicast mixed cell 102-2 is connected to the MCE 801-1 that allocates radio resources for all base stations in the MBSFN area # 1 through the interface M2. The MBMS dedicated cell 102-3 is connected by an interface M2 to the MCE 801-2 that allocates radio resources for all base stations in the MBSFN area # 2.

  The MBMS GW 802 can be classified into MBMS CP 802-1 that handles control data and MBMS UP 802-2 that handles user data. The MBMS / unicast mixed cell 102-2 and the MBMS dedicated cell 102-3 are connected to the MBMS CP 802-1 at the interface M1 for transmission / reception of MBMS-related control data. The MBMS / unicast mixed cell 102-2 and the MBMS dedicated cell 102-3 are connected to the MBMS UP 802-2 at the interface M1_U for transmission / reception of MBMS-related user data. The MCE 801 is connected to the MBMS CP 802-1 at the interface M3 for transmission / reception of MBMS-related control data. The MBMS UP 802-2 is connected to the eBMSC 901 through the interface SGimb. The MBMS GW 802 is connected to the eBMSC 901 through the interface SGmb. The eBMSC 901 is connected to a content provider. The eBMSC 901 is connected to the PDN GW 902 through an interface SGi. The MCE 801 is connected to the MME 103 via an MME-MCE interface (IF) which is a new interface.

  FIG. 11 is a block diagram showing a configuration of the mobile terminal 101 used in the present invention. In FIG. 11, the transmission processing of the mobile terminal 101 is executed as follows. First, control data from the protocol processing unit 1101 and user data from the application unit 1102 are stored in the transmission data buffer unit 1103. Data stored in the transmission data buffer unit 1103 is transferred to the encoder unit 1104 and subjected to encoding processing such as error correction. There may be data that is directly output from the transmission data buffer unit 1103 to the modulation unit 1105 without being encoded. The data encoded by the encoder unit 1104 is subjected to modulation processing by the modulation unit 1105. The modulated data is converted into a baseband signal, and then output to the frequency conversion unit 1106 where it is converted into a radio transmission frequency. Thereafter, a transmission signal is transmitted from the antenna 1107 to the base station 102. In addition, the reception process of the mobile terminal 101 is executed as follows. A radio signal from the base station 102 is received by the antenna 1107. The received signal is converted from a radio reception frequency to a baseband signal by the frequency converter 1106, and demodulated by the demodulator 1108. The demodulated data is transferred to the decoder unit 1109 and subjected to decoding processing such as error correction. Of the decoded data, control data is passed to the protocol processing unit 1101, and user data is passed to the application unit 1102. A series of processing of the mobile terminal is controlled by the control unit 1110. Therefore, although the control part 1110 is abbreviate | omitted in drawing, it is connected with each part (1101-1109).

  FIG. 12 is a block diagram showing the configuration of the base station 102. The transmission process of the base station 102 is executed as follows. The EPC communication unit 1201 transmits and receives data between the base station 102 and the EPC (MME 103 and S-GW 104). The other base station communication unit 1202 transmits / receives data to / from other base stations. The EPC communication unit 1201 and the other base station communication unit 1202 exchange information with the protocol processing unit 1203, respectively. Control data from the protocol processing unit 1203 and user data and control data from the EPC communication unit 1201 and the other base station communication unit 1202 are stored in the transmission data buffer unit 1204. Data stored in the transmission data buffer unit 1204 is transferred to the encoder unit 1205 and subjected to encoding processing such as error correction. There may exist data that is directly output from the transmission data buffer unit 1204 to the modulation unit 1206 without being encoded. The encoded data is subjected to modulation processing by the modulation unit 1206. The modulated data is converted into a baseband signal, and then output to the frequency conversion unit 1207 to be converted into a radio transmission frequency. Thereafter, a transmission signal is transmitted from the antenna 1208 to one or a plurality of mobile terminals 101. Further, the reception process of the base station 102 is executed as follows. Radio signals from one or a plurality of mobile terminals 101 are received by the antenna 1208. The received signal is converted from a radio reception frequency to a baseband signal by the frequency converter 1207, and demodulated by the demodulator 1209. The demodulated data is transferred to the decoder unit 1210 and subjected to decoding processing such as error correction. Of the decoded data, the control data is passed to the protocol processing unit 1203 or the EPC communication unit 1201 and the other base station communication unit 1202, and the user data is passed to the EPC communication unit 1201 and the other base station communication unit 1202. A series of processing of the base station 102 is controlled by the control unit 1211. Therefore, the control unit 1211 is connected to each unit (1201 to 1210), which is omitted in the drawing.

  FIG. 13 is a block diagram showing a configuration of MME (Mobility Management Entity). A PDN GW communication unit 1301 transmits and receives data between the MME 103 and the PDN GW 902. The base station communication unit 1302 transmits and receives data between the MME 103 and the base station 102 using the S1_MME interface. When the data received from the PDN GW 902 is user data, the user data is passed from the PDN GW communication unit 1301 to the base station communication unit 1302 via the user plane processing unit 1303 and transmitted to one or a plurality of base stations 102. The When the data received from the base station 102 is user data, the user data is transferred from the base station communication unit 1302 to the PDN GW communication unit 1301 via the user plane processing unit 1303 and transmitted to the PDN GW 902.

  The MCE communication unit 1304 transmits and receives data between the MME 103 and the MCE 801 using the MME-MCE IF. When the data received from the PDN GW 902 is control data, the control data is transferred from the PDN GW communication unit 1301 to the control plane control unit 1305. When the data received from the base station 102 is control data, the control data is transferred from the base station communication unit 1302 to the control plane control unit 1305. The control data received from the MCE 801 is transferred from the MCE communication unit 1304 to the control plane control unit 1305. The result of the processing in the control plane control unit 1305 is transmitted to the PDN GW 902 via the PDN GW communication unit 1301, transmitted to one or a plurality of base stations 102 via the S1_MME interface via the base station communication unit 1302, and MCE. The data is transmitted to one or a plurality of MCEs 801 by the MME-MCE IF via the communication unit 1304. The control plane control unit 1305 includes a NAS security unit 1305-1, an SAE bearer control unit 1305-2, an idle state mobility management unit 1305-3, and the like, and performs overall processing for the control plane. The NAS security unit 1305-1 performs security of a NAS (Non-Access Stratum) message. The SAE bearer control unit 1305-2 manages the SAE (System Architecture Evolution) bearer. The idle state mobility management unit 1305-3 manages mobility in a standby state (LTE-IDLE state, also simply referred to as idle), generates and controls a paging signal in the standby state, and one or a plurality of mobile terminals 101 being served thereby Add, delete, update, search, tracking area list (TA List) management, etc. The MME initiates a paging protocol by sending a paging message to a cell belonging to a tracking area (tracking area: TA) where the UE is registered. A series of processing of the MME 103 is controlled by the control unit 1306. Therefore, the control unit 1306 is connected to each unit (1301 to 1305), which is omitted in the drawing.

  FIG. 14 is a block diagram showing the configuration of MCE (Multi-cell / multicast Coordination Entity). The MBMS GW communication unit 1401 transmits and receives control data between the MCE 801 and the MBMS GW 802 using the M3 interface. A base station communication unit 1402 transmits and receives control data between the MCE 801 and the base station 102 using the M2 interface. The MME communication unit 1403 transmits and receives control data between the MCE 801 and the MME 103 by the MME-MCE IF. The MC transmission scheduler unit 1404 includes control data from the MBMS GW 802 passed via the MBMS GW communication unit 1401 and base stations in the MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area passed via the base station communication unit 1402 The control data from 102 and the control data from the MME 103 passed via the MME communication unit 1403 are used to schedule multi-cell transmission of one or more MBSFN areas managed by itself. Examples of scheduling include base station radio resources (time, frequency, etc.), radio structure (modulation scheme, code, etc.), and the like. The scheduling result of multi-cell transmission is passed to the base station communication unit 1402 and transmitted to one or a plurality of base stations 102 in the MBSFN area. A series of processing of the MCE 801 is controlled by the control unit 1405. Therefore, the control unit 1405 is connected to each unit (1401 to 1404), which is omitted in the drawing.

  FIG. 15 is a block diagram showing the configuration of the MBMS gateway. In FIG. 15, an eBMSC communication unit 1501 of the MBMS GW 802 transmits and receives data (user data and control data) between the MBMS GW 802 and the eBMSC 901. The MCE communication unit 1502 transmits and receives control data using the M3 interface between the MBMS GW 802 and the MCE 801. Control data received from the eBMSC 901 is transmitted to the MBMS CP unit 1503 via the eBMSC communication unit 1501, and after being processed by the MBMS CP unit 1503, is transmitted to one or a plurality of MCEs 801 via the MCE communication unit 1502. The control data received from the MCE 801 is transferred to the MBMS CP unit 1503 via the MCE communication unit 1502, and after being processed by the MBMS CP unit 1503, transmitted to the eBMSC 901 and / or the MCE 801 via the eBMSC communication unit 1501. The base station communication unit 1504 transmits user data (also referred to as traffic data) using the M1_U interface to the MBMS GW 802 and one or a plurality of base stations. User data received from the eBMSC 901 is transmitted to the MBMS UP unit 1505 via the eBMSC communication unit 1501, and after being processed by the MBMS UP unit 1505, transmitted to one or a plurality of base stations 102 via the base station communication unit 1504. The The MBMS CP unit 1503 and the MBMS UP unit 1505 are connected. A series of processing of the MBMS GW 802 is controlled by the control unit 1506. Therefore, the control unit 1506 is connected to each unit (1501 to 1506) although not shown in the drawing.

  Next, FIG. 16 shows an example of the flow of processing as a mobile communication system according to the present invention. FIG. 16 is a flowchart showing an outline of processing from the start of use of MBMS to the end of use by the mobile terminal in the LTE communication system. In step ST1601 of FIG. 16, the mobile terminal performs cell selection of the serving cell in the MBMS / unicast mixed cell. Hereinafter, the processing of step 1601 is referred to as “unicast side cell selection”. In step ST1601-1, the network side performs a “notice about receivable MBMS” process for the mobile terminal. Specifically, the mobile terminal is notified from the network side that there is an MBMS service that is currently available and information about the frequency (a list of frequencies). Since the mobile terminal can know that there is an available MBMS service and its frequency by the processing of ST1601-1, it is not necessary to search for a receivable frequency in a brute force manner. This has the effect of shortening the control delay until the mobile terminal receives a service from a frequency other than the current frequency.

  In step ST1602, the mobile terminal performs an MBMS transmission dedicated cell search process based on the information notified from the network side in step ST1601. Specific examples of the search process include timing synchronization (synchronization by radio frame timing), system bandwidth, number of transmission antennas, MBSFN area identifier (ID) (also referred to as MBSFN area number), MCCH (multicast control channel). System information such as related information is acquired. Hereinafter, the processing in step 1602 is referred to as “MBMS search”. In Step ST1603, the mobile terminal receives information for receiving the MBMS service (MCCH and MTCH) in the MBMS transmission dedicated cell from the network side. Hereinafter, the processing in step 1603 is referred to as “MBMS Area information acquisition”. In step ST1604, the user (mobile terminal) selects the MBMS service desired by the user using the information for receiving the MBMS service received from the network side in step ST1603. Hereinafter, the processing in step 1604 is referred to as “MBMS service selection”.

  As described above as the “fourth problem”, in the LTE communication system, a simple system is provided by providing only a downlink for transmitting broadcast data provided by the MBMS service to a mobile terminal and omitting the uplink. It has been studied to provide a cell dedicated to MBMS transmission to realize the configuration. Steps 1601-1 to ST1604 in the above description disclosed a method until the MBMS service by the MBMS transmission dedicated cell is selected. By the series of processes described above, the mobile terminal can receive a desired MBMS service in the MBMS transmission dedicated cell.

  In step ST1605, the mobile terminal makes preparations for intermittently receiving MBMS data from the MBMS transmission dedicated cell using the information for receiving the MBMS service received from the network side in step ST1603. Hereinafter, the processing in step 1605 is referred to as “preparation for intermittent reception during MBMS reception”. In Step ST1606, the mobile terminal performs “MBMS side reception status notification” processing for notifying the network side of the MBMS reception status in the MBMS transmission dedicated cell. Since the MBMS transmission dedicated cell is not provided with an uplink, a mobile terminal receiving MBMS data in the MBMS dedicated cell cannot perform location registration on the network side. In this case, since the network side cannot identify the cell in which the mobile terminal exists, it is difficult to send a paging signal when an incoming call directed to the mobile terminal occurs. By this step ST1606, the network side can know that the mobile terminal is receiving the MBMS service in the MBMS transmission dedicated cell and can track the mobile terminal. When an incoming call occurs for a mobile terminal that is using the service, the paging information is transferred to the MBMS transmission dedicated cell via the MME 103 and the MCE 801-1 to notify the mobile terminal that is using the MBMS service that the individual incoming call has occurred. be able to. Therefore, it is possible to solve the first problem related to paging for a mobile terminal that is using an MBMS service in an MBMS transmission dedicated cell.

  In Step ST1607, the mobile terminal performs measurement (measurement) processing including electrolytic strength measurement and cell selection of the unicast cell (FIG. 10 102-1) or / and the MBMS / unicast mixed cell (FIG. 10 102-2). . This process is referred to as “Unicast side measurement”. In step ST1607, even if the mobile terminal is receiving MBMS data in the MBMS transmission dedicated cell, the mobile terminal can measure the unicast cell (FIG. 10 102-1) or the MBMS / unicast mixed cell (FIG. 10 102-2). Processing such as selection and location registration can be performed. By performing this measurement process, the mobile terminal using the MBMS service in the MBMS transmission dedicated cell selects and updates the unicast cell or MBMS / unicast mixed cell to be transmitted, so that the uplink It is possible to secure mobility in an MBMS dedicated cell that does not exist. For this reason, a mobile terminal using an MBMS service in an MBMS dedicated cell can reliably perform a process related to mobility such as location registration via, for example, a unicast cell or an MBMS / unicast mixed cell. The network side can send a paging signal to the mobile terminal using the MBMS service in the MBMS transmission dedicated cell. Also, the mobile terminal establishes downlink synchronization through measurement with a unicast / mixed frequency layer according to a measurement cycle. Thereby, even in the case where the mobile terminal transmits a response to the paging signal via the MBMS / unicast mixed cell in the MBMS transmission dedicated cell in which no uplink exists, which is the second problem of the present invention, the control is performed. The delay can be reduced.

  In Step ST1608, the mobile terminal performs intermittent reception to receive a paging signal. More specifically, when an individual incoming call addressed to the mobile terminal occurs, the network side receives the MBMS service from the MBMS transmission dedicated frequency layer configured by the MBMS transmission dedicated cell. The paging signal is transmitted through the downlink of the MBMS transmission dedicated cell. In steps ST1605 to ST1608, it becomes possible to notify paging to the mobile terminal that is using the MBMS service in the MBMS transmission dedicated cell, which is the first problem of the present invention.

  The mobile terminal that has not received the paging signal in the “intermittent reception at the time of MBMS reception” in step ST1608 receives the MBMS traffic data transmitted from the MBMS transmission dedicated cell via the multicast traffic channel (MTCH) in step ST1609. . Hereinafter, the process of step ST1608 is referred to as “MTCH reception”. The mobile terminal performing “MTCH reception” moves to step ST1607 at the timing of “Unicast side measurement”. Alternatively, the mobile terminal performing “MTCH reception” moves to step ST1602, or step ST1604, or step ST1612 when the reception sensitivity deteriorates. On the other hand, in step ST1610, the mobile terminal that has received the paging signal in the “intermittent reception during MBMS reception” in step ST1608 determines the frequency in the unicast / mixed frequency layer from the frequency in the MBMS transmission dedicated frequency layer (f (MBMS)). The frequency is changed to (f (Unicast)), and control data is transmitted and received. Hereinafter, the process of step ST1610 is referred to as “Unicast side intermittent reception”. As a result, the mobile terminal can transmit uplink data such as a response to the paging signal to the network side via the unicast cell or the mixed cell. In Step ST1611, Step ST1612, the mobile terminal notifies the network side that the reception of MBMS data in the MBMS transmission dedicated frequency layer (MBMS transmission dedicated cell) is terminated. Through step ST1611, the network side can know that the mobile terminal has finished using the MBMS service. A paging signal may be transmitted via a unicast cell or a mixed cell to a mobile terminal that has finished using the MBMS service by the MBMS transmission dedicated frequency layer, so that the network side performs paging via the downlink of the MBMS transmission cell. The process of notifying the signal can be stopped, and the radio resources of the MBMS transmission dedicated cell are effectively used.

Embodiment 2. FIG.
In the present embodiment, a detailed specific example of the processing flow of the mobile communication system described in the first embodiment will be described with reference to FIG. FIG. 17 is a flowchart for explaining cell selection on the unicast side. In step ST1701, a unicast cell, an MBMS / unicast mixed cell (also simply referred to as a mixed cell) is a first synchronization channel (Primary Synchronization Channel: P-SCH) and a second synchronization channel (Secondary Synchronization Channel: S-SCH) and a reference signal (also referred to as reference symbol: Reference Symbol: RS) are broadcast to the mobile terminals being served thereby. In Step ST1702, the mobile terminal receives P-SCH, S-SCH, and RS from the base station (unicast cell or / and mixed cell). In Step ST1703, the mobile terminal performs an initial cell search operation using the received P-SCH, S-SCH, and RS. Details of the cell search operation currently being discussed in 3GPP will be described. As a first step, the mobile terminal performs blind detection of a first synchronization channel (P-SCH) in which three types of defined sequences exist as a mobile communication system. The P-SCH is mapped to the center 72 subcarriers of the system bandwidth as a frequency and first (# 0) and sixth (# 5) for each radio frame in terms of time. Therefore, the mobile terminal that has detected the P-SCH blindly can detect the 5 ms timing and know the cell group (1 to 3 groups corresponding to the previous P-SCH 3-week sequence). As a second stage, the mobile terminal performs blind detection on the second synchronization channel (S-SCH). The mapping position of S-SCH is the same as that of P-SCH. A mobile terminal that blindly detects S-SCH can detect 10 ms timing detection (frame synchronization) and a cell identifier (Cell ID).

  In step ST1704, the mobile terminal performs cell selection. Cell selection is a process of selecting one base station that satisfies a condition that can be a serving base station (cell) by using a measurement result obtained by the mobile terminal measuring downlink reception sensitivities from a plurality of base stations. Specific examples of conditions that can serve as a serving base station include those having the best reception sensitivity among downlink reception sensitivities from a plurality of base stations, or base stations that have exceeded the minimum threshold of reception sensitivity of the serving base station. It is done. Values actually measured by the mobile terminal include reference symbol received power (RSRP), E-UTRA carrier received signal strength indicator (RSSI), and the like. A serving base station is a base station that is responsible for scheduling of the mobile terminal. Even a base station other than the serving base station of the mobile terminal can be a serving base station for other mobile terminals. That is, all base stations of a unicast cell or a mixed MBMS / unicast cell have a scheduling function and can serve as a serving base station for any mobile terminal. In Step ST1705, the unicast cell and the MBMS / unicast mixed cell transmit broadcast information using a broadcast control channel (BCCH) that is one of logical channels. Specific examples of the broadcast information include a measurement cycle, an intermittent reception cycle, tracking area information (TA information), and the like. The measurement cycle is a cycle notified from the network side to a mobile terminal being served by the network, and the mobile terminal measures the electric field strength and the like according to this cycle. The intermittent reception period is a period for periodically monitoring the paging signal so that the mobile terminal receives the paging signal in the idle state. TA information is information related to a “Tracking Area”. The MME starts a paging process by sending a paging message to each eNB belonging to the tracking area in which the UE is registered (TS36.300 19.2.2.1). In Step ST1706, the mobile terminal receives a measurement period, an intermittent reception period, TA information, and the like from the serving base station via the BCCH.

  In Step ST1707, the unicast cell and the MBMS / unicast mixed cell use BCCH to the mobile terminal, the frequency of the MBMS service that can be used, that is, the frequency of the receivable MBSFN synchronization area (MBSFN Synchronization Area) (f (Referred to as “MBMS”). In the W-CDMA communication system, there is a parameter called preferred frequency information (Preferred frequency information: PL information). The PL information is mapped to a multicast control channel (MCCH), which is a logical channel, on the network side, and is broadcast to mobile terminals being served thereby. However, in the LTE system, it is planned to provide a unicast cell that does not provide an MBMS service. In such a unicast cell, a method of broadcasting f (MBMS) using MCCH, which is an MBMS channel, is adopted. There is a problem that you can not.

  In Step ST1708, the mobile terminal receives f (MBMS) transmitted from the serving base station using BCCH. When the mobile terminal receives f (MBMS), it is not necessary for the mobile terminal to comprehensively search for frequencies that may have a service other than the current frequency. This has the effect of shortening the control delay until the mobile terminal receives a service from a frequency other than the current frequency. Step ST1707 and step ST1708 are detailed specific examples of the “notification regarding receivable MBMS” described in the first embodiment. Here, if f (MBMS) is determined as static (Static) or quasi-static (Semi-Static) as the mobile communication system, the mobile terminal does not broadcast f (MBMS) from the base station. It is possible to obtain an effect that the control delay until the service is received from a frequency other than the current frequency is shortened. Furthermore, since it is not necessary to report f (MBMS), the effect of effective use of radio resources can also be obtained.

  On the other hand, in step ST1707 and step ST1708, in addition to f (MBMS), the system bandwidth and the number of transmission antennas in each f (MBMS) can be reported from the base station using BCCH. As a result, in step ST1708, the mobile terminal receives f (MBMS) transmitted from the serving base station using BCCH, thereby enabling system information (system bandwidth, transmission antenna) in the frequency layer dedicated to MBMS transmission. Therefore, it is possible to obtain an effect that the control delay can be shortened. Because it is necessary to receive BCCH from the serving base station in the unicast / frequency layer in order to receive f (MBMS), even if the information (system bandwidth, number of transmission antennas) increases, the processing of the mobile terminal The time should not be so long. On the other hand, in order to acquire the system information of the MBMS transmission-dedicated frequency layer after moving to the MBMS transmission-dedicated frequency layer, it is necessary to receive the BCCH in the MBMS transmission-dedicated frequency layer. Since decoding processing is necessary, a control delay occurs.

  In Step ST1709, the mobile terminal includes the TA information of the serving base station received in Step ST1706 in the current tracking area list (TA List) stored in the protocol processing unit 1101 or the control unit 1110. Check. If included, the process proceeds to step ST1720 in FIG. If not included, step ST1710 is executed. In Step ST1710, the mobile terminal notifies the serving base station of an “Attach Request”. As information included in the “attach request”, an identifier of a mobile terminal (IMSI (International Mobile Subscriber Identity) or S-TMSI (S-Temporary Mobile Subscriber Identity, S-TMSI) is simply referred to as Temporary Mobile Subscriber Identity (TMSI). The serving base station that has received the “attach request” in step ST1711 sends the “attach request” to the MME (Mobility Management Entity) or HSS in step ST1712. In step ST1713, the MME receives an “attach request.” The idle state mobility management unit 1305-3 of the MME manages the tracking area list of each mobile terminal. MME is managing the mobile terminal It is confirmed whether or not the serving base station of the mobile terminal is included in the tracking area list, and if it is included, the process proceeds to step ST1716 of Fig. 18. Otherwise, step ST1715 is executed. Then, the idle state mobility management unit 1305-3 of the MME performs a process of adding (or updating) the TA information of the serving base station of the mobile terminal to the tracking area list managed by the mobile terminal in Step ST1716. The MME notifies the serving base station of “Attach Accept.” Information included in the “Attach Accept” includes a tracking area list, an identifier (S-TMSI, etc.) given to the mobile terminal, and the like. “Attach Accept” at ST1717 Received serving base station, the "attach accept" in step ST1718 notifies to the mobile terminal. The mobile terminal, in step ST1719 receives the "attach accept".

  FIG. 18 is a flowchart showing the MBMS search process. Steps 1720 to 1725 in FIG. 18 are specific processing of “MBMS search” described in the first embodiment. In Step ST1720, the mobile terminal confirms whether or not the frequency of the MBSFN synchronization area that can be received in Step ST1708 (or the frequency of the frequency layer dedicated to MBMS transmission) has been received. That is, it is confirmed whether at least one f (MBMS) has been received. If it does not exist, the process ends. If present, step ST1721 is executed. In Step ST1721, the mobile terminal confirms whether or not the user intends to receive the MBMS service at f (MBMS). As a specific example of the confirmation, when the user has an intention to receive the MBMS service, an instruction is sent to the mobile terminal using the user interface, and the mobile terminal stores the user's intention in the protocol processing unit 1101. In step ST1721, the mobile terminal confirms whether or not it intends to receive the MBMS service stored in the protocol processing unit 1101. If there is no intention to receive the MBMS service, the process of step ST1721 is repeated. As a method of repeating, a method in which the mobile terminal performs the determination in step ST1721 at a constant period, or a method in which step ST1721 or step ST1720 is performed when there is a notification of change of intention to receive the MBMS service from the user through the user interface. and so on. If there is an intention to receive the MBMS service, the mobile terminal makes a transition to step ST1722. In Step ST1722, the mobile terminal changes the set frequency of the frequency conversion unit 1107 (synthesizer), and starts the MBMS search operation by changing the center frequency to f (MBMS). Changing the set frequency of the frequency conversion unit 1107 and changing the center frequency is referred to as re-tune. In Step ST1723, the MBMS dedicated cell is served by the first synchronization channel (Primary Synchronization Signal: P-SCH), the second synchronization channel (Secondary Synchronization Signal: S-SCH), the reference signal (RS (MBMS)), and the BCCH. Informs the mobile terminal. In Step ST1724, the mobile terminal receives P-SCH, S-SCH, RS (MBMS), and BCCH (broadcast control channel) from the MBMS dedicated cell.

  In step ST1725, the mobile terminal performs an MBMS search operation. A search operation in a frequency layer dedicated to MBMS transmission currently being discussed in 3GPP will be described. A sequence used exclusively in the frequency layer dedicated to MBMS transmission is added to the P-SCH. Additional dedicated sequences shall be defined statically. As a first step, the mobile terminal blind-detects the P-SCH with an additional dedicated sequence. The P-SCH is mapped to the center 72 subcarriers of the system bandwidth in terms of frequency, and to the first (# 0) and sixth (# 5) in terms of time for each radio frame. Therefore, the mobile terminal that has detected P-SCH blindly can detect the timing for 5 ms. In addition, P-SCH is transmitted in multicell. As a second stage, the mobile terminal performs blind detection on the S-SCH. The mapping position of S-SCH is the same as that of P-SCH. A mobile terminal that blindly detects S-SCH can detect 10 ms timing detection (frame synchronization) and the MBSFN area ID. S-SCH is transmitted in multicell. The BCCH is received using the scrambling code associated with the MBSFN area ID obtained in the second stage. The mobile terminal can obtain MCCH (multicast control channel) scheduling by decoding BCCH. This decoding process uses a scrambling code associated with the MBSFN area ID. BCCH is transmitted in multicell. In the present invention, it is assumed that the system bandwidth in f (MBMS) and the number of transmission antennas in f (MBMS) can be obtained by further decoding BCCH. Here, if the system bandwidth and the number of transmission antennas in f (MBMS) as a mobile communication system are determined to be static (Static) or quasi-static (Semi-Static), the base station determines the frequency in f (MBMS). There is no need to report the system bandwidth or / and the number of transmission antennas, and the effect of effective use of radio resources can be obtained. Further, since it is not necessary to decode and change the parameters (system bandwidth or / and the number of transmission antennas in f (MBMS)), it is possible to obtain the effects of reducing the power consumption of the mobile terminal and reducing the control delay.

