JP2009188612A - Mobile communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish an MBMS cell search method which is one among the processings to be executed, until a mobile terminal receives MBMS, in an MBMS exclusive cell. <P>SOLUTION: In the mobile communication system having three kinds of cells which are a unicast cell that is a cell, capable of transmitting and receiving individual communication data, the MBMS exclusive cell capable of receiving broadcast type data, and a unicast/MBMS mixed cell capable of providing the services of both the unicast cell and the MBMS exclusive cell, the MBMS exclusive cell and the unicast/MBMS mixed cell configure an MBSFN synchronization area, wherein a plurality of base stations synchronously transmit the broadcast type data; a mobile terminal receives synchronization information for receiving the broadcast type data in the MBSFN synchronization area, which is transmitted from the plurality of MBMS exclusive cells or unicast/MBMS mixed cells, and searches the MBMS exclusive cells or the unicast/MBMS mixed cells. <P>COPYRIGHT: (C)2009,JPO&INPIT

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 third generation, commercial services have been started in Japan since 2001 for the W-CDMA (Wideband Code division Multiple Access) system. In addition, 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 The HSDPA (High Speed Down Link Packet Access) service to be realized has been started. In addition, an HSUPA (High Speed Up Link Packet Access) system is also standardized in order to further increase the speed of data transmission in the uplink direction. W-CDMA is a communication system 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” is used for the entire system configuration including the core network (System Architecture Evolution). A new communication method called “Evolution SAE” is being studied. In LTE, the access method, wireless channel configuration, and protocol are completely different from those of 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 separate 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 an EPC (Evolved Packet Core) via an S1 interface, more specifically, connected to an MME 103 (Mobility Management Entity) via an S1_MME interface, and connected to an S-GW 104 (Serving Gateway) via an 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 subframe. 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 in 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 an 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 that is 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 transmitting 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 determines the details of the radio structure (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 for explaining 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 MTCH (multicast traffic channel) and MCCH (multicast control channel), which are downlink logical channels, are mapped to MCH (multicast channel) or DL-SCH (downlink shared channel), which is a downlink transport channel, in one-to-many transmission. The There is no uplink in the MBMS dedicated cell. In addition, unicast data cannot be transmitted / received within the MBMS dedicated cell. Also, no counting mechanism is set. Whether to provide paging signals (Paging messages) in the frequency layer dedicated to MBMS transmission is undecided.

  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 (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 R1-080073

3GPP R2-080463

  The first problem to be solved by the invention will be described. Non-Patent Document 1 discloses the existence 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. Furthermore, the existence of a plurality of MBSFN areas is discussed in the frequency layer dedicated to MBMS transmission, but there is no disclosure of a method for multiplexing MBSFN areas. An object of the present invention is to disclose a method for multiplexing MBSFN areas. It is another object of the present invention to disclose a method for selecting a desired service in a frequency layer dedicated to MBMS transmission according to a multiplexing method, and a mobile communication system therefor.

  Next, a second problem to be solved by the invention will be described. There is no uplink in the MBMS dedicated base station. When the mobile terminal moves and the base station that can receive the downlink (downlink signal, downlink radio wave) changes, and / or the best base station (cell with maximum received power) in the downlink that can be received (cell) There is no means to notify the MBMS dedicated base station from the mobile terminal even if the change occurs. Therefore, in the frequency layer dedicated to MBMS transmission configured by the MBMS dedicated base station, there is a problem that the mobility management of the mobile terminal is not possible with the current configuration and communication method of the mobile communication system. It is an object of the present invention to disclose a communication method capable of managing mobility of a mobile terminal even in a frequency layer dedicated to MBMS configured by an MBMS dedicated base station, and a mobile communication system therefor.

  Next, a third problem to be solved by the invention will be described. In the unicast / mixed frequency layer, the mobile terminal needs to perform measurement at a constant period. The cycle is instructed by the upper layer. In the measurement, the mobile station moves and the base station that can receive the downlink (downlink signal, downlink radio wave) has changed, the best base station (cell) in the downlink that can be received (maximum received power, etc.) This operation is also necessary for the mobile terminal to recognize the change. Therefore, unless the mobile terminal performs the measurement, mobility management as a mobile communication system becomes impossible. On the other hand, the base station constituting the MBSFN synchronization area (MBSFN Synchronization Area) in the MBMS transmission dedicated frequency layer and the base station constituting the unicast / mixed frequency layer are asynchronous. Therefore, in the present mobile communication system configuration and communication method, since the mobile terminal receiving the MBMS service in the MBMS transmission dedicated frequency layer performs the unicast / mixed frequency layer measurement, the MBMS reception is interrupted. The problem that it ends up occurs. In the present invention, a mobile terminal that is receiving an MBMS service in a frequency layer dedicated to MBMS transmission can perform unicast / mixed frequency layer measurement without interrupting reception of the MBMS service, and An object is to disclose a mobile communication system for that purpose.

  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 mobile communication system includes a unicast cell in which a mobile terminal can transmit and receive dedicated communication data, an MBMS dedicated cell and a unicast cell in which the mobile terminal can receive the broadcast type data but cannot transmit and receive dedicated communication data. And unicast / M that can provide both MBMS dedicated cell services MBSFN (Multimedia Broadcast Multicast Service Single Frequency Network) synchronization area, which has three types of MS mixed cell, MBMS dedicated cell and unicast / MBMS mixed cell, where multiple base stations synchronize and transmit broadcast type data The mobile terminal receives synchronization information for receiving broadcast-type data in the MBSFN synchronization area, transmitted simultaneously from a plurality of MBMS dedicated cells or unicast / MBMS mixed cells. The MBMS dedicated cell or the mixed unicast / MBMS cell is searched.

  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 mobile communication system includes a unicast cell in which a mobile terminal can transmit and receive dedicated communication data, an MBMS dedicated cell and a unicast cell in which the mobile terminal can receive the broadcast type data but cannot transmit and receive dedicated communication data. And unicast / M that can provide both MBMS dedicated cell services MBSFN (Multimedia Broadcast Multicast Service Single Frequency Network) synchronization area, which has three types of MS mixed cell, MBMS dedicated cell and unicast / MBMS mixed cell, where multiple base stations synchronize and transmit broadcast type data The mobile terminal receives synchronization information for receiving broadcast-type data in the MBSFN synchronization area, transmitted simultaneously from a plurality of MBMS dedicated cells or unicast / MBMS mixed cells. Since the MBMS dedicated cell or the mixed unicast / MBMS cell is searched, a method until the mobile terminal in the MBMS dedicated cell selects a desired service can be disclosed.

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. The 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 performs mobility management in a standby state (LTE-IDLE state, also simply referred to as idle), generation and control of a paging signal in the standby state, and one or more mobile terminals 101 being served thereby Add, delete, update, search, tracking area list (TA List) management, etc. The MME initiates the paging protocol by transmitting 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. The 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 through the MBMS GW communication unit 1401 and base stations in an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) area passed through 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 in one or more MBSFN areas managed by the mobile terminal. 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 between the MBMS GW 802 and the MCE 801 using the M3 interface. 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 “first 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 that realizes 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 mobile terminals that are using the MBMS service in the 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”. This step ST1607 enables a mobile terminal that is receiving the MBMS service in the MBMS transmission-dedicated frequency layer to perform unicast / mixed frequency layer measurement. As a result, even if the MBMS service is being received at the MBMS transmission dedicated frequency layer configured by the MBMS dedicated base station where there is no uplink, which is the second problem, the mobile terminal via the unicast / mixed frequency layer The effect that mobility management becomes possible can be obtained. In Step ST1608, the mobile terminal that is receiving the MBMS service in the frequency layer dedicated to MBMS transmission performs intermittent reception for paging signal reception. The network side notifies the paging signal to the mobile terminal receiving the MBMS service in the MBMS transmission dedicated frequency layer in the MBMS reception time missing reception configuration. Hereinafter, the processing in step 1608 is referred to as “intermittent reception during MBMS reception”. In steps ST1605 to ST1608, it is possible to disclose a paging signal notification method for a mobile terminal receiving an MBMS service in a frequency layer dedicated to MBMS transmission, and a mobile communication system therefor. Even in a mobile terminal that receives an MBMS service in a transmission-only frequency layer, there is an effect that a paging signal can be received. The mobile terminal that has not received the Paging signal in “Intermittent reception during MBMS reception” in Step ST1608 moves to Step ST1609.

  In Step ST1609, the mobile terminal receives MBMS traffic data (MTCH) from the frequency layer dedicated to MBMS transmission. Hereinafter, the process of step ST1609 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 when the reception sensitivity is deteriorated. The mobile terminal that has received the Paging signal in “Intermittent reception during MBMS reception” in Step ST1608 moves to Step ST1610. In Step ST1610, the mobile terminal moves from the frequency layer dedicated for MBMS transmission to the unicast / mixed frequency layer, and transmits and receives control data from the unicast cell or the mixed cell. Hereinafter, the process of step ST1610 is referred to as “Unicast side intermittent reception”. As a result, the mobile terminal can transmit uplink data to the network side in the unicast / mixed frequency layer. Therefore, a method for transmitting a response to a paging signal in a unicast / mixed frequency layer by a mobile terminal that has received the paging signal in an MBMS transmission-dedicated frequency layer without an uplink, and a mobile communication system therefor are disclosed. I can do it.

  In step ST1611, the mobile terminal notifies the network side that MBMS reception in the frequency layer dedicated for MBMS transmission is to be terminated. Hereinafter, the process of step ST1611 is referred to as “MBMS reception end”. Through this step ST1611, the network side can know that the mobile terminal ends the reception of the MBMS service in the frequency layer dedicated to 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. .

  Hereinafter, a specific example of the processing flow of the mobile communication system described in FIG. 16 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 a reference symbol: Reference Symbol: RS) are broadcast to a mobile terminal 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 of a 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 period is a period 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 period. 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 relating to a “Tracking Area”. The MME starts the 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 cycle, an intermittent reception cycle, 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 available MBMS service, 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 (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 the 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 to be static (Static) or quasi-static (Semi-Static) as the mobile communication system, the mobile terminal does not broadcast f (MBMS) from the base station. The effect that the control delay until the service is received from the frequency other than the current frequency can be obtained. 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 information in the MBMS transmission-dedicated frequency layer. Since decoding processing is required, 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. If not included, 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 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 makes a determination in step ST1721 at a fixed 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 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 the 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 has blindly detected 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 uses 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. Furthermore, since it is not necessary to decode and change the parameters (system bandwidth in f (MBMS) or / and the number of transmission antennas), 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 performed in step ST1725 is further examined. 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, how to multiplex a plurality of MBSFN areas at one frequency (Single Frequency) f (MBMS) has not been determined. Here, the “MBMS search” processing will be described for each multiplexing method so that the present invention can be applied even when the MBSFN area multiplexing method is different.

