WO2012058924A1

WO2012058924A1 - Method, terminal and system for point-to-multipoint call in trunking system

Info

Publication number: WO2012058924A1
Application number: PCT/CN2011/075105
Authority: WO
Inventors: 杜高鹏; 张现周; 朱永升; 韩小江
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-11-04
Filing date: 2011-06-01
Publication date: 2012-05-10
Also published as: CN102469415B; CN102469415A

Abstract

A method, terminal and system for point-to-multipoint call in a trunking system based on Long Term Evolution (LTE) technology are disclosed by the present invention, wherein a call channel between a source terminal and a destination terminal is established through a base station, core network, IP Multimedia Subsystem (IMS) domain and an application server, and voice data are transferred between the source terminal and the destination terminal through the call channel, a Broadcast Multicast Service Center (BM-SC) and a Multimedia Broadcast Multicast Services Gateway (MBMS-GW). The present invention completes the point-to-multipoint trunking communication mechanism by trying not to change or extending the function as least as possible on the basis of the prior air interface protocol, uses architecture with IMS and PTT Over Cellular (PoC), and performs function extension to partial network elements in the prior network architecture. Specifically, the call channel between the source terminal and the destination terminal is established through the base station, core network, IMS domain and application server, and the voice data are transferred between the source terminal and the destination terminal through the call channel and BM-SC, thus realizing the point-to-multipoint service of the trunking system in an LTE network, and being more beneficial to the compatibility and convergence between the trunking system and the prior LTE network.

Description

Point-to-multipoint calling method, terminal and system in cluster system

The present invention relates to the field of communications technologies, and in particular, to a point-to-multipoint calling method, terminal and system in a cluster system based on LTE (Long Term Evolution) technology. Background technique

At present, the trunking communication system is a dedicated wireless communication system developed for industrial users to command and dispatch requirements. It is a multi-purpose wireless communication system in which a large number of wireless users share a small number of wireless channels and use command and dispatch as the main application. High performance wireless communication system. The trunking communication system has a wide application market in the fields of government departments, public safety, emergency telecommunications, electric power, civil aviation, petrochemicals and military.

The trunked communication system has undergone a similar development process as cellular mobile communication systems. The first generation cluster system is an analog trunking communication system, which mainly supports voice communication; the second generation cluster system is a narrowband digital trunking communication system, which is the most widely used cluster communication system.

The existing trunking communication system is still relatively backward in terms of data transmission capability and multimedia service support capability, and its technical innovation and industrial chain are still not complete. For example, in the current digital narrowband trunking communication system, the iDEN system improves the time slot and modulation method and introduces a broadband integrated digital enhanced network (Wide-iDEN, WiDEN), which increases the peak transmission rate to 384 kbps; TETRA enhanced data. The TETRA Release 2 Enhanced Data Service (TEDS) can ideally support peak transmission rates of up to 700 kbps, which are not on the order of Mbps. In addition, existing digital trunking systems are not well suited to demand in terms of spectrum utilization and coverage.

At present, the broadband digital trunking system based on LTE technology has become the development direction of the next-generation cluster system, and the network architecture and business process of the broadband digital trunking system based on LTE technology. Standards such as business functions and key technologies have not yet been developed, while existing second-generation cluster systems are based

The evolution of broadband digital trunking systems based on LTE technology has great difficulties, and it does not have compatibility or compatibility with LTE networks. Summary of the invention

The main purpose of the present invention is to provide a point-to-multipoint calling method, terminal and system in a cluster system based on LTE technology, aiming at improving the compatibility of a trunking call service with an LTE network.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A point-to-multipoint calling method in a cluster system, the method comprising:

The source terminal establishes a communication channel with the destination terminal through the base station, the core network, the IP multimedia subsystem IMS domain, and the application server;

The voice data is transmitted to the destination terminal through the call channel, the broadcast multicast service center BM-SC, and the multimedia broadcast multicast service gateway MBMS-GW.