  In the present invention, the MCCH scheduling is further considered. In the current 3GPP standard, an MBSFN synchronization area (Multimedia Broadcast multicast service Single Frequency Network Synchronization Area (MBMS)) can support one or more MBSFN areas (see FIG. 7). . On the other hand, it is not determined how to multiplex a plurality of MBSFN areas with f (MBMS), which is a single frequency (Single Frequency). Here, the “MBMS search” process will be described for each multiplexing method so that the present invention can be applied even when the multiplexing method of the MBSFN area is different.

  First, a case where the MBSFN area is time division multiplexed (TDM) will be described. FIG. 25 shows a conceptual diagram of the geographical location of the base station when a plurality of MBSFN areas exist. FIG. 25 is an explanatory diagram showing a plurality of MBSFN areas constituting the MBSFN synchronization area. In FIG. 25, there are three areas, MBSFN area 1, MBSFN area 2, and MBSFN area 3, in one MBSFN synchronization area. A specific example of scheduling of MCCH in BCCH obtained in step ST1725 is not discussed in detail in the current 3GPP. In the present invention, in order to disclose a method for selecting a desired service in a frequency layer dedicated to MBMS transmission, which is a fourth problem, and a mobile communication system therefor, a case where an MBSFN area is time-division multiplexed. A specific example of scheduling of MCCH in BCCH will be described. FIG. 26 is a conceptual diagram of mapping of the MBSFN synchronization area to the physical channel when the MBSFN area is time-division multiplexed.

  FIG. 26 shows a concept in which channels to a plurality of MBMFN areas are time-division multiplexed in one MBSFN synchronization area. Since each MBFSN area included in one MBSFN synchronization area is temporally synchronized, the P-SCH (first synchronization channel) is an MBMS dedicated cell in the MBSFN area 1, an MBMS dedicated cell in the MBSFN area 2, and an MBSFN. The MBMS dedicated cell in area 3 is also transmitted at the same timing. If an additional dedicated sequence is used, the P-SCH sequences in all MBSFN areas are the same. Therefore, the same information is transmitted at the same timing in the MBSFN synchronization area using P-SCH. Further, as described above, it is considered that the MBSFN area ID is transmitted by S-SCH (second synchronization channel). In that case, different information for each MBSFN area is transmitted on the S-SCH at the same timing in the MBSFN synchronization area. In this case, the same information is transmitted at the same timing from all the MBMS dedicated cells in each MBSFN area. The mobile communication system multiplies the scrambling code associated with the MBSFN area ID when performing transmission using BCCH. This scrambling code is notified to the mobile terminal using S-SCH (second synchronization channel). Therefore, different information for each MBSFN area is transmitted at the same timing in the MBSFN synchronization area using BCCH. On the other hand, the content of BCCH is the same in all MBMS dedicated base stations in the MBSFN area. The mobile terminal can obtain MCCH scheduling by decoding BCCH.

  In the current 3GPP communication system, as described in Non-Patent Document 2, allocation of MBSFN subframes in an MBMS / unicast mixed cell is being studied. Since there is no unicast subframe in the MBMS dedicated cell provided in the LTE communication system, all are MBSFN subframes. However, it is important to match the configurations of the MBMS / unicast mixed cell and the MBMS dedicated cell as much as possible. Therefore, after following the concept of “MBSFN frame cluster” (MBSFN frame cluster) disclosed in Non-Patent Document 2, a method for scheduling an MBMS dedicated cell is disclosed. Furthermore, MCCH scheduling in the MBSFN subframe is also described. In FIG. 26, a cycle in which the MBSFN frame cluster is repeated is referred to as an MBSFN frame cluster repetition period. In addition, the cycle in which the MCCH is transmitted is defined as an MCCH repetition period (MCCH Repetiton Period). A case where the MBSFN frame cluster is smaller than the MCCH repetition period will be described.

  In FIG. 26, it is assumed that MCCH scheduling is notified of the starting point value of the time to which the MCCH is mapped and the MCCH repetition period. More specifically, a radio frame is used to specify the MCCH repetition period. SFN (System Frame Number) is used to specify the starting point value. A non-radio frame may be used to specify the MCCH repetition period. Specific examples include subframes. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. A specific calculation formula for obtaining the starting point value is represented by: starting point value = (first SFN number to which MCCH is mapped) mod (MCCH repetition period). In FIG. 26, the MCCH starting point value 1 of the MBSFN area 1 is 1 mod 7 = 1 or 8 mod 7 = 1... “1”. The MCCH starting point value 2 of the MBSFN area 2 is 4 mod 7 = 4..., And the MCCH scheduling parameters of the MBSFN area 2 are the MCCH repetition period 2 “7” and the starting point value 2 “4”. The MCCH starting point value 3 in the MBSFN area 3 is 6 mod 7 = 6..., And the MCCH scheduling parameters in the MBSFN area 3 are the MCCH repetition period 3 “7” and the offset value 3 “6”. If the SFN at this time is mapped to the BCCH, it is broadcast for each radio frame, and is effective when receiving the MCCH from the MCCH starting point value.

  That is, data transmitted from the base station belonging to the MBSFN area 1 is as follows. The additional dedicated sequence P-SCH (first synchronization channel), S-SCH1 (second synchronization channel) mapped with MBSFN area ID1, etc., MCCH starting point value 1 “1”, MCCH repetition period 1 “ 7 ”and the like are mapped and BCCH1 to which scrambling code 1 is applied, MCCH1 and MTCH1 of MBSFN area 1 are transmitted. Since 3 from the base station belonging to the MBSFN area 1 are time-division multiplexed, MCCH 2 and 3 and MTCH 2 and 3 from the base stations belonging to the MBSFN area 2 and 3 are stopped during the transmission period of the MBSFN area 1 ( DTX: Discontinuous transmission. A scrambling code 1 may be applied to MCCH1 and MTCH2. By applying scrambling codes to MCCH1 and MTCH1, it is possible to obtain an effect that the processing for MBSFN area-specific data (BCCH, MCCH, MTCH) is unified. On the other hand, MCCH and MTCH are time division multiplexed (TDM), so that it is not necessary to apply a scrambling code specific to the MBSFN area. By not applying scrambling codes to MCCH1 and MTCH1, it is possible to reduce the load of encoding processing on the base station side and decoding processing on the mobile terminal side and to reduce delay until data reception.

  The data transmitted from the base stations belonging to the MBSFN area 2 as in the MBSFN area 1 are as follows. The additional dedicated sequences P-SCH (first synchronization channel), S-SCH2 (second synchronization channel) to which MBSFN area ID2 and the like are mapped, MCCH starting point value 2 “4”, MCCH repetition period 2 “ 7 "etc. are mapped, and the scrambling code 2 applied BCCH2 and the base station MCCH2 and MTCH2 belonging to the MBSFN area 2 are transmitted. During this period, MCCHs 1 and 3 and MTCHs 1 and 3 of the base stations belonging to the MBSFN areas 1 and 3 are suspended (DTX). The data transmitted from the base stations belonging to the MBSFN area 3 as in the MBSFN area 1 are as follows. The additional dedicated sequences P-SCH (first synchronization channel), S-SCH3 (second synchronization channel) to which MBSFN area ID3, etc. are mapped, MCCH starting point value 3 “6”, MCCH repetition period 3 “ 7 "and the like are mapped, and BCCH3 to which scrambling code 3 is applied, MCCH3 and MTCH3 in MBSFN area 3 are transmitted. During this period, MCCHs 1 and 2 and MTCHs 1 and 2 of the base stations belonging to MBSFN areas 1 and 2 are suspended (DTX). Although FIG. 26 shows an example in which MCCH and MTCH are time-divided in units of radio frames for convenience, even if the multiplexing method of MCCH and MTCH is different, the unit of time-division multiplexing is other than radio frame units. Even so, the present invention is applicable. Further, if the MCCH repetition period is determined to be static (Static) or quasi-static (Semi-Static) as a mobile communication system, there is no need to report the MCCH repetition period from the base station. Since the information to be notified is reduced, the effect of effective use of radio resources can be obtained.

  Next, a case where the MBSFN area is code division multiplexed (CDM) will be described. The conceptual diagram of the location of the base station when there are a plurality of MBSFN areas is the same as in the case of time division multiplexing (TDM). FIG. 27 is a conceptual diagram of mapping of MBSFN synchronization areas to physical channels when MBSFN areas are code division multiplexed. In FIG. 27, it is assumed that MBMS services (MCCH, MTCH) are continuously transmitted in each MBSFN area. In such a case, the MBSFN frame cluster may not be defined. A case where the MBSFN frame cluster is smaller than the MCCH repetition period will be described. Since specific examples of P-SCH (first synchronization channel), S-SCH (second synchronization channel), and BCCH are the same as those in the case of time division multiplexing (TDM), description thereof is omitted. In the present invention, it is considered that the MCCH scheduling is notified of the starting point value of the time to which the MCCH is mapped and the MCCH repetition period. More specifically, the number of radio frames is used to specify the MCCH repetition period. SFN (System Frame Number) is used to specify the starting point value. A non-radio frame may be used to specify the MCCH repetition period. Specific examples include subframes. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. A specific calculation formula for obtaining the starting point value is represented by: starting point value = (first SFN number to which MCCH is mapped) mod (MCCH repetition period). In FIG. 27, the MCCH starting point value of the MBSFN area 1 is 1 mod 3 = 1, 4 mod 3 = 1..., And the MCCH scheduling parameters of the MBSFN area 1 are the MCCH repetition period 1 “3” and the starting point value “3”. 1 ". The MCCH starting point value of the MBSFN area 2 is 1 mod 2 = 1, 3 mod 2 = 1..., And the MCCH scheduling parameters of the MBSFN area 1 are the MCCH repetition period 2 “2” and the starting point value “1”. The MCCH starting point value of the MBSFN area 3 is 2 mod 4 = 2..., And the MCCH scheduling parameters of the MBSFN area 3 are the MCCH repetition period 3 “4” and the starting point value “2”.

  That is, data transmitted from the base station belonging to the MBSFN area 1 is as follows. P-SCH (first synchronization channel) which is a frequency layer-dedicated sequence dedicated to MBMS transmission (the above-mentioned additional dedicated sequence), S-SCH1 (second synchronization channel) to which MBSFN area ID1 and the like are mapped, MCCH starting point Value 1 “1”, MCCH repetition period 1 “3”, etc. are mapped, and BCCH1 to which scrambling code 1 is applied, and MCCH1 and MTCH1 of the base station belonging to MBSFN area 1 to which scrambling code 1 is applied are transmitted. The The data transmitted from the base stations belonging to the MBSFN area 2 as in the MBSFN area 1 are as follows. P-SCH (first synchronization channel) that is a frequency layer-dedicated sequence dedicated for MBMS transmission, S-SCH2 (second synchronization channel) to which MBSFN area ID2 and the like are mapped, MCCH starting point value 2 “1”, MCCH The repetition period 2 “2” or the like is mapped, and BCCH2 to which scrambling code 2 is applied, and MCCH2 and MTCH2 of the base station belonging to MBSFN area 2 to which scrambling code 2 is applied are transmitted. The data transmitted from the base stations belonging to the MBSFN area 3 as in the MBSFN area 1 are as follows. P-SCH (first synchronization channel), which is a frequency layer-dedicated sequence dedicated to MBMS transmission, S-SCH3 (second synchronization channel) mapped with MBSFN area ID3, etc., MCCH starting point value 3 “2”, MCCH The repetition period 3 “4” or the like is mapped, and BCCH3 to which scrambling code 3 is applied, and MCCH3 and MTCH3 of the base station belonging to MBSFN area 3 to which scrambling code 3 is applied are transmitted.

  Although FIG. 27 shows an example in which MCCH and MTCH are time-divided in units of radio frames for convenience, even if the multiplexing method of MCCH and MTCH is another method, the unit of time-division multiplexing is not in units of radio frames. Even if it exists, this invention is applicable. Further, if the MCCH repetition period is determined to be static (Static) or quasi-static (Semi-Static) as a mobile communication system, there is no need to report the MCCH repetition period from the base station. Since the information to be notified is reduced, the effect of effective use of radio resources can be obtained. When the MBSFN area is code division multiplexed (CDM), it is possible to set different repetition periods for each MBSFN area, compared with the case where the MBSFN area is time division multiplexed (TDM), and the MBMS service has a high degree of freedom. There is an effect that scheduling becomes possible. Furthermore, by using code division multiplexing, even if MTCH and MCCH from a plurality of MBSFN areas overlap at the same time in the mobile terminal, it can be separated (because it can be separated by a scrambling code). Therefore, since it becomes possible to transmit MTCH and MCCH from the MBSFN area 1-3 at the same time as the mobile communication system, it is possible to obtain an effect of expanding the frequency and time radio resources allocated to one MBSFN area. I can do it.

  Next, in the current 3GPP discussion, it is considered to provide an MBSFN area that covers a plurality of MBSFN areas. FIG. 28 is an explanatory diagram showing a plurality of MBSFN areas constituting an MBSFN synchronization area, and is an explanatory diagram showing an MBSFN area covering a plurality of MBSFN areas. In FIG. 28, MBSFN areas 1 to 4 exist in one MBSFN synchronization area. Among them, MBSFN area 4 covers MBSFN areas 1 to 3. Although it is discussed that the MBSFN area 4 is accessed via the covered MBSFN areas 1 to 3, details are not yet determined. Therefore, an access method to an MBSFN area that covers a plurality of MBSFN areas will be described below.

  As described above, since the MBSFN area multiplexing method has not been determined in detail, the MBSFN area 4 and the MBSFN areas 1 to 3 covered by the MBSFN area 4 are first time-division multiplexed, and A case where the covered MBSFN areas 1 to 3 are code division multiplexed will be described. A specific example of step ST1725 (see FIG. 18) in the case of the geographical location of the MBSFN area as shown in FIG. As a first step, the mobile terminal performs blind detection of the P-SCH (first synchronization channel) in the dedicated sequence. A mobile terminal that has blind-detected P-SCH can detect timing for 5 ms. P-SCH is multi-cell transmission. Base stations located in the MBSFN synchronization area are synchronized for multi-cell transmission. Therefore, multi-cell transmission of P-SCH is targeted for base stations included in the synchronization area. As a second stage, the mobile terminal performs blind detection of S-SCH (second synchronization channel). A mobile terminal that blindly detects S-SCH can detect 10 ms timing detection (frame synchronization) and the MBSFN area ID. S-SCH is multi-cell transmission. The MBSFN area ID at this time is the covered MBSFN area ID. That is, each covered MBSFN area ID (any of MBSFN areas 1 to 3) where the mobile terminal is located. Therefore, S-SCH multi-cell transmission is targeted for base stations included in each covered MBSFN area. The mobile terminal receives BCCH (broadcast control channel) using the scrambling code associated with the MBSFN area ID obtained in the second stage. By decoding BCCH, MCCH (multicast control channel) scheduling can be obtained. BCCH is multi-cell transmission. Since the scrambling code obtained in the second stage is used, the BCCH becomes the BCCH from the covered MBSFN area. Therefore, multi-cell transmission of BCCH is targeted for base stations included in each covered MBSFN area. The mobile terminal can obtain MCCH scheduling, system bandwidth in f (MBMS), the number of transmission antennas, and the like by decoding BCCH.

  Here, MCCH scheduling will be further examined. In FIG. 29, the covered MBSFN area (MBSFN area 4) and the covered MBSFN areas (MBSFN areas 1 to 3) are time division multiplexed, and the multiplexing method between the covered MBSFN areas is code division multiplexing. It is explanatory drawing which shows the mapping to the physical channel of the MBSFN synchronous area in a case. Since the MBSFN synchronization area is synchronized in time, the P-SCH (first synchronization channel) is transmitted to the MBMS dedicated cells in the MBSFN areas 1 to 3 at the same timing. Further, if the sequence dedicated to the frequency layer dedicated to the MBMS transmission (the additional dedicated sequence) is used, the sequences of P-SCHs (second synchronization channels) in all MBSFN areas are the same. Therefore, the same information is transmitted at the same timing in the MBSFN synchronization area for the P-SCH. As described above, it is considered that the MBSFN area ID is transmitted by S-SCH (second synchronization channel). Therefore, in this case, S-SCH is transmitted with different information for each MBSFN area at the same timing in the MBSFN synchronization area. In this case, the same information is transmitted at the same timing from all the MBMS dedicated cells in each MBSFN area. At this time, it is assumed that there is no S-SCH specific to the covering MBSFN area (MBSFN area 4). S-SCH uses the same radio resources in terms of frequency and time in the MBSFN synchronization area. Since the S-SCH is used for searching for the MBSFN area ID associated with each MBSFN area scrambling code, the S-SCH cannot be subjected to the scrambling code of each MBSFN area. The transmission of the covered MBSFN area S-SCH means that a plurality of MBSFN areas overlap as geographical locations, but in the overlapping MBSFN areas (for example, MBSFN areas 1 and 4), the S- Only one type of SCH needs to be transmitted. Thereby, it can prevent that S-SCH from a mutual MBSFN area becomes interference. The mobile communication system transmits a BCCH to which a scrambling code associated with an MBSFN area ID notified by S-SCH is applied. Therefore, in this case, the BCCH is transmitted with different information for each covered MBSFN area at the same timing in the MBSFN synchronization area. The contents of BCCH are the same in all MBMS dedicated base stations in the MBSFN area. The mobile terminal can obtain MCCH scheduling by decoding BCCH. The current 3GPP does not discuss specific examples of MCCH scheduling. The present invention shows a specific example of MCCH scheduling.

In FIG. 29, MCCH scheduling when the MBSFN frame cluster is larger than the MCCH repetition period will be described together. Two stages are considered for MCCH scheduling in the covered MBSFN area. In the following description, for convenience, a case will be described in which the mobile terminal is located in the MBSFN area 1 as the MBSFN area covered and the MBSFN area 4 exists as the covered MBSFN area. As a first stage, MCCH scheduling of MBSFN area 1 is notified on BCCH of MBSFN area 1. The present invention shows a specific example of MCCH scheduling. In the present invention, it is considered to notify the starting point value of the time when MCCH is mapped, the MBSFN frame cluster repetition period, and the number of MCCH transmissions within the MBSFN frame cluster repetition period as MCCH scheduling. More specifically, the number of radio frames is used for the repetition period of the MBSFN frame cluster. More specifically, SFN (System Frame Number) is used to specify the starting point value. A specific example of the MBSFN frame cluster repetition period other than the radio frame may be a subframe. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. As a specific calculation formula for obtaining the starting point value, starting point value = (first SFN number to which MCCH is mapped) mod (MBSFN FRAME Cluster Repetition Period) can be considered. More specifically, the number of MCCH transmissions in the MBSFN frame cluster (hereinafter referred to as N _MCCH ) is used as the number of MCCH transmissions in the MBSFN frame cluster repetition period. A concrete computation expression for calculating the N _{MCCH is} expressed by N MCCH = MBSFN frame cluster / MCCH repetition period (MCCH Repetition Period). In FIG. 29, the MCCH offset value 1 of the MBSFN area 1 is 1 mod 10 = 1. The MCCH starting point value 2 of the MBSFN area 2 is 1 mod 10 = 1. The MCCH starting point value 4 of the MBSFN area 4 is 7 mod 10 = 7. Next, N _MCCH 1 of MBSFN area 1 is _6/2 = 3. Also, N _MCCH 2 of MBSFN area 2 is _6/3 = 2. N _MCCH 4 in the MBSFN area 4 is _4/2 = 2. Therefore, the MCCH scheduling parameters of MBSFN area 1 are MBSFN frame cluster repetition period 1 “10”, starting point value 1 “1”, and N _MCCH 1 “3”. At this time, instead of notifying N _MCCH 1 as a parameter, MBSFN frame cluster 1 and MCCH repetition period 1 may be notified.

As a second step, the MCCH scheduling of the MBSFN area 4 is notified on the MCCH of the MBSFN area 1. A specific example of MCCH scheduling is the MBSFN of the MBSFN area covered in addition to the parameters of the MBSFN area 4 (MBSFN frame cluster repetition period 4 “10”, state point 4 “7”, N _MCCH 4 “2”). The area ID (MBSFN area 4) is notified. As the MCCH scheduling of the MBSFN area 4, a single-stage case may be considered. That is, the MCCH scheduling of the MBSFN area 4 is also notified by the BCCH of the MBSFN area 1. As a result, the mobile terminal that receives the service in the MBSFN area 4 does not need to receive and decode the MCCH in the MBSFN area 1, so that the control delay can be reduced. As the MCCH scheduling, the above-mentioned starting point, MBSFN frame cluster repetition period, N _MCCH (MBSFN frame cluster and MCCH repetition period may be used) is an MBSFN frame when the MBSFN area is time-division multiplexed (see FIG. 26). It can also be used when there are multiple MCCHs in a cluster.

That is, data transmitted from the base station belonging to the MBSFN area 1 is as follows. P-SCH (first synchronization channel) that is a frequency layer-dedicated sequence dedicated to MBMS transmission, S-SCH1 (second synchronization channel) to which MBSFN area ID1 and the like are mapped, MCCH starting point value 1 “1”, MBSFN Frame cluster repetition period 1 “10”, N _MCCH 1 “3”, and the like are mapped, and BCCH 1 to which scrambling code 1 is applied, MCCH 1 and MTCH 1 of MBSFN area 1 to which scrambling code 1 is applied are transmitted. In MCCH1, the MBSFN area ID (MBSFN area 4) of the MBSFN area 4 and the MCCH scheduling of the MBSFN area 4, the MCCH starting point value 4 “7”, the MBSFN frame cluster repetition period 4 “10”, and the N _MCCH 4 “2” Is sent. The data transmitted from the base stations belonging to the MBSFN area 2 as in the MBSFN area 1 are as follows. S-SCH2, which is a sequence dedicated to the frequency layer dedicated to MBMS transmission, S-SCH2 to which MBSFN area ID2 and the like are mapped, MCCH starting point value 2 “1”, MBSFN frame cluster repetition period 2 “10”, N _MCCH 2 “2” or the like is mapped and BCCH2 to which scrambling code 2 is applied and MCCH2 and MTCH2 of MBSFN area 2 to which scrambling code 2 is applied are transmitted. In MCCH2, the MBSFN area ID (MBSFN area 4) of the MBSFN area 4 and the MCCH scheduling of the MBSFN area 4, the MCCH offset value 4 “7”, the MBSFN frame cluster repetition period 4 “10”, and the N _MCCH 4 “2” are transmitted. Is done.

  As data transmitted from the MBSFN area 4, there is no transmission of P-SCH and S-SCH as described above. Further, if there is no need to notify more than the information transmitted on the BCCH of the MBSFN area (MBSFN areas 1 to 3) covered as the system information of the MBSFN area 4, transmission of BCCH from the MBSFN area 4 is omitted. I can do it. Thereby, the effect of effective utilization of radio resources can be obtained. MCCH4 and MTCH4 of MBSFN area 4 to which no scrambling code is applied are transmitted.

  FIG. 29 shows an example in which MCCH and MTCH are time-divided in units of radio frames for convenience. However, even if the multiplexing method of MCCH and MTCH is different, the unit of time-division multiplexing is not in units of radio frames. Even if it exists, this invention is applicable. A multiplexing method in which the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3) are time division multiplexed, and the covered MBSFN areas are code division multiplexed. Uses code division multiplexing as a multiplexing method for MBSFN areas 1 to 3 in which geographical locations are separated. Thereby, the advantage of effective use of frequency and time radio resources can be obtained. In code division multiplexing, each MBSFN area is separated only by a scrambling code assigned to each MBSFN area, so that there is a possibility that data between the MBSFN areas interfere with each other. However, in this multiplexing method, there is an effect that interference by transmission data is less likely to occur even if code division multiplexing is used in multiplexing of MBSFN areas 1 to 3 where geographical locations are separated. Time division multiplexing is used for multiplexing the MBSFN area 4 and the MBMSFN areas 1 to 3 whose geographical locations are not separated. Thereby, since it is not geographically separated, the multiplexing method of the MBSFN area 4 and the MBSFN areas 1 to 3 that are more likely to cause interference can be changed to a multiplexing method that hardly causes interference. With this multiplexing method, it is possible to obtain an effect that radio resources can be effectively used while suppressing interference between the MBSFN areas. Furthermore, P-SCH, S-SCH, and BCCH can be reduced by not performing MBMS search in the covered MBSFN area (MBSFN area 4). Thereby, the effect that the radio | wireless resource of the MBSFN area 4 can be used effectively can be acquired.

  Next, when the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3) are time division multiplexed, the multiplexing method between the covered MBSFN areas is also time division multiplexed. A specific example will be described. The conceptual diagram of the location of the base station when there are multiple MBSFN areas is covered by time-division multiplexing the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3). The multiplexing method between the MBSFN areas is the same as in the case of code division multiplexing. Since P-SCH, S-SCH, and BCCH are the same as those described above, description thereof is omitted. A specific example of MCCH scheduling will be described mainly with respect to different parts, which is almost the same as in the above case. As a first step, MCCH scheduling of MBSFN area 1 is notified on BCCH of MBSFN area 1. The present invention shows a specific example of MCCH scheduling. In the present invention, it is considered that the MCCH scheduling is notified of the starting point value of the time to which the MCCH is mapped and the MCCH repetition period. The number of radio frames is used to specify the MCCH repetition period. More specifically, SFN (System Frame Number) is used to specify the starting point value. A specific example of the MCCH repetition period other than the number of radio frames may be a subframe. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. A specific calculation formula for obtaining the starting point value is starting point value = (first SFN number to which MCCH is mapped) mod (MCCH repetition period). As a second step, the MCCH scheduling of the MBSFN area 4 is notified on the MCCH of the MBSFN area 1. A specific example of the MCCH scheduling is to notify the MBSFN area ID (MBSFN area 4) of the MBSFN area covered in addition to the parameters of the MBSFN area 4 similar to the MBSFN area 1 described above. A description of the parameters of the MBSFN area 4 is omitted.