  FIG. 22 shows the configuration of the PMCH provided for each MBSFN area. FIG. 22 shows time division multiplexing (TDM) for each MBSFN area. Cell # n1 (cell # n2, cell # n3) is a cell in MBSFN area 1 (MBSFN area 2, MBSFN area 3). In the current 3GPP, non-patent document 2 discusses allocation of MBSFN subframes in mixed cells. However, since there is no unicast subframe in the MBMS dedicated cell, all are MBSFN subframes. Therefore, the discussion in Non-Patent Document 2 cannot be used as it is. However, unifying the configurations of the mixed cell and the MBMS dedicated cell as much as possible is important to avoid complication of the mobile communication system. 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. Further, Non-Patent Document 2 is different from the present invention in that it does not mention scheduling of MCCH in the MBSFN subframe. Specific examples of MCCH scheduling are not discussed. The present invention shows a specific example of MCCH scheduling.

  Since the cell of the cell # n1 belongs to the MBSFN area 1, the PMCH corresponding to the MBSFN area is transmitted at a certain time. Since PMCH is transmitted by multicell in the MBSFN area, it is transmitted on the MBSFN subframe. A set of MBSFN frames to which MBSFN subframes are allocated is referred to as an “MBSFN frame cluster”. In the MBMS dedicated cell, all subframes in the MBSFN frame may be MBSFN subframes used for multicell transmission. A cycle in which the MBSFN frame cluster is repeated is referred to as an “MBSFN frame cluster repetition period”. One or a plurality of MBMS transport channels MCH are mapped to the PMCH, and either or both of the logical channel MCCH for MBMS control information and the logical channel MTCH for MBMS data are mapped to the MCH. MCCH and MTCH may be temporally divided and mapped onto PMCH, or may be further temporally divided and mapped to a physical region that is transmitted in multicell. For example, MBSFN subframes, which are physical areas to which MTCH and MCCH are mapped, may be different. MCCH may be mapped on each MBSFN frame cluster or only MTCH. When only MTCH exists, the MCCH repetition period is different from the MBSFN frame cluster repetition period. In some cases, a plurality of MCCHs are mapped on the MBSFN frame cluster.

  In FIG. 22, the cell of cell # n1 (cell # n2, cell # n3) belongs to MBSFN area 1 (MBSFN area 2, MBSFN area 3), and is transmitted at a certain PMCH time corresponding to each MBSFN area. MCCH1 (MCCH2, MCCH3) is MBMS control information for MBSFN area 1 (MBSFN area 2, MBSFN area 3), and MTCH1 (MTCH2, MTCH3) is MBMS data for MBSFN area 1 (MBSFN area 2, MBSFN area 3). is there. The MCCH repetition period may be different for each MBSFN area. In the figure, the MCCH repetition period of cell # n1 (cell # n2) is represented as “MCCH Repetition period1 (2)”. The PMCH for each MBSFN area is time-division multiplexed. Therefore, the orthogonality of the cells between the MBSFN areas is obtained in the MBSFN synchronization area in which the synchronization between the cells is ensured, and interference from cells in other MBSFN areas is prevented. I can prevent it. Since multi-cell transmission is used in the MBSFN area, the cells in each MBSFN area transmit the same data on the same PMCH. Even if a plurality of MBSFN areas overlap in one cell, the PMCH configuration can be applied while maintaining orthogonality between the MBSFN areas.

Details of MCCH scheduling will be described. A case where the MBSFN frame cluster is smaller than the MCCH repetition period will be described. The case where the MBSFN frame cluster is longer than the MCCH repetition period will be described later. Let us consider notifying the starting point value of the time to which the MCCH is mapped and the MCCH repetition period as MCCH scheduling. More specifically, SFN (System Frame Number) is used to specify the starting point value. A specific calculation formula for obtaining the MCCH starting point value is as follows.
MCCH starting point value = (first SFN number to which MCCH is mapped) mod (MCCH Repeat Period)
In FIG. 22, the MCCH starting point value 1 of MBSFN area 1 is 1 mod 18 = 1 or 19 mod 8 = 1..., And the MCCH scheduling parameters of MBSFN area 1 are MCCH repetition period 1 “18”, MCCH starting point value. 1 “1”. The MCCH starting point value 2 of the MBSFN area 2 is 4 mod 9 = 4 or 13 mod 9 = 4 or 22 mod 9 = 4... The MCCH scheduling parameter of the MBSFN area 2 is MCCH repetition period 2 “9”, and the MCCH starting point value 2 “4”. The same applies to the MBSFN area 3. If the system frame number SFN at this time is mapped to the BCCH, it is broadcast every subframe, and is effective when receiving the MCCH from the MCCH starting point value. Further, when the MCCH is mapped to some subframes in the radio frame, SFN and subframe number may be notified as a starting point.

  That is, the data transmitted from the base station (cell) belonging to the MBSFN area 1, for example, the cell # n1, is as follows. MB-MS transmission-dedicated frequency layer-dedicated sequence P-SCH, MBSFN area ID1, etc. mapped S-SCH1, MCCH starting point value 1 “1”, MCCH repetition period 1 “18”, etc. are mapped and spread BCCH1 to which code 1 (Scrambling code1) is applied, MCCH1 and MTCH1 of MBSFN area 1 are transmitted. The resources of MCCH 2 and 3 and MTCH 2 and 3 from the base stations belonging to MBSFN areas 2 and 3 are turned off (DTX: Discontinuous transmission). MCCH1 and MTCH2 may be multiplied by spreading code 1. By applying a spreading code to MCCH1 and MTCH1, it is possible to obtain the effect that the processing to data specific to the MBSFN area (BCCH, MCCH, MTCH) is unified. Conversely, since MCCH and MTCH are time-division multiplexed between areas, it is not necessary to apply a spreading code specific to the MBSFN area. By not applying spreading 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 the delay until data reception.

  Similar to the MBSFN area 1, data transmitted from the MBSFN area 2 is as follows. MB-MS transmission dedicated frequency layer sequence P-SCH, MBSFN area ID2 etc. mapped S-SCH2, MCCH starting point value 2 “4”, MCCH repetition period 2 “9” etc. are mapped and spread BCCH2 to which code 2 is applied and MCCH2 and MTCH2 of MBSFN area 2 are transmitted. The resources of MCCH 1 and 3 and MTCH 1 and 3 from the base stations belonging to MBSFN areas 1 and 3 are turned off (DTX). The same applies to MBSFN Area3. Although FIG. 22 shows an example in which MCCH and MTCH are time-divided in units of subframes for convenience, even if the multiplexing method of MCCH and MTCH is different, the unit of time-division multiplexing is not in units of subframes. Even if it exists, this invention is applicable. Further, if the MCCH repetition cycle is determined as static (Static) or quasi-static (Semi-Static) as the mobile communication system, it is not necessary to report the MCCH repetition cycle from the base station. Since the information to be notified is reduced, the effect of effective use of radio resources can be obtained.

  FIG. 23 shows the configuration of the PMCH provided for each MBSFN area. In FIG. 23, PMCH is code division multiplexed for each MBSFN area. Cell # n1 (cell # n2, cell # n3) is a cell in MBSFN area 1 (MBSFN area 2, MBSFN area 3). The PMCH corresponding to MBSFN area 1 is transmitted in the cell of cell # n1. Here, the PMCH may be continuous in time or discontinuous. In the case of discontinuity, the MBSFN frame cluster repetition period (MBSFN frame cluster Repetition period) coincides with the period in which the MBSFN frame cluster in which the PMCH corresponding to the MBSFN area is transmitted is repeated. Moreover, the MBSFN frame cluster repetition period (MBSFN frame cluster repetition period) in the case of continuous may be set to zero. In the case of continuous, the MBSFN frame cluster repetition period may not be explicitly notified. MCCH and MTCH may be temporally divided and mapped onto PMCH, or may be further temporally divided and mapped to a physical region that is transmitted in multicell. For example, MBSFN subframes that are physical areas to which MTCH and MCCH are mapped as a result may be different. The cycle in which the MCCH is repeated is defined as MCCH repetition cycle 1.

  Similarly, the PMCH corresponding to MBSFN area 2 (MBSFN area 3) is transmitted in the cell of cell # n2 (cell # n3). The MCCH repetition period may be different for each MBSFN area. The MCCH repetition period of cell # n2 (cell # n3) is MCCH repetition period 2 (MCCH repetition period 3). Since the data multiplied by the spreading code specific to the MBSFN area is mapped to the PMCH for each MBSFN area, interference between MBSFN areas can be suppressed in the MBSFN synchronization area in which synchronization between cells is ensured. Since multi-cell transmission is used in the MBSFN area, cells in each MBSFN area transmit the same data on the same PMCH, that is, data multiplied by a spreading code unique to the MBSFN area. Even if a plurality of MBSFN areas overlap in one cell, the PMCH configuration can be applied while suppressing interference between the MBSFN areas.

Data (P-SCH, S-SCH, BCCH) transmitted from each MBSFN area is the same as that described above for time division multiplexing, and thus the description thereof is omitted. The specific example of MCCH scheduling is also the same as described above for time division multiplexing. In the present invention, since the “starting point value of the time when MCCH is mapped” and “MCCH repetition period” are used for MCCH scheduling, it is considered that the cell notifies the terminal. More specifically, SFN (System Frame Number) is used to designate the offset value. A specific calculation formula for obtaining the starting point value is represented by the following formula.
MCCH starting point value = (first SFN number to which MCCH is mapped) mod (MCCH Repeat Period)

  In FIG. 23, the MCCH starting point value of MBSFN area 1 is 1 mod 9 = 1, 10 mod 9 = 1..., And the MCCH scheduling parameter of MBSFN area 1 is MCCH repetition period 1 “9”, the starting point. The value is “1”. The MCCH starting point value of MBSFN Area 2 is 4 mod 12 = 4, 16 mod 12 = 4..., And the MCCH scheduling parameters of MBSFN area 1 are MCCH repetition period 2 “12” and starting point value “4”. . The same applies to MBSFN Area3. Further, when the MCCH is mapped to some subframes in the radio frame, SFN and subframe number may be notified as a starting point.

That is, as data transmitted from a base station (cell) belonging to MBSFN area 1, for example, cell # n1, S-SCH1 in which P-SCH, MBSFN area ID1, and the like, which are sequences dedicated to the frequency layer dedicated to MBMS transmission, are mapped. MCCH starting point value 1 “1” and MCCH repetition period 1 “9”. These data are mapped to BCCH1, MCCH1, and MTCH1, and are further spread by spreading code 1 and transmitted. The same applies to the MBSFN areas 2 and 3.
Although FIG. 23 shows an example in which MCCH and MTCH are time-divided in units of subframes for convenience, even if the multiplexing method of MCCH and MTCH is different, the unit of time-division multiplexing is not in units of subframes. Even if it exists, this invention is applicable. Moreover, if the MCCH repetition period is determined as 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. Further, when MBSFN areas are code division multiplexed, different repetition periods can be set for each MBSFN area. Therefore, the MBMS service can be scheduled with a high degree of freedom as compared with the case of MBSFN area time division multiplexing. Can be obtained. In addition, even when the mobile terminal receives MTCH and MCCH from a plurality of MBSFN areas, they can be separated, so that it is possible to simultaneously transmit MTCH and MCCH from MBSFN areas 1 to 3, and one MBSFN. It is possible to obtain an effect that the frequency and time radio resources allocated to the area are expanded.

