KR20150015855A - Methods and apparatuses for Group Communication service - Google Patents

Abstract

The present invention provides a method and an apparatus for supplying a group communication service. The present invention relates to a method for supplying service continuity for supplying the group communication service through MBMS of an LTE mobile communication network. The method for supplying the group communication service includes the steps of: receiving mapping information among MBMS carrier frequencies for group communication and group communication services from an E-UTRAN network; and receiving the group communication service continuously through an MBMS or a unicast even if the terminals which is interested in group communication move.

Description

[0001] METHOD AND APPARATUS FOR GROUP COMMUNICATION SERVICE [0002]

The present invention relates to a method for providing service continuity in providing a group communication service through MBMS of an LTE mobile communication network.

In order to solve the above-mentioned problems, the present invention provides a method for a terminal to receive a group communication service, comprising: receiving mapping information between a group communication service and MBMS carrier frequencies for group communication from an E-UTRAN network; And continuously receiving the group communication service through the MBMS or unicast even when the terminals interested in the group communication or the terminals participating in the group communication move.

1 is a diagram showing an E-UTRAN MBMS structure.
2 is a diagram showing a layer 2 model (eNB side) for one MBSFN area.
3 is a view showing an MCCH information acquisition and an MBMS user data reception procedure.
4 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
5 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, the base station or the cell in this specification is interpreted as a comprehensive meaning indicating a partial region or function covered by BSC (Base Station Controller) in CDMA, NodeB in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) a device itself providing a megacell, a macrocell, a microcell, a picocell, a femtocell, or a small cell in relation to a wireless region, or ii) the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a megacell, a macrocell, a microcell, a picocell, a femtocell, a small cell, an RRH, an antenna, an RU, a low power node (LPN), a point, an eNB, Quot;

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In a system such as LTE and LTE-A, the uplink and downlink are configured based on one carrier or carrier pair to form a standard. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmission / reception points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multiplex transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiplex transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

Group communication

Group communication is a major function in private mobile radio and public safety systems. Group communication is widely used in the operation of traditional Land Mobile Radio (LMR) systems used for public safety organizations. The main use of group communication services in LMR is to provide Push to Talk (PTT) functionality. In addition to using group communications for public safety, group communications can be used for messaging for machine type communication device groups belonging to the same subscriber, and for the same content broadcast to group members in certain areas when large events occur. Users of group communication services can be organized into groups. A user can be a member of more than one group. Group members may be restricted to receiving and / or transmitting only within the cells corresponding to the area defined by the geographic area. Group communication needs to provide a fast and efficient mechanism for distributing the same content to a plurality of group members in a controlled manner.

E- URTRAN MBMS

1 is a diagram showing an E-UTRAN MBMS structure.

Conventional E-UTRAN (Evolved UTRAN) mobile communication networks do not support group communication. Therefore, the conventional Evolved UTRAN (E-UTRAN) mobile communication network does not guarantee the continuity of the group communication service. That is, when the terminal moves, the group communication service can not be continuously provided. Although the E-UTRAN does not support group communication, it can provide a point-to-multipoint service to a plurality of terminals using an evolved multimedia broadcast multicast service (eMBMS). A mobile communication service provider can use MBMS over-frequency (MBSFN) technology to provide services such as TV broadcasting through eMBMS. All cells included in the MBSFN transmission can be synchronized (time synchronized) to deliver the same contents to the UEs at the same time. The eMBMS service is provided through an MBMS bearer service in a broadcast mode. The broadcast MBMS bearer service operates on the structure of FIG.

Broadcast Multicast Service Center (BM-SC): It is possible to start MBMS bearer service transmission through MBMS session control signaling (MBMS Session Start, MBMS Session Stop) as an entity operating as a source of MBMS transmission. The BM-SC may assign a Temporary Mobile Group Identity (TMGI) for identifying the MBMS bearer service and a session ID for distinguishing each MBMS session.

- MCE (Multi cell / Multi Coordination Entity): participates in MBMS session control signaling and performs admission control and radio resource allocation. When a new MBMS bearer service session is started, the MCE determines whether to set up a radio bearer for the session. The MCE may control the MBMS counting procedure. When the MCE determines the radio configuration of the MBMS bearer service and signals it to the eNBs, the eNBs signals the radio resource configuration sent by the MCE to the UEs through the RRC message.