  Next, the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3) are code division multiplexed, and the multiplexing method between the covered MBSFN areas is also code division multiplexed. A specific example in the case will be described. The conceptual diagram of the location of the base station when there are multiple MBSFN areas is covered by time-division multiplexing the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3). The multiplexing method between the MBSFN areas is the same as in the case of code division multiplexing. Since P-SCH, S-SCH, and BCCH are the same as those described above, description thereof is omitted. A specific example of MCCH scheduling will be described mainly with respect to different parts, which is almost the same as in the above case. As a first step, MCCH scheduling of MBSFN area 1 is notified on BCCH of MBSFN area 1. The present invention shows a specific example of MCCH scheduling. In the present invention, it is considered to notify the starting point value of MCCH mapping time and the MCCH repetition period as MCCH scheduling. The number of radio frames is used to specify the MCCH repetition period. More specifically, SFN (System Frame Number) is used to specify the starting point value. Other than the number of radio frames may be used for designating the MCCH repetition period. Specific examples include subframes. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. A specific calculation formula for obtaining the starting point value is starting point value = (first SFN number to which MCCH is mapped) mod (MCCH repetition period). As a second step, the MCCH scheduling of the MBSFN area 4 is notified on the MCCH of the MBSFN area 1. As a specific example of MCCH scheduling, the MBSFN area ID (MBSFN area 4) of the covered MBSFN area is notified in addition to the parameters of the MBSFN area 4 like the MBSFN area 1 described above. A description of the parameters of the MBSFN area 4 is omitted. The scrambling code used in the MBSFN area 4 is determined based on the MBSFN area ID (MBSFN area 4) notified on the MCCH1 of the MBSFN area 1.

  Next, the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3) are code division multiplexed, and the multiplexing method between the covered MBSFN areas is time division multiplexing. A specific example in the case will be described. The conceptual diagram of the location of the base station when there are multiple MBSFN areas is covered by time-division multiplexing the covered MBSFN area (MBSFN area 4) and the covered MBSFN area (MBSFN areas 1 to 3). The multiplexing method between the MBSFN areas is the same as in the case of code division multiplexing. Since P-SCH, S-SCH, and BCCH are the same as those described above, description thereof is omitted. A specific example of MCCH scheduling will be described mainly with respect to different parts, which is almost the same as in the above case. As a first step, MCCH scheduling of MBSFN area 1 is notified on BCCH of MBSFN area 1. The present invention shows a specific example of MCCH scheduling. In the present invention, it is considered that the MCCH scheduling is notified of the starting point value of the time to which the MCCH is mapped and the MCCH repetition period. The number of radio frames is used to specify the MCCH repetition period. More specifically, SFN (System Frame Number) is used to specify the starting point value. Other than the number of radio frames may be used for designating the MCCH repetition period. Specific examples include subframes. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. A specific calculation formula for obtaining the starting point value is starting point value = (first SFN number to which MCCH is mapped) mod (MCCH repetition period). As a second step, the MCCH scheduling of the MBSFN area 4 is notified on the MCCH of the MBSFN area 1. As a specific example of MCCH scheduling, a specific example of MCCH scheduling notifies the MBSFN area 4 parameters of a standing point, an MCCH repetition period, and an MBSFN area ID (MBSFN area 4) of the covered MBSFN area.

  The MCCH starting point may be an MCH starting point or a PMCH starting point in MCCH scheduling in all the multiplexing methods of the MBSFN area described above. In the case of the MCH starting point, the parameter MCCH repetition period in MCCH scheduling is the MCH repetition period. At that time, if MCCH is always mapped in each MCH, MCH repetition period = MCCH repetition period. On the other hand, when the MCCH is not necessarily mapped in each MCH, the MCCH repetition period may be included as a parameter together with the MCH repetition period. In the case of the PMCH starting point, the parameter MCCH repetition period in MCCH scheduling is the PMCH repetition period. At that time, when MCCH is always mapped in each PMCH, PMCH repetition period = MCCH repetition period. On the other hand, when the MCCH is not necessarily mapped in each PMCH, the MCCH repetition period may be included as a parameter together with the PMCH repetition period.

  Next, in 3GPP, discussions are progressing in a direction in which single cell transmission is supported in a frequency layer dedicated to MBMS transmission. As a support method thereof, a method of realizing single cell transmission in an MBSFN area having a single cell configuration has been discussed. However, there is no discussion about a specific implementation method. In the present invention, in order to disclose a method for selecting a desired service in a frequency layer dedicated to MBMS transmission, which is a fourth problem, and a mobile communication system therefor, a specific example of a support method for single cell transmission Show. The specific implementation example in the case where there is an MBSFN area that covers a plurality of MBSFN areas has been described above. In the above method, the covered MBSFN areas (MBSFN Area1 to 3) are replaced with cells that perform single-cell transmission, and the covered MBSFN area (MBSFN Area4) is subjected to multi-cell transmission. By replacing with, single cell transmission can be realized in an MBSFN area having a single cell configuration.

  Next, “MBMS area information acquisition” described in Embodiment 1 will be described more specifically using steps ST1726 and 1727 in FIG. 18 and steps ST1728 and 1729 in FIG. The MCCH (multicast control channel) in each MBSFN area considers multi-cell transmission. Therefore, in step ST1726, the MCE transmits the contents of the MCCH and the assignment of radio resources for transmitting the MCCH to the base station in the MBSFN area. In Step ST1727, each MBMS dedicated base station receives the contents of the MCCH and assignment of radio resources for transmitting the MCCH from the MCE. In step ST1728, each base station transmits multi-cell control information such as MBMS area information, discontinuous reception (DRX) information, and the number of paging groups K using MCCH according to radio resources allocated from the MCE. In Step ST1729, the mobile terminal receives MCCH from each base station in the MBSFN area. MCCH reception uses the scheduling of MCCH received from the network side in step ST1725.

  A specific example of the reception method will be described. As a representative, a case will be described in which a plurality of base stations are arranged as shown in FIG. 25 and each MBSFN area is time-division multiplexed as shown in FIG. A case where the mobile terminal is located under the MBSFN area 1 will be described. By decoding BCCH1 (broadcast control channel) in MBSFN area 1, the mobile terminal receives MCCH1 scheduling parameters of starting point value 1 “1” and MCCH repetition period 1 (MCCH Repetiton Period) “7”. If SFN (System Frame Number) is mapped to BCCH, the mobile terminal can know the SFN number by decoding BCCH. The mobile terminal can obtain the SFN number to which the MCCH is mapped by the following formula. SFN = MCCH repetition period 1 × α + starting point value 1 (α is a positive integer). The mobile terminal can receive MCCH1 by receiving and decoding the radio resource of the SFN number to which MCCH1 is mapped. Control information for MBMS service transmitted in multicell from MBSFN area 1 is mapped to MCCH1. Specific examples of the control information include MBMS area information, DRX information, MBMS reception time missing reception parameters, and the like.

  A specific example of MBMS area information will be described with reference to FIG. As the MBMS area information, the frame configuration of each area (MBSFN frame cluster, MBSFN subframe, etc.), service content, MTCH modulation information, and the like can be considered. As the MBSFN frame cluster 1, the number of frames in the set of frames allocated to the MBSFN area 1 within the 1 MBSFN frame cluster repetition period is notified. As MBSFN subframe 1, a subframe number in which MBMS data (MTCH or / and MCCH) is actually mapped in one radio frame in MBSFN frame cluster 1 is notified. In providing an MBMS service using an MBMS dedicated base station, unlike an MBMS / unicast mixed cell, it is not necessary to share radio resources with unicast data. Therefore, MBMS data can be mapped to all subframes in one radio frame (except for the P-SCH, S-SCH, and BCCH mapping portions). When mapping MBMS data to all subframes, it is not necessary to notify the parameters of the MBSFN subframe from the network side to the mobile terminal side. Thereby, effective utilization of radio resources can be achieved. Alternatively, when MBMS data is statically transmitted from an MBMS dedicated cell as a wireless communication system, it is possible to transmit a large amount of MBMS data by mapping the MBMS data to all subframes. Since it is not necessary to notify the parameter of the MBSFN subframe, it is possible to further effectively use radio resources. As the service content, the service content performed in the MBMS area 1 is notified. When a plurality of services (movies and sports broadcasts, etc.) are performed in the MBSFN area 1, a plurality of service contents and their multiple parameters are notified.

  FIG. 30 is an explanatory diagram illustrating a relationship between a DRX period in which transmission of MBMS data to a mobile terminal is stopped and reception of MBMS data at the mobile terminal is stopped, and a DRX period in which the DRX period is repeated. . Specific examples of DRX (Discontinuous reception) information will be described with reference to FIG. In order to notify the mobile terminal that uses the MBMS service in the MBMS transmission dedicated cell, which is the first problem of the present invention, the mobile terminal that is receiving the MBMS service in the MBMS transmission dedicated cell is unidirectional. It is necessary to perform location registration in the network through a cast cell or a mixed MBMS / unicast cell. For this purpose, measurement and location registration (cell re-selection of a serving base station) of a unicast cell or a mixed MBMS / unicast cell is required. Thereby, the effect that it becomes possible to ensure the mobility in a MBMS exclusive cell without an uplink via a unicast / mixed cell can be acquired. For this reason, it is possible to receive a paging signal even in a mobile terminal receiving an MBMS service in a frequency layer dedicated to MBMS transmission. Therefore, even for a mobile terminal that is receiving an MBMS service in an MBMS transmission dedicated cell, it is necessary to measure a unicast cell and an MBMS / unicast mixed cell at a fixed period. In the conventional method (3GPP W-CDMA), the measurement period is an integral multiple of the intermittent reception period and is notified to the mobile terminal from the network side in the upper layer.

  Here, the mobile terminal receiving the MBMS service in the MBMS transmission dedicated cell applies the measurement in the measurement cycle notified from the upper layer of the unicast cell and the MBMS / unicast mixed cell by applying the conventional method. If so, the base station constituting the MBMSFN synchronization area of the MBMSFN dedicated frequency cell and the base station constituting the unicast / mixed frequency layer are not synchronized (asynchronous) with each other. Therefore, there is a problem that the MBMS reception must be interrupted in order to perform the above.

  Therefore, in the present invention, as a solution to the above problem, one DRX period is provided in the MBSFN synchronization area (see FIG. 30). In the first embodiment, the DRX period is a period in which transmission of MBMS data from the network side to the mobile terminal is stopped for the MBMS service in all MBSFN areas in the MBSFN synchronization area, that is, when viewed from the mobile terminal side, the MBMS data It means a period when no reception is performed. The mobile terminal using the MBMS service in the MBMS transmission dedicated frequency layer uses the MBMS service by performing measurement of the unicast cell and the MBMS / unicast mixed cell during the DRX period in which MBMS data is not transmitted from the network side. The effect of eliminating the need to interrupt is obtained. Further, by providing the DRX period in the MBSFN synchronization area, the mobile terminal can simultaneously receive MBMS data from the MBSFN area in the MBSFN synchronization area without adding any control.

  Next, the DRX cycle shown in FIG. 30 will be described. The DRX cycle is a cycle in which the DRX period described above is repeated. In the conventional method, the measurement cycle is set (notified) from the network side to the mobile terminal. If this method is followed also in LTE, if a mobile terminal receiving the MBMS service in the MBMS transmission dedicated frequency layer performs measurement in the unicast / mixed frequency layer in the DRX period, the MBMS transmission dedicated frequency is used. It is necessary to notify the control device (base station, MME, PDNGW, etc.) on the unicast cell, MBMS / unicast mixed cell side through any route of the DRX cycle and DRX period information of the layer. Furthermore, since the base stations constituting the unicast / mixed frequency layer are basically configured asynchronously, the DRX cycle and DRX period of the MBMS transmission-dedicated frequency layer are set to each unicast cell or each MBMS / unicast. It becomes necessary to notify the mixed cell. This method complicates the mobile communication system and is not preferable. Therefore, the present invention discloses the following method. The DRX cycle in the MBMS transmission dedicated cell is the minimum value of the measurement cycle that can be taken by the unicast cell or the unicast / mixed frequency cell or a divisor of the minimum value. A measurement cycle that can be set for a mobile terminal that is receiving an MBMS service in a frequency layer dedicated to MBMS transmission in a unicast cell or a mixed MBMS / unicast cell is a measurement cycle that can be taken in the unicast / mixed frequency layer. If they are different, the DRX cycle is approximately the measurement cycle that can be set for the mobile terminal that is receiving the MBMS service in the frequency layer dedicated to MBMS transmission, or the minimum value of the measurement cycle, or the minimum value of the measurement cycle. It is a number. Thereby, no matter what measurement cycle is notified (set) to the mobile terminal in the unicast cell, MBMS / unicast mixed cell, in the DRX period provided in the DRX cycle in the frequency layer dedicated to MBMS transmission, If measurement of the unicast / mixed frequency layer is performed, the measurement cycle notified from the network side can be satisfied. By adopting this method, the MBMS transmission dedicated cell is controlled from the MBMS transmission dedicated cell control device (base station, MCE, MBMS gateway, eBNSC, etc.) to the unicast cell, MBMS / unicast mixed cell control device. There is no need to notify the DRX cycle or DRX period. Therefore, the mobile terminal receiving the MBMS service in the MBSFN transmission dedicated frequency layer interrupts the reception of the MBMS service while preventing the mobile communication system from becoming complicated, that is, avoiding additional signaling on the radio interface or in the network. Therefore, it is possible to obtain an effect that the measurement can be executed in the measurement cycle notified (set) by the unicast cell or the MBMS / unicast mixed cell to the mobile terminal. Also, broadcast information may be acquired from the serving cell of the unicast / mixed frequency layer in the DRX period, and for example, it is possible to cope with a case where the broadcast information in the serving cell is modified.

  A specific parameter example of the DRX information will be described with reference to FIG. Specifically, DRX information parameters may include a DRX period, a DRX cycle, and a starting point value (DRX). Specifically, the number of radio frames is used to specify the DRX period and the DRX cycle. In FIG. 30, the DRX period is “4” radio frames (a period between SFN4 and SFN7). The DRX cycle is “7” radio frames (periods from SFN4 to SFN10). Further, SFN is used to specify the starting point value (DRX) at which the DRX period starts. Specific examples of the DRX period and DRX cycle other than the number of radio frames may include subframes. Other than SFN may be used to specify the starting point value. Specific examples include an offset value from some reference value. When MCCH is mapped to some subframes in a radio frame, SFN and subframe number may be notified as a starting point. A specific calculation formula for obtaining the starting point value (DRX) is the starting point value (DRX) = (first SFN number at which the DRX period starts) mod (DRX cycle). In FIG. 30, the starting point value (DRX) is 4 mod 7 = 4 or 11 mod 7 = 4. Here, an example is shown in which SFN is used to specify the starting point value (DRX). Here, an example in which one DRX period is provided in the MBSFN synchronization area has been described. Therefore, the starting point value (DRX) is also common to the base stations in the MBSFN synchronization area. Consider a case where SFN is used as a starting point value (DRX). Assume that the same number is transmitted from the base station in the MBSFN synchronization area at the same timing. In the above, an example has been described in which DRX information is mapped to MCCH and notified from a base station in MBSFN Area to a mobile terminal. Similarly, the same effect can be obtained by mapping DRX information to BCCH and notifying a mobile terminal from a base station in the MBSFN area. Furthermore, the same effect can be obtained by mapping DRX information to BCCH and notifying the mobile terminal from the serving base station. Furthermore, the same effect can be obtained even if the DRX information is determined to be static or semi-static. This eliminates the need for notification, so that the effect of effective use of radio resources can also be obtained.

A specific example of the MBMS reception time missing reception parameter will be further described. As described above, Non-Patent Document 1 discloses that the paging group is notified by the L1 / L2 signaling channel (PDCCH). Whether or not the L1 / L2 signaling channel exists in the radio resource transmitted from the MBMS dedicated cell has not yet been determined. In this embodiment, it is assumed that there is no L1 / L2 signaling channel in radio resources transmitted from an MBMS dedicated cell. However, it is preferable that the paging notification methods for the unicast cell, MBMS / unicast mixed cell, and MBMS transmission dedicated cell existing in the same mobile communication system called LTE be unified as much as possible. This is because the unification of the mobile communication system can be avoided by unifying. In the following description, the number of paging groups (hereinafter referred to as K _MBMS ) is considered as a parameter for reception of missing MBMS reception time. Next, a case where a plurality of base stations are arranged as shown in FIG. 25 and each MBSFN area is code division multiplexed as shown in FIG. 27 will be described. In this case, the DRX information is the same as that in the case of the time division multiplexing, and a description thereof will be omitted.

  Next, “MBMS service selection” described in the first embodiment will be described in more detail with reference to FIG. In step ST1730, the mobile terminal confirms the service content included in the MBMS area information in order to know whether the user-desired service is being performed in the corresponding MBMS area. When a user-desired service is performed in the MBSFN area, the mobile terminal makes a transition to step ST1731. If the service desired by the user is not provided, the mobile terminal makes a transition to step ST1733. In Step ST1731, the mobile terminal receives a reference signal (RS) using radio resources in the MBSFN area and measures received power (RSRP). It is determined whether or not the received power is equal to or greater than a threshold value determined statically or semi-statically. If the threshold value is equal to or greater than the threshold value, it indicates that the sensitivity is satisfactory for receiving the MBMS service, and if the threshold value is less than the threshold value, it indicates that the sensitivity is not sufficient for receiving the MBMS service. If it is equal to or greater than the threshold, the process proceeds to step ST1732, and if it is equal to or less than the threshold, the process proceeds to step ST1733. In Step ST1732, the mobile terminal acquires a frequency f (MBMS) dedicated to MBMS transmission and an MBSFN area ID for the user to receive a desired MBMS service. On the other hand, in step ST1733, the mobile terminal determines whether there is another MBMS area that can be received within the same frequency (f (MBMS)). This step ST1733 is particularly effective when there is an MBSFN area (MBSFN area 4) that is covered as shown in FIG. If there is another MBMS area that can be received within the same frequency (f (MBMS)), the process returns to step ST1730 and is repeated. When it does not exist, it transfers to step ST1734. In step 1734, the mobile terminal determines whether another frequency exists in the frequency list of the receivable MBSFN synchronization area received in step ST1708. If it exists, the process returns to step ST1722, and the process is repeated by switching the synthesizer to a new frequency (f2 (MBMS)). If not, the process returns to step ST1720 and repeats the process. Further, instead of receiving the reference signal in step 1731 and measuring the received power, it is also possible to actually receive and decode the MBMS service (MTCH or / and MCCH) in the MBSFN area. In this case, the user himself / herself can determine whether or not the reception sensitivity is acceptable by listening or viewing the decoded data. If permitted, the process proceeds to step ST1732, and if not permitted, the process proceeds to step ST1733. Since there are individual differences in permissible reception sensitivity for each user, an effect of becoming a mobile terminal more suitable for the user can be obtained.

Step 1735 in FIG. 19 is a process indicating “MBMS reception time missing reception preparation” described in the first embodiment. In Step ST1735, the mobile terminal performs MBMS reception time missing reception preparation using the MBMS reception time missing reception parameter received in Step ST1729. Specifically, the paging group of its own mobile terminal is calculated using paging group number K _MBMS received in step ST1729. The mobile terminal identification ID (UE-ID, IMSI) is used to calculate the paging group. The paging group is represented by IMSI mod K _MBMS .

  FIG. 20 is a flowchart for explaining the MBMS-side reception status notification process. This process will be described more specifically with respect to “MBMS side reception status notification” described in the first embodiment with reference to FIG. In FIG. 20, in step ST1736, the mobile terminal changes the set frequency of frequency conversion section 1107, and changes the center frequency to the frequency of the unicast / mixed frequency layer (hereinafter referred to as f (unicast)). Move to the unicast / mixed frequency layer. In Step ST1737, the mobile terminal transmits an uplink scheduling request (UL Scheduling Request) to the serving cell. In Step ST1738, the serving cell receives the uplink scheduling request from the mobile terminal. In Step ST1739, the serving cell performs uplink scheduling (UL Scheduling) to allocate uplink radio resources to the mobile terminal. In Step ST1740, the serving cell transmits uplink radio resource allocation (also referred to as UL allocation or Grant) to the mobile terminal, which is a result of the uplink scheduling in Step ST1739, to the mobile terminal. A mobile terminal receives UL allocation from a serving cell in step ST1741. In Step ST1742, the mobile terminal transmits an “MBMS side reception status notification” to the serving cell according to the UL allocation received in Step ST1741. Examples of parameters included in the “MBMS side reception status notification” include mobile terminal identifiers (UE-ID, IMSI, S-TMSI, etc.), MBMS service reception frequency (f (MBMS)), MBSFN Area number (ID). )and so on. In Step ST1743, the serving cell performs reception processing for receiving various parameters transmitted from the mobile terminal by the "MBMS side reception status notification" processing in Step ST1742. In step ST1743, the network side receives the MBMS service in the frequency layer dedicated to MBMS transmission without adding an uplink to the MBMS dedicated cell, that is, without increasing the complexity as a mobile communication system. You can know that it is. Thereby, there is an effect that it is possible to change from the configuration in which the network side notifies the normal paging signal to the MBMS reception time missing reception configuration. In step ST1744, the serving cell transmits, to the MME, the parameter transmitted in the “MBMS side reception status notification” performed by the mobile terminal in step ST1742. In Step ST1745, the MME receives this.

  In Step ST1746, the MME determines a tracking area (hereinafter referred to as TA (MBMS)) that is receiving the MBMS service at the frequency dedicated to MBMS transmission of the mobile terminal. When determining the tracking area, the MME determines based on the MBMS side reception status notification (MBMS side reception status parameters, f (MBMS) and MBSFN area number) notified from the mobile terminal via the serving cell in step ST 1742. In step ST1747, the tracking area list of the mobile terminal is updated. In Step ST1747, the TA list including TA (unicast) and / or TA (MBMS) is managed (saved, added, updated, deleted). TA (unicast) is the tracking area of the mobile terminal in the unicast / mixed frequency layer. FIG. 31 is an explanatory diagram illustrating details of the tracking area list. Hereinafter, a specific example of tracking area list management will be described with reference to FIG. The tracking area list is managed for each mobile terminal as shown in FIG. In the example of FIG. 31A, TAs of UE # 1 are TA (unicast) # 1 and TA (unicast) # 2, and TAs of UE # 2 are TA (unicast) # 1 and TA (MBMS) # 1. It is. Further, the MME also manages base stations included in each tracking area (TA (unicast)). This will be described with reference to FIG. TA (unicast) # 1 includes MBMS / unicast mixed cells having cell IDs 1, 2, 3, 4, and 5. Also, TA (unicast) # 2 includes MBMS / unicast mixed cells with cell IDs 23, 24, and 25. Next, description will be made with reference to FIG. TA (MBMS) # 1 corresponds to an MBSFN area ID in which the mobile terminal receives an MBMS service in a frequency layer dedicated to MBMS transmission. That is, in the present invention, in step ST 1742, the parameter is transmitted from the mobile terminal by “MBMS side reception status notification”, and in step ST 1745, the MME uses the parameter f (MBMS) and MBSFN area ID to perform TA. (MBMS) will be determined.

  Details of the management of the TA list in step ST1747 will be described. The MME searches for the TA (MBMS) number managed in the MME based on the f (MBMS) and MBSFN area ID received in step ST1745 (for example, using FIG. 31 (c)). Next, it is determined whether or not TA (MBMS) found as a result of the search exists in the TA list of the mobile terminal. If it exists, the current TA list is saved. If not, the TA (MBMS) is added to the TA list of the mobile terminal. In Step ST1748, the MME transmits a response signal Ack indicating that the MBMS side reception status notification has been received to the serving cell. It is conceivable to include the TA list of the mobile terminal in this response signal. In Step ST1749, the serving cell receives an MBck side reception status notification Ack from the MME, and transmits an MBMS side reception status notification Ack to the mobile terminal in Step ST1750. In Step ST1751, the mobile terminal receives an Ack of MBMS side reception status notification from the serving cell. In Step ST1752, the mobile terminal changes the set frequency of the frequency conversion section 1107 and moves to the frequency layer dedicated to MBMS transmission by changing the center frequency to the frequency of the frequency layer dedicated to MBMS transmission (f (MBMS)). .

  FIG. 21 is a flowchart showing the unicast-side measurement process. Hereinafter, “Unicast side measurement” described in the first embodiment will be described in more detail with reference to FIG. In Step ST1753, the mobile terminal determines whether the DRX period start timing of the MBMS service has arrived using the DRX information received in Step ST1729 of FIG. As a specific example, the first SFN number at which the DRX period starts is obtained using the DRX cycle and the starting point value (DRX) of the parameter example received in step ST1729, and the SFN mapped to BCCH (broadcast control channel) or the like. Based on the above, it is determined whether or not it is the DRX period start timing. A specific calculation example is SFN = DRX cycle × α + starting point value (DRX) α: a positive integer. When it is not a start timing, it transfers to step ST1772. When it is a start timing, it transfers to step ST1754. A mobile terminal judges whether it is the measurement period in the MBMS / unicast mixed cell received in step ST1705 in step ST1754. When it is not a measurement cycle, it transfers to step ST1772. When it is a measurement cycle, it transfers to step ST1755. In Step ST1755, the mobile terminal changes the set frequency of the frequency conversion unit 1107 (synthesizer) and changes the center frequency to f (Unicast) to receive the downlink signal of the MBMS / unicast mixed cell. In Step ST1756, the mobile terminal performs measurement on the unicast side (unicast cell or / and MBMS / unicast mixed cell). As values actually measured by the mobile terminal, RSRP, RSSI, etc. of the serving cell and the neighboring cells are conceivable. The information on neighboring cells may be broadcast from the serving cell as neighboring cell information (list).

  In Step ST1757, the mobile terminal determines whether or not the serving cell re-selection is necessary as a result of the measurement in Step ST1756. As a specific example of the determination, there may be a case where the measurement result of one cell among the neighboring cells exceeds the measurement result of the serving cell. If reselection is not necessary, the process proceeds to step ST1771. If reselection is necessary, steps ST1758 and 1759 are executed. A base station (new serving cell) to be newly selected as a serving cell in step 1758 is subordinate to the measurement period, intermittent reception period, and tracking area information (TA information) in BCCH (broadcast control channel) as in step ST1705. Informs the mobile terminal. In Step ST1759, the mobile terminal receives the BCCH from the new serving cell and decodes it, thereby receiving the measurement period, intermittent reception period, and TA information. The description from step ST1761 to step ST1770 is the same as the description from step ST1710 to step ST1719, and will be omitted. In Step ST1771, the mobile terminal moves to the frequency layer dedicated to MBMS transmission by changing the set frequency of the frequency conversion unit 1107 and changing the center frequency to f (MBMS).

  Through the “unicast side measurement” process from step ST1753 to step ST1771, the mobile terminal can receive the unicast cell and / or the mixed MBMS / unicast cell even when receiving the MBMS service in the MBMS transmission dedicated frequency layer. Measurement is possible. As a result, the mobile terminal receiving the MBMS service in the MBMS transmission dedicated frequency layer can secure mobility in the unicast cell and / or the MBMS / unicast mixed cell. Thereby, the effect that it becomes possible to ensure the mobility in the MBMS dedicated cell without an uplink via a MBMS / unicast mixed cell can be acquired. For this reason, it is possible to receive a paging signal even in a mobile terminal receiving an MBMS service in a frequency layer dedicated to MBMS transmission. In addition, even in a mobile terminal that is receiving a service in the MBSFN transmission-dedicated frequency layer, downlink synchronization establishment through measurement with a unicast cell or MBMS / unicast mixed cell is performed according to a measurement cycle. As a result, the mobile terminal that has received the paging signal in the frequency layer dedicated to MBMS transmission that does not have an uplink, which is the second problem of the present invention, can respond to the paging signal in the unicast cell or the MBMS / unicast mixed cell. Even when a response is transmitted, an effect that can be realized with a small control delay can be obtained.