  Next, “MBMS area information acquisition” in step ST1603 in FIG. 16 will be described more specifically with reference to FIGS. 18 and 19 as appropriate. The MCCH (multicast control channel) in each MBSFN area considers multi-cell transmission. Therefore, in step ST1726 in FIG. 18, 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 of FIG. 19, each base station performs MBMS area information, discontinuous reception (DRX) information, MBMS reception time missing reception parameters (specifically, the number of paging groups is K) according to radio resources allocated from the MCE. Control information such as is transmitted by multi-cell using MCCH. 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, the case where each MBSFN area is time-division multiplexed as shown in FIG. 22 will be described. A case where the mobile terminal is located in cell # n1 belonging to MBSFN area 1 will be described. By decoding BCCH1 (broadcast control channel), the mobile terminal receives the starting point value 1 “1” and the MCCH repetition period 1 (MCCH Repetition Period) “7” as the scheduling parameters of MCCH1. 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 (MBSFN frame cluster, MBSFN subframe), service content, MTCH modulation information, and the like of each area 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 one 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 MBSFN subframe parameters 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 contents, the service contents performed in the MBMS area 1 are 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. 24 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. As a solution for enabling mobility management of a mobile terminal even in a frequency layer dedicated to MBMS configured by an MBMS dedicated base station, which is a second problem of the present invention, MBMS service reception is performed in the MBMS transmission dedicated frequency layer. Even within, it is disclosed to perform unicast / mixed frequency layer measurements. 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. Therefore, even a mobile terminal that is receiving an MBMS service in an MBMS transmission dedicated cell needs to perform measurement of a unicast cell and an MBMS / unicast mixed cell at a constant 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 by the upper layer from the network side.

  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, a third problem arises in that MBMS reception must be interrupted.

  Therefore, in the present invention, as a solution to the above problem, one DRX period is provided in the MBSFN synchronization area (see FIG. 24). The DRX period refers to 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, a period in which MBMS data is not received when viewed from the mobile terminal side. I mean. The mobile terminal using the MBMS service in the MBMS transmission dedicated frequency layer uses the MBMS service by measuring 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. 24 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 an MBMS / unicast mixed 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 the unicast / mixed frequency layer measurement 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, it is possible to obtain the effect of solving the second and third problems while preventing the mobile communication system from being complicated, that is, avoiding additional signaling on the radio interface or in the network. 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. 24, the DRX period is “4” radio frames (periods 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 the DRX period is a part of subframes in a radio frame, the SFN and the 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. 24, 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 the mobile terminal from the 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 as 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. Non-Patent Document 1 discloses that a paging group is notified by an 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, “MBMS service selection” described with reference to FIG. 16 will be described more specifically. In step ST1730 in FIG. 19, 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 is equal to or higher than the threshold, it indicates that the sensitivity is satisfactory for receiving the MBMS service, and if the threshold is less than the threshold, it indicates that the sensitivity for receiving the MBMS service is not satisfied. If it is equal to or greater than the threshold value, the process proceeds to step ST1732, and if it is equal to or less than the threshold value, 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)). 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.

  FIG. 20 is a flowchart showing the unicast-side measurement process. In Step ST1753 of FIG. 20, 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 is 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. 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 period, 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, and the like of the serving cell and 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 re-selection of the serving cell (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 of 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 to receive 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 converting 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 a unicast cell or / and a mixed MBMS / unicast cell even if it is receiving an 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 or / and 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. In addition, even in a mobile terminal that is receiving a service in the MBMS transmission dedicated frequency layer, it is possible to establish downlink synchronization through measurement with a unicast cell or an MBMS / unicast mixed cell with a measurement cycle. Thereby, even when the mobile terminal transmits a message in the unicast / mixed frequency layer, it is possible to obtain an effect that can be realized with a small control delay.

  Next, the “MTCH reception” described in FIG. 16 will be specifically described. 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 the reception timing of MCCH, it transfers to step ST1840. When it is not the reception timing of MCCH, it transfers to step ST1841. In Step ST1840, the mobile terminal performs MCCH reception / decoding. Thereafter, the process proceeds to step ST1842. In Step ST1841, the mobile terminal determines whether it is the MTCH reception timing using the MCCH scheduling received in Step ST1725 and / or the MBMS Area information received in Step ST1729. When it is the reception timing of MTCH, it transfers to step ST1843. When it is not the reception timing of MTCH, it transfers to step ST1753. In Step ST1842, the mobile terminal determines whether it is the MTCH reception timing using the MCCH scheduling received in Step ST1725 and / or the MBMS Area information received in Step ST1729. When it is the reception timing of MTCH, it transfers to step ST1843. When it is not MTCH reception timing, it transfers to step ST1794. In Step ST1843, the mobile terminal performs MTCH reception / decoding. Then, the process proceeds to step ST1794.

  In ST1794 of FIG. 21, 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 is equal to or higher than the threshold, it indicates that the sensitivity is satisfactory for receiving the MBMS service, and if the threshold is less than the threshold, it indicates that the sensitivity for receiving the MBMS service is not satisfied. 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 and decode the MBMS service (MTCH or / and MCCH) in the MBSFN area. 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 desires to end the reception of the MBMS service being received, the process ends. In Step ST1796, the mobile terminal determines whether there is another MBMS area that can be received within the same frequency (f (MBMS)). When it exists, it returns to step ST1730 and repeats a process. If not, the process proceeds to step ST1797. 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 returns to step ST1720 of FIG.

  It is possible to disclose a method for selecting a desired service in the frequency layer dedicated to MBMS transmission, which is the first problem in the mobile communication system disclosed above, and a mobile communication system therefor.

Modification 1
Next, in the current 3GPP discussion, it is said that a base station (cell) in an MBSFN synchronization area may constitute a plurality of MBSFN areas. However, as described above, in the current 3GPP, the MBSFN area multiplexing method has not been determined in detail. In the first modification, a specific example of an MBSFN area multiplexing method in such a case will be described, and a method for selecting a desired service in the frequency layer dedicated to MBMS transmission, which is the first problem of the present invention And a mobile communication system therefor. In addition, it demonstrates centering on a different part from Embodiment 1, and description of the part similar to Embodiment 1 is abbreviate | omitted.

  In the first embodiment, as a PMCH configuration, a method of time division multiplexing (TDM) for each MBSFN area and code division multiplexing (CDM) for each MBSFN area has been disclosed. In the first modification, a method of mixing time division multiplexing (TDM) and code division multiplexing (CDM) for each MBSFN area as the configuration of the PMCH is disclosed. FIG. 25 shows the configuration of the PMCH provided for each MBSFN area. In FIG. 25, time division multiplexing (TDM) and code division multiplexing are mixed for each MBSFN area. Cell # n1 is a cell in MBSFN area 1, cell # n2 is a cell in MBSFN area 2, and cell # n3 is a cell in MBSFN area 3. Further, the cells # n1, # n2, and # n3 are also cells in the MBSFN area 4. FIG. 35 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. 35, MBSFN areas 1 to 4 exist in one MBSFN synchronization area. Among them, MBSFN area 4 covers MBSFN areas 1 to 3. The PMCHs of MBSFN area 1, MBSFN area 2, and MBSFN area 3 are code division multiplexed, and the PMCHs of MBSFN area 1, MBSFN area 2, MBSFN area 3, and PMCH of MBSFN area 4 are time division multiplexed. Since the cell of the cell # n1 belongs to the MBSFN area 1, the PMCH corresponding to the MBSFN area 1 is transmitted at a certain time. Since PMCH is transmitted by multicell in the MBSFN area, it is transmitted on the MBSFN subframe.

  A set of MBSFN frames, which are radio frames to which MBSFN subframes are allocated, is referred to as an “MBSFN frame cluster” (MBSFN frame cluster). In the MBMS dedicated cell, all subframes in the MBSFN frame may be MBSFN subframes used for multicell transmission. A period in which an MBSFN frame cluster corresponding to an MBSFN area is repeated is referred to as an “MBSFN frame cluster repetition period”. The MBCH transport channel MCH is mapped to the PMCH, and either or both of the logical channel MCCH of MBMS control information and the MBMS data logical channel MTCH are mapped to the MCH. MCCH and MTCH may be temporally divided and mapped onto PMCH, or may be further temporally divided and mapped to a physical region that is transmitted in multicell. For example, MBSFN subframes that are physical areas to which MTCH and MCCH are mapped as a result may be different. MCCH may be mapped on each MBSFN frame cluster or only MTCH. When only MTCH exists, the MCCH repetition period is different from the MBSFN frame cluster repetition period. In some cases, a plurality of MCCHs are mapped on the MBSFN frame cluster. The MCCH repetition period is “MCCH Repetition period 1”.

  In FIG. 25, MCCH1 is MBMS control information for MBSFN area 1, and MTCH1 is MBMS data for MBSFN area 1. Since the cell # n1 belongs to the MBSFN area 1 and the MBSFN area 4, the PMCH in the MBSFN area 1 and the PMCH in the MBSFN area 4 are time division multiplexed. Similarly, since the cell of cell # n2 belongs to MBSFN area 2 and MBSFN area 4, the PMCH of MBSFN area 2 and the PMCH of MBSFN area 4 are time-division multiplexed, and the cell of cell # n3 is MBSFN area 3 and MBSFN area 4 Therefore, the PMCH in the MBSFN area 3 and the PMCH in the MBSFN area 4 are time division multiplexed. Since the PMCH in the MBSFN area 4 is transmitted by multicell transmission in the MBSFN area 4, the PMCH transmission timings are all the same in the cells # n1, # n2, and # n3. As described above, by mixing the PMCH for each MBSFN area with time division multiplexing and code division multiplexing, for example, time division multiplexing is performed for MBSFN areas that overlap between MBSFN areas, and code division multiplexing is performed for non-overlapping MBSFN areas. Can be used. Therefore, the efficiency of radio resources can be improved because code division multiplexing is used as compared with the case of only time division multiplexing. Furthermore, it is possible to reduce mutual interference between overlapping MBSFN areas as compared with the case of only code division multiplexing, and it is possible to reduce reception errors of MBMS data at a mobile terminal.

  Hereinafter, a specific example of step ST1725 in FIG. 18 will be shown. As a first step, the mobile terminal performs blind detection of the P-SCH using 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 on the S-SCH. A mobile terminal that has blindly detected S-SCH can detect 10 ms timing detection (frame synchronization) and the MBSFN area ID. S-SCH is multi-cell transmission. In this modification, it is assumed that one base station belongs to a plurality of MBSFN areas. Therefore, there is a problem in which MBSFN area the MBSFN area ID mapped to the S-SCH indicates. In this case, the MBSFN area ID mapped to the S-SCH is any one MBSFN area ID to which the base station belongs. Furthermore, the ID is the smallest (covered) MBSFN area to which the base station belongs. Therefore, multi-cell transmission of S-SCH is targeted for base stations included in each covered MBSFN area. The mobile terminal receives BCCH using the spreading code associated with the MBSFN area ID obtained in the second stage. MCCH scheduling can be obtained by decoding BCCH. BCCH is multi-cell transmission. Since the spreading code obtained in the second stage is used, BCCH becomes BCCH from the covered MBSFN area. Therefore, BCCH multi-cell transmission 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. Since the MBSFN synchronization area is synchronized in time, the P-SCH is transmitted to the MBMS dedicated cell in the MBSFN area 1, the MBMS dedicated cell in the MBSFN area 2, and the MBMS dedicated cell in the MBSFN area 3 at the same timing. Yes. Further, if the sequence dedicated to the frequency layer dedicated to MBMS transmission is used, the sequence of P-SCH in all MBSFN areas is the same. Therefore, the same information is transmitted at the same timing in the MBSFN synchronization area for the P-SCH. It is considered that the MBSFN area ID is transmitted by S-SCH as described above. Therefore, S-SCH is transmitted at the same timing in the MBSFN synchronization area with different information for each MBSFN area. In this case, the same information is transmitted at the same timing from all the MBMS dedicated cells in each MBSFN area. 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 the spreading code of each MBSFN area, the spreading code of each MBSFN area cannot be applied to the S-SCH. In order to realize that one base station belongs to a plurality of MBSFN areas while following such S-SCH functions, as described above, the S-SCH specific to the covering MBSFN area is used. This can be realized by setting the MBSFN area ID mapped to the S-SCH as the smallest MBSFN area ID to which the base station belongs.