MBMS gateway: exists between BM-SC and eNBs to forward MBMS user data to eNBs. The MBMS gateway forwards the MBMS user data to the eNBs that join the MBMS service using the IP Multicast protocol.

MBMS  channel

The E-UTRAN provides two point-to-multipoint channels for MBMS over the air interface.

- MCCH (Multicast Control Channel): Used to broadcast an MBMS RRC message corresponding to the MBSFN area on a logical channel existing on the control plane of the air interface between the UE and the eNB. The RRC layer of the eNB generates an RRC message based on the MBMS control information received from the MCE. There is a one-to-one relationship between one MBSFN region and one MCCH.

- MTCH (Multicast Traffic Channel): Used to broadcast MBMS user data related to the MBMS service on a logical channel existing on the user plane of the air interface between the UE and the eNB. And is mapped to a multicast channel (MCH) transport channel mapped to a physical multicast channel (PMCH) physical channel. One or more MTCHs may be mapped to one MCH.

The cell supporting MBMS notifies the UE about the MCCH information change using the PDCCH. For the MCCH information change notification, the MBMS Radio Temporary Identifier (M-RNTI) is carried on the PDCCH. When the UE starts to receive user data for an MBMS service session of interest, the UE continuously receives MCCH information related to the session as well as user data for the session on the MTCH.

MBMS  Layer 2 structure

2 is a diagram showing a layer 2 model (eNB side) for one MBSFN area.

As shown in FIG. 2, Packet Data Convergence Protocol (PDCP) layer is not applied to MCCH or MTCH, and RLC (Radio Link Control) layer is configured in unacknowledged mode (UM). Since Hybrid Automatic Repeat reQuest (HARQ) is not used for data delivery through MCCH and MTCH, reordering of RLC entities configured for MCCH and MTCH is not applied.

In the MAC layer, the eNB may multiplex one or more MTCHs with one MCCH. The MCH Scheduling Information MAC Control Element is used to notify the UEs when the MBMS service user data is scheduled for each MTCH.

MCCH  Information

The RRC layer broadcasts MCCH information to inform UEs of MBMS control information. MCCH information is periodically broadcast for each MCCH in each MBSFN region. For periodic repetition of MCCH information, the RRC layer uses the concept of an MCCH repetition period and an MCCH modification period. For reliable delivery of MCCH information, the RRC layer within the eNB repeatedly broadcasts MCCH information of the same content every MCCH repetition period. The eNB may initiate the transmission of the updated MCCH information from the boundary of the MCCH modification period, such as the system information on the BCCH. When the MCCH information needs to be changed, the eNB informs the UE about the MCCH information change by marking the M-RNTI on the PDCCH within one MCCH modification period before the updated MCCH information starts to be transmitted. The PDCCH indicating the M-RNTI can inform the UE about the information on one or more MBSFN areas to which the MCCH information change is related by using 8 bits. The eNB may set the bit to notify the terminal about the beginning of the session or a counting procedure in progress. The MCE informs the eNBs about the configuration of the MCCHs. The RRC layer broadcasts the configuration of the MCCHs through the system information (SIB13). SIB13 is broadcast over a DL-SCH from a single cell as in the normal SIB type. In addition to the SIB 13, the RRC layer provides MCCH information through an MBSFNAreaConfiguration message and an MBMSCountingRequest message.

MBMS Procedure

The network provides MBMS to one or more terminals in the following order.

When the MBMS service session is started, the eNB joins the MBMS service and delivers the MBMS data to one or more UEs.

When the session is started, the UE receives MCCH information related to the MBMS service and sets up an MBMS Point-to-Multipoint radio bearer (hereinafter referred to as "MRB" or "MBMS radio bearer" or "MBMS bearer").

While the eNB is sending a session to one or more terminals, the session may be updated.

When the MBMS service session is stopped, the eNB leaves the MBMS service and ends the MBMS data transmission to one or more UEs.