  FIG. 22 is a flowchart showing the intermittent reception processing at the time of MBMS reception. FIG. 22 is a more specific description of “intermittent reception at the time of MBMS reception” described in the first embodiment with reference to FIG. . In Step ST1772 of FIG. 21, the mobile terminal determines whether it is the MCCH reception timing of the MBSFN area number being received based on the MCCH scheduling information. That is, the mobile terminal determines whether it is the MCCH reception timing using the MCCH (multicast control channel) scheduling received in step ST1725. Specifically, the MCCH repetition period of the parameter example received in step ST1725, the head SFN number to which the MCCH is mapped is obtained using the starting point value, and the MCCH is mapped based on the SFN mapped to the BCCH or the like. It is determined whether or not it is the head SFN number to which the MCCH is mapped by determining whether or not it is the head. When it is not the head timing to which MCCH is mapped, it transfers to step ST1753. When it is the head timing to which MCCH is mapped, it transfers to step ST1773. In addition, step ST1772 may be determined for each MCCH repetition period 1 in FIG. 26, for example.

  Here, in step ST1772, the MCCH reception timing (the first SFN number to which the MCCH is mapped) and the intermittent reception cycle at the time of MBMS reception may be different. By making it separate, it becomes possible to set the intermittent reception cycle at the time of MBMS reception to “long” or “short” according to the network conditions, etc., and it is possible to construct a mobile communication system with a higher degree of freedom. Become. The intermittent reception period at the time of MBMS reception may be mapped from the serving cell to BCCH in step ST1707 and notified to the mobile terminal, or may be mapped from the MBMS dedicated cell to BCCH and notified to the mobile terminal in step ST1723. . Further, in step ST1728, the MBMS dedicated cell may be mapped to MCCH and notified to the mobile terminal. Specifically, in step ST1772, it is determined whether it is the intermittent reception timing at the time of MBMS reception. If it is the intermittent reception timing, the process proceeds to step 1784. If it is not intermittent reception timing, it is determined whether it is MCCH reception timing, and if it is MCCH reception timing, it will transfer to step ST1788. If it is not the reception timing of MCCH, it will transfer to step ST1753 of FIG.

  When paging occurs in the mobile terminal in step ST1773, in step ST1774, the MME tracks the tracking area of the mobile terminal based on the identifier (UE-ID, IMSI, S-TMSI, etc.) of the mobile terminal that is the destination of paging. (TA) Check the list. In Step ST1775, the MME determines whether TA (MBMS) is included in the tracking area list of the mobile terminal. As a specific example, the tracking area list of the mobile terminal is searched based on the UE-ID in the list as shown in FIG. When the mobile terminal is UE # 1 (UE-ID # 1) in FIG. 31A, it is determined that TA (MBMS) is not included. On the other hand, when the mobile terminal is UE # 2 (UE-ID # 2) in FIG. 31A, it is determined that TA (MBMS) is included because TA (MBMS) # 1 is included. To do. When TA (MBMS) is not included, it transfers to step ST1814. If TA (MBMS) is included, the process proceeds to step ST1776. In Step ST1776, the MME transmits a paging request to the MCE. That is, the MME 103 in FIG. 10 transmits a paging request to the MCE 801 using the MME-MCE interface. As MCEs that transmit a paging request from the MME, all MCEs that manage base stations that are geographically overlapped with the base stations managed by the MME can be considered.

Specific examples of parameters in the paging request include mobile terminal identifiers (UE-ID, IMSI, S-TMSI, etc.), TA (MBMS) numbers, and the like. At this time, instead of the TA (MBMS) number, both f (MBMS) and the MBSFN area ID, or only the MBSFN area ID may be used. In step ST1777, the MCE receives the paging request. Among the MCEs that have received the paging request in step ST1778, the MCE that is notified as a parameter in the paging request and that controls the MBSFN area ID associated with the TA (MBMS) number prepares for paging transmission. On the other hand, the MCE that does not control the MBSFN area ID associated with the TA (MBMS) number does not prepare for paging transmission. As a specific example of paging transmission preparation, the paging group of the mobile terminal is calculated using the paging group number K _MBMS of the own base station (own MBSFN area) and the received paging request. In the calculation, the same formula as that used on the mobile terminal side is used (Paging group = IMSI mod K _MBMS ). As described above, the method of managing the association between the TA (MBMS) number (MBSFN area) and the MCE on the MCE side that has received the paging request is the relationship between the MBSFN area ID and the MCE that controls the MBS service ID. Since it can be performed only within the architecture, that is, it can be performed independently of the MME, it is possible to obtain an effect that a mobile communication system with a high degree of freedom can be constructed.

  Further, the MME manages the MBSFN area ID related to the TA (MBMS) number as shown in FIG. 31 (c), and further, as shown in FIG. 31 (d), the MBSFN area ID and the MCE that controls the MBSFN area ID. Consider the case of managing numbers. In this case, in step ST1776, the MME transmits a paging request only to the MCE that manages the MBSFN area ID related to the TA (MBMS) number. As a specific example of the parameter in the paging request at that time, an identifier of the mobile terminal can be considered. The MCE that has received the paging request in Step ST1778 prepares for paging transmission as described above. As described above, in the method of managing the relationship between the MBSFN area ID and the MCE that controls the ID within the MME (FIG. 31D), the number of MCEs that notify the paging request from the MME decreases, so that the resource is effective. The effect that can be utilized is obtained. Further, since the amount of information to be notified is reduced, it is possible to obtain an effect that resources can be effectively used.

  Further, the MME manages the MBSFN area ID related to the TA (MBMS) number as shown in FIG. 31 (c), and further, as shown in FIG. 31 (e), the MBMS included in the MBSFN area ID and the MBSFN area ID. Consider a case where the cell ID of a dedicated cell and / or MBMS / unicast mixed cell is managed. In this case, in Step ST1776, the MME transmits a paging request to the cell included in the MBSFN area ID managed by the MME, not the MCE. As a specific example of the parameter in the paging request at that time, an identifier of the mobile terminal can be considered. As described above, the method for managing the relationship between the MBSFN area ID and the cell included in the MBSFN area ID in the MME (FIG. 31 (e)) does not require the MCE to perform processing related to paging signal transmission of the mobile terminal. Get better. This eliminates the need for adding a function to the MCE, so that the effect of avoiding the complexity of the MCE can be obtained. In addition, the effect of reducing the processing load of the MCE can be obtained.

  FIG. 32 is an explanatory diagram illustrating a channel configuration example for mapping a paging signal in the MBMS transmission dedicated frequency layer. FIG. 32A is a diagram showing a configuration including MBMS related information and a paging signal on a PMCH (Physical multicast channel). MBMS-related information is carried on the logical channels MTCH and MCCH for MBMS. The MBMS-related information and the paging signal may exist as information elements in the MTCH and MCCH, respectively, or the physical area (resource) to which each is mapped may be time-division multiplexed. All cells in a certain MBSFN area periodically perform multi-cell transmission of MCCH in the MBSFN area in the PMCH corresponding to the MBSFN area. On the other hand, a mobile terminal that is receiving or intending to receive an MBMS service transmitted from a cell in the MBSFN area periodically receives the MCCH, and receives the contents of the MBMS service, the frame configuration, etc. The MBMS service can be received.

  By including a paging signal in the MCCH, it is possible to receive paging information when a mobile terminal receiving or trying to receive the MBMS service receives the MCCH. This eliminates the need for the mobile terminal to separately receive paging at a timing other than receiving the MCCH, and thus enables paging to be received without interrupting reception of the MBMS service. Further, the DRX operation (reception operation is stopped) can be performed during the time when the MCCH is not received and the time when the MBMS service is not received, and the power consumption of the mobile terminal can be reduced. Also, the MCCH and the PCCH carrying the paging signal may be configured in the same MBSFN subframe, or the MBSFN subframe carrying the MCCH and the MBSFN subframe carrying the paging signal may be temporally adjacent to each other. You can leave it. With this configuration, it is possible to continuously receive a paging signal when a mobile terminal that is receiving or intending to receive an MBMS service receives an MCCH. This eliminates the need for the mobile terminal to receive for paging at timings other than receiving successive MBSFN subframes carrying MCCH and paging signals, and therefore receives the paging signal without interrupting reception of the MBMS service. It becomes possible. Further, the DRX operation can be performed during the time when the MCCH and the paging signal are not received and during the time when the MBMS service is not received, and the power consumption of the mobile terminal can be reduced.

  FIG. 32B discloses a configuration in which an indicator indicating whether MBMS control information has been changed and an indicator indicating whether a paging signal has been transmitted are provided. An indicator that indicates whether the MBMS control information has been changed is an MBMS-related information change presence / absence indicator, and an indicator that indicates whether a paging signal has been transmitted is a paging signal presence / absence indicator. The physical area to which the indicator is mapped may be provided in the MBSFN subframe in which the PMCH is transmitted, or may be provided in the physical area temporally adjacent to the MBSFN subframe in which the PMCH is transmitted. By doing so, the mobile terminal can receive and decode the MCCH or paging signal on the PMCH immediately after receiving the indicator. Specifically, for example, 1-bit information is used as an indicator. Each indicator is multiplied by a spreading code unique to the MBSFN area and is mapped to a predetermined physical area. As another method, for example, each indicator may be composed of a sequence specific to the MBSFN area and mapped to a predetermined physical area. When the mobile terminal receives an incoming call, for example, the paging signal presence / absence indicator is set to “1”, and when there is no incoming call, the paging signal presence / absence indicator is set to “0”. Also, for example, when the MBMS control information on the MCCH is changed due to a change in the content of the MBMS service transmitted in the MBSFN area, for example, the change presence / absence indicator of the MBMS related information is set to “1”. . A cycle (MBMS modification period) in which MBMS related information including one or more MBMS control information and an MBMS related information change presence / absence indicator can be changed is determined, and an MBMS related information change presence / absence indicator “1” is determined within the cycle. Is sent repeatedly. The MBMS modification period, start timing (SFN, starting point), etc. may be determined in advance, or may be notified by broadcast information from a serving cell in a unicast service or from an MBMS dedicated cell. If there is no further change in the MBMS related information after the MBMS change period has elapsed, for example, the change presence / absence indicator of the MBMS related information is set to “0”. The mobile terminal receives an indicator in the MCCH of the desired MBSFN area, performs despreading, etc., and determines whether the indicator is 1 or 0, so that whether the MBMS-related information existing in the MCCH has changed or not It is possible to determine whether a paging signal exists.

  By providing the indicator in this manner, when there is no change in the MBMS control information or when there is no paging signal, the mobile terminal does not need to receive or / and decode the entire PMCH information. For this reason, it is possible to reduce the reception power of the mobile terminal. By determining a cycle in which MBMS related information can be changed and transmitting the same MBMS control information at least once within the one cycle period, the mobile terminal transmits the same MBMS control information at least once. Since reception is possible, the reception error rate of MBMS control information can be reduced, and therefore the reception quality of the MBMS service can be improved. The physical area to which the MBMS-related information change presence / absence indicator indicating whether the MBMS control information has been changed may be the first MBSFN subframe of one or more MBSFN subframes to which the MBMS control information is mapped. Further, it may be the first OFDM symbol of the first MBSFN subframe. Accordingly, the mobile terminal can determine whether the MBMS control information has changed by receiving the first OFDM symbol.

  Further, a physical area to which a paging signal presence / absence indicator indicating whether or not a paging signal is present may be used as the first MBSFN subframe of one or a plurality of MBSFN subframes to which the paging signal is mapped. Further, it may be the first OFDM symbol of the first MBSFN subframe. As a result, the mobile terminal can determine whether a paging signal exists by receiving the first OFDM symbol. By mapping each indicator to the physical area as described above, when there is no MBMS control signal change, when there is no paging information, it is not necessary to receive or / and decode each subsequent OFDM symbol. It is possible to reduce received power. In addition, since it can be determined early with the first MBSFN subframe or the first OFDM symbol, the MBMS control information can be received immediately or the paging signal can be received immediately. Control delay can be reduced.

  As an indicator, the MBMS-related information change presence / absence indicator and the paging signal presence / absence indicator may be mapped to the same physical area, or may be mapped to different physical areas. When mapping to the same physical area, an OR operation of each indicator may be taken. As a result, the mobile terminal needs only one indicator to receive, so the effect of simplifying the receiving circuit configuration can be obtained. When mapping to different physical areas, the mobile terminal only needs to receive necessary indicators, and does not need to receive other indicators. Therefore, it is possible to further reduce the reception power of the mobile terminal and further reduce the reception delay of necessary information. For example, a mobile terminal that has received an MBMS service but is set not to receive a paging signal need only receive an MBMS-related information change presence / absence indicator, eliminating the need to receive a paging signal presence / absence indicator. Can do. If the MBMS-related information change presence / absence indicator and the paging signal presence / absence indicator are mapped to different physical areas, the reception timing of MCCH (first SFN number to which MCCH is mapped) or the MBMS-related change presence / absence indicator in step ST1772 When the repetition period and the paging signal presence / absence indicator repetition period are set to different values, only the MBMS related information change presence / absence indicator repetition period is received or / and decoded and received during the MCCH reception timing or MBMS related change presence / absence indicator repetition period. In the signal presence / absence indicator repetition period, only the paging signal presence / absence indicator can be received or / and decoded. As a result, the processing time of the mobile terminal can be shortened, and the effect that the power consumption can be reduced can be obtained.

  The repetition period of each indicator may be the same or different. The repetition period of each indicator may be the same as or different from the repetition period of MCCH. For example, the repetition cycle of the MBMS-related information change presence / absence indicator is the same as the MCCH repetition cycle, and the paging signal presence / absence indicator repetition cycle is n times the MCCH repetition cycle (n is an integer of 2 or more). . By doing so, it becomes possible to set the intermittent reception cycle at the time of MBMS reception to “long” or “short” according to the network conditions and the like, and it becomes possible to construct a mobile communication system with a higher degree of freedom. . The repetition period of the indicator is a paging signal presence / absence indicator repetition period (Repetition period) and an MBMS-related change presence / absence indicator repetition period (Repetition period), respectively. The start timing (SFN, starting point) of the MBSFN subframe in which the indicator exists, the subframe number, the repetition period of each indicator, etc. may be notified by the broadcast information of the serving cell of the unicast service, or the broadcast of the MBMS dedicated cell It may be notified by information or may be determined in advance. In this case, the mobile terminal performs step ST1772, or step ST1788, or step ST1789 for each MBMS-related change presence / absence indicator repetition period. The channel dedicated to the MBMS-related information change presence / absence indicator may be, for example, a MICH (MBMS Indicating CHannel), and a paging signal presence / absence indicator may be configured in the MICH. The MICH repetition period is referred to as a “MICH repetition period”. The repetition period of the paging signal presence / absence indicator may be the same as or different from the MICH repetition period. The notification of the indicator can be performed by the same method as described above. In this case, the mobile terminal performs step ST1772 or step ST1784 for each paging signal presence / absence indicator repetition period. Thereby, the time when each indicator is transmitted is not limited to the time when MCCH is transmitted, and the system can be designed flexibly.

  When the paging signal is included in the PMCH, there is a problem that it takes too much time to detect the paging signal addressed to the own mobile terminal when the number of mobile terminals that have received an incoming call becomes enormous. Further, there arises a problem that an area for mapping paging signals of all mobile terminals that have received incoming calls cannot be secured in a predetermined physical area carrying a paging signal. In order to solve these problems, a paging grouping method is disclosed. FIG. 32C shows a paging grouping method. All mobile terminals are divided into K groups, and a paging signal presence / absence indicator is provided for each group. The physical area for paging signal presence / absence indicator in MCCH is divided into K pieces, and the paging signal presence / absence indicator of each group is mapped to each of the divided physical areas. Here, K can take from 1 to the value of the total number of mobile terminals. When an incoming call is received at a certain mobile terminal, the paging signal presence / absence indicator of the group to which the mobile terminal belongs is set to “1”. When all mobile terminals belonging to a certain group do not receive an incoming call, the paging signal presence / absence indicator of that group is set to “0”. The paging signal presence / absence indicator may be subjected to repetition or the like in order to satisfy a desired reception error rate at the mobile terminal. The physical area to which the paging signal is mapped is also divided into K pieces so as to correspond to the K groups. The paging signal may be an identifier (identification number, identification code) for each mobile terminal. One physical area divided into K is a physical area in which paging signal data required by one mobile terminal is accommodated by adding the number of mobile terminals in the group. The number of mobile terminals in a group may be the same for all groups, or may be different for each group.

  For example, the number of mobile terminals in the group may be an average value of the number of mobile terminals that simultaneously receive incoming calls. Alternatively, the number of mobile terminals that can be allocated to one OFDM symbol in the entire frequency band may be used, and each OFDM symbol may be associated with each group. When an incoming call arrives at a certain mobile terminal, the paging signal presence / absence indicator of the group to which the mobile terminal belongs is set to “1” and mapped to the paging signal presence / absence indicator physical area corresponding to the group. At the same time, the paging signal for the mobile terminal that has received the incoming call is mapped to the physical area of the paging signal corresponding to the group to which the mobile terminal belongs. The mapping of the paging signal to the physical area is performed by multiplying each mobile terminal by an identification code unique to the mobile terminal. The paging signal may be an identifier for each mobile terminal. In this case, the control for multiplying the mobile terminal specific identification code can be omitted. The mobile terminal receives the paging signal presence / absence indicator of the group to which the mobile terminal belongs to determine whether an incoming call has been made to the group to which the mobile terminal belongs. When it is determined that the incoming call is received, the physical area to which the paging signal associated with the group to which the mobile terminal belongs is received and decoded. After decoding, blind detection is performed by performing a correlation operation with an identification code unique to the mobile terminal, and it is possible to determine that there is an incoming call to the mobile terminal by specifying a paging signal for the mobile terminal. Become. If no paging signal for the mobile terminal is detected, it is determined that there is no incoming call to the mobile terminal.

  By grouping the mobile terminals into K groups, the mobile terminal does not need to receive the entire paging signal area, and only receives the necessary area, that is, only the physical area to which the group to which the mobile terminal belongs corresponds. As a result, the paging signal detection time at the mobile terminal can be shortened, and further, the reception power of the mobile terminal can be reduced because it is not necessary to receive the corresponding physical area of the group to which the mobile terminal does not belong. Furthermore, by using a paging signal presence / absence indicator corresponding to each group, a paging signal presence / absence indicator can be provided with few physical resources even when there are a large number of mobile terminals. Furthermore, the mobile terminal only needs to receive the paging signal area as needed, and it is possible to reduce the reception power of the mobile terminal, and when it is not necessary to receive the paging signal, the mobile terminal immediately moves to the next operation. Therefore, the control delay can be reduced.

  In the above-described embodiment, one physical area divided into K pieces for mapping the paging signal is obtained by adding the physical area in which the paging signal data required by one mobile terminal is accommodated by the number of mobile terminals in the group. It was in the physical area. However, when the number of mobile terminals increases, the required physical area increases, and the overhead for transmitting the MBMS service increases, so the transmission speed of MBMS service data decreases. In order to prevent this, the paging signal for the mobile terminal is multiplied by an identification code unique to the mobile terminal for each mobile terminal. As a result, the mobile terminal can perform blind detection (Blind Detection) using the identification code unique to the mobile terminal to determine whether the information is addressed to the mobile terminal itself. There is no need to fix the area in advance. Therefore, a physical area for paging signals for all mobile terminals is not required, and it is sufficient if there is an area for the number of mobile terminals that are expected to actually receive incoming calls. As an example, there is a method in which the number of mobile terminals in the group is an average value of the number of mobile terminals that receive incoming calls simultaneously. This method makes it possible to effectively use limited physical resources. In addition, by using the above method, even when the number of mobile terminals receiving more than expected is increased, it becomes possible to transmit a paging signal to a new incoming mobile terminal on the next PMCH, etc. It becomes possible to respond flexibly by scheduling at the base station.

  When the total number of mobile terminals is small, only the paging signal presence / absence indicator may be transmitted with the value of K as the total number of mobile terminals. In this case, it is not necessary to secure a paging-related physical area, and it is sufficient to secure physical areas for paging signal presence / absence indicators for all the mobile terminals. For this reason, the efficiency of radio resources can be improved. In this case, a physical area for a paging signal presence / absence indicator corresponding to each mobile terminal exists. For this reason, in the mobile terminal, it is possible to determine the presence / absence of an incoming call without receiving the paging signal area only by receiving and decoding the physical area for the paging signal presence / absence indicator corresponding to the mobile terminal. The control delay in the paging operation can be reduced.

  FIG. 33 shows an example of a method for mapping a paging signal to a physical area carrying a paging signal on the PMCH. Of the mobile terminals belonging to the paging group n, the paging signal is mapped to the physical area for the group n for the mobile terminals n1, n2, etc. that are receiving calls. The base station multiplies the paging signal of each mobile terminal by an identification code (number, sequence) unique to the mobile terminal, adds a CRC, and performs processing such as encoding and rate matching. When the paging signal is an identifier for each mobile terminal, the control for multiplying the mobile terminal specific identification code can be omitted. The result of this series of processing is assigned to information element units corresponding to the size of the physical area to be mapped, and connected to each mobile terminal that is receiving an incoming call. The concatenated result is subjected to scrambling processing, modulation processing, and the like using a scrambling code unique to the MBSFN area. The modulation process may be specific to the MBSFN area. The result of performing these processes is mapped to the physical area corresponding to the paging group n. At this time, the base station sets “1” to the paging signal presence / absence indicator of the paging group n and maps it to the physical area of the paging group n of the paging signal presence / absence indicator. The physical area corresponding to the paging group n may be determined in advance, or may be notified as broadcast information from the unicast serving cell or the MBMS dedicated cell. The mobile terminal receives the paging signal presence / absence indicator of the paging group to which the mobile terminal belongs. If “1”, the mobile terminal receives the paging signal physical area corresponding to the paging group. The paging signal physical area is received, demodulated, descrambled by an MBSFN area specific scrambling code, and the result is divided into information element units. By performing a process such as decoding for each divided information element unit and performing a correlation operation using an identification number unique to the mobile terminal, the paging signal for the mobile terminal is blind-detected. If the correlation calculation result is greater than a certain threshold, it is determined that there is paging for the mobile terminal, and a paging incoming operation is started by a paging signal. If it is less than a certain threshold value, it is determined that there is no paging for the own terminal, and the process shifts to reception of MBMS related information, or shifts to DRX operation if there is no need to receive MBMS related information. Which group the own mobile terminal belongs to may be derived by a predetermined calculation method, or may be notified from a higher layer as a broadcast information from a serving cell or MBMS dedicated cell of unicast service.

  FIG. 34 shows another example of a method for mapping a paging signal to a physical area carrying a paging signal on the PMCH. Of the mobile terminals belonging to the paging group n, the paging signal is mapped to the physical area for the group n for the mobile terminals n1, n2, etc. that are receiving calls. The base station adds CRC (Cyclic Redundancy Check) to the paging signal of each mobile terminal, and performs processing such as encoding and rate matching. The results of these processes are multiplied by an identification code (number) unique to the mobile terminal. The orthogonality is obtained between the mobile terminals by using an identification code unique to the mobile terminal as a spreading code having orthogonality. The base station multiplexes the result of multiplying the spreading code for each mobile terminal that is receiving an incoming call. The multiplexed result is subjected to scrambling processing, modulation processing, and the like using a scrambling code unique to the MBSFN area. The modulation process may be specific to the MBSFN area. The result of performing these processes is mapped to the physical area corresponding to the paging group n. At this time, the base station sets “1” to the paging signal presence / absence indicator of the paging group n and maps it to the physical area of the paging group n of the paging signal presence / absence indicator. The physical area corresponding to the paging group n may be determined in advance, or may be notified as broadcast information from the unicast-side serving cell or the MBMS dedicated cell.

  The mobile terminal receives the paging signal presence / absence indicator of the paging group to which the mobile terminal belongs. If “1”, the mobile terminal receives the paging signal physical area corresponding to the paging group. The paging signal physical area is received, demodulated, and descrambled by a scrambling code unique to the MBSFN area. By performing a correlation operation on the result using an identification number unique to the mobile terminal, a paging signal for the mobile terminal is blind-detected. When the correlation calculation result is larger than a certain threshold value, it is determined that there is paging for the mobile terminal, and the paging incoming operation is started by the paging signal after decoding. If it is less than a certain threshold value, it is determined that there is no paging for the terminal itself, and the process shifts to reception of MBMS related information, or shifts to DRX operation if there is no need to receive MBMS related information. Which group the mobile terminal belongs to may be derived by a predetermined calculation method, or may be notified from a higher layer as a broadcast information from a unicast service serving cell or an MBMS dedicated cell. Note that the paging signal described in FIGS. 33 and 34 may be a transport channel to which the paging signal is mapped. This can be applied to the following embodiments. Any information that carries a paging signal, which is paging-related information required when the mobile terminal receives paging, may be used.

  Several methods for mapping the paging signal to the area carrying the paging signal of the PMCH have been disclosed, but the mapping to the area carrying the paging signal may be any predetermined area or localized (frequency It may be mapped to a physical area continuous on the axis) or may be mapped to a distributed (physical area distributed on the frequency axis).

  In the above example, the paging signal is multiplied by an identification number or spreading code unique to the mobile terminal. By adopting such a configuration, when the information amount of the paging signal is the same in each mobile terminal, the size of the area in units of information elements to be allocated by making the processing such as encoding and rate matching the same between the mobile terminals. Can be made the same. Therefore, since the size of the information element unit area for blind detection in the mobile terminal is limited to one, the number of blind detections can be reduced, and the detection time can be shortened. Therefore, it is possible to obtain an effect that the circuit configuration of the mobile terminal, power consumption, and control delay can be reduced.

  As described above, the mobile terminal receives the entire paging signal area by multiplying the paging signal by the identification number or spreading code unique to the mobile terminal and mapping it to the area where the paging signal of the PMCH is carried for each paging group. This eliminates the need to receive only the necessary area, that is, only the physical area to which the group to which the mobile terminal belongs corresponds, so that the paging signal detection time at the mobile terminal can be shortened, and further the group to which the mobile terminal does not belong Therefore, the received power of the mobile terminal can be reduced. Furthermore, a paging signal presence / absence indicator corresponding to each group can be used, and even when there are a large number of mobile terminals, the paging signal presence / absence indicator can be provided with few physical resources. Furthermore, the mobile terminal only needs to receive the paging signal area as needed, and it is possible to reduce the reception power of the mobile terminal, and when it is not necessary to receive the paging signal, the mobile terminal immediately moves to the next operation. Therefore, the control delay can be reduced. Furthermore, since the mobile terminal can blindly detect whether the information is addressed to the mobile terminal by using an identification code or a spreading code unique to the mobile terminal, a physical area for mapping a paging signal for each mobile terminal Since there is no need to have a fixed paging signal area for all mobile terminals, there is no need for a physical area for paging signals for all mobile terminals, and there is only an area for the number of mobile terminals that are expected to actually receive calls. It is possible to effectively use physical resources. Furthermore, even if the number of mobile terminals that receive more than expected is increased, a paging signal to a new incoming mobile terminal can be transmitted on the PMCH carrying the next MCCH. It is possible to respond flexibly by scheduling.