  Further, the S-SCH transmission is not performed from the covering MBSFN area, but a plurality of MBSFN areas overlap as geographical locations, but in the overlapping MBSFN areas (for example, MBSFN area 1 and MBSFN area 4) Therefore, only one type of S-SCH needs to be transmitted. Thereby, the effect that it can prevent that S-SCH from a mutual MBSFN area becomes interference is acquired. A mobile communication system transmits BCCH which performed the spreading | diffusion process using the spreading code linked | related with MBSFN area ID notified by S-SCH. 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.

With reference to FIG. 25, MCCH scheduling when the MBSFN frame cluster is longer than the MCCH repetition period will be described together. Two stages are considered for the scheduling of the MCCH in the covering MBSFN area, for example, the MBSFN area 4 in FIG. In the following description, a case where the mobile terminal is under the control of base stations belonging to the MBSFN area 1 and the MBSFN area 4 will be described for convenience. 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, “starting point value of time for mapping MCCH”, “MBSFN frame cluster repetition period”, and “number of MCCH transmissions within MBSFN frame cluster repetition period” are transferred from the cell to the terminal for MCCH scheduling. Shall be notified. More specifically, SFN (System Frame Number) is used to specify the starting point value. The specific calculation formula for obtaining the starting point value is as follows.
Starting point value = (first SFN number to which MCCH is mapped in the MBSFN frame cluster) mod (MBSFN frame cluster repetition period)

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 specific calculation formula for _obtaining N _MCCH is as follows.
N _MCCH = MBSFN frame cluster / MCCH repetition period In FIG. 25, the starting point value 1 of MBSFN area 1 is 5 mod 16 = 5 or 21 mod 16 = 5. The starting point value 2 of the MBSFN area 2 is 5 mod 16 = 5 or 21 mod 16 = 5. The MBSFN area 3 is the same. Next, N _MCCH 1 of MBSFN area 1 is _12/6 = 2, and N _MCCH 2 of MBSFN area 2 is _12/4 = 3. In the case of MBSFN area 3, it is obtained in the same manner. Therefore, the MCCH scheduling parameters of MBSFN area 1 are MBSFN frame cluster repetition period 1 “16”, starting point value 1 “5”, and N _MCCH 1 “2”. 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. The calculation method of MCCH scheduling parameters is the same as that in FIG. 22 because the MBSFN frame cluster is smaller than the MCCH repetition period. The starting point value 4 of the MBSFN area 4 is 1 mod 16 = 1 or 17 mod 16 = 1. A specific example of MCCH scheduling is to notify the MBSFN area ID of the covering MBSFN area 4 in addition to the parameters of the MBSFN area 4 (MCCH repetition period 4 “16”, state point 4 “1”). Since there is no S-SCH dedicated to MBSFN area 4, it is necessary to notify the MBSFN area ID here.

That is, the data transmitted from the MBSFN area 1 is as follows. S-SCH1, which is a sequence dedicated to the frequency layer dedicated to MBMS transmission, S-SCH1 mapped with MBSFN area ID1, etc., MCCH starting point value 1 “5”, MBSFN frame cluster repetition period 1 “16”, N _MCCH 1 “2” or the like is mapped, and BCCH1 to which spreading code 1 is applied and MCCH1 and MTCH1 of MBSFN area 1 to which spreading code 1 is applied are transmitted. In MCCH1, an MBSFN area ID (MBSFN area 4) and MCCH scheduling point value 4 “1” and MCCH repetition period 4 “16”, which are MCCH scheduling of MBSFN area 4, are transmitted.

Similar to the MBSFN area 1, data transmitted from the MBSFN area 2 is as follows. S-SCH2, which is a sequence dedicated to the MBMS transmission and dedicated to the frequency layer, S-SCH2 to which MBSFN area ID2 and the like are mapped, MCCH starting point value 2 “5”, MBSFN frame cluster repetition period 2 “16”, N _MCCH 2 “3” or the like is mapped, BCCH2 to which spreading code 2 is applied, and MCCH2 and MTCH2 of MBSFN area 2 to which spreading code 2 is applied are transmitted. In MCCH2, an MBSFN area ID (MBSFN area 4) and an MCCH scheduling point value 4 “1” and an MCCH repetition period 4 “16”, which are MCCH scheduling of the MBSFN area 4, are transmitted. 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 information to be notified other than the information transmitted on the BCCH of the covered MBSFN area (MBSFN areas 1 to 3) 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 spreading code is applied are transmitted. A spreading code peculiar to the MBSFN area 4 may be applied to MCCH4 and MTCH4. The effect that the interference between each MBSFN area is suppressed can be acquired. In this case, it is assumed that the MBSFN area 4 specific spreading code is associated with the MBSFN area ID of the MBSFN area 4 notified through the MCCH such as the MBSFN area 1, the MBSFN area 2, the MBSFN area 3, and the like. Thereby, the effect that the further signaling is unnecessary can be acquired.

  FIG. 25 shows an example in which MCCH and MTCH are time-divided in units of subframes for convenience. However, even if the multiplexing method of MCCH and MTCH is different, the unit of time-division multiplexing is in units of subframes. The present invention can be applied to other than the above. In the mobile communication system described above, even when the base station configures a plurality of MBSFN areas, a method for selecting a desired service in the frequency layer dedicated to MBMS transmission, which is the first problem, And a mobile communication system therefor can be disclosed.

  In the above, the service content of MBSFN area 4 is included in the MBMS area information in MCCH4. Here, when reporting the MCCH scheduling information of the covering MBSFN area (MBSFN area 4, see FIG. 35) using the MCCH of the covering MBSFN area (MBSFN area 1-3, see FIG. 35), The service content of the MBSFN area 4 may be notified together with the scheduling information. Thereby, the mobile terminal (user) can grasp the service contents of a plurality of MBSFN areas to which the base station belongs at the stage where the MCCH of the covered MBSFN area is decoded. Therefore, it is not necessary to sequentially receive and decode the MCCHs of a plurality of MBSFN areas to which the base station belongs to perform MBMS service selection, and an effect of reducing control delay can be obtained. Specifically, in step ST1729 in FIG. 19, the mobile terminal uses the MCCH of the covered MBSFN area (MBSFN area 1-3, see FIG. 35) to cover the covered MBSFN area (MBSFN area 1− 3) and the service content of the covering MBSFN area (MBSFN area 4, see FIG. 35). As a result, the mobile terminal can grasp the MBMS service content that can be received at the current location. In Step ST1730 of FIG. 19, the mobile terminal confirms the MBSFN area where the desired MBMS service content is transmitted.

In addition, for MCCH scheduling of MBSFN area 4, a method of notifying on the BCCH of MBSFN area 1 is also conceivable. 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-described starting point, MBSFN frame cluster repetition period, and N _MCCH (which may be an MBSFN frame cluster and an MCCH repetition period) are used in the case of MBSFN area time-division multiplexed (see FIG. 22). It can also be used when there are multiple MCCHs in the cluster.

Modification 2
In Embodiment 1, the service content for each MBSFN area is included in the MBMS area information in the MCCH. Here, the service contents for each MBSFN area may be notified together with MCCH scheduling on the BCCH. Thereby, the mobile terminal (user) can grasp the service contents of the MBSFN area to which the base station belongs at the stage of decoding the BCCH. Therefore, it is possible to determine whether or not a desired service exists before receiving and decoding the MCCH, and it is not necessary to receive and decode the MCCH in the MBSFN area where the desired service is not performed, thereby reducing control delay. The effect that can be obtained. Specifically, in step ST1725 of FIG. 18, the mobile terminal receives the service content of the MBSFN area. Thereby, the mobile terminal can grasp the service contents of MBMS that can be received at the current position (location). After that, the mobile terminal confirms whether the service desired by the user is performed in the corresponding MBSFN area prior to ST1729 in step FIG. If the desired service has been performed, the process proceeds to step ST1729. After step ST1729, the process proceeds to step ST1731. On the other hand, when the desired service is not performed, the processing of step ST1729 and step ST1731 is omitted, and the process proceeds to step ST1733.

  Further, MBMS area information, DRX information, MBMS reception time missing reception parameters, etc. mapped to MCCH may be notified together with BCCH. Thereby, MCCH becomes unnecessary and the efficiency of radio resources can be improved. Therefore, there is no need to notify MCCH scheduling on the BCCH, and the efficiency of radio resources can be further improved. The second modification can be applied to the first modification, and the same effect can be obtained.

  Next, in 3GPP, application of single-cell transmission in a frequency layer dedicated to MBMS transmission is also under consideration. As a method therefor, a method of realizing single cell transmission in an MBSFN area having a single cell configuration is conceivable. However, the specific implementation method has not been determined. In the above description, assuming that one base station belongs to the MBSFN area, a mobile communication system that realizes single cell transmission in an MBSFN area having a single cell configuration can be disclosed.

Embodiment 2. FIG.
In the second embodiment, a mobile communication system different from the first embodiment is disclosed mainly in the MBMS search part. The processing flow as the mobile communication system according to the second embodiment is almost the same as that in FIGS. 16 and 17 of the first embodiment. In the description, the description will focus on parts different from the first embodiment. In step ST1707 of FIG. 17, the unicast cell or the unicast / MBMS mixed cell uses BCCH to select one or a plurality of frequencies for which the MBMS service is performed at a frequency other than the current unicast / mixed frequency layer. , Notify the mobile terminal being served. That is, one or a plurality of receivable MBSFN synchronization area frequencies (f (MBMS)) are broadcast. In addition, the system bandwidth in each f (MBMS), the number of transmission antennas, or both are notified. In step ST1708 of FIG. 17, the mobile terminal receives and decodes the BCCH from the serving base station, thereby receiving f (MBMS), the system bandwidth in each f (MBMS), and the number of transmission antennas. In addition, for each f (MBMS), information indicating whether the frequency layer is configured with a unicast / MBMS mixed cell or the frequency layer configured with an MBMS dedicated cell may be notified. As a result, the operation of the mobile terminal can be changed in the frequency layer configured with the unicast / MBMS mixed cell and the frequency layer configured with the MBMS dedicated cell. As a specific operation, there is an MBMS search operation. Since a unicast / MBMS mixed cell provides a unicast service, it is difficult to reduce P-SCH, S-SCH and the like used in the unicast service. Therefore, the MBMS search operation in the frequency layer configured with the unicast / MBMS mixed cell uses the method described in the first embodiment. On the other hand, since the unicast service is not provided in the MBMS dedicated cell, reducing P-SCH, S-SCH, etc. has fewer restrictions compared to the unicast / MBMS mixed cell. Therefore, the processing described below is applied to the MBMS search operation of the frequency layer configured by the MBMS dedicated cell.