When the MBMS service session is stopped, the UE receives the updated MCCH information and releases the MRB associated with the MBMS service.

3 is a view showing an MCCH information acquisition and an MBMS user data reception procedure.

3 shows a procedure for a UE to receive user data for an MBMS service session from an eNB. As shown in FIG. 3, when the UE receives system information for MCCH information and receives an MBMS scheduling information message for starting a session with the eNB, the eNB displays the M-RNTI on the PDCCH within one MCCH modification period . The eNB then updates the MCCH information broadcast on the MCCH within the next MCCH modification period. If the PDCCH indicates a change in the MCCH information in the MBSFN area, the terminal receives the MCCH to obtain updated MCCH information. Then, the UE sets the MRB corresponding to the session having the updated MCCH information. When the MRB is set, the MTCH and the PMCH corresponding to the MRB are also configured. After setting the MRB, the terminal can receive MBMS user data from the MTCH.

As described above, group communication in the conventional E-UTRAN is not supported. In a case where a plurality of UEs are located in one cell and MBMS is to be used for downlink transmission for group communication, the MBMS capable general UE can receive private group communication via the eMBMS, The group communication of interest could not be easily identified and received. In other words, it was difficult to provide the group communication dedicated service through the E-UTRAN. Accordingly, there is a problem that it is difficult to provide continuous group communication service when the group member terminal moves.

In the E-UTRAN, a group communication terminal receives a downlink transmission for a group communication through an eMBMS, and only terminals interested in group communication or groups interested in group communication (MBMS) radio bearer (MRB) for group communication to receive group communication through an eMBMS, and to provide a continuous service when the mobile station moves.

EMBMS can be used for downlink transmission to group communication. A unicast bearer can be used for uplink transmission. If eMBMS is not supported, a unicast bearer can be used for downlink transmission. Even when the eMBMS is supported, a unicast bearer can be used for downlink transmission when the number of group member terminals to receive group communication in the cell is less than a certain number. A pre-established MBMS bearer between BM-SC and eNBs can be used for fast group communication setup. Alternatively, when the number of group member terminals in a specific eNBs cell is equal to or greater than a predetermined number, an MBMS bearer can be established and used between the BM-SC and the eNBs at the request of the group member terminals.

(MBMS Session Identity) for distinguishing each MBMS session from the Temporary Mobile Group Identity (TMGI) for identifying the downlink MBMS bearer service for group communication, MBSFN zone identification information for group communication or group communication area or group communication One or more pieces of information may be provisioned to the terminal by an EPS entity (e.g., GCSE AS, IMS, PCRF, or other EPS entity) assigned by the BM-SC or other Evolved Packet System entity to control group communication. For example, the TMGI and MBSFN area identification information for session ID, group communication or group communication area or group communication may be stored in a USIM or the like using OMA DM (Open Mobile Alliance Device Management) or OTA (Over The Air) Signaling (eg, registration, setting) between an EPS entity that is stored in the terminal through a Non-Access Stratum (NAS) procedure (eg, attach area tracking), or an EPS entity that controls the terminal and a GCSE application server or group communication. Lt; / RTI >

 In order for the terminal to receive the downlink transmission for the group communication using the MBMS, the terminal must register with the EPS entity that controls the GCSE application server or group communication. If the EPS entity controlling the GCSE application server or group communication decides to provide the downlink transmission for group communication in the particular cell (s) via eMBMS, the EPS entity that controls the GCSE application server or group communication is the BM-SC Lt; RTI ID = 0.0 > eNB. ≪ / RTI >

A group communication capable terminal or a terminal (group member terminal) interested in a specific group communication can identify and receive a downlink transmission of a specific group communication transmitted through the MBMS. A terminal that does not support group communication or a terminal that is not a specific group member may be prevented from ignoring or receiving downlink transmissions of a particular group communication over the MBMS.

When a group communication capable terminal receiving a downlink transmission of a specific group communication transmitted through MBMS or a terminal (group member terminal) interested in a specific group communication changes a cell (for example, between cells and between base stations) It is possible to continue reception of the group communication service through the MBMS. The following methods can be used for this purpose.