  In the above example, the base station multiplies the paging signal by the identification number unique to the mobile terminal. However, it is also possible to use a method of multiplying CRC instead of a paging signal by an identification number unique to the mobile terminal. The method of multiplying the CRC by the identification number unique to the mobile terminal is effective when the information amount of the paging signal of each mobile terminal is different. By adopting the method of putting a paging signal on the PMCH disclosed above, the mobile communication system can transmit the paging signal of all the mobile terminals that are receiving or trying to receive the MBMS service from the MBMS dedicated cell. This enables the mobile terminal to receive a paging signal from the MBMS dedicated cell.

  Hereinafter, the channel configuration for mapping the paging signal in the MBMS transmission dedicated frequency layer will be described with reference to FIGS. 32 (c) and 33. In Step ST1779, the MCE schedules the paging signal of the mobile terminal. Specifically, it is determined to which number of information elements mapped to the physical area assigned to the paging group number of the mobile terminal calculated in step ST1778 is assigned the mobile terminal identifier. By performing this scheduling in the MCE, the identifier of the mobile terminal is transmitted from the same physical resource of the base station included in the MBSFN area. As a result, the mobile terminal can receive the paging signal benefiting from the SFN gain by receiving the PMCH transmitted in multicell in the MBSFN area. In Step ST1780, the MCE transmits a paging request for the mobile terminal to the base station in the MBSFN area. Specific examples of parameters included in the paging request include mobile terminal identifiers (UE-ID, IMSI, S-TMSI, etc.), and paging signal scheduling results (specifically, SFN and MBSFN subframes) performed in step ST1779. Number, information element number) and the like. In step ST1781, each base station in the MBSFN area receives a paging request from the MCE.

  Instead of providing the MME-MCE IF between the MME 103 and the MCE 801 shown in FIG. 10, an MME-MBMS GW interface may be provided between the MME 103 and the MBMS GW 802 (more specifically, MBMS CP 802-1). Even if the processing contents of MCE from step ST1776 to step ST1780 are performed by the MBMS GW, the same effect as the present invention can be obtained.

In Step ST1782, each base station in the MBSFN area calculates the mobile terminal paging group. As a specific example of the calculation method, the paging group of the mobile terminal is calculated using the paging group number K _MBMS of the own base station (own MBSFN area) and the received paging request. In the calculation, the same formula as that used on the mobile terminal side is used (paging group = IMSI mod K _MBMS ). If the paging group of the mobile terminal is also notified in step ST1780, step ST1782 can be omitted. Thereby, effects, such as reduction of the control load of each base station in the MBSFN area, can be obtained. On the other hand, in the method of calculating the paging group in each base station in the MBSFN area in step ST1782 without notifying the paging group of the mobile terminal in step ST1780, notification information from the MCE to each base station in the MBSFN area Can be reduced, and the effect of effective use of resources can be obtained. Each base station in the MBSFN area in Step ST1783 uses the identifier of the mobile terminal received in Step ST1781, the scheduling result of the paging signal, the paging group of the mobile terminal calculated in Step ST1782, and the like. The PMCH carrying the above is transmitted. In this case, the above-described method can be used as a mapping method to a paging-related area in the PMCH, a specific mapping method to a physical channel, and the like.

  In Step ST1784, the mobile terminal receives a paging-related change presence / absence indicator corresponding to the paging group calculated in Step ST1735 of the own mobile terminal in the PMCH. In Step ST1785, the mobile terminal determines whether there is a change in the paging-related change presence / absence indicator. When there is no change, it transfers to step ST1788. If there is a change, the process proceeds to step ST1786. In Step ST1786, the mobile terminal continues to receive and decode the physical area to which the paging related information of the own paging group is mapped. At that time, blind detection is performed by performing a correlation calculation with an identification code unique to the mobile terminal. In step ST1787, the mobile terminal determines whether the identifier of the mobile terminal has been detected in the blind detection performed in step ST1786. When not detected, it transfers to step ST1788. If detected, the process proceeds to step ST1814. The contents described in step ST1773 to step ST1787 are specific examples of the “MBMS reception time missing reception configuration” described in the first embodiment. As a result, it is possible to disclose a paging signal notification method and a mobile communication system therefor for a mobile terminal receiving an MBMS service in a frequency layer dedicated to MBMS transmission, which is the first problem of the present invention. As a result, the mobile terminal receiving the MBMS service in the frequency layer dedicated for MBMS transmission can also receive the paging signal.

  Next, “MTCH reception” described in Embodiment 1 with reference to FIG. 17 will be described in more detail with reference to FIG. 22 and FIG. In Step ST1788, the mobile terminal determines whether the MBMS service in the MBSFN area is being continuously received. When not continuously receiving, it moves to step ST1792. If continuous reception is in progress, the mobile terminal makes a transition to step ST1789. In Step ST1789, the mobile terminal receives an MBMS-related change presence / absence indicator in the PMCH. In Step ST1790, the mobile terminal determines whether there is a change in the MBMS-related change presence / absence indicator. When there is no change, it transfers to step ST1791. If there is a change, the process proceeds to step ST1792. In Step ST1791, the mobile terminal does not change the MCCH at the reception timing of this MCCH, and therefore does not perform MBMS-related reception or / and decoding in the MCCH. The mobile terminal receives and decodes the MTCH without updating the control information (MCCH). In Step ST1792, the mobile terminal performs MBMS-related reception and decoding in the MCCH, and updates the control information. In Step ST1793, the mobile terminal receives and decodes the MTCH according to the control information received in Step ST1792.

  In Step ST1794 of FIG. 23, the mobile terminal measures the reception quality of the MBMS service being received. The mobile terminal receives the reference signal (RS) with the radio resource in the MBSFN area and measures the received power (RSRP). It is determined whether or not the received power is equal to or greater than a threshold value determined statically or semi-statically. If the threshold value is equal to or greater than the threshold value, it indicates that the sensitivity is satisfactory for receiving the MBMS service, and if the threshold value is less than the threshold value, it indicates that the sensitivity is not sufficient for receiving the MBMS service. If it is equal to or greater than the threshold, the process proceeds to step ST1795, and if it is equal to or less than the threshold, the process proceeds to step ST1796. Further, instead of receiving the reference signal in step 1794 and measuring the received power, it is also possible to actually receive the MBMS service (MTCH or / and MCCH) in the MBSFN area and perform decoding. In that case, the user himself / herself can determine whether or not the reception sensitivity is acceptable by listening or viewing the decoded data. If allowed, the process proceeds to step ST1795, and if not permitted, the process proceeds to step ST1796. Since there are individual differences in permissible reception sensitivity for each user, an effect of becoming a mobile terminal more suitable for the user can be obtained. In step ST1795, the mobile terminal confirms the user's intention. If the user wants to continue receiving the currently received MBMS service, the mobile terminal makes a transition to step ST1753. If the user wants to finish receiving the currently received MBMS service, the mobile terminal makes a transition to step ST1798. In Step ST1796, the mobile terminal determines whether there is another MBMS area that can be received within the same frequency (f (MBMS)). This step ST1796 is particularly effective when there is an MBSFN area to be covered. When it exists, it returns to step ST1730 and repeats a process. If not, the process proceeds to step ST1797.

  However, if another receivable MBMS area desired by the user is not found after that, the process of “MBMS reception end A” after step ST1798 is performed. Thereby, the network side can know that the said mobile terminal complete | finishes reception of the MBMS service in the frequency layer only for MBMS transmission. Accordingly, the configuration in which the network side notifies the paging signal to the mobile terminal in the frequency layer dedicated to MBMS transmission can be stopped. This makes it possible to cancel the paging signal to the mobile terminal from the frequency layer dedicated to MBMS transmission that is not received by the mobile terminal as a mobile communication system, and has an effect of effective use of radio resources. . In step 1797, the mobile terminal determines whether another frequency exists in the frequency list of the receivable MBSFN synchronization area received in step ST1708. If it exists, the process returns to step ST1722, and the process is repeated by switching the synthesizer to a new frequency (f2 (MBMS)). If not, the process proceeds to step ST1798.

  Next, “MBMS reception end A” described in the first embodiment will be described more specifically with reference to FIG. In Step ST1798, the mobile terminal moves to the MBMS / unicast mixed cell by changing the set frequency of the frequency conversion unit 1107 and changing the center frequency to f (unicast). The description of step ST1799 to step ST1803 is the same as the description of step ST1737 to step ST1741 and will be omitted. In Step ST1804, the mobile terminal transmits “MBMS reception end” to the serving cell according to the UL (Uplink) allocation received in Step ST1803. Examples of parameters included in “end of MBMS reception” include an identifier (UE-ID, IMSI, S-TMSI, etc.) of a mobile terminal, a frequency (f (MBMS)) at which MBMS service reception ends, and an MBSFN area number (ID). and so on. In step ST1805, the serving cell receives the MBMS reception end from the mobile terminal. In step ST1805, the network side can know that the mobile terminal ends the reception of the MBMS service in the frequency layer dedicated for MBMS transmission without adding an uplink to the MBMS dedicated cell. As a result, there is an effect that the network side can be changed from the MBMS reception time missing reception configuration to a configuration for notifying a normal paging signal. In step ST1806, the serving cell transmits an MBMS reception end to the MME. In Step ST1807, the MME receives the MBMS reception end from the serving cell.

  In Step ST1808, the MME searches for a TA (MBMS) for terminating the MBMS reception of the mobile terminal. An example of the relationship between the parameters included in the end of MBMS reception and TA (MBMS) is the same as that in step ST1747, and a description thereof will be omitted. In step ST1809, TA (MBMS) obtained as a result of the search in step ST1808 is deleted from the tracking area list of the mobile terminal. In step ST1810, when the MME receives the signal notifying completion of MBMS reception transmitted via the serving cell, the MME transmits Ack as a response signal to the serving cell. As an example of parameters included in the response signal Ack, a tracking area list of the mobile terminal can be considered. In step ST1811, the serving cell receives the response signal Ack transmitted from the MME. In step ST1812, the serving cell transmits the received response signal Ack to the mobile terminal. In Step ST1813, the mobile terminal receives the response signal Ack from the MME transmitted via the serving cell.

  Next, “unicast side intermittent reception” described in the first embodiment will be described more specifically with reference to FIG. In Step ST1814, the MME confirms the tracking area list of the mobile terminal based on the identifier (UE-ID, IMSI, S-TMSI, etc.) of the mobile terminal where paging has occurred. TA (Unicast) is searched in the tracking area list of the mobile terminal. As a specific example, the tracking area list of the mobile terminal is searched based on the UE-ID in the list as shown in FIG. When the mobile terminal is UE # 1 in FIG. 31A, TA (Unicast) includes # 1 and # 2. Next, the MME searches for the identifier (cell ID) of the base station included in TA (Unicast) in the list as shown in FIG. When the mobile terminal is UE # 1 in FIG. 31A, the cell IDs included in the tracking area list of the mobile terminal are cell IDs 1, 2, 3, 4, 5, 23, 24, 25. It becomes. The MME transmits a paging request to a base station (including a serving cell) included in the tracking area list of the mobile terminal. Specific examples of parameters in the paging request include mobile terminal identifiers (UE-ID, IMSI, S-TMSI, etc.). In step ST1815, the base station (including the serving cell) included in the tracking area list (TA (Unicast)) of the mobile terminal receives the paging request.

  Here, the third problem of the present invention will be described. Even in a mobile terminal in an idle state in an MBMS / unicast mixed cell, details of a notification method of a paging message have not been established. Non-Patent Document 1 discloses that PCH is mapped to PDSCH or PDCCH. Non-Patent Document 1 discloses that the paging group uses the L1 / L2 signaling channel (PDCCH), and the clear identifier (UE-ID) of the mobile terminal can be found on the PCH. On the other hand, there is no disclosure of how mobile terminals are divided into paging groups and how PCHs are notified for each paging group. There is also no disclosure of how the mobile terminal performs intermittent reception in a standby state. It is an object of the present invention to disclose details of a method of notifying a paging signal to a mobile terminal in a standby state in a unicast and / or mixed frequency layer, and a mobile communication system therefor.

Therefore, a specific example of a paging signal notification method will be disclosed. Mobile terminals are divided into paging groups. In the conventional technique (W-CDMA system), the number of S-CCPCH (Secondary Common Control CHannel) to which PCH is mapped (number of channelization codes) is defined as the number of groups. However, since the LTE system is not a code division multiplexing (CDM) system, the concept of the number of channelization codes cannot be adapted. In Non-Patent Document 1 in the current 3GPP, it is disclosed that the paging group uses the L1 / L2 signaling channel (PDCCH), and the clear identifier (UE-ID) of the mobile terminal can be found on the PCH. Has been. However, no specific examples are disclosed. Calculation expression for determining a paging group and _{K Unicast} the (IMSI mod _{K Unicast)} is the number of paging groups in an MBMS / Unicast-mixed cell. As a specific example of the value of K, the L1 / L2 signaling channel (PDCCH) is mapped to each subframe. There are 10 subframes in one radio frame. Therefore, the number of paging groups is 10. That is, the paging group can identify which subframe in the radio frame is mapped with the paging information of the group to which it belongs. Next, to which radio frame the paging information of the group to which the user belongs is mapped, this can follow the conventional technique (W-CDMA). A specific calculation formula is “Paging Occasion = (IMSI div K _unicast ) mod (intermittent reception period in unicast / mixed frequency layer) + n × (intermittent reception period in unicast / mixed frequency layer) n: 0, 1, 2 ... However, “Paging Occlusion ≦ maximum value of SFN”. Here, SFN is an integer from 0 to the maximum value of SFN.

  Next, in the current 3GPP, Non-Patent Document 1 discloses that a clear identifier (UE-ID) of a mobile terminal can be found on the PCH. However, there is no disclosure about specific examples. As a specific example of the mapping method of specific paging information to the PCH, the PCH is configured with identification information of the mobile terminal, or is configured to be correlated by applying the identification information of the mobile terminal. . The PCH is mapped in units of CCE on the L1 / L2 signaling channel. Also, it is assumed that the PCH includes allocation of downlink radio resources of the control channel that the mobile terminal should receive next. As a result, there is no need for downlink assignment again, and the effect that the control delay can be reduced can be obtained. A method of not transmitting the downlink radio resource assignment of the control channel that the mobile terminal should receive next on the PCH may be used. In this method, a paging indicator is transmitted on the L1 / L2 signaling channel, the paging indicator addressed to itself is blindly detected, and the received mobile terminal transmits an uplink RACH to request the base station for radio assignment. You can think of a way to keep it.

  In step ST1816, the base station (including the serving cell) included in the tracking area list (TA (Unicast)) of the mobile terminal prepares for unicast-side intermittent reception. Specifically, the paging group and the paging occasion are calculated from the identifier of the mobile terminal received in step ST1815. Specific examples of the calculation formula are as described above. In step ST1817, the base station (including the serving cell) included in the tracking area list (TA (Unicast)) of the mobile terminal transmits the paging information of the mobile terminal according to the paging group and paging occurrence calculated in step ST1816. To map. At this time, any CCE is acceptable as long as it is a CCE in the L1 / L2 signaling channel in the subframe indicated by the paging group in the radio frame indicated by the Paging Occlusion. Or it maps to CCE where allocation to PCH was decided. When the allocation of the PCH is determined, the number of times that the mobile terminal performs blind detection is reduced, so that an effect that the control delay is reduced can be obtained. In Step ST1818, the base station (including the serving cell) included in the TA list (TA (Unicast)) of the mobile terminal transmits the PCH.

  In Step ST1819, the mobile terminal moves to the unicast / mixed frequency layer by changing the set frequency of the frequency converting unit 1107 and changing the center frequency to f (unicast). In Step ST1820, the mobile terminal prepares for unicast side intermittent reception. Specifically, the paging group and the paging occasion are calculated from the identifier of the own mobile terminal. The calculation formula is the same as that described above on the network side. In Step ST1821, the mobile terminal performs blind detection of the PCH on the L1 / L2 signaling channel according to the paging group calculated in Step ST1820 and the Paging Occlusion. For blind detection, the identifier of the mobile terminal is used. The correlation value is obtained by multiplying the identifier of the mobile terminal by the CCE unit of the PCH. If the correlation value is greater than or equal to the threshold value, it is determined that there is paging to the own mobile terminal. In Step ST1822, the mobile terminal decodes the PCH and obtains downlink assignment for the next control channel. Control information is received according to the allocation.

  Next, in the current 3GPP, in a mixed cell, it is determined that in the MBSFN frame (subframe), except for the first 1-2 OFDM symbols in subframe units, it should not be used for unicast transmission. In other words, resources other than the first 1-2 OFDM symbols are dedicated to MBMS transmission. This is because the MBSFN frame is not assigned to subframes # 0 and # 5 and is a subframe to which the SCH is mapped. Here, the following problems occur. If the calculation formula of the paging group and the paging occasion is used, the paging signal may be generated every radio frame and every subframe. Since PCH uses an L1 / L2 signaling channel, it can be mapped even in an MBSFN frame. On the other hand, in the MBSFN frame, when the downlink radio resource of the next control information is allocated in the PCH, the downlink radio resource on the same subframe is dedicated to MBMS transmission, so the control information is allocated in the same subframe. The problem of not being able to do occurs. As a first solution, the downlink radio resource allocation of the next control information in PCH is a radio frame other than the subsequent MBSFN frame. As a second solution, a paging signal is assigned to one or a plurality of subframes excluding the MBSFN subframe. For example, the number of paging groups is made equal to or less than the number of subframes excluding the MBSFN subframe in the radio frame. This eliminates the need to assign a paging signal to the MBSFN subframe. As a specific example, the number of paging groups is 2, and the paging group calculation formula is “IMSI mod 2” as follows. As a specific group assignment example, if paging group = 0, subframe # 0 is assigned. If paging group = 1, subframe # 5 is allocated. As a result, it is possible to notify paging information only in subframes (# 0, # 5) to which no MBSFN frame is assigned, so that the next control information can be assigned in the same subframe as the paging signal. Can solve the problem of not.

  FIG. 24 shows the processing details of MBMS reception end B. In FIG. 24, step ST1823 to step ST1837 are the same as step ST1799 to step ST1813, and thus the description thereof is omitted. The difference is that “response to Paging” is included in step ST1828. By this MBMS reception end B processing, the network side can know that the mobile terminal ends the reception of the MBMS service in the MBMS transmission dedicated frequency layer without adding an uplink to the MBMS dedicated cell. . As a result, there is an effect that the network side can be changed from the MBMS reception time missing reception configuration to a configuration for notifying a normal paging signal. In the second embodiment, the case where the frequency layer dedicated to MBMS transmission is configured by the MBMS dedicated cell has been described. Even if the frequency layer dedicated to MBMS transmission is configured by an MBMS / unicast mixed cell, the second embodiment can be applied. In addition to the first embodiment, the third, fourth, fifth, and sixth embodiments described below are also applicable even if the MBMS transmission-dedicated frequency layer is configured with an MBMS / unicast mixed cell.

Embodiment 3 FIG.
In the present embodiment, with reference to FIG. 35, among the processes of the mobile communication system described in Embodiments 1 and 2, “Receivable MBMS notification”, “MBMS search”, “MBMS” The “service selection” portion will be further described. In step ST3501 of FIG. 35, the serving cell notifies the mobile terminal of information related to receivable MBMS. A serving cell is a base station that performs scheduling to allocate uplink radio resources and downlink radio resources to the mobile terminal. Base stations that can serve as serving cells include unicast cells or mixed MBMS / unicast cells. As a specific example of receivable MBMS information, the frequency of an available MBMS service, that is, the frequency of a receivable MBSFN synchronization area (MBSFN Synchronization Area), that is, the frequency of a receivable MBMS transmission dedicated frequency layer (f ( One or more) (referred to as MBMS). A broadcast control channel (BCCH) is used when notifying information related to receivable MBMS from the serving cell to the mobile terminal. Information about receivable MBMS is first mapped to a broadcast control channel (BCCH) which is a logical channel, and further mapped to a broadcast channel (BCH) which is a transport channel and a physical broadcast channel (PBCH) which is a physical channel. The In addition, information relating to receivable MBMS is mapped to a broadcast control channel (BCCH) that is a logical channel, and then a downlink shared channel (DL-SCH) that is a transport channel, and a physical downlink shared channel that is a physical channel (PDSCH) may be mapped.

  In Step ST3502, the mobile terminal receives f (MBMS) transmitted from the serving cell. Here, in step ST3501, there is a problem as to how the serving cell obtains information regarding receivable MBMS notified from the serving cell to the mobile terminal. Specifically, if the information regarding receivable MBMS is not frequently changed and is determined to be semi-static, it can be set in the serving cell every time it is changed. Further, information regarding receivable MBMS may be notified from a frequency layer control device dedicated to MBMS transmission to a unicast / mixed frequency layer control device or periodically. As a further specific example, information regarding receivable MBMS is notified from the MCE to the MME or the base station. Further, the MBMS GW may notify the MME or the base station.

  In step ST3503, the mobile terminal confirms in step ST3502 whether or not it has received one or more frequencies of a receivable frequency layer dedicated to MBMS transmission. If it has not been received, the process ends. When having received, it transfers to step ST3504. In Step ST3504, the mobile terminal confirms whether or not the user intends to receive the MBMS service in the frequency layer dedicated to MBMS transmission. As a specific example of the confirmation, when the user has an intention to receive the MBMS service, an instruction is sent to the mobile terminal using the user interface, and the mobile terminal stores the user's intention in the protocol processing unit 1101. In Step ST3504, the mobile terminal confirms whether or not there is an intention to receive the MBMS service stored in the protocol processing unit 1101. If there is no intention to receive the MBMS service, the processing in step ST3504 is repeated. As a method of repeating, when the mobile terminal makes a determination in step ST3504 at a certain period, or when there is a change notification of intention to receive the MBMS service input by the user through the user interface, step ST3504 or step ST3504 There is a method of performing ST3503. If there is an intention to receive the MBMS service, the mobile terminal makes a transition to step ST3505. The order of the processing of step ST3503 and step ST3504 is arbitrary and may be simultaneous. In Step ST3505, the mobile terminal moves to the frequency layer dedicated to MBMS transmission by changing the set frequency of the frequency conversion section 1107 and changing the center frequency to f (MBMS). Changing the set frequency of the frequency conversion unit 1107 and changing the center frequency is referred to as re-tune.

  In Step ST3506, the mobile terminal performs an MBMS search operation. Details of the MBMS search operation are described in the second embodiment, and are omitted here. The mobile terminal establishes synchronization with the MBMS dedicated cell, acquires system information of the MBMS dedicated cell, acquires MCCH scheduling, and the like by the MBMS search operation. In Step ST3507, the MBMS dedicated cell notifies the mobile terminal of the MBMS service content. Non-Patent Document 1 describes that the MCE 801 assigns radio resources to all base stations in the MBSFN area in order to perform multi-cell MBMS transmission. From this, it is considered that the same MBMS service capable of SFN combining (Combining) is provided in the MBSFN area. Therefore, notification of MBMS service contents in step ST3507 is performed for each MBSFN area using a channel for each MBSFN area. Non-Patent Document 1 describes that the MBSFN synchronization area includes one or more MBSFN areas. Thus, notification of the MBMS service content in step ST3507 is performed for each MBSFN area for all MBSFN areas included in the MBSFN synchronization area using a channel for each MBSFN synchronization area.

  Specific examples of MBMS service contents include direct service contents such as “weather forecast”, “baseball broadcast”, and “news”. Further, the service number or the MBSFN area number (ID) may be used instead of the direct service content. When the MBMS service content is notified by the service number or the MBSFN area number (ID), the service number or the MBSFN area number (ID) is directly associated with the service content statically or semi-statically (see FIG. 36). ) On the network side and mobile terminal side. When the correspondence between the service number and the direct service content is determined semi-statically, the correspondence between the service number and the direct service content from the network side to the mobile terminal side every time it is changed or periodically Need to be notified.

  The correspondence between the service number and the direct service content is mapped to the broadcast control channel (BCCH) that is a logical channel of the MBMS dedicated cell, and further, the broadcast channel (BCH) that is a transport channel, and the physical broadcast channel that is a physical channel Mapped to (PBCH). It may be mapped to a broadcast control channel (BCCH) that is a logical channel, and further mapped to a downlink shared channel (DL-SCH) that is a transport channel and a physical downlink shared channel (PDSCH) that is a physical channel. Further, it may be mapped to a multicast control channel (MCCH) that is a logical channel, and may be mapped to a multicast channel (MCH) that is a transport channel and a physical multicast channel (PMCH) that is a physical channel. Further, it may be mapped to a multicast control channel (MCCH) that is a logical channel and mapped to a downlink shared channel (DL-SCH) that is a transport channel and a physical downlink shared channel (PDSCH) that is a physical channel.

  Further, not the direct service content but the channel number or the MBSFN area number (ID) may be notified from the network side to the mobile terminal side. The channel number or MBSFN area number (ID) here is assumed to be a channel number of a television. In this case, the user needs to know the program guide for each channel (direct service contents for each time) separately. This program guide may be notified from the network side to the mobile terminal side every time it is changed, or may be posted on an existing medium such as a newspaper. A specific example of the channel used for notifying the program guide for each channel from the network side to the mobile terminal side is the same as that for notifying the correspondence between the service number and the direct service content, and thus the description thereof is omitted. In Step ST3508, the mobile terminal receives the MBMS service content transmitted from the MBMS dedicated cell.

  In step ST3509, the mobile terminal confirms the service content of the MBMS received in step ST3508 in order to know whether the service desired by the user is being performed. If the service desired by the user is being performed, the process proceeds to step ST3510. If the service desired by the user is not provided, the mobile terminal makes a transition to step ST3512. In Step ST3510, the mobile terminal receives the reference signal (RS) by the radio resource in the MBSFN area where the service desired by the user is performed, and measures the received power (RSRP). In Step ST3510, the mobile terminal determines whether or not the received power is equal to or higher than a threshold determined statically or semi-statically. If the threshold is equal to or greater than the threshold, it indicates that the quality is satisfactory for receiving the MBMS service, and if the threshold is less than the threshold, it indicates that the quality is not sufficient for receiving the MBMS service. If it is equal to or greater than the threshold value, the process proceeds to step ST3511. If it is equal to or less than the threshold value, the process proceeds to step ST3512. In step ST3510, as long as it is possible to determine whether or not the reception quality satisfies a quality sufficient for receiving the MBMS service, the above method of measuring the reception power of the reference signal (RS) may not be used. In Step ST3511, the mobile terminal selects the MBMS service. Specifically, the mobile terminal acquires and determines the MBMS transmission-dedicated frequency f (MBMS), MBSFN area ID (number), and the like for receiving the MBMS service desired by the user. In Step ST3512, the mobile terminal receives other frequencies (frequency of a frequency layer dedicated to MBMS transmission different from the current frequency) in the receivable MBSFN synchronization area frequencies (frequency list) received in Step ST3502. ) Exists. If it exists, the process returns to step ST3505, the set frequency is switched to a new frequency (for example, f2 (MBMS)), and the process is repeated. If it does not exist, the process ends.