  In Embodiment 2, steps ST1723 to ST1725 in FIG. 18 are changed as shown in FIG. FIG. 26 is a flowchart showing an MBMS search method. In FIG. 26, in step ST2201, MBMS GW 802, more specifically, MBMS CP 802-1 notifies MCE 801 of the contents of a physical channel (referred to as main PMCH) transmitted in multi-cells within the MBSFN synchronization area. Since the main PMCH is transmitted by multicell in the MBSFN synchronization area, the same information needs to be transmitted from the base station in the MBSFN synchronization area using the same radio resource. Therefore, the MBMS GW notifies scheduling information about radio resources (frequency, time, etc.) in addition to notifying the contents of the main PMCH in step ST2201.

  FIG. 27 is an explanatory diagram showing the configuration of the main PMCH in the MBSFN synchronization area. FIG. 27 shows a case where the PMCH provided for each MBSFN area is multiplexed by time division multiplexing and code division multiplexing. Cell # n1 is a cell in MBSFN area 1, cell # n2 is a cell in MBSFN area 2, and cell # n3 is a cell in MBSFN area 3. Further, the cells # n1, # n2, and # n3 are also cells in the MBSFN area 4. The PMCHs in MBSFN area 1 to MBSFN area 3 are code division multiplexed, and further, time division multiplexed with the PMCH in MBSFN area 4. The main PMCH is time-division multiplexed with the PMCH for each MBSFN area. Since cell # n1 belongs to MBSFN area 1 and MBSFN area 4, PMCH1 and PMCH4 are time-division multiplexed, and the main PMCH is time-division multiplexed. The same applies to cell # 2 and cell # 3. Since the main PMCH is transmitted by multicell in the MBSFN synchronization area, it is transmitted on the MBSFN subframe in which SFN combining is performed. A set of MBSFN frames to which MBSFN subframes are allocated is defined as an MBSFN frame cluster. In the MBMS dedicated cell, all subframes in the MBSFN frame may be MBSFN subframes used for multicell transmission. A cycle in which the main PMCH is repeated is defined as a main PMCH repetition cycle.

  The MCH of the transport channel for MBMS is mapped to the main PMCH. The logical channel MCCH of MBMS control information and the logical channel MTCH of MBMS data are mapped to the MCH. MCCH and MTCH may be divided in time and mapped onto the main PMCH, or may be further divided in time and mapped to a physical area where multi-cell transmission is performed. For example, MBSFN subframes that are physical areas to which MTCH and MCCH are mapped as a result may be different. The MCCH may be mapped to each MBSFN frame cluster in which the main PMCH is transmitted, or only the MTCH may be used. When only MTCH exists, the MCCH repetition period is different from the main PMCH repetition period. In some cases, a plurality of MCCHs are mapped on the MBSFN frame cluster in which the main PMCH is transmitted.

  In FIG. 27, MCCH1 is MBMS control information for MBSFN area 1, and MTCH1 is MBMS data for MBSFN area 1. MCCH2 is MBMS control information for MBSFN area 2, and MTCH2 is MBMS data for MBSFN area 2. MCCH3 is MBMS control information for MBSFN area 3, and MTCH3 is MBMS data for MBSFN area 3. MCCH4 is MBMS control information for MBSFN area 4, and MTCH4 is MBMS data for MBSFN area 4. Each MCCH may be mapped on each PMCH, or only MTCH. When only the MTCH exists, the MCCH of each MBSFN area may be mapped to the main PMCH. Further, it may be included as an information element of MCCH mapped to the main PMCH. Since the main PMCH is transmitted by multicell in the MBSFN synchronization area, it is impossible to multiply the main PMCH by a scrambling code unique to the MBSFN area so that the PMCH is spread in each MBSFN area. This is because, since the main PMCH is transmitted from the cells of different MBSFN areas at the same timing, when the main PMCH is spread with the spreading code specific to the MBSFN area, it is transmitted from each MBSFN area at the receiver of the mobile terminal. This is because the phase of the main PMCH becomes random and SFN synthesis cannot be performed. Therefore, as shown above, the main PMCH and the PMCH of each MBSFN area are time-division multiplexed, so that scrambling codes unique to each MBSFN area can be multiplied in subframe units, and only the main PMCH Can not be multiplied by a scrambling code unique to each MBSFN area. As a result, the main PMCH can be transmitted in a multi-cell manner in the MBSFN synchronization area, and the mobile terminal receives the main PMCH regardless of which MBMS service in the MBSFN synchronization area is being received or is about to be received. In addition, an SFN gain can be obtained. In the main PMCH, it has been described that a unique scrambling code is not multiplied. However, any scrambling code unique to the MBSFN synchronization area may be multiplied. In this case, interference from other cells in the MBSFN synchronization area can be suppressed, and reception errors of the MBMS service in the mobile terminal can be reduced. The scrambling code unique to the MBSFN synchronization area may be defined statically or mapped to the BCCH from the serving base station defined semi-statically, and in step ST1705, the mobile terminal May be notified.

Further, scheduling of radio resources (frequency, time, etc.) of the main PMCH in step ST2201 of FIG. 26 will be described. Specific examples of frequency scheduling include frequency and band. A specific example of time scheduling will be described with reference to FIG. For scheduling of the main PMCH, it is considered to notify the starting point value of the time to which the main PMCH is mapped and the main PMCH repetition period. More specifically, SFN (System Frame Number) is used to specify the starting point value. A specific calculation formula for obtaining the main PMCH starting point value is as follows.
Main PMCH starting point value = (first SFN number to which main PMCH is mapped) mod (main PMCH repetition period)

  In FIG. 27, the main PMCH starting point value is 1 mod 11 = 1, 12 mod 11 = 1..., And the main PMCH scheduling parameters are the main PMCH repetition period 1 “11” and the main PMCH starting point value “1”. "

  Next, a specific example of the contents of the main PMCH in step ST2201 in FIG. 26 will be described. As specific examples of information notified on the main PMCH, the numbers (IDs and identifiers) of all MBSFN areas existing in the MBSFN synchronization area, MCCH scheduling of each MBSFN area, DRX information, and the like can be considered. Detailed description of the DRX information is the same as in the first embodiment, and will be omitted. The same effect can be obtained even if the DRX information is reported on the MCCH of each MBSFN area. Furthermore, the same effect can be obtained by mapping DRX information to the BCCH of the serving cell and notifying the mobile terminal in step ST1705 of FIG. Furthermore, the same effect can be obtained even if DRX information is a statically defined value. When the value is defined statically, there is no need to notify the mobile terminal of the value, so that the effect of effective use of radio resources can be obtained. The MCCH scheduling in each MBSFN area is the same as in the first embodiment. In FIG. 27, the MCCH scheduling information (parameter) of the MBSFN area 1 is MCCH repetition period 1 “11” and MCCH starting point value 1 “2”. The MCCH scheduling information (parameters) of the MBSFN area 2, MBSFN area 3, and MBSFN area 4 is the same as that of the MBSFN area 1. Here, by mapping MCCH scheduling of all MBSFN areas in the MBSFN synchronization area to the main PMCH, the main PMCH can be transmitted in multicells in the MBSFN synchronization area.

  In step ST2202 of FIG. 26, the MCE receives the contents of the main PMCH and the scheduling information from the MBMS GW. In Step ST2203, the MCE transmits the contents of the main PMCH and the scheduling information to the base station belonging to the MBSFN area that is controlled by the MCE. In Step ST2204, the base station receives the contents of the main PMCH and scheduling information. In Step ST2205, the base station transmits the main PMCH according to the scheduling from the MCE.

  In Step ST2206, the mobile terminal performs an MBMS search. In step ST2206, timing synchronization is particularly performed. The prescribed information is mapped to a part of the main PMCH. Accordingly, the mobile terminal establishes timing synchronization by blindly detecting the prescribed information of the main PMCH. In Embodiment 1, timing synchronization is performed by P-SCH and S-SCH in a frequency layer dedicated to MBMS transmission, but in Embodiment 2, this can be realized without using P-SCH and S-SCH. . Therefore, the MBMS search method according to the second embodiment makes it possible to reduce P-SCH and S-SCH in a frequency layer (MBMS dedicated base station) dedicated to MBMS transmission. Thereby, the effect of effective utilization of radio resources can be obtained. In step ST2207, the mobile terminal receives and decodes the main PMCH detected in step ST2206. The mobile terminal receives all MBSFN area IDs mapped to the main PMCH, MCCH scheduling of each MBSFN area, and DRX information.

  Information mapped to BCCH in the first embodiment includes MCCH scheduling, system bandwidth in f (MBMS), number of transmission antennas in f (MBMS), SFN, and the like. In Embodiment 2, MCCH scheduling is mapped to the main PMCH. The system bandwidth in f (MBMS) and the number of transmission antennas in f (MBMS) are mapped to BCCH in a unicast cell and a unicast / MBMS mixed cell. Here, by mapping the SFN to the main PMCH, BCCH transmission from the MBMS transmission dedicated frequency layer (MBMS dedicated cell) can be reduced. Thereby, the effect of effective utilization of radio resources can be obtained. Furthermore, it is not necessary to receive BCCH, which is a channel different from the main PMCH, in order to receive SFN. Therefore, the control load on the mobile terminal is reduced, and the effects of reducing the control delay and reducing the power consumption of the mobile terminal can be obtained. Since the process after step ST1726 of FIG. 18 is the same as that of Embodiment 1, detailed description thereof is omitted. In step ST1729 of FIG. 19, the control information for the MBMS service obtained by the mobile terminal receiving and decoding the MCCH of each MBSFN area includes MBMS area information, MBMS reception time missing reception parameters, and the like. As specific examples of the MBMS area information, the frame configuration (MBSFN frame cluster, MBSFN subframe) of each area, service content, MTCH modulation information, and the like are conceivable.

  Further, step ST1723 to step ST1725 of FIG. 18 described in Embodiment 1 may be used. In that case, the scheduling information of the main PMCH may be notified in place of the MCCH scheduling of the first embodiment on the BCCH from the frequency layer dedicated to MBMS transmission. This eliminates the need for blind detection in step ST2206 in FIG. As a result, the effects of reducing the processing load on the mobile terminal and reducing the power consumption can be obtained.