Method 1 : Including information related to group communication through system information

The E-UTRAN procedure may support service continuity for mobility within the same group communication area or group communication MBSFN area. Group communication services over the MBMS within the same geographic area may be provided over one or more frequency (s).

In order to avoid group communication related MBMS system information and potentially MCCH reading at neighbor frequencies, the MBMS group communication capable terminal or the group communication interested terminal may transmit the group communication area or group And may be aware of which MBMS group communication service is provided through the communication MBSFN area.

User service description (USD): TMGI, session start time, session end time, frequencies, group communication service area identifier (SAI) for each group communication service in the application / service layer,

- System information: MBMS and non-MBMS cells are used to indicate the MBMS group communication service area identifier of the current frequency and each neighbor frequency through system information

As described above, the E-UTRAN can broadcast the MBMS carrier frequencies for the MBSFN region for the group communication, the group communication region, or the group communication through the system information. The UE can recognize carrier frequencies for MBSFN areas for group communication or group communication areas or group communication provided through MBMS. As an example of this, the eNB may broadcast carrier frequencies for MBSFN regions for group communication or group communication area or group communication using system information block type 15 configured as follows.

The UE can recognize the carrier frequencies (eg group-mbms-SAI-IntraFreq-r12) for the MBSFN region for group communication or group communication region or group communication provided through MBMS.

As another example of this, the eNB may broadcast the carrier frequencies for the MBSFN area for group communication or group communication area or group communication using system information block type 15 configured as follows.

The UE can recognize carrier frequencies for MBSFN regions for group communication, group communication, or group communication through group communication service area identifier information (e.g., group communication-SAI-r12) provided through MBMS.

Another example of this is to broadcast the group communication through the system information block type 13 configured as follows or the identification information on the MBSFN area for the group communication area or the group communication as follows, so that the UE can transmit the system information on the existing 3GPP 36.331 v11.4 Using normal MBMS carrier frequencies on block type 15, the terminal can recognize carrier frequencies for MBSFN regions for group communication or group communication regions or group communication provided over MBMS.

Another example of this is to broadcast carrier frequencies for MBSFN area for group communication or group communication area or group communication using eNB new system information block type, May be aware that a group communication service is provided.

Method 2 : MCCH Include information about group communication through information

Most of the MBMS control information is provided through the MCCH, which is a specific logical channel for MBMS common control information. An MCCH logical channel may be applied for a single group communication or one group communication area or a radio resource configuration corresponding to an MBMS session for a plurality of group communications in one group communication area. A group communication or a group communication area or a plurality of group communication in a group communication area may be provided through one MBSFN. A group communication or a group communication area or a plurality of group communication in a group communication area may be provided through a plurality of MBSFNs in one MBMS service area.

An eNB (or cell) using the MBMS for downlink transmission to the group communication may carry an MBSFNAreaConfiguration message indicating the radio resource configuration corresponding to the group communication MBMS session in progress via the MCCH.

Limited MBMS control information, which is mainly used for acquiring MCCH information, is provided through the BCCH. This information is provided through the MBMS specific system information block (system information block type 13).

When a terminal interested in receiving a group communication service or a terminal interested in receiving a group communication service through an MBMS service enters an MBSFN area for a corresponding group communication area or group communication and notifies that the MCCH information for group communication has been changed And receives an MBSFNAreaConfiguration message through an MCCH information acquisition procedure for group communication at the time of reception.

The E-UTRAN procedure may support service continuity for mobility within the same group communication area or group communication MBSFN area. Group communication services over the MBMS within the same geographic area may be provided over one or more frequency (s).

In order to avoid group communication related MBMS system information and potentially MCCH reading at neighbor frequencies, the MBMS group communication capable terminal or the group communication interested terminal may transmit the group communication area or group And may be aware of which MBMS group communication service is provided through the communication MBSFN area.

User service description (USD): TMGI, session start time, session end time, frequencies, group communication service area identifier (SAI) for each group communication service in the application / service layer,

- MCCH information: Indication of MBMS group communication service area identifier of current frequency and each neighbor frequency through MCCH used to provide group communication service

As described above, the E-UTRAN can broadcast the MBMS carrier frequencies for the MBSFN region for the group communication, the group communication region, or the group communication through the MCCH information. The UE can recognize carrier frequencies for MBSFN areas for group communication or group communication areas or group communication provided through MBMS. As an example of this, the eNB may broadcast the carrier frequencies for the MBSFN region for group communication or group communication area or group communication using the MBSFNAreaConfiguration message configured as follows.