  According to the third embodiment, it is possible to obtain a method for moving a mobile terminal to a frequency layer dedicated to MBMS transmission and a method for selecting a desired service, which is a first problem of the present invention. Furthermore, since the MBMS service that can be used exists and the frequency thereof can be known at the location where the mobile terminal is geographically located, the mobile terminal intends to receive the MBMS service in the frequency layer dedicated to MBMS transmission. If there is, there is no need to search for brute force frequencies that may have a frequency layer dedicated to MBMS transmission. This has the effect of reducing the control delay of the mobile terminal until receiving a service with a frequency other than the current frequency. Thereby, the effect of reducing the power consumption of the mobile terminal can also be obtained. Further, as compared with the fourth embodiment to be described later, in solving the first problem, the amount of information notified from the serving cell may be small. This means that the time for receiving information from the serving cell, that is, the reception time, the decoding time of received data, and the like are shorter than those in the fourth embodiment. As a result, there is an effect that the control delay of the mobile terminal until a service with a frequency other than the current frequency is received is shortened. Furthermore, the effect of reducing the power consumption of the mobile terminal can also be obtained.

Modification 1
Hereinafter, Modification 1 of the present embodiment will be described. When information on neighboring cells (neighboring cell information (list), neighboring cell (neighboring cell) information (list)) is notified from the serving cell to the mobile terminal, information on MBMS that can be received in the neighboring cell is notified from the serving cell. Also good. Information regarding receivable MBMS in the neighboring cell may be notified simultaneously with the neighboring cell information, or may not be notified at the same time. A specific example of information regarding receivable MBMS is the same as that in the third embodiment, and a description thereof will be omitted. According to the first modification, the following effects can be obtained. Let us consider a case where the reception sensitivity of the adjacent cell becomes good in the unicast / mixed frequency layer, that is, the case where the timing for executing the handover arrives. If f (MBMS) currently received by the mobile terminal does not exist in the information on the receivable MBMS in the base station (new serving cell: handover destination base station) to be newly selected as the serving cell, It can be determined that the sensitivity of the service by the currently received f (MBMS) deteriorates. The determination result can be notified to the user by displaying on the display unit, ringing, or the like. As a result, when the user gives priority to the current MBMS service reception over the movement, the movement can be stopped, and an effect that the usage can be more adapted to the needs of the user can be obtained. In addition, when the reception sensitivity of f1 (MBMS) being received has deteriorated, it does not exist in the information on MBMS that can be received by the serving cell (own cell), but f2 ( When MBMS) exists, it is possible to try operations such as MBMS search at f2 (MBMS). As a result, it is possible to obtain an effect that enables usage in accordance with the needs of the user.

Embodiment 4 FIG.
In the present embodiment, with reference to FIG. 37, “Receivable MBMS notification” and “MBMS search” in the processing flow of the mobile communication system described in Embodiment 1 and Embodiment 2. The “MBMS service selection” part will be further described. In FIG. 37, the same steps as those in FIG. In Step ST3701, the serving cell notifies the mobile terminal of information regarding receivable MBMS. As a specific example of receivable MBMS information, the frequency of an available MBMS service, that is, the frequency of a receivable MBSFN synchronization area (MBSFN Synchronization Area), that is, the frequency of a receivable MBMS transmission dedicated frequency layer (f ( One or more). Also, the contents of service that can be received by the f (MBMS) are notified. The notification of service contents that can be received by f (MBMS) and f (MBMS) may or may not be simultaneous. A specific example of a channel used when notifying information about receivable MBMS is the same as that in Embodiment 3, and thus description thereof is omitted. In addition, a specific example of the service content is the same as that in the third embodiment, and thus description thereof is omitted. In Step ST3702, the mobile terminal receives the service contents that can be received by f (MBMS) and f (MBMS) transmitted from the serving cell. Here, in step ST3701, there is a problem as to how the serving cell obtains information on receivable MBMS notified from the serving cell to the mobile terminal. Specifically, if the information regarding receivable MBMS is not frequently changed and is determined to be semi-static, it can be set in the serving cell every time it is changed. Further, information regarding receivable MBMS may be notified from a frequency layer control device dedicated to MBMS transmission to a unicast / mixed frequency layer control device at the time of change or periodically. As a further specific example, information regarding receivable MBMS is notified from the MCE to the MME or the base station. Further, the MBMS GW may notify the MME or the base station. In Step ST3504, the mobile terminal confirms whether or not the user intends to receive the MBMS service in the frequency layer dedicated to MBMS transmission. If there is an intention to receive the MBMS service, the mobile terminal makes a transition to step ST3703. If there is no intention to receive the MBMS service, the processing in step ST3504 is repeated.

  In step ST3703, the mobile terminal confirms in step ST3702 whether or not at least one frequency of a receivable MBMS transmission-dedicated frequency layer performing a user-desired service has been received. If it has not been received, the process ends. If received, the mobile terminal makes a transition to step ST3704. For example, it is assumed that the frequency of the frequency layer dedicated to MBMS transmission that can be received and that provides the service desired by the user is fa (MBMS). In step ST3704, the set frequency of frequency conversion section 1107 is changed, and the center frequency is changed to fa (MBMS), thereby moving to a receivable MBMS transmission-dedicated frequency layer that provides a user-desired service. In Step ST3506, the mobile terminal performs an MBMS search operation. In Step ST3507, the MBMS dedicated cell notifies the mobile terminal of the MBMS service content. In Step ST3508, the mobile terminal receives the MBMS service content from the MBMS dedicated cell. In Step ST3510, the mobile terminal determines whether or not the reception sensitivity of the MBSFN area where the user-desired service is performed is of sufficient quality for reception. When reception quality is favorable, it transfers to step ST3511. When reception quality is not favorable, it transfers to step ST3705. In Step ST3511, the mobile terminal selects the MBMS service. In Step ST3705, the mobile terminal receives other frequencies (different from the current frequency) that perform the service desired by the user in the receivable MBSFN synchronization area frequencies (frequency list) received in Step ST3702. It is determined whether there is a frequency layer frequency dedicated for MBMS transmission. If it exists, the process returns to step ST3704, the synthesizer is switched to a new frequency, for example, fb (MBMS), and the process is repeated. If it does not exist, the process ends.

  According to the fourth embodiment, it is possible to obtain a method for moving to a frequency layer dedicated to MBMS transmission and a method for selecting a desired service, which is a first problem of the present invention. Compared to the third embodiment, the following effects can be obtained in solving the first problem. In the third embodiment, there is no means for knowing whether a user-desired service is being performed in the MBMS transmission-dedicated frequency layer before changing the frequency and moving to the MBMS transmission-dedicated frequency layer. Therefore, in the third embodiment, when the user intends to receive the MBMS service in the MBMS transmission-dedicated frequency layer, the user performs re-tuning for the frequency of the receivable MBMS transmission-dedicated frequency layer, and the user It is necessary to confirm whether a desired service is being performed. On the other hand, in Embodiment 4, before the mobile terminal changes the frequency and moves to the frequency layer dedicated to MBMS transmission, the frequency of the frequency layer dedicated to MBMS transmission that can be received and the service contents that can be received at the frequency Can know. Therefore, it is not necessary to perform the process for the frequency where the service desired by the user is not performed, the process after step ST3704 in FIG. As described above, in the fourth embodiment, when the mobile terminal intends to receive the MBMS service in the MBMS transmission-dedicated frequency layer, it is not necessary to search for all the receivable MBMS transmission-dedicated frequencies. This has the effect of shortening the control delay until the mobile terminal receives a service from a frequency other than the current frequency. Thereby, the effect of reducing the power consumption of the mobile terminal can also be obtained.

Modification 1
Hereinafter, modifications of the present embodiment will be described. In step ST3701 of FIG. 37, the serving cell notifies the mobile terminal of information related to receivable MBMS. As a specific example of receivable MBMS information, the frequency of an available MBMS service, that is, the frequency of a receivable MBSFN synchronization area (MBSFN Synchronization Area), that is, the frequency of a receivable MBMS transmission dedicated frequency layer (f ( One or more). Also, the contents of service that can be received by the f (MBMS) are notified. At that time, not all the service contents that can be received by f (MBMS), but the service contents performed in the MBSFN area having the coverage area overlapping the coverage area of the serving cell are notified. In the fourth embodiment, the mobile terminal does not have a means for knowing the service content performed in the MBSFN area, which has a coverage area overlapping with the coverage area of the serving cell. Therefore, the following situation occurs. Even if the mobile terminal is not located in the coverage area of the MBSFN area where the user performs the desired service, the mobile terminal performs the service desired by the user in step ST3703 in FIG. Then, it is determined that there is a frequency layer frequency (fc (MBMS)) dedicated to MBMS transmission that can be received, and then the mobile terminal moves to fc (MBMS) in step ST3704. However, since the mobile terminal is located outside the coverage area of the MBSFN area where the service desired by the user is performed, in step ST3510, the mobile terminal is in the MBSFN area (fc (MBMS)) where the service desired by the user is performed. There is a high possibility that it is determined that the reception quality is not good.

  According to the first modification, the following further effects can be obtained as compared with the fourth embodiment. Compared to the fourth embodiment, in the first modification, the mobile terminal receives the service content performed in the MBSFN area having the coverage area that overlaps the coverage area of the serving cell, and in step ST3703 the coverage of the serving cell In the MBSFN area having the coverage area overlapping with the area, it is possible to confirm whether or not one or more frequencies of a receivable MBMS transmission-dedicated frequency layer performing the service desired by the user have been received. Therefore, in step ST3510, it is less likely that the reception quality of the MBSFN area where the service desired by the user is performed is not sufficiently good for reception. This has the effect of shortening the control delay until the mobile terminal receives a service from a frequency other than the current frequency. Thereby, the effect of reducing the power consumption of the mobile terminal can also be obtained.

Modification 2
When neighboring cell (neighboring cell) information is notified from the serving cell to the mobile terminal, information regarding MBMS that can be received in the neighboring cell may be notified from the serving cell to the mobile terminal. Information regarding receivable MBMS in the neighboring cell may be notified simultaneously with the neighboring cell information, or may not be notified at the same time. A specific example of information regarding receivable MBMS is the same as in the fourth embodiment, and a description thereof will be omitted. According to the modification 2, the following effects can be obtained. Let us consider a case where the reception sensitivity of adjacent cells becomes better in the unicast / mixed frequency layer, that is, the case where the timing for performing the handover process approaches. If the information on the MBMS that can be received in the base station (new serving cell: handover destination base station) that is newly selected as the serving cell does not include the service content currently being received by the mobile terminal, It can be determined that the sensitivity of the service currently being received deteriorates. The determination result can be notified to the user by displaying on the display unit, ringing, or the like. As a result, when the user gives priority to the current MBMS service reception over the movement, the movement can be stopped, and an effect that the usage can be more adapted to the needs of the user can be obtained. In addition, when the reception quality of the service at the frequency f1 (MBMS) being received is deteriorated, the frequency that is not present in the information on the receivable MBMS of the serving cell, but is different in the information on the receivable MBMS in the neighboring cell. When the same service exists at f2 (MBMS), an operation such as MBMS search can be tried at f2 (MBMS). As a result, it is possible to obtain an effect that enables usage in accordance with the needs of the user. The second modification can be applied not only to the fourth embodiment but also to the first modification of the fourth embodiment.

Embodiment 5 FIG.
Non-Patent Document 3 describes an event used to notify measurement results of a serving cell and neighboring cells from the mobile terminal to the network side (base station) in the current 3GPP. The measurement within the same frequency as the serving cell will be described below. It is disclosed that a mobile terminal notifies an event A1 to a network side (base station) when a measurement result of a serving cell becomes larger than a certain threshold (threshold). When the measurement result of the serving cell becomes smaller than a certain threshold (threshold), the mobile terminal notifies the network A (base station) of event A2. When the measurement result of the neighboring cell becomes larger than the value obtained by adding the offset value (offset) in the measurement result of the serving cell, the mobile terminal notifies the network side (base station) of the event A3. Event A3 is used for handover within the same frequency. Non-Patent Document 3 does not describe the second problem of the present invention. There is no description of having a plurality of threshold values and offset values. Furthermore, there is no description that uses a plurality of threshold values and offset values depending on the state of the mobile terminal.

  In the unicast / mixed frequency layer, FIG. 38 shows a specific example of a sequence diagram in the case where a mobile terminal receiving an MBMS service, which has been transmitted from a mixed unicast / MBMS cell, performs handover. In Step ST3801, the serving cell notifies the mobile terminal being served thereby of the system information of the own cell. Specific examples of the system information to be notified include a measurement cycle, an intermittent reception cycle, tracking area information (TA information), and the like. The measurement period is a period in which the network side notifies a mobile terminal being served thereby, and the mobile terminal measures the electric field strength and the like according to this period. Further, when reporting the own cell information from the serving cell to the mobile terminal, the own cell information is mapped to the broadcast control channel (BCCH) that is a logical channel, and further, the broadcast channel (BCH) that is a transport channel, It is mapped to a physical broadcast channel (PBCH) that is a channel. In addition, the own cell information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further mapped to a downlink shared channel (DL-SCH) that is a transport channel and a physical downlink shared channel (PDSCH) that is a physical channel. May be.

  In Step ST3802, the mobile terminal receives the system information of the own cell transmitted from the serving cell. In Step ST3803, the serving cell notifies the mobile terminal being served thereby of the MBMS scheduling information of the own cell. As a specific example of MBMS scheduling information to be notified, MBSFN sub-frame allocation may be considered. Further, when MBMS scheduling information is notified from the serving cell to the mobile terminal, the MBMS scheduling information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further, a broadcast channel (BCH) that is a transport channel, It is mapped to a physical broadcast channel (PBCH) that is a physical channel. The MBMS scheduling information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further mapped to a downlink shared channel (DL-SCH) that is a transport channel and a physical downlink shared channel (PDSCH) that is a physical channel. May be. In Step ST3804, the mobile terminal receives the MBMS scheduling information of the own cell transmitted from the serving cell.

  In Step ST3805, the mobile terminal confirms whether the user intends to receive the MBMS service. If the user intends to receive the MBMS service, the mobile terminal makes a transition to step ST3807. If the user does not intend to receive the MBMS service, the process ends. In Step ST3806, the serving cell notifies the mobile terminal of control information of the MBMS service. In Step ST3807, the mobile terminal receives MBMS service control information. As a specific example of the control information of the MBMS service, the service content of the MBMS can be considered. A specific example of the MBMS service content is the same as that in the third embodiment, and a description thereof will be omitted. In addition, when the control information of the MBMS service is notified from the serving cell to the mobile terminal, the control information of the MBMS service is mapped to the broadcast control channel (BCCH) that is a logical channel, and further, the broadcast channel that is the transport channel ( BCH) and physical broadcast channel (PBCH) which is a physical channel. Also, the control information of the MBMS service is mapped to the broadcast control channel (BCCH) that is a logical channel, and further, the downlink shared channel (DL-SCH) that is a transport channel, and the physical downlink shared channel (PDSCH) that is a physical channel May be mapped. Also, the control information of the MBMS service is mapped to the multicast control channel (MCCH) that is a logical channel, and further mapped to the multicast channel (MCH) that is a transport channel and the physical multicast channel (PMCH) that is a physical channel. Good. When mapped to MCCH, the mobile terminal receives data in the MBSFN subframe according to the MBMS scheduling information (MBSFN subframe allocation information) received in step ST3804. In Step ST3808, the mobile terminal determines whether a user-desired service is being performed according to the MBMS service control information received in Step ST3807. If the service desired by the user is being performed, the mobile terminal makes a transition to step ST3809. If the service desired by the user is not performed, the process is terminated. In Step ST3809, the mobile terminal starts receiving the MBMS service (MTCH, MCCH). When receiving the MBMS service, the mobile terminal receives the data in the MBSFN subframe according to the MBMS scheduling information (MBSFN subframe allocation information) received in step ST3804.

  In step ST3810, the mobile terminal determines whether the measurement cycle received in step ST3802 is in parallel with the reception operation of the MBMS service. When it is a measurement period, it transfers to step ST3811. If it is not the measurement cycle, the determination in step ST3810 is repeated. In step ST3811, the mobile terminal performs measurement. Values actually measured by the mobile terminal include reference symbol received power (RSRP), E-UTRA carrier received signal strength indicator (RSSI), etc. for the serving cell and neighboring cells. Can be considered. The information on neighboring cells may be broadcast from the serving cell as neighboring cell information (list) (or sometimes called neighboring cell information (list)). In Step ST3812, the mobile terminal determines whether or not a serving cell re-selection is necessary as a result of the measurement in Step ST3811. As a specific example of the determination, a case where the measurement result of the neighboring cell is larger than a value obtained by adding the offset value (offset) to the measurement result of the serving cell may be considered. When reselection is not necessary, the mobile terminal makes a transition to step ST3810. If reselection is necessary, the mobile terminal makes a transition to step ST3813. In Step ST3813, the mobile terminal notifies the serving cell of an event used for notification of the measurement result. As a specific example of the event when the serving cell needs to be reselected, the mobile terminal notifies the serving cell of event A3. In Step ST3814, the serving cell receives event A3 from the mobile terminal. Thereafter, a handover process is performed as the mobile communication system, and the mobile terminal makes a transition to step ST3815.

  In step ST3815, the base station (new serving cell: handover destination base station) to be newly selected as the serving cell notifies the mobile terminal being served thereby of the system information of the own cell, as in step ST3801. In Step ST3816, the mobile terminal receives the system information of the own cell from the new serving cell, similarly to Step ST3802. In step ST3817, the new serving cell notifies the mobile terminal being served thereby of the MBMS scheduling information of the own cell as in step ST3803. In Step ST3818, the mobile terminal receives MBMS scheduling information of its own cell from a new serving cell, as in Step ST3804. In Step ST3819, the new serving cell notifies the mobile terminal of the control information of the MBMS service as in Step ST3806. In Step ST3820, the mobile terminal receives the control information of the MBMS service as in Step ST3807. In step ST3821, the mobile terminal determines whether a user-desired service is being performed according to the MBMS service control information received in step ST3820, as in step ST3808. When the service desired by the user is being performed, the mobile terminal makes a transition to step ST3822. When the service desired by the user is not performed, the mobile terminal makes a transition to step ST3823. In Step ST3822, the mobile terminal starts receiving the MBMS service (MTCH, MCCH) according to the MBMS scheduling information (MBSFN subframe allocation information) of the new serving base station received in Step ST3818. In Step ST3823, the mobile terminal performs MBMS service reception stop processing.

  As shown in Step ST3821 and Step ST3823 in FIG. 38, there arises a problem that MBMS service reception is interrupted due to handover. In the fifth embodiment, it is considered to solve the above problem by adding the service content of the MBMS service to the neighboring cell information. A detailed method will be described with reference to FIG. Also, since FIG. 39 is similar to FIG. 38, the description of the same part is omitted. In Step ST3901, the serving cell notifies the neighboring mobile terminal of neighboring cell information. The service content of the MBMS service of the adjacent cell is newly provided in the adjacent cell information. A specific example of the service content is the same as that in the third embodiment, and thus the description thereof is omitted. Further, the allocation information of the MBSFN subframe of the neighboring cell may be used instead of the MBMS service content of the neighboring cell. If the allocation of the MBSFN subframe of the neighboring cell is the same as the allocation of the MBSFN subframe of the serving cell, it can be determined that the neighboring cell and the serving cell are performing multi-cell transmission of the MBMS service to support SFN combining. Therefore, it can be determined that the neighboring cell and the serving cell are performing the same MBMS service. Further, when the neighboring cell information is notified from the serving cell to the mobile terminal, the neighboring cell information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further, a broadcast channel (BCH) that is a transport channel, It is mapped to a physical broadcast channel (PBCH) that is a channel. The neighboring cell information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further mapped to a downlink shared channel (DL-SCH) that is a transport channel and a physical downlink shared channel (PDSCH) that is a physical channel. May be.

  In addition, the serving cell may transmit the service content of each neighboring cell as control information of the MBMS service in Step ST3806, instead of adding the service content of the MBMS service to the neighboring cell information. In this case, it is necessary to notify the service content for each neighboring cell in a form corresponding to the neighboring cell number (ID). The information “service content of the MBMS service performed in the adjacent cell” is transmitted from the unicast / MBMS mixed cell in the unicast / mixed frequency layer, and the mobile terminal receiving the MBMS service is handed over. In order to solve the problem of interruption of MBMS reception when performing the above, it is a parameter newly provided in the fifth embodiment. Therefore, this parameter is effective only for a mobile terminal receiving the MBMS service. Therefore, there is no problem even if it is added to the control information of the MBMS service received only by the mobile terminal that receives the MBMS service. This makes it possible to prevent an increase in the information amount of BCCH and to obtain an effect of preventing a control delay of the entire mobile communication system. Furthermore, in step ST3809, the mobile terminal may receive and decode the service content for each neighboring cell added to the MBMS service control information only after actually starting to receive the MBMS service. Here, the problem is how the serving cell obtains the service content of each neighboring cell. As a solution, it is conceivable to use the inter-base station communication, that is, to notify the service content from each neighboring cell to the serving cell. Another possible solution is to notify the service content from each cell to the MME, and from the MME to the serving cell, to notify the service content of the cell included in the neighboring cell. As another solution, the MCE may notify the service content of each cell to the MME, and notify the service content of the cell included in the neighboring cell from the MME to the serving cell. As another solution, a case where the service content of each neighboring cell is notified directly from the MCE to each serving cell is conceivable. In Step ST3902, the mobile terminal receives neighboring cell information.

  In Step ST3903, the mobile terminal confirms the service content of the MBMS service in the neighboring cell, and determines whether or not the service currently being received by the mobile terminal is being performed in the new serving cell. When the service is being performed, the mobile terminal makes a transition to step ST3813. When service is not performed, it transfers to step ST3904. In Step ST3904, the mobile terminal does not notify the event used for notifying the measurement result to the serving cell. Specifically, notification of an event when the serving cell needs to be reselected is not performed. More specifically, event A3 is not notified to the serving cell. Thereby, the handover process as the mobile communication system is not started, and the serving cell is not reselected. Therefore, the conventional serving cell in which the user-desired MBMS service is performed is not changed, and the MBMS service reception is not interrupted. Thereby, in the unicast / mixed frequency layer, which is the second problem of the present invention, the mobile terminal receiving the MBMS service transmitted in multicell from the MBMS dedicated cell or the unicast / MBMS mixed cell is This solves the problem of interruption of MBMS service reception.

  Also, in step ST3812, it is a fact that it is determined that the cell re-selection of the serving cell is necessary as a result of the measurement in step ST3811. Therefore, it is not desired to interrupt the MBMS service. For example, it is considered that the user should interrupt the movement. Therefore, even though it is determined that the serving cell needs to be reselected, the fact that the desired MBMS service is not being performed in the new serving cell, the fact that the handover process has been stopped is displayed on the display unit, by ringing, etc. You may inform the user. As a result, when the user gives priority to the current MBMS service reception over the movement, it is possible to stop the movement and to obtain an effect that the usage can be more adapted to the user's needs. In addition, in step ST3904, instead of not notifying the serving cell of event A3, notifying the serving cell of an event (event A3) when the serving cell needs to be reselected, and notifying the user's intention Also good. As a specific example of the user's intention, it can be considered that handover is not desired.

  According to the fifth embodiment, in the unicast / mixed frequency layer, which is the second problem of the present invention, the mobile terminal receiving the MBMS service transmitted in multicell from the unicast / MBMS mixed cell can perform MBMS by handover. The problem of interruption of service reception can be solved.

Embodiment 6 FIG.
FIG. 40 shows a sequence diagram of the mobile communication system used in the sixth embodiment. In FIG. 40, the same steps as those in FIG. 38 indicate the same or corresponding processes, and thus description thereof is omitted. In step ST4001, the serving cell notifies the mobile terminal being served thereby of the system information of the own cell. Specific examples of the system information to be notified include a measurement cycle, an intermittent reception cycle, tracking area information (TA information), and the like. The measurement cycle is a cycle notified from the network side to a mobile terminal being served by the network, and the mobile terminal measures the electric field strength and the like according to this cycle. The system information of the own cell includes measurement reporting parameters used when measuring the serving cell and the neighboring cells. As a specific example of the parameter for measurement report, “threshold”, “offset value”, etc. shown in Non-Patent Document 3 can be considered. In the sixth embodiment, for a mobile terminal that has not received an MBMS service transmitted in a multicell from a unicast / MBMS mixed cell in the unicast / mixed frequency layer (hereinafter, simply receiving no MBMS service) In the unicast / mixed frequency layer, the mobile terminal is receiving the MBMS service transmitted from the unicast / MBMS mixed cell in the multi-cell mode (hereinafter simply referred to as the mobile terminal receiving the MBMS service). ) And to separate the parameters for measurement report. Further, consider that an offset value is separated for a mobile terminal that has not received the MBMS service and a mobile terminal that is receiving the MBMS service. Further, consider that the offset value for the mobile terminal receiving the MBMS service is set to a value larger than the offset value for the mobile terminal not receiving the MBMS service.

  When reporting the own cell information from the serving cell to the mobile terminal, the own cell information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further, a broadcast channel (BCH) that is a transport channel, a physical channel To the physical broadcast channel (PBCH). In addition, the own cell information is mapped to a broadcast control channel (BCCH) that is a logical channel, and further mapped to a downlink shared channel (DL-SCH) that is a transport channel and a physical downlink shared channel (PDSCH) that is a physical channel. May be. The “measurement report parameter” for a mobile terminal that is receiving an MBMS service indicates that a mobile terminal that has received an MBMS service transmitted in a multicell from a unicast / MBMS mixed cell performs handover in the unicast / mixed frequency layer. This is a new parameter to solve the problem of MBMS reception interruption that may occur when performing. Therefore, this parameter is effective for the mobile terminal receiving the MBMS service. Therefore, there is no problem even if it is added to the control information of the MBMS service received by the mobile terminal that receives the MBMS service separately from other system information. This makes it possible to prevent an increase in the information amount of BCCH and to obtain an effect of preventing a control delay of the entire mobile communication system. When reporting the control information of the MBMS service from the serving cell to the mobile terminal, the control information of the MBMS service is mapped to the broadcast control channel (BCCH) that is a logical channel, and further, the broadcast channel (BCH that is a transport channel) ) And mapped to a physical broadcast channel (PBCH) which is a physical channel. The control information of the MBMS service is mapped to the broadcast control channel (BCCH) that is a logical channel, and further, the downlink shared channel (DL-SCH) that is a transport channel, and the physical downlink shared channel (PDSCH) that is a physical channel May be mapped. Also, the control information of the MBMS service is mapped to the multicast control channel (MCCH) that is a logical channel, and further mapped to the multicast channel (MCH) that is a transport channel and the physical multicast channel (PMCH) that is a physical channel. Good. In Step ST4002, the mobile terminal receives the system information of the own cell from the serving cell.