The process of establishing a call channel between the source terminal and the destination terminal by using the base station, the core network, the IMS domain, and the application server includes:

The source terminal establishes an RRC connection by sending a radio resource control protocol RRC connection request to the base station;

Sending a service request carrying a point-to-multipoint cluster call identifier to the base station, and the base station forwards the service request to the core network, and performs security authentication of the IMS domain at the same time;

Establishing a radio bearer with the base station, and updating the bearer information by using the mobility management entity MME, the serving gateway SGW, and the public data network gateway PDN-GW in the core network;

Sending a session establishment request message to the application server, and receiving a call permission message fed back by the application server according to the session establishment request message, establishing a communication channel with the destination terminal.

The process of transmitting voice data to the destination terminal through the call channel, the BM-SC, and the MBMS-GW includes:

The source terminal sends voice data to the application server through the call channel, and the application service Transmitting the voice data to a PDN-GW in a core network;

When the PDN-GW determines that the bearer in which the voice data is located is a point-to-multipoint type, the PDN-GW forwards the voice data to the BM-SC; after the BM-SC starts the session through the MBMS-GW and the MME, The voice data is forwarded to the destination terminal through the MBMS-GW and the base station.

A point-to-multipoint calling terminal in a cluster system, the terminal comprising:

a call channel establishing module, configured to establish a call channel with the destination terminal through the base station, the core network, the IMS domain, and the application server;

The voice data delivery module is configured to perform voice data transmission with the destination terminal through the call channel, the BM-SC, and the MBMS-GW.

The call channel establishing module includes:

An RRC connection establishing unit, configured to establish an RRC connection by sending an RRC connection request to the base station;

a service request sending unit, configured to send a service request carrying a point-to-multipoint cluster call identifier to the base station, triggering the base station to forward the service request to the core network, and performing security authentication of the IMS domain;

a radio bearer establishment update unit, configured to establish a radio bearer with the base station, and perform update of the bearer information by using the MME, the SGW, and the PDN-GW in the core network;

The session request message sending unit is configured to send a session establishment request message to the application server, and the call channel establishing unit is configured to receive a call permission message fed back by the application server according to the session establishment request message, and establish a call channel with the destination terminal.

The voice data delivery module is further configured to:

Transmitting the voice data to the application server by using the call channel, triggering the application server to forward the voice data to the PDN-GW in the core network; triggering the PDN-GW to determine that the bearer where the voice data is located is a point-to-multipoint Type, the voice data is forwarded to the BM-SC; After the BM-SC starts the session through the MBMS-GW and the MME, the voice data is forwarded to the destination terminal through the MBMS-GW and the base station.

A point-to-multipoint calling system in a cluster system, the system comprising: a source terminal and a destination terminal capable of communicating with a base station, and an application server connected to the base station through a core network, wherein:

The source terminal is configured to establish a call channel with the destination terminal by using the base station, the core network, the IMS domain, and the application server, and perform voice data with the destination terminal by using the call channel, the BM-SC, and the MBMS-GW. Pass

The application server is configured to establish, by the base station, the core network, and the IMS domain, a call channel between the source terminal and the destination terminal, so that the source terminal can refer to the call channel and the BM-SC and the The destination terminal performs voice data transmission;

The destination terminal is configured to perform voice data transmission with the source terminal through the call channel and the BM-SC.

The source terminal is further configured to:

Establishing an RRC connection by sending an RRC connection request to the base station; transmitting a service request carrying the point-to-multipoint cluster call identifier to the base station, triggering the base station to forward the service request to the core network, and performing security authentication of the IMS domain at the same time; a radio bearer between the base stations, and performing update of the bearer information by using the MME, the SGW, and the PDN-GW in the core network; and sending a session establishment request message to the application server; receiving the call permission fed back by the application server according to the session establishment request message a message, establishing a communication channel with the destination terminal;

The application server is further configured to receive a session establishment request message sent by the source terminal, and feed back a call permission message to the source terminal according to the session establishment request message.

among them,

The source terminal is further configured to send voice data to the application server by using the call channel;

The application server is further configured to forward the voice data to a PDN-GW in a core network, where The triggering PDN-GW forwards the voice data to the BM-SC when determining that the bearer in which the voice data is located is a point-to-multipoint type; triggering the BM-SC to open the session through the MBMS-GW and the MME, The data is forwarded to the destination terminal through the MBMS-GW and the base station.