As another example of this, the eNB may broadcast the carrier frequencies for the MBSFN area for group communication or group communication area or group communication using the MBSFNAreaConfiguration message configured as follows.

As another example of this, the eNB may broadcast carrier frequencies for group communication or group communication areas in a different MCCH message (MBMSCountingrequest message) for a group communication MBMS session or MBSFN area for a group communication in a new MCCH message.

When the eNB broadcasts the MBMS carrier frequencies for the MBSFN region for the group communication, the group communication region, or the group communication through the MCCH information, the UE transmits the MBMS carrier frequencies for the group communication or the group communication region or the group communication The carrier frequencies for the MBSFN region can be recognized.

Recognizing the carrier frequencies for the MBSFN region for the group communication or the group communication region or the group communication provided by the UE through the MBMS can be performed by a group communication MBMS radio bearer configuration (MBMS radio bearer setup or MBMS radio bearer release) and / The group communication reception includes a session ID, a group communication, or a group for distinguishing between the TMGI for group communication and the MBMS session for group communication to a terminal interested in receiving a group communication capable terminal or group communication service or a terminal interested in receiving a group communication service through an MBMS service When the MBSFN region identification information for the communication area or the group communication is provisioned, and / or the group communication reception is performed by the terminal interested in receiving the group communication capable terminal or group communication service or the terminal interested in receiving the group communication service through the MBMS service TMGI for Provisioned Group Communications A session ID for identifying each MBMS session, MBSFN area identification information for group communication or group communication or group communication, a session ID for distinguishing the TMGI received through the eNB and each MBMS session, a group communication or a group communication area, Lt; RTI ID = 0.0 > MBSFN < / RTI >

Method 3 : Unicast RRC  For group communication via message MBMS  wireless Bearer  How to support service continuity when set up

If a pre-established MBMS bearer is established between the BM-SC and the eNB for group communication and / or the terminal conveys an interest indication for the group communication to the eNB, or if the eNB sends another network entity (e.g. MME or MCE or MBMS GW or GCSE AS, or an EPS entity that controls group communication), the eNB uses the unicast RRC message to receive the indication of interest in the group communication, the group communication subscription information, and the group communication indication through the MBMS MBMS radio bearer configuration information for group communication to the UE.

If a pre-established MBMS bearer is established between the BM-SC and the eNB for group communication and / or the terminal conveys an interest indication for the group communication to the eNB, or if the eNB sends another network entity (e.g. MME or MCE or MBMS GW or GCSE AS, or an EPS entity that controls group communication), the eNB uses the unicast RRC message to receive the indication of interest in the group communication, the group communication subscription information, and the group communication indication through the MBMS And may transmit information instructing reception of the group communication through the MBMS to the terminal.

As an example of the unicast RRC message, the RRC message may use an RRC Connection reconfiguration message. The RRC Connection reconfiguration message may be configured as follows, including information for MBMS session and radio resource configuration.

The RRC Connection reconfiguration message may include only some information elements among the pmch-Info information for the MBMS session and the radio resource configuration for group communication.

As another example of the above unicast RRC message, the RRC message may include additional information (e.g., an indication to instruct MBMS reception for group communication) in an existing RRC message or an MBMS session for group communication through a new RRC message (E. G. Pmch-Info) or additional information (e. G. Indication to receive MBMS for group communication) for wireless resource configuration.

When receiving MBMS radio bearer configuration information for group communication using a unicast RRC message, a UE interested in receiving the group communication service or a UE interested in receiving the group communication service through the MBMS service can receive the group communication service session The MBMS radio bearer setup procedure can be applied to get started. When setting up the MBMS radio bearer, the UE configures the MTCH logical channel using the locgicalChannelIdentity information included in the unicast RRC message. Then, the UE configures the physical layer using the pmch-Config information included in the unicast RRC message.