Modification 1
In the second embodiment, the service contents for each MBSFN area are included in the MBMS area information in the MCCH. Here, service contents for each MBSFN area may be notified together with MCCH scheduling on the main PMCH. Thereby, the mobile terminal (user) can grasp the service content of each MBSFN area at the stage of decoding the main PMCH. Therefore, it is possible to determine whether or not a desired service exists before receiving and decoding the MCCH, and it is not necessary to receive and decode the MCCH in the MBSFN area where the desired service is not performed, thereby reducing control delay. The effect that can be obtained. Specifically, in step ST2207 of FIG. 26, the mobile terminal receives the service content of each MBSFN area. Thereby, the mobile terminal can grasp the service contents of each MBSFN area. Thereafter, prior to step ST1729 in FIG. 19, the mobile terminal searches for an MBSFN area where a service desired by the user is performed. If there is an MBSFN area where a desired service is performed, step ST1729 is executed according to the MCCH scheduling of the corresponding MBSFN area in order to receive the MCCH of the corresponding MBSFN area. On the other hand, if there is no MBSFN area where the desired service is performed, the processing of step ST1729, step ST1730, and step ST1733 in FIG. 19 is omitted, and the process proceeds to step ST1734.

  Furthermore, MBMS area information mapped to each MCCH, MBMS reception time missing reception parameters, and the like may be notified together in the main PMCH. This eliminates the need for MCCH for each MBSFN area, thereby improving the efficiency of radio resources (see FIG. 28). Therefore, it is not necessary to notify the MCCH scheduling of each MBSFN area on the main PMCH, and the efficiency of radio resources can be further improved. In addition, since it is not necessary for the mobile terminal to receive the MCCH for each MBSFN area, it is possible to obtain the effect of reducing the load on the mobile terminal and reducing the power consumption.

Modification 2
Instead of Step ST2201 to Step ST2207 in FIG. 26 in Embodiment 2, the following processing is performed in Modification 2. The flow of processing as the mobile communication system according to the second modification is substantially the same as that described in the second embodiment. In the description, the description will focus on parts that are different from the second embodiment. In the second modification, steps ST2201 to ST2207 in FIG. 26 are changed as shown in FIG. In step ST2501 in FIG. 29, the mobile terminal performs an MBMS search. In step ST2501, the mobile terminal performs timing synchronization. The prescribed information is mapped to a part of the MCCH for each MBSFN area. Thereby, the mobile terminal establishes timing synchronization by blindly detecting the prescribed information of each MBSFN area. By not applying the scrambling code specific to each MBSFN area to the prescribed information used for blind detection, the mobile terminal can be blindly detected. Therefore, in the multiplexing method of each MBSFN area, time division multiplexing has a high affinity with Modification 2 (see FIG. 22). In Embodiment 1, timing synchronization is performed using P-SCH and S-SCH in a frequency layer dedicated to MBMS transmission, but in Embodiment 2, this can be achieved without using P-SCH and S-SCH. Therefore, the MBMS search method according to the second embodiment makes it possible to reduce P-SCH and S-SCH in a frequency layer (MBMS dedicated base station) dedicated to MBMS transmission. Furthermore, in the second embodiment, timing synchronization is performed on the main PMCH, but in the second modification, it is performed on the MCCH for each MBSFN area. Accordingly, timing synchronization is performed only by the MCCH in the MBSFN area that can be received at the current position (location) of the mobile terminal. Therefore, it is less determined in step ST1731 that the sensitivity sufficient for receiving the MBMS service is not satisfied as compared with the first and second embodiments. Thereby, the effect that the control delay as a mobile communication system can be reduced can be acquired. In step ST2502 in FIG. 29, the mobile terminal receives and decodes the MCCH in the MBSFN area detected in step ST2501. The mobile terminal receives the control information for the MBMS service mapped to the MCCH. Specific examples of the control information include MBMS area information, MBMS reception time missing reception parameters, and the like. As the MBMS area information, the frame configuration (MBSFN frame cluster, MBSFN subframe) of each area, service content, MTCH modulation information, and the like can be considered.

  In step ST1730 of FIG. 19, the mobile terminal confirms the service content included in the MBMS area information. 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 process proceeds to step ST2503 in FIG. In Step ST1731, the mobile terminal receives the 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 is equal to or higher than the threshold, it indicates that the sensitivity is satisfactory for receiving the MBMS service, and if the threshold is less than the threshold, it indicates that the sensitivity for receiving the MBMS service is not satisfied. 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 ST2503. In step ST2503, the mobile terminal searches for MBMS using the same method as in step ST2501. In Step ST2504, the mobile terminal determines that the MBSFN area in which the desired service is not performed in Step 1730, or the MBSFN area that does not satisfy the sufficient sensitivity for receiving the MBMS service in Step ST1731. It is determined whether the timing synchronization of the other MBSFN areas has been achieved. When the timing synchronization of another MBSFN area is taken, it transfers to step ST2502. When the timing synchronization of another MBSFN area cannot be taken, it transfers to step ST1734. Further, DRX information mapped to the main PMCH, SFN, and the like may be notified together in each MCCH. As a result, the main PMCH is not required, and the efficiency of radio resources can be improved.

Embodiment 3 FIG.
In the third embodiment, a mobile communication system different from that in the first embodiment is disclosed mainly with DRX information. The processing flow as the mobile communication system according to the third embodiment is almost the same as that in FIGS. 16 and 17 of the first embodiment. In the description, the description will focus on parts different from the first embodiment. In the first embodiment, one DRX period is provided in the MBSFN synchronization area (see FIG. 24), but in the third embodiment, one DRX period is provided in the MBSFN area. The DRX period in the third embodiment is a period in which MBMS service transmission from the corresponding MBSFN area is OFF. A specific example will be described with reference to FIG. 30 and FIG. First, a description will be given with reference to FIG. FIG. 30 is an explanatory diagram showing a PMCH configuration for each MBSFN area. The DRX period for the mobile terminal receiving the MBMS service from the MBSFN area 1 is DRX period 1 and the DRX period is DRX period 1. A specific parameter example of the DRX information will be described. Specifically, a DRX period, a DRX cycle, and a starting point value (DRX) can be considered. The DRX period 1 is a “6” radio frame. Also, DRX cycle 1 is a “9” radio frame. Further, SFN is used to specify the starting point value (DRX) at which the DRX period starts. A specific calculation formula for obtaining the starting point value (DRX) is as follows.
Starting point value (DRX) = (first SFN number at which the DRX period starts) mod (DRX cycle), and starting point value 1 (DRX) is 4 mod 9 = 4 or 13 mod 9 = 4.
The DRX period for the mobile terminal receiving the MBMS service from the MBSFN area 2 is DRX period 2 and the DRX period is DRX period 2. The DRX period 2 is a “6” radio frame. The DRX cycle 2 is a “9” radio frame. The starting point value 2 (DRX) is 7 mod 9 = 7 or 16 mod 9 = 7. The DRX information for the mobile terminal that is receiving the MBMS service from the MBSFN area 3 is the same.

  Next, it demonstrates using FIG. The DRX period for the mobile terminal receiving the MBMS service from the MBSFN area 1 is DRX period 1 and the DRX period is DRX period 1. The DRX period 1 is “4” radio frames. The DRX cycle 1 is “16” radio frames. The starting point value 1 (DRX) is 1 mod 16 = 1 or 17 mod 16 = 1. The same applies to the DRX information for the mobile terminal receiving the MBMS service from the MBSFN area 2 and the MBSFN area 3. The DRX period for the mobile terminal receiving the MBMS service from the MBSFN area 4 is DRX period 4 and the DRX period is DRX period 4. The DRX period 4 is a “12” radio frame. The DRX cycle 4 is a “16” radio frame. The starting point value 4 (DRX) is 5 mod 16 = 5 or 21 mod 16 = 5. When there is a main PMCH described in Embodiment 2, it is necessary to receive the main PMCH even if the mobile terminal is receiving the MBMS service in each MBSFN area. Therefore, the DRX period for each MBSFN area is required. To the main PMCH transmission period.

  The mobile terminal can perform unicast / mixed frequency layer measurement using the DRX period provided for each MBSFN area. As a result, the second problem is that the mobile terminal via the unicast / mixed frequency layer is receiving the MBMS service in the MBMS transmission dedicated frequency layer configured by the MBMS dedicated base station having no uplink. The effect that enables mobility management can be obtained.

  In addition, receiving the MBMS service without notifying the unicast / mixed layer side control device (base station, MME, PDN GW, etc.) of the DRX cycle and DRX period information of the frequency layer dedicated to MBMS transmission through any route In order to be able to satisfy the measurement period of the unicast / mixed frequency layer notified from the network side without interruption, the present invention discloses the following method as in the first embodiment. The DRX cycle in the frequency layer dedicated to MBMS transmission is the minimum value of the measurement cycle that can be taken in the unicast / mixed frequency layer or a divisor of the minimum value. When the measurement cycle that can be set for the mobile terminal that is receiving the MBMS service in the MBMS transmission dedicated frequency layer is different from the measurement cycle that can be taken in the unicast / mixed frequency layer, the DRX cycle is the frequency dedicated to MBMS transmission. The measurement period that can be set for the mobile terminal that is receiving the MBMS service in the layer, or the minimum value of the measurement period, or the divisor of the minimum value of the measurement period. As a result, the third problem can be solved.

  In Step ST1729 of FIG. 19, the mobile terminal receives DRX information. Since the DRX information is different for each MBSFN area, mapping the DRX information to the MCCH of each MBSFN area can prevent the mobile terminal from receiving unnecessary information (DRX information of other MBSFN areas). Thereby, the effect of reducing the processing load of the mobile terminal and reducing the power consumption can be obtained. However, even if DRX information is mapped to BCCH or main PMCH in a frequency layer dedicated to MBMS transmission, the same effect as in the third embodiment can be obtained.

  Compared with the mobile communication system disclosed in Embodiment 1, the mobile communication system of Embodiment 3 can obtain the following effects. In the first embodiment, one DRX period is provided in the MBSFN synchronization area (see FIG. 24). The DRX period in the method of Embodiment 1 is the MBMS service transmission OFF in all MBSFN areas within the MBSFN synchronization area. On the other hand, in the third embodiment, a DRX period is provided for each MBSFN area, that is, if one MBSFN area 1 is seen, the DRX period 1 is MBMS service OFF, but if another MBSFN area 2 is seen, the DRX period 1 is An MBMS service may be provided. That is, it is not necessary to turn off the MBMS service of all MBSFN areas in the MBSFN synchronization area. Therefore, the third embodiment can obtain an effect that radio resources can be effectively used as compared with the first embodiment.

Modification 1
On the other hand, in the first embodiment, since the mobile terminal provides one DRX period in the MBSFN synchronization area, it can simultaneously receive MBMS data from the MBSFN area in the MBSFN synchronization area without adding any control. . In other words, when the MBMS service from each MBSFN area is received at the same time, the mobile terminal (user) can freely select the MBSFN area combination method. However, in Embodiment 3, the mobile terminal cannot receive the MBSFN area at the same time. A specific example will be described with reference to FIG. The DRX period for the mobile terminal receiving the MBMS service from the MBSFN area 1 is DRX period 1 and the DRX period is DRX period 1. The DRX period 1 is a “6” radio frame. Also, DRX cycle 1 is a “9” radio frame. The starting point value 1 (DRX) at which the DRX period starts is “4”. When the mobile terminal performs the measurement of the unicast / mixed frequency layer using the DRX period 1 as in Embodiment 1, the MBSFN area 2 transmitted from the base station overlapping with the DRX period 1 in time, and The MBMS service from the MBSFN area 3 cannot be received. Similarly, for a mobile terminal that is receiving an MBMS service from MBSFN area 2, when the unicast / mixed frequency layer measurement is performed by the method of Embodiment 3, the MBMS service from MBSFN area 1 and MBSFN area 3 is received. Impossible. The same applies to the MBSFN area 3.