The application server is a cluster push application server based on a push-to-talk over PoC. The point-to-multipoint calling method, terminal and system in a cluster system based on LTE technology proposed by the present invention complete point pairing by performing function expansion on the basis of the existing air interface protocol and not changing as much as possible or as small as possible Multi-point cluster communication mechanism, using IMS (IP Multimedia Subsystem, IP Multimedia Subsystem) + PoC (PTT Over Cellular) architecture, and functional expansion of some network elements in the existing network architecture, specific The call channel between the source terminal and the destination terminal is established through the base station, the core network, the IMS domain, and the application server; the multicast service gateway is broadcasted through the call channel, the BM-SC (Broadcast Multicast Service Center) The destination terminal performs voice data transmission, realizes point-to-multipoint service of the cluster system in the LTE network, and more utilizes the compatibility and fusion of the cluster system and the existing LTE network. DRAWINGS

1 is a schematic flowchart of an embodiment of a point-to-multipoint calling method in a cluster system based on the LTE technology according to the present invention;

2 is a schematic diagram of a network structure of a broadband digital trunking communication system based on the LTE technology in the foregoing embodiment;

3 is a schematic diagram of a process of establishing a call channel between a source terminal and a destination terminal through a base station, a core network, an IMS domain, and an application server according to an embodiment of the LTE technology-based point-to-multipoint call method in a cluster system;

4 is a schematic structural diagram of an embodiment of a point-to-multipoint calling terminal in a cluster system based on the LTE technology according to the present invention;

FIG. 5 is a schematic diagram of a point-to-multipoint calling terminal in a cluster system based on LTE technology according to the present invention; FIG. Schematic diagram of the structure of the middle call channel establishment module;

6 is a schematic structural diagram of an embodiment of a point-to-multipoint calling system in a cluster system based on the LTE technology of the present invention. detailed description

The solution of the embodiment of the present invention is mainly to complete the point-to-multipoint cluster communication mechanism by performing function expansion on the basis of the existing air interface protocol and doing as little as possible or as small as possible.

IMS+PoC architecture, and functional expansion of some network elements in the existing network architecture, specifically establishing a call channel between the source terminal and the destination terminal through the base station, the core network, the IMS domain, and the application server; through the call channel, BM- The SC and the MBMS-GW transmit voice data to the destination terminal to implement point-to-multipoint service of the cluster system in the LTE network.

As shown in FIG. 1, an embodiment of the present invention provides a point-to-multipoint calling method in a cluster system based on LTE technology, including:

Step S101: The source terminal establishes a call channel with the destination terminal by using the base station, the core network, the IMS domain, and the application server.

The method in this embodiment involves a trunking system call service based on an LTE network. When a cluster terminal (that is, the source terminal in this embodiment) in the cluster system initiates a call to another cluster terminal in the cluster system (that is, the destination terminal in this embodiment) When you first need to establish a call channel between the source terminal and the destination terminal.

As shown in FIG. 2, the network structure of the broadband digital trunking communication system based on the LTE technology includes: a terminal (UE, User Equipment, user), a network side, and an application side, where:

The application side, which includes the cluster application server, completes the scheduling function of the cluster service and is the entry point of the PDN gateway. The cluster application server includes, for example, a PoC-based cluster application server, a cluster application server based on Gota (Global Open Truciening Architecture), and other types of cluster application servers. For the PoC-based cluster application server, when the end-to-end cluster call service is completed, the application side also includes an IMS domain. CSCF (Call Session Control Function) is a functional entity inside the IMS. It is the core of the entire IMS network and is mainly responsible for handling signaling control during the multimedia call session. It manages user authentication of the IMS network, QoS of the IMS bearer plane, coordination with other network entities for SIP session control, and service negotiation and resource allocation.