When receiving information instructing reception of a group communication through an MBMS through a unicast RRC message, a terminal capable of group communication or a terminal interested in receiving a group communication service through MBMS can receive group communication via MBMS .

The E-UTRAN procedure may support service continuity for mobility within the same group communication area or group communication MBSFN area. Group communication services over the MBMS within the same geographic area may be provided over one or more frequency (s).

In order to avoid the need to read MBMS system information or MCCH related to group communication at neighbor frequencies, an MBMS group communication capable terminal or a group communication interested terminal transmits a group communication area or a group communication MBSFN It may be aware of which MBMS group communication service is provided over the area.

User service description (USD): TMGI, session start time, session end time, frequencies, group communication service area identifier (SAI) for each group communication service in the application / service layer,

- RRC information: indicates the MBMS group communication service area identifier of the current frequency and each neighbor frequency through a dedicated RRC message (e.g. RRC Connection reconfiguration) used to provide the group communication service

As described above, the E-UTRAN can transmit MBMS carrier frequencies for the MBSFN region for the group communication, the group communication region, or the group communication through the dedicated RRC message. The UE can recognize carrier frequencies for MBSFN areas for group communication or group communication areas or group communication provided through MBMS. For example, the eNB may broadcast carrier frequencies for the MBSFN region for group communication or group communication or group communication using an RRC Connection reconfiguration message configured as follows.

For example, the eNB may broadcast carrier frequencies for the MBSFN region for group communication or group communication or group communication using an RRC Connection reconfiguration message configured as follows.

As another example of this, the eNB may broadcast carrier frequencies for MBSFN regions for group communication or group communication area or group communication in another dedicated RRC message for a group communication MBMS session or a new dedicated RRC message.

Method 4 : Communicating group communication interest by terminal

The UE can notify the E-UTRAN of interest in receiving the group communication via the MBMS or the group communication via the MBMS. A terminal interested in receiving the group communication service in the RRC Connected state or a terminal capable of group communication through the MBMS service can start or end a session when entering or leaving the MBSFN area for RRC connection setup or group communication area or group communication , When changing the priority of reception and unicast reception through MBMS, changing system information block type 15 or system information block type 13, or the like.

If the terminal has delivered an indication of interest for group communication (via MBMS) to the eNB, and / or a pre-established MBMS bearer between the BM-SC and the eNB is established for group communication, and / When receiving an indication of interest in group communication, a group communication subscription information, and a group communication provision indication via MBMS from an entity (eg, an MME or an MCE or an MB entity in an MBMS GW or an EPS entity controlling a GCSE AS or group communication) May transmit MBMS radio bearer configuration information for group communication to the UE using the RRC message.

And / or if a pre-established MBMS bearer between the BM-SC and the eNB is set up for group communication, and / or if the eNB is in a different network entity (eg MME or MCE or MBMS GW or GCSE AS or an EPS entity that controls group communication), the eNB uses the RRC message when receiving an indication of interest in group communication, group communication subscription information, and group communication indication through MBMS And transmit information instructing to receive the group communication via the MBMS.

The UE transmits an indication of interest to the eNB (via MBMS) on the reception of the group communication, for example, through a MBMSInterestIndication message composed as follows (E. G., Groupcommunicationinterest) for receiving group communications (via MBMS).

The MBMSInterestIndication message includes an MBSFN area identification information (eg, one or more of group communication-SAI, group communication mbsfn-AreaId, TMGI, and session ID) for group communication or group communication area or group communication desired to be received by the UE . The identification information of the MBSFN area for the group communication or group communication area or the group communication desired to be received by the terminal may indicate the identification information of the MBSFN area for the group communication or the group communication area or the group communication through the integer value.

Another example of a terminal for conveying an indication of interest in receiving a group communication (via MBMS) to the eNB is for the terminal to indicate an interest in receiving the group communication via the existing terminal assistance information RRC message or the new terminal assistance information RRC message May be provided.

If the eNB can receive group communication via the MBMS or if the number of terminals to be received exceeds a certain number, the eNB may transmit the group communication to the other network entity (eg, the BM-SC or the MME or the MCE or the MBMS GW or the GCSE AS, ) To request a group communication session via MBMS.