  The following solution is disclosed for the problem that when one DRX period is provided in the MBSFN area, MBMS services from each MBSFN area cannot be received simultaneously. The MBSFN area that can be received simultaneously is notified from the network side to the mobile terminal. Further, DRX information for each MBSFN area that can be received simultaneously is notified. A specific example of DRX information will be described with reference to FIG. The DRX period when the mobile terminal receives the MBMS service from the MBSFN area 1 and the MBSFN area 2 is DRX period (1 + 2) = [3]. The DRX cycle at that time is DRX cycle (1 + 2) = [9]. Furthermore, the starting point value (1 + 2) (DRX) at which the DRX period starts becomes 7 mod 9 = 7 or 16 mod 9 = 7, and the starting point value 1 + 2 (DRX) = [7]. The DRX period when the mobile terminal receives the MBMS service from the MBSFN area 1 and the MBSFN area 3 is DRX period (1 + 3) = [3]. The DRX cycle at that time is DRX cycle (1 + 3) = [9]. Further, the starting point value (1 + 3) (DRX) at which the DRX period starts is 4 mod 9 = 4 or 13 mod 9 = 4, and the starting point value (1 + 3) (DRX) = [4].

  In Step ST1729 of FIG. 19, the mobile terminal receives DRX information. FIG. 33 summarizes specific examples of DRX information received by the mobile terminal in step ST1729. FIG. 33 [a] is a specific example of DRX information mapped to the MCCH of MBSFN area 1. FIG. 33 [b] is a specific example of DRX information mapped to the MCCH of MBSFN area 2. FIG. 33 [c] is a specific example of DRX information mapped to the MCCH of the MBSFN area 3. Here, the DRX period and the DRX cycle are shown in units of subframes, but may be in units other than subframes. Further, although the starting point value (DRX) is indicated by the SFN number, another designation method may be used.

  In addition, receiving the MBMS service without notifying the unicast / mixed layer side control device (base station, MME, PDN GW, etc.) of the DRX cycle and DRX period information of the frequency layer dedicated to MBMS transmission through any route In order to make it possible to satisfy the measurement period of the unicast / mixed frequency layer notified from the network side without interruption, the present invention discloses the following method as in the first and third embodiments. The DRX cycle in the frequency layer dedicated to MBMS transmission is the minimum value of the measurement cycle that can be taken in the unicast / mixed frequency layer or a divisor of the minimum value. When the measurement cycle that can be set for the mobile terminal that is receiving the MBMS service in the MBMS transmission dedicated frequency layer is different from the measurement cycle that can be taken in the unicast / mixed frequency layer, the DRX cycle is the frequency dedicated to MBMS transmission. The measurement period that can be set for the mobile terminal that is receiving the MBMS service in the layer, or the minimum value of the measurement period, or the divisor of the minimum value of the measurement period. As a result, the third problem can be solved.

  Since the MBSFN area information that can be received simultaneously is notified from the network side to the mobile terminal, the MBMS service from each MBSFN area can be received simultaneously. By notifying the DRS information at that time together with the MBSFN area information that can be received simultaneously, the second and third problems can be solved.

  In the first modification, the MBSFN area information that can be simultaneously received and the DRX information at that time are mapped to the MCCH for each MBSFN area. The same effect as that of the first modification can be obtained by mapping simultaneously receivable MBSFN area information mapped to the MCCH of each MBSFN area and DRX information at that time to the BCCH of the frequency layer dedicated to MBMS transmission. Further, the same effect as that of the first modification can be obtained even when mapping to the main PMCH.

Modification 2
In the case where one DRX period is provided in the MBSFN area, a solution different from the following Modification 1 is disclosed regarding the problem that the MBMS service from each MBSFN area cannot be received simultaneously. The DRX information of each MBSFN area is notified from the network side, and the DRX information in the MBSFN area that the mobile terminal desires to receive simultaneously is calculated. A mobile terminal receives DRX information in step ST1729. FIG. 34 is a specific example of DRX information mapped to the MCCH of each MBSFN area notified from the network side to the mobile terminal in Modification 2 in the case of FIG. As a specific example of the DRX information, the MBSFN area number (ID) for each MBSFN area, service contents, MBSFN frame cluster, MBSFN frame cluster repetition period, and MBSFN frame cluster starting point are notified. Thereby, the effect that DRX information can be calculated in a mobile terminal can be acquired. Here, the service content of each MBSFN area may be notified in addition to the DRX information. As a result, it is possible to obtain an effect that the mobile terminal can select the MBSFN area to be simultaneously received by the user by receiving and decoding the MCCH from one MBSFN area.

In Step ST1730, the mobile terminal calculates DRX information in the MBSFN area that is simultaneously received as desired by the user. A specific example will be described with reference to FIG. For example, when the user wishes to simultaneously receive “weather forecast” and “news”, the mobile terminal calculates DRX information in simultaneous reception of MBSFN area 1 and MBSFN area 2. The DRX period will be described. In order to receive the MBSFN area 1 and the MBSFN area 2, a period in which the transmission of the MBSFN area 1 and the MBSFN area 2 is not performed is a DRX period ( 1 + 2 ) . A DRX cycle in which the DRX period (1 + 2) = 3 will be described with reference to FIGS. 32 and 34. FIG. In order to receive the MBSFN area 1 and the MBSFN area 2, the period in which the transmission of the MBSFN area 1 and the MBSFN area 2 is not performed is the DRX period (1 + 2). DRX cycle (1 + 2) = MBSFN frame cluster Repeat cycle 3 = 9. The starting point of DRX will be described. In order to receive MBSFN area 1 and MBSFN area 2, the starting point value during a period in which transmission of MBSFN area 1 and MBSFN area 2 is not performed becomes a starting point (1 + 2) (DRX). Starting point (1 + 2) (DRX) = 7.

  In addition, receiving the MBMS service without notifying the unicast / mixed layer side control device (base station, MME, PDN GW, etc.) of the DRX cycle and DRX period information of the frequency layer dedicated to MBMS transmission through any route In order to make it possible to satisfy the measurement period of the unicast / mixed frequency layer notified from the network side without interruption, the following method is disclosed. The mobile terminal selects the multiplexing of the MBSFN area so that the DRX cycle in the frequency layer dedicated to MBMS transmission is the minimum value of the measurement cycle that can be taken in the unicast / mixed frequency layer or a divisor of the minimum value. In other words, the mobile terminal calculates DRX information and does not select a combination of MBSFN areas whose DRX cycle does not satisfy the above condition. When the measurement cycle that can be set for the mobile terminal that is receiving the MBMS service in the MBMS transmission dedicated frequency layer is different from the measurement cycle that can be taken in the unicast / mixed frequency layer, the DRX cycle is the frequency dedicated to MBMS transmission. The measurement period that can be set for the mobile terminal that is receiving the MBMS service in the layer, or the minimum value of the measurement period, or the divisor of the minimum value of the measurement period. As a result, the third problem can be solved.

  In the second modification, the same effect as in the first modification can be obtained. Furthermore, when the number of MBSFN areas is increased and the number of MBSFN areas is increased, the amount of DRX information to be notified from the network side to the mobile terminal is smaller in Modification 2 than in Modification 1. I'll do it. Thereby, the effect of effective utilization of radio resources can be obtained.

  In the second modification, the MBSFN area information that can be simultaneously received and the DRX information at that time are mapped to the MCCH for each MBSFN area. The same effect as that of the second modification can be obtained by mapping the simultaneously receivable MBSFN area information mapped to the MCCH of each MBSFN area and the DRX information at that time to the BCCH of the frequency layer dedicated to MBMS transmission. Further, the same effect as that of the second modification can be obtained by mapping to the main PMCH.

  The third embodiment and its modification can be applied to the first embodiment and its modification, and the second embodiment and its modification.

Embodiment 4 FIG.
Error about the fourth problem the invention is trying to solve! The referrer is not found. Will be described. 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, a 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. Error! Reference source not found. It is written 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 3 has the following description regarding paging signal transmission to a mobile terminal. 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. PICH is transmitted using the L1 / L2 signaling channel, that 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 fourth problem to be solved by the present invention also occurs in the paging signal transmission procedure of Non-Patent Document 3. In other words, when MBSFN subframes are configured in an MBMS / unicast mixed cell, even if PICH is transmitted in the first 1-2 OFDM symbols of the MBSFN subframe, the same subframe as 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 3 has no suggestion about the fourth problem to be solved by the present invention.

  Non-Patent Document 4 has the following description of 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 4 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 4 does not describe the relationship between subframes and MBSFN subframes in a radio frame for paging occasions, and does not suggest the fourth 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, the fourth embodiment discloses a method for determining a radio frame for paging occasion in consideration of MBSFN subframes.

  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, the fourth embodiment discloses a method for determining a radio frame for paging occasion in consideration of MBSFN subframes.

  As shown in FIG. 3, the MBSFN subframe is assigned to each MBSFN frame (MBSFN frame). An MBSFN frame set repetition period (Repetition Period) is provided, and an MBSFN frame set (MBSFN frame Cluster) is scheduled within the repetition period. The MBSFN subframe assigned to each MBSFN frame may be the same or different. An allocation pattern of MBSFN subframes within a repetition period is determined by a set of MBSFN frames. The allocation pattern of the MBSFN subframe is repeated every repetition cycle. In the figure, the allocation pattern of the MBSFN subframes in the MBSFN frame is the same, but by doing so, the number of bits necessary to represent the subframe number of the MBSFN subframe is reduced compared to the case where the MBSFN subframes are not the same. be able to. In the figure, the MBSFN frames are continuous, but are not necessarily continuous. In the case of continuous, the number of bits necessary to represent the frame number of the MBSFN frame can be reduced as compared with the case of not continuous.

The repetition period of the set of MBSFN frames, the allocation pattern within the repetition period of MBSFN frames and MBSFN subframes are mapped to the broadcast control channel (BCCH) which is a logical channel, and further, the broadcast channel (BCH) which is a transport channel, It is mapped to a physical broadcast channel (PBCH) that is a physical channel and notified to the mobile terminal. 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. To the mobile terminal. On the other hand, the following calculation formula can be considered as a method of determining a radio frame for paging occasion.
“Paging occurrence radio frame” (Paging Occasion) = identifier (such as IMSI) of mobile terminal mod X + n × (intermittent reception cycle), n: 0, 1, 2,..., Where Paging Occusion ≦ 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, and X ≦ intermittent reception cycle (the number of radio frames). A value of X (residue value at X) and a radio frame number (SFN) are associated with each other.

  As can be seen from the above equation, a paging occasion occurs in the radio frame related to the number of radio frames X with paging within the intermittent reception cycle. In other words, the occurrence of the paging occasion is repeated at every intermittent period in the radio frame pattern related to the X. Parameters necessary for deriving a paging occasion, mobile terminal identifier, intermittent reception period, X, etc. are mapped to a broadcast control channel (BCCH) that is a logical channel, and further a broadcast channel (BCH) that is a transport channel Then, it is mapped to a physical broadcast channel (PBCH) that is a physical channel and notified to the mobile terminal. 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. To the mobile terminal.