CSCF is divided into proxy CSCF (P-CSCF, Proxy CSCF) according to function, query CSCF

(I-CSCF, Interrogating CSCF) and the service CSCF (S-CSCF, Serving CSCF), which are essentially SIP servers, are used to process SIP signaling. among them:

The P-CSCF is the unified entry point for the IMS visited network. All session messages initiated and terminated by the IMS terminal to the IMS terminal are passed through the P-CSCF. As a SIP Proxy, the P-CSCF is responsible for user authentication and IPSec management independent of the access network, network anti-attack and security protection, SIP signaling compression and decompression for saving wireless network resources, and user roaming control through PDF ( Policy Decision Function) Performs functions such as NAT and QoS on the bearer plane. Its main functions are: forwarding the SIP registration request sent by the UE to the I-CSCF, determining the I-CSCF by the domain name provided by the UE; forwarding the SIP message sent by the UE to the S-CSCF, when the P-CSCF initiates the registration process at the UE Determine the S-CSCF.

The I-CSCF is the entry point to the IMS home network. During the registration process, the I-CSCF selects an S-CSCF for the user by querying the HSS. During the call, the call to the IMS network is first routed to the I-CSCF, and the I-CSCF obtains the S-SCSCF address registered by the user from the HSS and routes the message to the S-CSCF. Its main functions are: Specifying an S-CSCF for the user to perform SIP registration; Obtaining the address of the S-CSCF from the HSS, forwarding the SIP request; Routing the SIP request from other networks to the S-CSCF.

The S-CSCF is at the core of IMS network session control. It accepts registration requests forwarded from the visited network through the P-CSCF, and cooperates with the HSS for user authentication. And download the business data signed by the user from the HSS. The S-CSCF performs route management on the calling and called sides of the user, and performs SIP AS triggering according to the initial filtering rule (iFC, Initial Filter Criteria) of the user subscription. Achieve rich IMS business functions. Its main functions are: After receiving the registration request, the registration request is validated by the HSS; the controlled session terminal can be used as the Proxy-Server. After receiving the request, it performs internal processing or forwarding. It can also be used as a UA to interrupt or initiate SIP transactions. It interacts with the service platform to provide multimedia services.

On the network side, on the basis of supporting existing functions, the cluster service function is added, that is, the cluster user subscription information and the cluster network service network group call are stored and managed. The network side includes a base station and a core network, where the core network involves a PDN gateway, an MME (Mobility Management Entity), and an HSS.

PDN (Public Data Network) Gateway (PDN-GW), which supports existing functions and supports interfaces with a variety of cluster application servers to support various cluster services according to different needs. For the cluster service, the PDN-GW can select whether the downlink data is distributed to the SGW (Seving GateWay, Service Gateway) or the BM-SC according to whether the single call (ordinary bearer) or the group call (each cluster service group is assigned a TMGI identifier). That is, whether unicast mode or multicast mode (MBSFN mode) is selected.

The HSS (Home Subscriber Server) supports existing functions and adds cluster-capable modules for storing and managing group user information related to cluster services.

The MME supports the existing functions and adds modules that support the cluster function. The new module that supports the cluster services implements the information about the cluster user terminals and is responsible for obtaining the subscription information of the cluster user terminals from the HSS. The MME is a key control node of the 3GPP protocol LTE access network, which is responsible for the positioning of the idle mode UE, the paging process, including the relay. It involves the bearer activation/shutdown process. And when a UE is initialized, the UE is selected to connect to one SGW. A user is authenticated by interacting with the HSS, and a temporary ID is assigned to a user. MME also supports interception and monitoring within the scope permitted by law. The MME provides a control function interface for the 2G/3G access network, and the S6 interface is also provided for the roaming UE to the HSS through the S3 interface. Both the SGW and the eNB support existing functions in accordance with the LTE standard.

The BM-SC supports existing functions in accordance with the LTE standard.

The MBMS-GW supports existing functions in accordance with the LTE standard.

In this embodiment, a cluster application server is used as a PoC-based cluster application server as an example.