  In step ST4003, the mobile terminal determines whether MBMS is being received. Specifically, in the unicast / mixed frequency layer, it is determined whether or not an MBMS service transmitted in multicell from a unicast / MBMS mixed cell is received. If it is receiving, it will transfer to step ST4004. If not receiving, it moves to step ST4005. In Step ST4004, the mobile terminal sets the measurement report parameter for the mobile terminal that is receiving the MBMS in the measurement report parameter. Specifically, an offset value for a mobile terminal that is receiving MBMS is set as the offset value. In Step ST4005, the mobile terminal sets the measurement report parameter for the mobile terminal not receiving MBMS in the measurement report parameter. More specifically, an offset value for a mobile terminal not receiving MBMS is set as the offset value.

  According to the sixth embodiment, it is possible to change the measurement result of a neighboring cell (new serving cell) in which handover processing is performed for a mobile terminal that is receiving the MBMS service and that has not received the MBMS service. Further, by setting the offset value for the mobile terminal receiving the MBMS service to a value larger than the offset value for the mobile terminal not receiving the MBMS service, measurement of neighboring cells in which the mobile terminal receiving the MBMS service performs the handover process is performed. The result can be made higher than when the MBMS service is not received. Thereby, in the unicast / mixed frequency layer, the mobile terminal receiving the MBMS service transmitted from the unicast / MBMS mixed cell to the multicell is transmitted from the unicast / MBMS mixed cell to the multicell in the unicast / mixed frequency layer. Compared to a mobile terminal that has not received the transmitted MBMS service, it is possible to make handover difficult when located in the same geographical location. As a result, it is possible to widen the geographical range in which the MBMS service transmitted from the unicast / MBMS mixed cell to the multi-cell can be received from the same base station in the unicast / mixed frequency layer. As a result, in the unicast / mixed frequency layer, the mobile terminal receiving the MBMS service transmitted from the unicast / MBMS mixed cell to the multicell can reduce the occurrence of interruption of the MBMS service reception due to the handover. I can do it. In the fifth embodiment, the second problem is solved by newly adding the service content of the MBMS service of the neighboring cell to the neighboring cell information. However, it is conceivable that the information content of the service content of the MBMS service for each adjacent cell increases. In the sixth embodiment, the second problem is solved without adding the service content of the MBMS service in the adjacent cell. Therefore, the second problem can be solved while reducing the amount of information notified from the serving cell to the mobile terminal as compared with the fifth embodiment. Therefore, the effect of effective use of radio resources can be obtained as compared with the fifth embodiment.

Modification 1
If Embodiment 6 is modified as follows, further effects can be obtained. FIG. 41 shows a sequence diagram of the mobile communication system used in the first modification of the sixth embodiment. In FIG. 41, steps having the same numbers as those in FIGS. 38 to 40 indicate the same or equivalent processes, and thus description thereof is omitted. In step ST4003, the mobile terminal determines whether MBMS is being received. More specifically, in the unicast / mixed frequency layer, it is determined whether or not an MBMS service transmitted in multicell from a unicast / MBMS mixed cell is received. If it is receiving, it moves to step ST4101. If not receiving, it moves to step ST4005. In step ST4101, the mobile terminal confirms the user's intention. More specifically, it is determined whether to give priority to MBMS service reception over unicast communication. More specifically, in the unicast / mixed frequency layer over the unicast communication, it is determined whether or not to give priority to reception of the MBMS service transmitted from the unicast / MBMS mixed cell to the multicell. When giving priority, it moves to step ST4004. When priority is not given, it transfers to step ST4005.

  The following further effects can be obtained by the first modification of the sixth embodiment. In step ST4004, when an offset value for a mobile terminal that is receiving MBMS is set in the offset value, a mobile terminal that has not received the MBMS service has a poor reception status from the current serving cell, and is handed over to a new serving cell. Even if the process is started (even if the event A3 is notified to the serving cell), the mobile terminal that is receiving the MBMS service does not start the handover process even in the same reception situation (also the same geographical location). This is because even if a mobile terminal that has not received the MBMS service starts a handover process on the assumption that the reception status from the current serving cell is bad, the mobile terminal that is receiving the MBMS service has changed to the current serving cell. It means staying. Therefore, the MBMS service reception is not interrupted, but it may be considered that the reception quality of the unicast service is deteriorated. Therefore, if this modification is used, the user's intention is reflected whether the reception of the MBMS service is not to be interrupted as much as possible, or the reception of the MBMS service is allowed to be prevented and the deterioration of the reception quality of the unicast service is prevented. Thus, it is possible to obtain the effect of enabling the use of the mobile communication system according to the needs of the user.

Modification 2
If Embodiment 6 is modified as follows, further effects can be obtained. FIG. 42 shows a sequence diagram of the mobile communication system used in the second modification of the sixth embodiment. In FIG. 42, steps having the same numbers as those in FIGS. 38 to 40 indicate the same or equivalent processes, and thus description thereof is omitted. In step ST4003, the mobile terminal determines whether MBMS is being received. If it is receiving, it will transfer to step ST4201. If not receiving, it moves to step ST4005. In Step ST4201, the mobile terminal confirms the service content of the MBMS service in the neighboring cell using the neighboring cell information received in Step ST3902 for the neighboring cell to be measured. In the neighboring cell to be measured, it is determined whether the MBMS service being received in the current serving cell is being performed. If it has been performed, the process proceeds to step ST4005. When not performed, it transfers to step ST4004.

  According to the second modification of the sixth embodiment, the following further effects can be obtained. When the MBMS service being received in the current serving cell is being performed in the new serving cell, the problem of interruption of MBMS service reception due to handover does not occur. Therefore, when the MBMS service being received in the current serving cell is being performed in the new serving cell, the parameter for measurement report during the reception of the MBMS service, which leads to deterioration in the reception quality of the unicast service (including the MBMS service). Can be prevented. Further, the first modification of the sixth embodiment and the second modification of the sixth embodiment can be used in combination.

Embodiment 7 FIG.
Consider that base stations belonging to all MBSFN areas in an MBSFN synchronization area use the same radio resources for multicell transmission from a unicast / MBMS mixed cell in a unicast / mixed frequency layer. More specifically, it is considered that all MBSFN areas in the MBSFN synchronization area use together MBSFN subframes used for MBMS service (MCCH, MTCH) transmission. More specifically, a radio resource (MBSFN subframe) common in the MBSFN synchronization area is multiplexed and used in each MBSFN area. A specific example of the multiplexing method is shown in FIG. FIG. 43 is an explanatory diagram showing a concept of multiplexing MBSFN subframes in an MBSFN area. In FIG. 43, in pattern A, radio resources (MBSFN subframes) used by base stations belonging to MBSFN area A and base stations belonging to MBSFN area B are time-division multiplexed. During the MBSFN subframe, the base station belonging to the MBSFN area A is transmitting the MBMS service, and the MBMS service and the unicast service are not transmitted from the base station belonging to the MBSFN area B. It is a period. The time during which the base station belonging to the MBSFN area B is transmitting the MBMS service is a period in which the MBMS service and the unicast service are not transmitted from the base station belonging to the MBSFN area A, that is, the transmission is off. The pattern B is also a specific example of time division multiplexing, but the pattern B does not time-divide the MBSFN subframe but determines the MBSFN subframe to be used for each MBSFN area. However, pattern B also does not transmit MBMS service and unicast service from the base station belonging to MBSFN area B in the MBSFN subframe in which the base station belonging to MBSFN area A is transmitting the MBMS service, similarly to pattern A. That is, transmission is off. Further, in the MBSFN subframe in which the base station belonging to the MBSFN area B is transmitting the MBMS service, the transmission of the MBMS service and the unicast service from the base station belonging to the MBSFN area A is not performed, that is, transmission is off.

  Pattern C is an example in which radio resources (MBSFN subframes) used by base stations belonging to MBSFN area A and base stations belonging to MBSFN area B are frequency division multiplexed (FDM). In the MBSFN subframe, the base station belonging to the MBSFN area A does not transmit the MBMS service and the unicast service from the base station belonging to the MBSFN area B on the frequency at which the base station belonging to the MBSFN area A transmits the MBMS service. It is. In the MBSFN subframe, the MBMS service and the unicast service are not transmitted from the base station belonging to the MBSFN area A at the frequency at which the base station belonging to the MBSFN area B transmits the MBMS service. is there. Pattern D is an example in which radio resources (MBSFN subframes) used by base stations belonging to MBSFN area A and base stations belonging to MBSFN area B are code division multiplexed. The base station belonging to the MBSFN area A uses the common radio resource (MBSFN subframe) in the MBSFN synchronization area, and transmits the MBMS service by multiplying the data by the code A. In the MBSFN synchronization area, the base station belonging to the MBSFN area B transmits the MBMS service by multiplying the data by the code B using the common radio resource (MBSFN subframe). Further, although an example in which base stations belonging to all MBSFN areas in the MBSFN area use the same radio resource (MBSFN subframe) has been described, base stations belonging to MBSFN areas adjacent to the base station constituting the MBSFN area are the same radio. Resources may be used.

  According to the seventh embodiment, in the unicast / mixed frequency layer, which is the second problem, the mobile terminal receiving the MBMS service transmitted from the unicast / MBMS mixed cell by multi-cell is interrupted by the handover. The effect of reducing the occurrence of can be obtained. This is because the base station belonging to the MBSFN synchronization area provides the MBMS service using the same radio resource (MBSFN subframe) by the mobile communication system as in the seventh embodiment. Consider the case where the current serving cell belongs to MBSFN area A and the new serving cell belongs to MBSFN area B. The unicast service performs transmission / reception with a new serving cell having good reception quality, and the new serving cell performs scheduling. On the other hand, the MBMS service can receive the MBMS service in the MBSFN area where the service desired by the user is performed. Further, since the base station belonging to the MBSFN synchronization area is targeted, it is not necessary to newly increase the number of base stations that maintain synchronization between base stations in order to realize the present embodiment. Will not increase. Compared with Embodiment 5, the following effects can be obtained. The service content of the MBMS service in the adjacent cell required in the fifth embodiment is not necessary. Therefore, the second problem can be solved while reducing the amount of information notified from the serving cell to the mobile terminal as compared with the fifth embodiment. Therefore, the effect of effective use of radio resources can be obtained as compared with the fifth embodiment.

  Compared with Embodiment 6, the following effects can be obtained. For mobile terminals not receiving the MBMS service transmitted from the unicast / MBMS mixed cell in the unicast / mixed frequency layer required in the sixth embodiment, and in the unicast / mixed frequency layer, unicast / MBMS mixing The parameter for measurement report separated for the mobile terminal receiving the MBMS service transmitted in multi-cell from the cell becomes unnecessary. Therefore, the second problem can be solved while reducing the amount of information notified from the serving cell to the mobile terminal as compared with the sixth embodiment. Therefore, the effect of effective use of radio resources can be obtained as compared with the sixth embodiment. Furthermore, in Embodiment 7, even if a mobile terminal is receiving an MBMS service, if the reception quality of the serving cell becomes as bad as that of a mobile terminal not receiving the MBMS service, the MBMS service currently being received by the new serving cell Handover can be performed regardless of whether or not is performed. Therefore, compared to the sixth embodiment, it is possible to obtain an effect that the reception quality of the unicast service does not deteriorate.

Embodiment 8 FIG.
A third problem to be solved by the invention will be described with reference to FIG. As described in Non-Patent Document 2, the assignment of MBSFN subframes in an MBMS / unicast mixed cell has been studied. As described in Non-Patent Document 1, multiplexing of channels other than MBSFN and MBSFN is performed in units of subframes. Hereinafter, the subframe for MBSFN transmission is referred to as an MBSFN sub-frame. Further, in the current 3GPP, it is determined that in the mixed cell, in the MBSFN frame (subframe), except for the first 1 to 2 OFDM symbols in subframe units, it should not be used for unicast transmission. In other words, resources other than the first 1-2 OFDM symbols are dedicated to MBMS transmission. In FIG. 44, it is described as PMCH. On the other hand, Non-Patent Document 1 discloses that PCH is mapped to PDSCH or PDCCH. Non-Patent Document 1 discloses that the paging group uses the L1 / L2 signaling channel (PDCCH), and the clear identifier (UE-ID) of the mobile terminal can be found on the PCH. Therefore, since PCH uses the L1 / L2 signaling channel, it can be mapped even in the MBSFN frame. On the other hand, in the MBSFN frame, when the downlink radio resource of the next control information is allocated in the PCH, the downlink radio resource on the same subframe is dedicated to MBMS transmission, so the control information is allocated in the same subframe. The problem of not being able to do occurs.

  Non-Patent Document 4 describes the following about paging signal transmission to mobile terminals. A PICH (Paging Indicator channel) that indicates that a paging signal addressed to any mobile terminal belonging to the paging group has been generated is transmitted using the L1 / L2 signaling channel. The mobile terminal decodes the paging signal to determine whether the paging signal is addressed to itself. The PCH can have one or more paging signals. The PICH is transmitted using the L1 / L2 signaling channel, that is, is positioned in the first 1 to 3 OFDM symbols in subframe units. On the other hand, PCH is mapped to PDSCH in the same subframe as PICH. The third problem to be solved by the present invention also occurs in the paging signal transmission procedure of Non-Patent Document 4. In other words, when MBSFN subframes are configured in an MBMS / unicast mixed cell, even if a PICH is transmitted using the first to second OFDM symbols of the MBSFN subframe, the same subframe as the PICH is a resource dedicated to MBMS transmission. is there. Therefore, it is not possible to transmit a PCH that maps a paging signal for determining whether or not the paging signal is addressed to itself. Further, Non-Patent Document 4 has no suggestion about the third problem to be solved by the present invention.

  Non-Patent Document 5 has the following description about an expression for obtaining a time when paging occurs (paging occasion (paging occasion)). In order to obtain the paging occasion, two parameters are necessary: a paging interval (corresponding to the intermittent reception period in the mixed frequency layer in the present invention) and the number of paging occasions in the paging interval. It is not described. Further, it is described that a subframe in a radio frame in which paging occasion occurs is a fixed value. However, Non-Patent Document 5 does not describe a method for determining a subframe in a radio frame of a paging occasion to which a paging signal is mapped. Further, Non-Patent Document 5 does not describe the relationship between subframes and MBSFN subframes in radio frames for paging occasions, and does not suggest the third problem to be solved by the present invention.

  Other than the first 1-2 OFDM symbols in the MBSFN subframe, the resources are dedicated to MBMS transmission. When the subframe in the radio frame of the paging occasion overlaps with the allocation of the MBSFN subframe, other than the first 1-2 OFDM symbols become resources dedicated to MBMS transmission and cannot be used for paging processing. Since the conventional paging processing method does not consider the MBSFN subframe at all, there is a problem that it cannot be applied to the paging processing in the MBMS / unicast mixed cell. In order to solve this problem, in the eighth embodiment, it is determined which subframe in the radio frame for paging occasion is used for paging processing (transmission of paging signal (paging message), PICH, PCH, etc.). A method is disclosed. FIG. 45 shows a specific example of a sequence diagram in the case of determining a subframe in a radio frame of a paging occasion to which a paging signal is mapped. Since the process with the same step number as in FIG. 40 is the same process, the description thereof is omitted. In step ST4001, the serving cell notifies the mobile terminal being served thereby of the system information of the own cell. Specific examples of the system information to be notified include a measurement cycle, an intermittent reception cycle, tracking area information (TA information), and the like. It is assumed that the system information of the own cell includes a parameter for intermittent reception. Specific examples of the intermittent reception parameter include an intermittent reception period (T) in the mixed frequency layer, and the number of paging occasions (N) in the paging interval (or the number of paging groups). A specific example of how to represent the intermittent reception period includes the number of radio frames. In Step ST4002, the mobile terminal receives the system information of the own cell from the serving cell. In step ST4501, the serving cell transmits MBSFN subframe allocation information. In the current 3GPP discussion on MBSFN subframe allocation, the following is spoken: The mapping positions of the reference signal in the MBSFN subframe and the reference signal of the subframe that is not the MBSFN subframe as radio resources are different. Therefore, in order to perform measurement using a more accurate reference signal, there is a discussion that even a mobile terminal that does not have the ability to receive an MBMS service needs to grasp allocation information of MBSFN subframes of a serving cell. (Non-patent document 2). As a specific example of the allocation information of the MBSFN subframe, the subframe number of the subframe allocated as the MBSFN subframe (for example, subframe number # 1 in FIG. 44) can be considered. In Step ST4502, the mobile terminal receives MBSFN subframe allocation information from the serving cell.

  In step ST4503, the mobile terminal obtains a paging occasion. In the eighth embodiment, a method for determining a subframe in a radio frame for paging occasions for solving the third problem is disclosed. The method disclosed in the eighth embodiment can be used regardless of how to obtain paging occasions (paging occasion radio frames). In Step ST4504, the serving cell obtains a radio frame for paging occasion using the same method as the mobile terminal as the mobile communication system. In Step ST4505, the mobile terminal obtains a subframe in the radio frame of the paging occasion. In step ST4506, the serving cell obtains a subframe in the radio frame of the paging occasion using the same method as the mobile terminal as the mobile communication system.

Details of a method for obtaining a subframe in a radio frame for paging occasion in step ST4505 will be described below. Based on the allocation information of the MBSFN subframe received in step ST4502, the mobile terminal causes subframes other than the MBSFN subframe to be subframes in the radio frame of the paging occasion. More specifically, subframe renumbering is performed except for the MBSFN subframe. This will be described with reference to FIG. FIG. 46A shows a radio frame in which no MBSFN subframe exists. FIG. 46B shows an example of subframe renumbering when an MBSFN subframe is assigned to subframe number # 3, for example. Before and after renumbering, the following correspondence is taken. (Before renumbering-After renumbering), (# 0- # 0 (MBSFN)) (# 1- # 1 (MBSFN)) (# 2- # 2 (MBSFN)) (# 3-MBSFN subframe) (# 4- # 3 (MBSFN)) (# 5- # 4 (MBSFN)) (# 6- # 5 (MBSFN)) (# 7- # 6 (MBSFN)) (# 8- # 7 (MBSFN))) (# 9- # 8 (MBSFN)). Hereinafter, (MBSFN) is added to the subframe number after renumbering. FIG. 46 (c) shows a case where two MBSFN subframes are allocated in one radio frame. The details of the renumbering are the same as in the case of one MBSFN subframe, and a description thereof will be omitted. A subframe in a radio frame for paging occasion is determined in association with the number of subframes excluding the MBSFN subframe. As a specific example, a correspondence table is shown in FIG. FIG. 47 (a) will be described. When the number of subframes excluding the MBSFN subframe is “9” (that is, the assignment as the MBSFN subframe in the radio frame is one subframe), the subframe in the radio frame of the paging occasion is # 4 (MBSFN). 47A, subframes in the radio frame of the paging occasion in the case of FIG. 46C are obtained. In the case of FIG. 46C, the number of subframes excluding the MBSFN subframe is “8”. When the subframe in the radio frame of the paging occasion is determined using FIG. 47A, # 3 (MBSFN) is obtained. FIG. 47B shows a correspondence table in consideration of a case where a plurality of subframes are generated in a radio frame for paging occasion in one radio frame.
For example, if the number of occurrences of paging occasion subframes in one radio frame in FIG. 47 (b) is “2”, each mobile terminal performs paging occasions in one radio frame in FIG. 47 (b). It is not known which subframe shown in the column when the number of generated subframes is “2” should be received (monitored) by intermittent reception. This can be solved by the following method. Mobile terminal identifier mode 1 Determine the number of subframes for paging occasions in a radio frame. When the number of subframes for paging occasions in one radio frame is “2”, the solution of the above equation is 0 or 1. Therefore, as a specific example, when the solution of the above equation is “0”, it is defined as the upper subframe number of the correspondence table, and when it is “1”, it is defined as the lower subframe number of the correspondence table. Alternatively, the information is included in the correspondence table. As another solution, the mobile terminal receives (monitors) all of the subframes of a paging instance that exist in one radio frame. Furthermore, there are cases where the necessary number of subframe numbers for paging occasions cannot be defined due to the allocation of MBSFN subframes, even though a plurality of paging occasions occur in one radio frame. Specifically, this is a case where the number of paging occasion subframes generated in one radio frame in FIG. 47B is “2” and the number of subframes excluding MBSFN subframes is “1”. This problem can be solved by the following method. The number of paging groups and / or the intermittent reception period (T) in the mixed frequency layer or / and the allocation of MBSFN subframes so that the number of paging occasions present in one radio frame is equal to or less than the number of subframes excluding MBSFN subframes Determine (number of assignments). That is, paging satisfying the following formula (“number of paging groups (N) / intermittent reception period (T) in mixed frequency layer = <10 (number of subframes in one radio frame) −number of allocated MBSFN subframes”)) The number of groups (N), the intermittent reception period (T) in the mixed frequency layer, and the number of MBSFN subframes allocated may be determined.

A specific example in the case where a plurality of subframes for paging occasions occur in one radio frame described above will be described below. Consider a case where Non-Patent Document 5 is used in a method for obtaining a radio frame for paging occasion. In Non-Patent Document 5, as described above, in order to obtain the paging occasion, the paging interval (corresponding to the intermittent reception period in the mixed frequency layer in the present invention) (T) and the paging occasion in the paging interval are determined. It is described that two parameters of number (N) are necessary and no other parameters are necessary. When a plurality of paging-acquisition subframes occur in one radio frame, it can be expressed by the following equation (1 <N / T). A specific example of the method used in FIG. 47 (b) is shown below.
When 1 <N / T = <2, there are two subframes corresponding to paging occasions of different paging groups in one radio frame. Therefore, in the case of 1 <N / T = <2, the column “2” in which the number of subframes for paging occasions in one radio frame in FIG. 47B is used.

  The correspondence table as shown in FIG. 47 needs to be recognized on both the network side and the mobile terminal side. The correspondence table may be statically determined as the mobile communication system. Thereby, since there is no need to notify the mobile terminal side from the network side, a further effect of effective utilization of radio resources can be obtained. On the other hand, if the correspondence table can be changed, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the broadcast channel (BCH) of the transport channel, and mapped to the physical broadcast channel (PBCH) of the physical channel. It can be considered. As another specific example, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the downlink shared channel (DL-SCH) of the transport channel, and mapped to the physical downlink shared channel (PDSCH) of the physical channel. It can be considered. By making the correspondence table changeable, it is possible to obtain a further effect that makes it possible to construct a more flexible mobile communication system.

  In the eighth embodiment, subframe renumbering is performed except for the MBSFN subframe, and the subframe in the radio frame of the paging occasion is determined based on the subframe number after the renumbering. Therefore, the subframe in the radio frame of the paging occasion and the MBSFN subframe do not become the same subframe. Therefore, the effect that the third problem of the present invention can be solved can be obtained.

The first modification shows a different method of the process in step ST4505 of the eighth embodiment. Based on the allocation information of the MBSFN subframe received in step ST4502, the mobile terminal causes subframes other than the MBSFN subframe to be subframes in the radio frame of the paging occasion. More specifically, subframe renumbering is performed except for the MBSFN subframe. Details thereof are the same as those in the eighth embodiment, and thus description thereof is omitted. In the first modification, unlike the eighth embodiment, it is considered to maintain a constant relationship between the number of subframes excluding the MBSFN subframes and the subframes in the radio frame of the paging occasion, instead of the correspondence table. In other words, a relational expression between the number of subframes excluding the MBSFN subframe and the subframe in the radio frame of the paging occasion is defined. Specific examples of the relational expressions are shown below.
Mobile terminal identifier (UE-ID, IMSI, S-TMSI, etc.) mod (number of subframes excluding MBSFN subframe) = subframe in radio frame of paging occasion (subframe number after renumbering) (Formula 1)
(Identifier of mobile terminal (UE-ID, IMSI, S-TMSI, etc.) div Number of paging groups (N)) mod Number of subframes excluding MBSFN subframe = Subframe in radio frame of paging occasion (however, renumbering Subframe number after adding) (Equation 2) is considered.

  According to the first modification, the following effects can be obtained in addition to the effects of the eighth embodiment. It is possible to obtain an effect that it is not necessary to store a large amount of information such as a correspondence table between the network side and the mobile terminal side. Even if the correspondence between the number of subframes excluding the MBSFN subframe and the subframe in the radio frame of the paging occasion is changed, it is only necessary to notify the relational expression from the network side to the mobile terminal side. The effect that it is not necessary to notify a large amount of information such as a correspondence table can be obtained.

Although the above relational expression can be applied regardless of how to obtain paging occasions (radio frames for paging occasions), there is a bias in subframes to which paging occasions are actually assigned in one radio frame. May occur. The formula for calculating the paging acquisition is “paging occasion = (identifier of mobile terminal mod paging group number (N)) × Int (intermittent reception period (T) / number of paging groups (N) in mixed frequency layer)”. It is possible. In this case, if Equation 1 is applied to the subframe determination formula in the radio frame of the paging acquisition, there may be a bias in the subframe to which the paging acquisition is assigned. For example, N = 3 and the number of subframes excluding MBSFN subframes = 3. Since N = 3, paging occasions occur in the # 0 radio frame, but the identifier (IMSI, etc.) of the mobile terminal assigned to this radio frame is a multiple of three. Therefore, when Equation 1 is applied, since K = 3, the subframe allocated in the radio frame becomes the subframe # 0 in all the mobile terminals. As described above, in some cases, there is a case where a subframe to which a paging occasion is actually allocated in one radio frame is biased. Here, a method for preventing a bias from occurring in subframes to which paging occasions are actually allocated in one radio frame is disclosed. For example, there is a method in which the mobile terminal identifier is not used as an equation for performing a mod operation on the number of subframes excluding N and MBSFN subframes in both the paging-acquisition radio frame and subframe. As a specific example, when the subframe determination formula is (Formula 1), the following paging occasion shown in the second embodiment is obtained.
“Paging Occasion = (IMSI div K) mod (intermittent reception period in unicast / mixed frequency layer) + n × (intermittent reception period in unicast / mixed frequency layer) n: 0, 1, 2,... Occasion ≦ maximum value of SFN ”. Here, SFN is an integer from 0 to the maximum value of SFN. K is the number of subframes excluding the MBSFN subframe. Further, when the subframe determination formula is (Formula 2), the following paging average is obtained.
Paging acknowledgment = (identifier of mobile terminal mod number of paging groups (N)) x Int (intermittent reception period (T) / number of paging groups (N) in mixed frequency layer)

As another method, when the subframe determination formula is (Formula 2), the following paging approximation is obtained.
“Paging Occasion” = (IMSI div K) mod X + n × (intermittent reception cycle in the MBMS transmission frequency layer), n: 0, 1, 2,..., Where Paging Occation ≦ SFN . SFN is an integer from 0 to the maximum value of SFN. X is the number of radio frames in which paging occurs within the intermittent reception cycle in the MBMS transmission frequency layer, and X ≦ intermittent reception cycle (number of radio frames) in the MBMS transmission frequency layer. A value of X (residue value at X) and a radio frame number (SFN) are associated with each other. By doing this, there is an effect that a radio frame in which paging occurs can be set arbitrarily. As another method, when the subframe determination formula is (Formula 2), the following paging approximation is obtained.
“Paging Occasion” = ((IMSI div K) mod (Int (T / TX))) × TX + n × (intermittent reception cycle in MBMS transmission frequency layer), n: 0, 1, 2,. .. However, the maximum value of Paging Occlusion ≦ SFN. SFN is an integer from 0 to the maximum value of SFN. TX ≦ Intermittent reception period (number of radio frames) in the MBMS transmission frequency layer.
By making the radio frame in which paging occurs periodically, it is not necessary to relate the above-described X value (the remainder value in X) and the radio frame number (SFN), so that the calculation calculation is simplified. Can do.