  As described above, the MBSFN subframe cannot be used for the paging process because the resources other than the first 1-2 OFDM symbols of the MBSFN subframe are dedicated to MBMS transmission. Therefore, 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, here is disclosed a method for avoiding that the MBSFN frame and the frame in which the paging occasion occurs are always the same radio frame. Specifically, the repetition period (Repetition Period) of the set of MBSFN frames is different from the intermittent reception period. In particular, the repetition period and the intermittent reception period of the set of MBSFN frames are not made the same or do not have a multiple relationship.

An example is shown below. Conventionally, 2 ^a × radio frame (unit is number or time) and a is a positive integer is used as the intermittent reception cycle. The value of a is determined by the base station or the network and notified to the mobile terminal through the serving cell.
In this case, the repetition period (Repetition Period) of the set of MBSFN frames is set as the following derivation formula.
2 ^b × radio frame (unit: number or time), b is a positive integer.
However, a ≠ b.
By doing so, the periods do not become the same, and even if the initial assigned radio frame number (offset value) is the same, the MBSFN frame and the paging occasion always occur in the same radio frame. It can be avoided.
This enables paging processing in an MBMS / unicast mixed cell in which MBSFN subframes exist. In the above example, the occurrence of MBSFN frames and paging occasions can always be avoided in the same radio frame. However, since the derivation formula for both periods is 2 ^m × radio frame (m = a, b), each period has a multiple relationship, and the MBSFN frame and the paging are performed once in the same radio frame several times. Occurrence will occur.

In order to avoid this, as another example, the derivation formula for each period may be as follows.
S ^m × radio frame (unit: number or time), S is a prime number, and m is a positive integer.
Different values of S are used for the repetition period of the set of MBSFN frames and the intermittent reception period. Since S is a prime number, by using different values of S for each period, it is possible to avoid the occurrence of MBSFN frames and paging occasions in the same radio frame. Therefore, it is possible to further reduce the frequency at which the MBSFN frame and the frame in which the paging occasion occurs are the same.

  If an MBSFN frame and a paging occasion occur in the same radio frame, the base station or network prioritizes the MBSFN frame over the paging occasion and gives priority to information communication for MBMS. To send. By determining the priorities in advance, the mobile terminal can determine which information is transmitted in the radio frame that is generated at the same time, and can receive and decode the information. The priority may be higher for either the MBSFN frame or the paging occasion. When the priority order of the MBSFN frame is increased, it is possible to receive the MBMS service without missing or delaying MBMS data. In the case of increasing the priority of paging occasions, it is possible to reduce the time required for the incoming call processing to the mobile terminal, and it is possible to reduce the delay time at the time of incoming call.

  The derivation formula for each period in these examples may be determined statically. Two or more types of derivation formulas may be prepared in advance and it may be determined which one to select. Also, which derivation formula to select may be used as a parameter. The parameters used in the derivation formula may be determined statically, quasi-statically or dynamically. When determined semi-statically or dynamically, each parameter is determined by the base station or the network, and is notified to the mobile terminal through the serving cell by BCCH, MCCH, or L1 / L2 signaling. With regard to the parameter to determine which derivation formula is used, two types of derivation formulas are set in advance, so that the parameter can be notified in 1 bit, and the base station or network can be notified to the mobile terminal with the minimum amount of information. This increases the use efficiency of radio resources.

  Error! Reference source not found. 3 shows a specific example of a sequence diagram in the case of performing notification of MBSFN subframe allocation information and derivation of a paging occasion to which a paging signal is mapped. In step ST4001, the serving cell notifies the mobile terminal being served thereby of the system information of the own cell. Specific examples of system information to be notified include measurement cycle, tracking area information (TA information), and intermittent reception cycle. It is assumed that the system information of the own cell includes a parameter for intermittent reception. The intermittent reception cycle is derived using the intermittent reception parameters by the method for determining a paging occasion generation radio frame disclosed above. Specific examples of the intermittent reception parameter include a parameter for derivation of the intermittent reception cycle, a, m, S, information on which derivation formula is used, and the number of paging occasions during the intermittent reception cycle (X) (Or the number of paging groups), the relationship between the value of X (the remainder value at X) and the radio frame number (SFN). 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 for allocation of MBSFN subframes, the following is discussed. 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, it has been argued that it is necessary to grasp the allocation information of the MBSFN subframe of the serving cell even if the mobile terminal does not have the ability to receive the MBMS service. (Non-patent document 2). As specific examples of allocation information of MBSFN subframes, parameters for deriving the repetition period of a set of MBSFN frames and MBSFN subframe allocation patterns within the period can be considered. The repetition cycle of the MBSFN frame set is derived using the MBSFN frame set repetition cycle determination method disclosed above and using the MBSFN frame set repetition cycle derivation parameter. Specific examples of the parameters for deriving the repetition period of the MBSFN frame set include b, m, and S, which are parameters for deriving the repetition period, and information on which derivation formula is used. Specific examples of the MBSFN subframe allocation pattern within the period include an MBSFN frame number within the repetition period and / or an MBSFN subframe number. 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 steps ST4503 and 4504, the mobile terminal and the serving cell obtain a radio frame for paging occasion using the same method 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.

  As disclosed in the fourth embodiment, it is possible to solve the fourth problem of the present invention by preventing the MBSFN frame and the frame in which the paging occasion is generated from always being the same radio frame, so that the MBSFN can be solved. It is possible to enable paging processing in an MBMS / unicast mixed cell in which a subframe exists.

Modification 1
In the fourth embodiment, the repetition period of the MBSFN frame set is different from the intermittent reception period in the paging occasion, but the pattern of the MBSFN frame in the repetition period of the MBSFN frame set and the intermittent reception period The generation pattern of the paging occasion radio frame may not be the same. For example, the repetition cycle of the set of MBSFN frames is 32 radio frames. Assume that MBSFN frames in the repetition period are # 0 to # 7 (the first radio frame in the repetition period is # 0). In this case, for example, using the above paging occasion derivation formula, the intermittent reception cycle is 32 radio frames, the paging-generated radio frame number X is 4, and the relationship between the remainder value at X and the radio frame number is expressed as follows: Keep it like that.
When the remainder of X = 0, radio frame number # 8,
When the remainder value of X = 1 Radio frame number # 14,
When the remainder of X = 2 Radio frame number # 20,
When the remainder of X = 3 Radio frame number # 26.
However, in the radio frame number, the first radio frame in the intermittent reception cycle is set to # 0.
By associating in this way, the pattern of the MBSFN frame within the repetition cycle of the set of MBSFN frames and the generation pattern of the radio frame of the paging occasion within the intermittent reception cycle can be prevented from being the same. Therefore, even if the repetition period of the set of MBSFN frames and the intermittent reception period in the paging occasion are the same, the patterns in the period are different from each other, and therefore the occurrence of the MBSFN frame and the paging occasion is always the same. It can be avoided that it occurs in a radio frame.
In this modification, the paging occasion occurrence radio frame is determined based on the MBSFN frame, but conversely, the MBSFN frame may be determined based on the paging occasion occurrence radio frame. For example, when the paging occasion generation radio frame is statically determined and the MBSFN frame is determined semi-statically or dynamically, a radio frame different from the paging occasion generation radio frame within the intermittent reception period is set as the MBSFN frame. You can do that. By doing so, for example, it is possible to flexibly determine MBSFN subframes according to the amount of MBMS data, and it is possible to increase the use efficiency of radio resources. A method of statically determining a radio frame in which paging occasions are generated and determining an MBSFN frame semi-statically or dynamically can be applied to the fourth embodiment or the second modification. In addition, the method described in Embodiment 4 can be applied to the parameter notification method in the present modification.

  By using the method of the first modification, in addition to the effect of the fourth embodiment, there is an effect that the repetition period of the MBSFN frame set and the intermittent reception period may be the same. By making the repetition period and the intermittent reception period of the set of MBSFN frames the same, the number of parameters notified from the base station or the network to the mobile terminal can be reduced, and the use efficiency of radio resources can be increased.

  In the above example, the MBSFN frame pattern within the repetition period of the set of MBSFN frames is used, but an MBSFN subframe allocation pattern within the repetition period (Repetition Period) may be used. In this case, the MBSFN frame including the MBSFN subframe may be a pattern of MBSFN frames within the repetition cycle of the set of MBSFN frames. Thereby, an equivalent effect 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 which shows the processing method of the unicast side cell selection. 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 unicast side measurement process. It is a flowchart which shows a MTCH reception process. It is explanatory drawing which shows the structure of PMCH for every MBSFN area. It is explanatory drawing which shows the structure of PMCH for every MBSFN area. 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 which shows the structure of PMCH for every MBSFN area. 6 is a flowchart illustrating an MBMS search method described in the second embodiment. It is explanatory drawing which shows the structure of main PMCH in a MBSFN synchronous area. It is explanatory drawing which shows the structure of main PMCH of a MBSFN synchronous area. 6 is a flowchart illustrating an MBMS search method described in the second embodiment. It is explanatory drawing which shows the structure of PMCH for every MBSFN area. It is explanatory drawing which shows the structure of PMCH for every MBSFN area. It is explanatory drawing which shows the structure of PMCH for every MBSFN area. It is explanatory drawing which shows an example of discontinuous reception information. It is explanatory drawing which shows an example of discontinuous reception information. 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. It is explanatory drawing of the 4th subject. It is a sequence diagram in the case of performing derivation | leading-out of the notification of the allocation information of a MBSFN sub-frame, and paging signal mapping a paging signal.

Explanation of symbols

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

Claims (5)

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. The unicast / MBMS mixed cell can provide services of both the unicast cell and the MBMS dedicated cell, and the MBMS dedicated cell and the unicast / MBMS mixed cell include a plurality of base stations. An MBSFN (Multimedia Broadcast multicast service Single Frequency Network) synchronization area that transmits the broadcast type data in synchronization is configured,
The mobile terminal receives and receives synchronization information for receiving the broadcast data in the MBSFN synchronization area, which is transmitted simultaneously from the plurality of MBMS dedicated cells or the unicast / MBMS mixed cell. A mobile communication system characterized by searching for an MBMS dedicated cell or a unicast / MBMS mixed cell. The mobile communication system according to claim 1, wherein the unicast / MBMS mixed cell transmits synchronization information to the mobile terminal using a downlink synchronization channel. The mobile communication system according to claim 1, wherein the MBMS dedicated cell transmits synchronization information to the mobile terminal using a physical multicast channel. The MBMS dedicated cell provides a reception stop period in which the mobile terminal does not receive the MBMS data by stopping transmission of MBMS data to the mobile terminal for a predetermined time, and the mobile terminal performs unicast in this reception stop period. The mobile communication system according to any one of claims 1 to 3, wherein a measurement process of a cell or a unicast / MBMS mixed cell is performed. The mobile station according to claim 4, wherein the reception stop period is a minimum value of a measurement period in which a mobile terminal performs measurement processing of a unicast cell or a unicast / MBMS mixed cell, or a divisor of the minimum value. Body communication system.

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