In this embodiment, the source terminal in the cluster system establishes a call channel with the destination terminal through the base station, the core network, the IMS domain, and the application server, and the specific process is:

For the source terminal and the destination terminal in the cluster system, both are in an idle state. When the source terminal initiates a call service to the destination terminal, the source terminal and the base station first establish a radio bearer, and then perform random access and perform RRC (Radio Resource). Control, Radio Resource Control Protocol) connection established. The problem of bearer, that is, bearloading and radio bearer selection, is actually the question of which wireless data service to choose as the data path.

The RRC processes the third layer information of the control plane between the UE and the UTRAN. The RRC mainly includes the RRC CONNECTION MANAGEMENT PROCEDURES, the RADIO BEARER CONTROL PROCEDURES, the RRC CONNECTION MOBILITYPROCEDURES, and the MEASUREMENT PROCEDURES.

The RRC connection setup procedure includes reselection of available cells, access grant control, and establishment of Layer 2 signal links. The RRC connection release is requested by the upper layer for tearing down the last signal connection; or when the RRC link fails, it is initiated by the RRC layer. If the connection fails, the UE will request to re-establish the RRC connection. If the RRC connection fails, the RRC releases the allocated resources.

After the RRC is established, the source terminal sends an initial UE message to the core network through the base station, and interacts with the SCSCF and the HSS in the IMS domain to complete the security authentication of the source terminal and the IMS domain. The initial UE message includes a service request, and the service request type identifier For point-to-multipoint cluster calls. After the security authentication of the IMS domain is completed, the NAS security mechanism between the source terminal and the MME in the core network is negotiated. MME performs initial context setup procedure, to produce EPS bearer context in the eNB and the terminal, and for establishing a wireless air interface resources that is RB (radio bearer, wireless carrier ⁷⁾ established.

The MME updates the relevant bearer for the serving gateway and the PDN-GW, where the information includes a point-to-multipoint bearer type, so that the PDN-GW uses the information to distinguish the data flow direction in a subsequent process.

Then, after the source terminal and the Poc server perform SIP application layer signaling interaction, an end-to-end SIP session is established. At this time, the PoC server initiates a message of the right to grant permission to the source terminal, and simultaneously sends a message of the right to the destination terminal to the destination terminal. Then, the voice call service can be performed, and the call channel establishment between the source terminal and the destination terminal is completed.

After receiving the voice data of the source terminal, the PoC server sends voice data to the PDN-GW. The PDN-GW determines that the bearer of the voice data is a point-to-multipoint type, and then sends the data to the BM-SC, and then follows the data. The normal process is to send voice data.

Step S102: Perform voice data transmission with the destination terminal through the call channel, the BM-SC, and the MBMS-GW.

As described above, the source terminal sends voice data to the application server through the call channel, and the application server forwards the voice data to the PDN-GW in the core network. When the PDN-GW determines that the bearer of the voice data is a point-to-multipoint type, The voice data is forwarded to the BM-SC by the PDN-GW, and the BM-SC forwards the voice data through the MBMS-GW and the MME, and then forwards the voice data to the destination terminal through the MBMS-GW and the base station.

The voice data transmission process is illustrated by the cluster terminal A (source terminal) and the cluster terminal group B (multiple destination terminals). The specific process of voice data transmission is as follows:

After receiving the voice data of the cluster terminal A, the PoC server sends voice data to the PDN-GW. The PDN-GW determines that the bearer of the voice data is a point-to-multipoint type (TMGI), and then sends the data to the BM-SC. After receiving the voice data, the BM-SC sends a session open request message. (Session Start request message) to the MBMS Gateway (MBMS GW), indicating that the MBMS transmission is about to begin, providing session parameters to the MBMS Gateway. The MBMS gateway sends a session start response message to the BM-SC, and the MBMS gateway creates an MBMS Bearer Context to save the session attribute and sends a session open request message to the MME. If it is a static MBSFN area, The MBMS-GW allocates an IP multicast address to the session. If it is a dynamic MBSFN area, the MME allocates an IP multicast address to the session.