  The above relational expression may be determined statically. Thereby, since there is no need to notify the mobile terminal side from the network side, a further effect of effective utilization of radio resources can be obtained. On the other hand, if the relational expression can be changed, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the broadcast channel (BCH) of the transport channel, and mapped to the physical broadcast channel (PBCH) of the physical channel. It can be considered. As another specific example, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the downlink shared channel (DL-SCH) of the transport channel, and mapped to the physical downlink shared channel (PDSCH) of the physical channel. It can be considered. By making the correspondence table changeable, it is possible to obtain a further effect that makes it possible to construct a more flexible mobile communication system. In the specific example of the above relational expression, the following effects can be obtained. Even for mobile terminals that belong to the same paging group, the value of the subframe in the radio frame of the paging occasion changes according to the identifier of the mobile terminal. This reduces the number of mobile terminals that use the same subframe. Therefore, it is possible to obtain an effect that radio resources used for PICH and PCH are reduced in one subframe.

In the second modification, a different method of the process in step 4505 of the eighth embodiment is shown. In the second modification, subframe renumbering is not performed. The mobile terminal determines the subframe in the radio frame of the paging occasion in association with the MBSFN subframe allocation information received in step ST4502 (so as to avoid allocation). As a specific example, FIG. 48 shows a correspondence table. FIG. 48 (a) will be described. When the assignment of the MBSFN subframe is “# 1”, the subframe in the radio frame of the paging occasion is “# 4”. FIG. 48B shows a correspondence table in consideration of a case where a plurality of subframes are generated in a radio frame for paging occasion in one radio frame. For example, when the number of paging occasion subframes generated in one radio frame in FIG. 48 (b) is “2”, each mobile terminal transmits paging occasions in one radio frame in FIG. 48 (b). It is not known which subframe shown in the column when the number of generated subframes is “2” should be received (monitored) by intermittent reception. This can be solved by the following method. Mobile terminal identifier mode 1 Determine the number of subframes for paging occasions in a radio frame. When the number of subframes for paging occasions in one radio frame is “2”, the solution of the above equation is 0 or 1. Therefore, as a specific example, when the solution of the above equation is “0”, it is defined as the upper subframe number of the correspondence table, and when it is “1”, it is defined as the lower subframe number of the correspondence table. Alternatively, the information is included in the correspondence table. As another solution, the mobile terminal receives (monitors) all of the subframes of a paging instance that exist in one radio frame. Furthermore, there are cases where the necessary number of subframe numbers for paging occasions cannot be defined due to the assignment of MBSFN subframes, even though a plurality of paging occasions occur in one radio frame. This problem can be solved by the following method. The number of paging groups and / or the intermittent reception period (T) in the mixed frequency layer or / and the allocation of MBSFN subframes so that the number of paging occasions present in one radio frame is equal to or less than the number of subframes excluding MBSFN subframes Determine (number of assignments). That is, the number of paging groups (N) satisfying the following expression, the intermittent reception period (T) in the mixed frequency layer, and the number of MBSFN subframes allocated may be determined.
Number of paging groups (N) / intermittent reception period (T) in mixed frequency layer = <10 (number of subframes in one radio frame) −number of allocated MBSFN subframes

  A specific example in the case where a plurality of subframes for paging occasions occur in one radio frame described above will be described below. Consider a case where Non-Patent Document 5 is used in a method for obtaining a radio frame for paging occasion. In Non-Patent Document 5, as described above, in order to obtain the paging occasion, the paging interval (corresponding to the intermittent reception period in the mixed frequency layer in the present invention) (T) and the paging occasion in the paging interval are determined. It is described that two parameters of number (N) are necessary and no other parameters are necessary. When a plurality of paging-acquisition subframes occur in one radio frame, it can be expressed by the following equation (1 <N / T). A specific example of the method used in FIG. 48 (b) is shown below. When 1 <N / T = <2, there are two subframes corresponding to paging occasions of different paging groups in one radio frame. Therefore, in the case of 1 <N / T = <2, the column “2” in which the number of subframes for paging occasions in one radio frame in FIG. 48B is used.

  The correspondence table as shown in FIG. 48 needs to be recognized on the network side and the mobile terminal side in advance. The correspondence table may be statically determined as the mobile communication system. Thereby, since there is no need to notify the mobile terminal side from the network side, a further effect of effective utilization of radio resources can be obtained. On the other hand, if the correspondence table can be changed, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the broadcast channel (BCH) of the transport channel, and mapped to the physical broadcast channel (PBCH) of the physical channel. It can be considered. As another specific example, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the downlink shared channel (DL-SCH) of the transport channel, and mapped to the physical downlink shared channel (PDSCH) of the physical channel. It can be considered. By making the correspondence table changeable, it is possible to obtain a further effect that makes it possible to construct a more flexible mobile communication system.

  In the second modification, subframes in the radio frame of the paging occasion are associated in accordance with the allocation of MBSFN subframes (so as to avoid the allocation). Therefore, the subframe in the radio frame of the paging occasion and the MBSFN subframe do not become the same subframe. Therefore, the effect that the third problem of the present invention can be solved can be obtained. Compared to the eighth embodiment and the first modification, the second modification can obtain an effect that the process of subframe renumbering can be omitted on the mobile terminal and the network side.

In the third modification, a different method of the process in step 4505 of the eighth embodiment is shown. In the third modification, unlike the second modification, it is considered that the relationship between the allocation of MBSFN subframes, not the correspondence table, and the subframes in the radio frame of the paging occasion is kept constant. In other words, a relational expression between the allocation of the MBSFN subframe and the subframe in the radio frame of the paging occasion is defined. Specific examples of the relational expressions are shown below. The following description will be made using subframe numbers that do not renumber subframes. However, the idea of this modification can be used even when the subframe is renumbered.
Subframe in radio frame of paging occasion = MBSFN subframe allocation number + P (P: integer)
When the subframe in the radio frame of the paging occasion obtained by the above formula exceeds # 9,
Subframe in radio frame of paging occasion = MBSFN subframe allocation number + P− (9 × n) (P: integer, n: positive integer, n is incremented by “1” every time 9 is exceeded)
It is also conceivable that the subframe in the radio frame of the paging occasion obtained by the above equation further overlaps with the MBSFN subframe. This problem can be solved as follows. Subframe in radio frame for paging occasion = MBSFN subframe allocation number + P + (m × Q) − (9 × n) (P: integer, n: positive integer, m = 1, 2, 3,... 10)
The value of m is advanced until the subframe in the radio frame of the paging occasion obtained by the above formula becomes a value that does not overlap the MBSFN subframe.
Q is an integer having no common divisor with 1 and 10. Specifically, Q = 1, 3, 7, 9,. At this time, P = Q may be set.
The above relational expression may be determined statically. Thereby, since there is no need to notify the mobile terminal side from the network side, a further effect of effective utilization of radio resources can be obtained. On the other hand, if the relational expression can be changed, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the broadcast channel (BCH) of the transport channel, and mapped to the physical broadcast channel (PBCH) of the physical channel. It can be considered. As another specific example, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the downlink shared channel (DL-SCH) of the transport channel, and mapped to the physical downlink shared channel (PDSCH) of the physical channel. It can be considered. By making the correspondence table changeable, it is possible to obtain a further effect that makes it possible to construct a more flexible mobile communication system.

  According to the third modification, in addition to the effects of the second modification, the following effects can be obtained. It is possible to obtain an effect that it is not necessary to store a large amount of information such as a correspondence table between the network side and the mobile terminal side. Also, even when the assignment of MBSFN subframes and the correspondence of subframes in the radio frame of the paging occasion is changed, it is only necessary to notify the relational expression from the network side to the mobile terminal side. The effect that it is not necessary to notify a large amount of information can be obtained.

  In the fourth modification, a different method of the process in step 4505 of the eighth embodiment is shown. As the mobile communication system, subframes excluding the MBSFN subframe are defined as subframes in the radio frame of the paging occasion. More specifically, it is defined as # 0 and / or # 5 in which no MBSFN subframe is assigned because the SCH is mapped as a subframe in the radio frame of the paging occasion. The subframe in the radio frame of the paging occasion may be determined statically. Thereby, since there is no need to notify the mobile terminal side from the network side, a further effect of effective utilization of radio resources can be obtained. On the other hand, if the subframe in the radio frame of the paging occasion can be changed, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the broadcast channel (BCH) of the transport channel, and the physical channel physical It may be mapped to the broadcast channel (PBCH). As another specific example, it is mapped to the broadcast control channel (BCCH) as a logical channel, mapped to the downlink shared channel (DL-SCH) of the transport channel, and mapped to the physical downlink shared channel (PDSCH) of the physical channel. It can be considered. By making the correspondence table changeable, it is possible to obtain a further effect that makes it possible to construct a more flexible mobile communication system. In the fourth modification, a subframe that avoids assignment of the MBSFN subframe is defined as a subframe in the radio frame of the paging occasion. Therefore, the subframe in the radio frame of the paging occasion and the MBSFN subframe do not become the same subframe. Therefore, the effect that the third problem of the present invention can be solved can be obtained. Compared to the eighth embodiment and the first modification, the second modification can obtain an effect that the process of subframe renumbering can be omitted on the mobile terminal and the network side. In the fourth modification compared to the second modification and the third modification, the mobile terminal and the network side may omit the process of determining a subframe in the radio frame of the paging occasion according to the MBSFN subframe allocation. The effect that it is possible can be obtained.

  The fifth modification shows a different method of the process in step ST4505 of the eighth embodiment. In Step ST4505, the mobile terminal obtains a subframe in the radio frame of the paging occasion. In the fifth modification, the process shown in FIG. 49 is performed in place of step 4505. In step ST4901, the mobile terminal obtains a subframe in the radio frame of the paging occasion. In the fifth modification, there is no particular designation as a method for obtaining a subframe in the radio frame of the paging occasion in step ST4901. A method that does not consider assignment of MBSFN subframes may be used. As an example of a method for obtaining a subframe in a radio frame of a specific paging occasion, a fixed value can be used without depending on the assignment of MBSFN subframes as in the method described in Embodiment 2 and the method described in Non-Patent Document 5. Can be used. In Step ST4902, the mobile terminal uses the assignment of the MBSFN subframe received in Step ST4502 and the subframe in the radio frame of the paging occasion obtained in Step ST4901 to determine whether or not both are the same subframe. Judging. When it becomes the same sub-frame, it transfers to step ST4903. If the subframes are not the same, the process ends without moving to step ST4903. That is, the subframe in the radio frame of the paging occasion obtained in step ST4901 is used as it is. In Step ST4903, the mobile terminal changes the subframe in the radio frame of the paging occasion obtained in Step ST4902 to a subframe other than the next MBSFN subframe. For example, consider a case where the subframe in the radio frame of the paging occasion obtained in step ST4901 is # 2, and the assignment of the MBSFN subframe received in step ST4502 is # 2. In this case, it is determined in step ST4902 that both become the same subframe. Therefore, in step ST4903, the subframe in the paging-acquisition radio frame is a subframe other than the next MBSFN subframe, that is, # 3. At this time, in step ST4903, the subframe in the radio frame of the paging occasion may be changed to a subframe other than the previous MBSFN subframe, that is, # 1. The determination in step ST4902 may be performed for each radio frame of the paging occasion obtained in step ST4503. In addition, the determination in step ST4902 is performed once when intermittent reception is started in the serving cell, and / or once when the assignment of the MBSFN subframe is changed, for the repetition period of the set of MBSFN frames. It is also good. In this case, if any subframe in the radio frame of one paging occasion overlaps with the allocation of the MBSFN subframe, step ST4903 is processed for the subframe in the radio frame of every paging occasion. Further, step ST4903 may be processed only for the subframes in the radio frame of the corresponding paging case (overlapping with the allocation of the MBSFN subframe). In this case, in the repetition cycle of the set of MBSFN frames, the corresponding (MBSFN subframe The processing of step ST4903 is performed on the subframe in the radio frame of the paging occasion (which overlaps with the allocation). In step 4506, the serving cell performs the processes of step ST4901 to step ST4903 similar to those of the mobile terminal.

  Further, the subframe in the radio frame of the paging occasion obtained by the processing in step ST4903 is the subframe in the radio frame of the original paging occasion (the subframe in the radio frame of the paging occasion obtained in step ST4901). The frame may not be within the same radio frame. Processing in that case will be described below. It is assumed that the subframe in the radio frame of the paging occasion obtained by the processing in step ST4903 may be a radio frame different from the subframe in the radio frame of the original paging occasion. Alternatively, the subframe in the radio frame of the paging case obtained in step ST4903 is the same as the subframe in the radio frame of the original paging case obtained in step ST4903. The value is a radio frame. As a specific example, the subframe in the radio frame of the paging occasion obtained in step ST4901 is excluded from the last subframe (# 9) of the radio frame, or the last subframe from a specified value Excluding As a specific example of a subframe number of a certain prescribed value, “subframe number of a prescribed value = last subframe−number of consecutive allocations of MBSFN subframes”.

  In the fifth modification, after subframes in the radio frame of the paging occasion are obtained without considering the MBSFN subframe, when the subframe in the radio frame of the paging occasion and the MBSFN subframe overlap, The subframe in the radio frame of the paging occasion is changed to a subframe other than the next MBSFN subframe. Therefore, the subframe in the radio frame of the paging occasion and the MBSFN subframe do not become the same subframe. Therefore, the effect that the third problem of the present invention can be solved can be obtained.

  The sixth modification shows a different method of the process in step ST4503 of the eighth embodiment. Consider the case where the method described in Non-Patent Document 5 is used in Step ST4503. Here, the paging occasion is obtained assuming that the paging interval and the number of paging occasions in the paging interval are equal. Thereby, the effect that the parameter for calculating | requiring a paging occasion is decreased by one can be acquired. This leads to reduction of the system information of the own cell in step ST4001. Thereby, the effect of effective utilization of radio resources can be obtained.

  The eighth embodiment and the first to sixth modifications can be applied to “Unicast side intermittent reception” shown in the first and second embodiments.

Embodiment 9 FIG.
Other than the first 1-2 OFDM symbols in the MBSFN subframe, the resources are dedicated to MBMS transmission. When the subframe in the radio frame of the paging occasion overlaps with the allocation of the MBSFN subframe, other than the first 1-2 OFDM symbols become resources dedicated to MBMS transmission and cannot be used for paging processing. Therefore, in order to solve the third problem that the conventional paging processing method causes inconvenience, the ninth embodiment discloses a processing method in the case where the subframe in the radio frame of the paging occasion and the MBSFN subframe overlap. To do. In the ninth embodiment, when the allocation of the subframe and the MBSFN subframe in the radio frame of the paging occasion overlaps, radio resources other than the first 1-2 OFDM symbols dedicated to MBSFN transmission are used for unicast transmission, and more specifically In particular, it is not used for paging processing. In addition, when allocation of subframes and MBSFN subframes in a radio frame for paging occasions overlaps, information on paging processing transmitted by radio resources other than the first 1-2 OFDM symbols dedicated to MBSFN transmission, It is assumed that transmission is performed in a subframe other than the next MBSFN subframe. A specific example of the processing method is shown below. The processing method of the paging signal is similar to the processing in which the processing of step ST4505 in FIG. 45 is changed to FIG. The description will focus on the different parts. In Step ST4902, the mobile terminal uses the assignment of the MBSFN subframe received in Step ST4502 and the subframe in the radio frame of the paging occasion obtained in Step ST4901 to determine whether or not both are the same subframe. Judging. When it becomes the same sub-frame, it transfers to step ST4903. In Embodiment 9, the following process is performed instead of the process of step ST4903. When allocation of the subframe in the radio frame of the paging occasion and the MBSFN subframe does not overlap using the first or second OFDM symbol of the subframe in the radio frame of the paging occasion obtained in step ST4901 Information that should have been transmitted in the first 1 to 3 OFDM symbols (L1 / L2 signaling channel) is transmitted. In addition, when the subframe in the radio frame of the paging occasion and the MBSFN subframe allocation do not overlap, the information that should have been transmitted in other than the first 1 to 3 OFDM symbols (PDSCH) is transmitted to the next MBSFN subframe. It transmits with other than the first 1-3 OFDM symbols (PDSCH) of other subframes. In the case of the other than the first 1 to 3 OFDM symbols (PDSCH) of the subframe other than the next MBSFN subframe, the radio resources in the PDSCH are allocated by the subframe and the MBSFN subframe in the radio frame of the paging occasion. If it is the same as the allocation in the case where they do not overlap, re-allocation or the like becomes unnecessary, and the effect of effective use of radio resources can be obtained. If it is determined in step ST4902 that the subframes are not the same, the process ends without moving to step ST4903. That is, the subframe in the radio frame of the paging occasion obtained in step ST4901 is used as it is.

  When allocation of the subframe in the radio frame of the paging occasion and the MBSFN subframe does not overlap using the first or second OFDM symbol of the subframe in the radio frame of the paging occasion obtained in step ST4901 A specific example of information that should have been transmitted in the first 1 to 3 OFDM symbols (L1 / L2 signaling channel) is shown below. Non-Patent Document 1 discloses that PCH is mapped to PDSCH or PDCCH. Non-Patent Document 1 discloses that the paging group uses the L1 / L2 signaling channel (PDCCH), and the clear identifier (UE-ID) of the mobile terminal can be found on the PCH. Therefore, PCH is transmitted using the L1 / L2 signaling channel. On the other hand, Non-Patent Document 4 describes that a PICH (Paging Indicator channel) that reports that a paging signal addressed to any mobile terminal belonging to a paging group is generated is transmitted using the L1 / L2 signaling channel. Yes.

  A specific example of information that should have been transmitted in other than the first 1 to 3 OFDM symbols (PDSCH) when the subframes in the radio frame of the paging occasion and the MBSFN subframes do not overlap is shown below. In Non-Patent Document 1, when the downlink radio resource of the next control information is assigned by PCH, the control information is mapped to PDSCH. On the other hand, Non-Patent Document 4 describes that PCH is mapped to PDSCH in the same subframe as PICH.

  In the ninth embodiment, when the allocation of the subframe and the MBSFN subframe in the radio frame of the paging occasion overlaps, radio resources other than the first 1-2 OFDM symbols dedicated to MBSFN transmission are used for unicast transmission, that is, paging It was decided not to use for processing. As a result, even if the subframes in the radio frame of the paging occasion and the MBSFN subframe allocation overlap, the information necessary for the paging process does not become impossible to transmit from the network side to the mobile terminal. Therefore, the effect that the third problem of the present invention can be solved can be obtained.

  Modification 1 will be described. When it is determined that both are the same subframes using the allocation of the MBSFN subframe received in step ST4502 and the subframes in the radio frame of the paging occasion obtained in step ST4901, the first modification is an embodiment of the first embodiment. The following processing is performed in place of the processing of 9. Information that should have been transmitted in the first 1 to 3 OFDM symbols (L1 / L2 signaling channel) and the radio of the paging occasion when the subframes in the paging occasion radio frame and the MBSFN subframe allocation do not overlap. In the radio frame of the paging occasion obtained in step ST4901 the information that should have been transmitted in other than the first 1 to 3 OFDM symbols (PDSCH) when the allocation of the subframe in the frame and the MBSFN subframe does not overlap The first 1 to 2 OFDM symbols of the first subframe are used for transmission.

  In the first modification, when the subframes in the radio frame of the paging occasion and the MBSFN subframe allocation overlap, radio resources other than the first 1-2 OFDM symbols dedicated to MBSFN transmission are used for unicast transmission, that is, paging processing. It was decided not to use it. As a result, even if the subframes in the radio frame of the paging occasion and the MBSFN subframe allocation overlap, the information necessary for the paging process does not become impossible to transmit from the network side to the mobile terminal. Therefore, the effect that the third problem of the present invention can be solved can be obtained.

It is explanatory drawing which shows the structure of the communication system of a LTE system. It is explanatory drawing which shows the structure of the communication system of a LTE system. FIG. 2 is an explanatory diagram showing a configuration of a radio frame used in an LTE communication system. It is explanatory drawing which shows the structure of a MBSFN (Multimedia Broadcast multicast service Single Frequency Network) frame. It is explanatory drawing explaining the physical channel used with the communication system of a LTE system. It is explanatory drawing explaining the transport channel used with the communication system of a LTE system. It is explanatory drawing explaining the logical channel used with the communication system of a LTE system. It is explanatory drawing explaining the relationship between a MBSFN synchronous area and a MBSFN area. It is explanatory drawing explaining the logical structure (Logical Architecture) of E-MBMS. It is explanatory drawing explaining the architecture (Architecture) of E-MBMS. 1 is a block diagram showing an overall configuration of a mobile communication system according to the present invention. It is a block diagram which shows the structure of a mobile terminal. It is a block diagram which shows the structure of a base station. It is a block diagram which shows the structure of MME (Mobility Management Entity). It is a block diagram which shows the structure of MCE (Multi-cell / multicast Coordination Entity). It is a block diagram which shows the structure of a MBMS gateway. 4 is a flowchart illustrating an outline of processing from when a mobile terminal starts to use MBMS until the end of use in an LTE communication system. It is a flowchart explaining the cell selection by the side of a unicast. It is a flowchart which shows a MBMS search process. It is a flowchart which shows a MBMS service selection process. It is a flowchart which shows a MBMS side reception condition notification process. It is a flowchart explaining a unicast side measurement process. It is a flowchart explaining the intermittent reception process at the time of MBMS reception. It is a flowchart which shows a MTCH reception process and a MBMS reception end process. It is a flowchart which shows a unicast side intermittent reception process and a MBMS reception completion process. It is explanatory drawing which shows the some MBSFN area which comprises an MBSFN synchronous area. It is a conceptual diagram of the mapping to the physical channel of the MBSFN synchronization area when the MBSFN area is time division multiplexed. It is a conceptual diagram of mapping to the physical channel of the MBSFN synchronization area when the MBSFN area is code division multiplexed. It is explanatory drawing which shows several MBSFN area which comprises an MBSFN synchronous area, Comprising: It is explanatory drawing which shows the MBSFN area which covers several MBSFN area. Explanatory drawing which shows the mapping to the physical channel of the MBSFN synchronous area when the covered MBSFN area and the covered MBSFN area are time division multiplexed, and the multiplexing method between the covered MBSFN areas is code division multiplexing. It is. It is explanatory drawing which shows the relationship between the intermittent reception period when the transmission of MBMS data to a mobile terminal is stopped, and the reception operation | movement of MBMS data in a mobile terminal stops, and the intermittent reception period which is a period which performs intermittent reception. It is explanatory drawing explaining the detail of a tracking area list. It is an example of a channel structure which maps the paging signal in an MBMS transmission-dedicated frequency layer. It is explanatory drawing which shows an example of the method of mapping a paging signal to the physical area | region where the paging signal on a physical multicast channel (PMCH) is carried. It is explanatory drawing which shows an example of the method of mapping a paging signal to the physical area | region where the paging signal on a physical multicast channel (PMCH) is carried. It is a flowchart which shows the alerting | reporting regarding MBMS which can be received, MBMS search, and a MBMS service selection process. It is a table | surface explaining matching of a service number and service content. It is a flowchart which shows the alerting | reporting regarding MBMS which can be received, MBMS search, and a MBMS service selection process. It is a flowchart which shows the process in which the mobile terminal which has received the MBMS service transmitted multicell from the unicast / MBMS mixed cell performs a handover. It is a flowchart which shows the process in which the mobile terminal which has received the MBMS service transmitted multicell from the unicast / MBMS mixed cell performs a handover. It is a flowchart which shows the process in which the mobile terminal which has received the MBMS service transmitted multicell from the unicast / MBMS mixed cell performs a handover. It is a flowchart which shows the process in which the mobile terminal which has received the MBMS service transmitted multicell from the unicast / MBMS mixed cell performs a handover. It is a flowchart which shows the process in which the mobile terminal which has received the MBMS service transmitted multicell from the unicast / MBMS mixed cell performs a handover. It is explanatory drawing which shows the concept which multiplexes an MBSFN sub-frame in an MBSFN area. It is explanatory drawing explaining the 3rd subject. It is a sequence diagram in the case of determining the sub-frame in the radio | wireless frame of the paging occasion to which a paging signal is mapped. It is a sequence diagram in the case of determining the sub-frame in the radio | wireless frame of the paging occasion to which a paging signal is mapped. It is a correspondence table of the number of subframes excluding the subframe and the MBSFN subframe in the radio frame of the paging occasion. It is a correspondence table of subframes and MBSFN subframe numbers in radio frames of paging occasions. FIG. 29 is a sequence diagram in the case of determining a subframe in a radio frame for paging occasions used in Modification 5 of Embodiment 8.

Explanation of symbols

101 mobile terminals, 102 base stations,
103 MME (Mobility Management Entity),
104 S-GW (Serving Gateway)

Claims (3)

An OFDM (Orthogonal Frequency Division Multiplexing) method is used as a downlink access method, and an SC-FDMA (Single Career Frequency Division Multiple Access) method is used as an uplink access method. In a mobile communication system capable of transmitting broadcast type data providing MBMS (Multimedia Broadcast Multicast Service) and one-to-one type individual communication data to the mobile terminal,
The mobile communication system includes a unicast cell in which a mobile terminal can transmit and receive the dedicated communication data, and an MBMS dedicated cell in which the mobile terminal can receive the broadcast type data but cannot transmit and receive the dedicated communication data. 3 types of unicast / MBMS mixed cells that can provide services for both the unicast cell and the MBMS dedicated cell, and the MBMS dedicated cell and the unicast / MBMS mixed cell are configured with the same frequency. An MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area for transmitting broadcast type data is configured, and one or a plurality of MBSFN areas are used for transmitting the broadcast type data in synchronization with the plurality of base stations. Multimedia Broadcast multicast service Single Frequency Network) And it is,
Among the unicast cell, the MBMS dedicated cell, and the unicast / MBMS mixed cell, a serving cell performing a scheduling process for allocating radio resources to the mobile terminal is located in an MBSFN area adjacent to the cell where the mobile terminal is located. A mobile communication system, wherein the mobile terminal is notified of the contents of an available MBMS service. The mobile communication system according to claim 1, wherein the serving cell reports either or both of the frequency of the available MBMS service and the content of the available MBMS service on the broadcast channel. The mobile communication system according to claim 1, wherein the serving cell reports either or both of the frequency of the available MBMS service and the content of the available MBMS service by mapping the downlink shared channel.

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