The eNB can transmit MBMS radio bearer configuration information for group communication to the UE using the RRC message if the eNB can receive the group communication through the MBMS or if the number of the UEs to receive is more than a predetermined number.

The eNB can initiate the group communication transmission through the MBMS when the number of the terminals that can receive the group communication through the MBMS or the number of the terminals to be received exceeds a certain number.

Method 5 : Between nodes RRC  Message contains group communication information

While the UE in the RRC Connected state receives the downlink transmission for the group communication service through the MBMS, the handover can be performed according to the UE movement.

During handover preparation, the E-UTRAN is allowed to transmit group communication interest information or method 3 (or method 1/2) of the terminal of method 4 if possible to the inter-node RRC message (e.g. HandoverPreparationInformation message) to provide group communication service continuity And may include carrier frequency information for the MBSFN area for group communication or group communication area or group communication.

During handover preparation, the source eNB may use the HandoverPreparationInformation message to convey the RRC information to be used by the target eNB. The source eNB may forward the HandoverPreparationInformation message to the target eNB including the group communication interest information of the terminal, or the carrier frequency information for the group communication or group communication area or the MBSFN area for group communication.

For example, the above information may be included in the AS-Context information of the HandoverPreparationInformation message. The HandoverPreparationInformation message and the AS-Context information may be configured as follows.

As another example of this, the above information may be included in the AS-Config information of the HandoverPreparationInformation message. The HandoverPreparationInformation message and the AS-Config information may be configured as follows.

The base station, which has received the group communication interest information of the terminal or the carrier frequency information for the group communication or group communication area or the MBSFN area for group communication during the handover preparation, continuously transmits the group communication service after the handover You can take action to receive. For example, if the target eNB is configured to provide the group communication service through the MBSFN area for the same group communication or group communication area or group communication, information on the target eNB is transmitted to the source eNB by the handover response message, Over command message (including an RRC Connection reconfiguration message) to the UE through the source eNB.

As another example of this, the target eNB transmits the MBMS radio bearer for group communication to the UE through the source eNB by handover command message (including the RRC Connection reconfiguration message) Lt; RTI ID = 0.0 > communication. ≪ / RTI >

Another example of this is that if the target eNB does not provide the group communication service through the MBSFN area for the same group communication or group communication area or group communication (eg, does not support MBSFN or does not support MBMS) And can transmit the information on the source eNB to the source eNB by the handover response message or the source eNB by the handover command message (including the RRC Connection reconfiguration message). And / or the source eNB may not decide handover to the target eNB. And / or send group communications via unicast. (e.g., sending group communication user plane data in unicast in the target eNB, setting unicast bearer for group communication via RRC message, and instructing to receive group communication via unicast data radio bearer using RRC message)

As described above, according to the present invention, the E-UTRAN network informs the group communication terminal of the mapping information between the MBMS carrier frequencies and the group communication service for group communication so that terminals interested in group communication or terminals interested in group communication It is possible to receive the group communication service continuously through MBMS or unicast even when moving.

4 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Referring to FIG. 4, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The control unit 1010 notifies the group communication terminal of the mapping information between the MBMS carrier frequencies and the group communication service for the group communication to the group communication, And controls the overall operation of the base station to continuously receive the group communication service through MBMS or unicast even when the terminals interested in the mobile communication terminal move.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

5 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

5, the user terminal 1100 according to another embodiment includes a receiving unit 1110, a control unit 1120, and a transmitting unit 1130.

The receiving unit 1110 receives downlink control information, data, and messages from the base station through the corresponding channel.

In addition, the controller 1120 informs the group communication terminal of the mapping information between the MBMS carrier frequencies and the group communication service for group communication, which is necessary for performing the above-described present invention, And controls the overall operation of the terminal according to the continuous reception of the group communication service through MBMS or unicast even when the terminals interested in communication move.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (1)

A method for a terminal to receive a group communication service,
Receiving mapping information between MBMS carrier frequencies and group communication services for group communication from an E-UTRAN network; And
And continuously receiving the group communication service through MBMS or unicast even when the terminals participating in the group communication or the terminals interested in the group communication move.

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