It should be noted that the current protocol supports one TMGI corresponding to one MBMS service area, and one MBMS service area may have multiple TMGIs. That is, for cluster services (TMGI ID), multiple different cluster services can be sent on the same MBMS service area.

1) For the static MBSFN area, the MBMS-GW stores TNL information (ie: "List of downstream nodes"), that is, the eNB information contained in the area. If the BM-SC knows a cluster service start (TMGI) from the PDN GW, and then sends it to the MBMS GW through the Session Start (the message carries the TMGI and MBMS service area), the MBMS-GW sends it to the MME through the Session Start (in the message) Carrying the TMGI/MBMS service area), and also TNL information (ie, "List of downstream nodes") is carried to the MME, and the "TNL information" overwrites the "TNL information" generated by the MME itself.

2) For the dynamic MBSFN area, the MBMS-GW does not store TNL information (ie: "List of downstream nodes"), that is, the eNB information contained in the area. If the BM-SC knows a cluster service start (TMGI) from the PDN GW, and then sends it to the MBMS GW through the Session Start (the message carries the TMGI and the MBMS service area), the MBMS GW sends the message to the MME through the Session Start (the message carries The TMGI/MBMS service area) does not carry the information to the MME because the MBMS GW does not have TNL information. The MME automatically generates TNL information according to the eNB information to which the cluster terminal belongs. After receiving the session open request, the MME sends a session open request to the eNB/MCE, and the eNB/MCE creates an MBMS bearer context to save the session attribute and returns a session open response message.

The MME saves the session attribute, adds the eNodeB to the downstream node list, and sends a response to the MBMS gateway.

E-UTRAN establishes radio resources for MBMS data transmission and completes the radio bearer configuration of MBSFN transmission.

If the E-UTRAN can receive IP multicast, join the IP multicast address assigned by the MBMS gateway.

The BM-SC starts to send MBMS data, and the MBMS gateway sends the received MBMS data to the eNBs that have joined the IP multicast, and the terminal in the cluster terminal group B decodes the TB carried by the corresponding PDSCH channel, and The correctly decoded MAC PDUs are respectively transmitted to the higher layer signaling plane or user plane according to the logical channel ID.

As shown in FIG. 3, step S101 includes:

Step S1011: The source terminal sends an RRC connection to the base station to request to establish an RRC connection. Step S1012: Send a service request carrying a point-to-multipoint cluster call identifier to the base station, and the base station forwards the service request to the core network, and simultaneously performs the IMS domain. Safety certification;

Step S1013: Establish a radio bearer with the base station, and perform update of the bearer information by using the MME, the SGW, and the PDN-GW in the core network.

After the source terminal establishes the radio bearer with the base station, the MME sends the update bearer request information to the SGW in the core network, where the update bearer request information carries the point-to-multipoint cluster call identifier, and the SGW simultaneously forwards the update bearer request information to the SGW. The PDN-GW, based on the received update bearer request information, can determine that the call is a group call (each TM service group is assigned a TMGI identifier), and the PDN-GW selects to distribute downlink data to the BM according to the group call. -SC, select the multicast mode. Step S1014: Send a session establishment request message to the application server.

Step S1015: Receive a call permission message fed back by the application server according to the session establishment request message, and establish a call channel with the destination terminal.

As can be seen from the above process, for the point-to-multipoint call service in the cluster system, the existing network architecture and message flow of the LTE network are used, and the IMS+PoC architecture is used to realize the compatibility of the trunk call with the existing LTE network. .

In this embodiment, the point-to-multipoint cluster communication mechanism is completed on the basis of the existing air interface protocol and the function expansion is performed as little as possible or as small as possible, and the IMS+PoC architecture is adopted, and the existing network architecture is used. Some of the network elements are functionally extended, and the call channel between the source terminal and the destination terminal is established through the base station, the core network, the IMS domain, and the application server. The voice data is transmitted through the call channel and the BM-SC and the destination terminal to implement LTE. Point-to-multipoint services of cluster systems in the network, and the integration of cluster systems with existing LTE networks.

As shown in FIG. 4, an embodiment of the present invention provides a point-to-multipoint calling terminal in a cluster system based on the LTE technology, including: a call channel establishing module 401 and a voice data transmitting module 402, where:

a call channel establishing module 401, configured to establish a call channel between the target terminal and the destination terminal by using the base station, the core network, the IMS domain, and the application server;

The method in this embodiment involves a cluster system call service based on an LTE network. When a cluster terminal (that is, a terminal in this embodiment) in the cluster system initiates a call to another cluster terminal in the cluster system (that is, the destination terminal in this embodiment) First, the call channel establishing module 401 first establishes a call channel between the terminal and the destination terminal.

The voice data delivery module 402 is configured to transmit voice data to the destination terminal through the call channel, the BM-SC, and the MBMS-GW.

In this embodiment, the terminal in the cluster system establishes a call channel with the destination terminal through the base station, the core network, the IMS domain, and the application server, and performs the call channel with the destination terminal through the call channel. The specific process of voice data transmission is:

Both the terminal and the destination terminal are in an idle state. When the terminal initiates a call service to the destination terminal, the terminal and the base station first establish a radio bearer, and then perform random access and perform RRC connection establishment.

After the RRC is established, the terminal sends an initial UE message to the core network through the base station, and interacts with the SCSCF and the HSS in the IMS domain to complete the security authentication of the terminal and the IMS domain. The initial UE message includes a service request, and the service request type identifier is a point. Call to a multipoint cluster.

After the security authentication of the IMS domain is completed, the NAS security mechanism between the terminal and the MME in the core network is negotiated. The MME performs an initialization context establishment process, generates an EPS bearer and a terminal context in the eNB, and performs RB establishment on the air interface to establish the radio resource.

Then, after the terminal performs the SIP application layer signaling interaction with the Poc server, an end-to-end SIP session is established. At this time, the PoC server initiates a message for the right of the right to the terminal, and simultaneously sends a message for the right of the call to the destination terminal, and then The voice call service can be performed, and the call channel establishment between the terminal and the destination terminal is completed.

After receiving the voice data of the terminal, the PoC server sends voice data to the PDN-GW. If the PDN-GW determines that the bearer of the voice data is a point-to-multipoint type, the data is sent to the BM-SC, and the subsequent data is normal. The process of sending voice data.

As shown in FIG. 5, the call channel establishing module 401 includes: an RRC connection establishing unit 4011, a service request sending unit 4012, a radio bearer setup updating unit 4013, a session request message sending unit 4014, and a call channel establishing unit 4015, where:

The RRC connection establishing unit 4011 is configured to establish an RRC connection by sending an RRC connection request to the base station.

The service request sending unit 4012 is configured to send, to the base station, a point-to-multipoint cluster call identifier For the service request, the base station forwards the service request to the core network, and performs security authentication of the IMS domain at the same time;

The radio bearer establishment update unit 4013 is configured to establish a radio bearer with the base station, and perform update of the bearer information by using the MME, the SGW, and the PDN-GW in the core network;

The session request message sending unit 4014 is configured to send a session establishment request message to the application server.

The call channel establishing unit 4015 is configured to receive a call permission message fed back by the application server according to the session establishment request message, and establish a call channel with the destination terminal.

Further, the voice data delivery module 402 is further configured to send voice data to the application server through the call channel, and the application server forwards the voice data to the PDN-GW in the core network, where the PDN-GW determines that the bearer of the voice data is a point pair. In the multi-point type, the voice data is forwarded to the BM-SC by the PDN-GW, and the BM-SC forwards the voice data to the destination terminal through the MBMS-GW and the base station after the session is opened by the MBMS-GW and the MME.

As shown in FIG. 6, an embodiment of the present invention provides a point-to-multipoint calling system in a cluster system based on the LTE technology, including: a source terminal 602 and a destination terminal 603 respectively connected to the base station 601, and a base network 601 through the core network. Connected application server 604, where:

The source terminal 602 is configured to establish a call channel with the destination terminal 603 through the base station 601, the core network, the IMS domain, and the application server 604. The voice data is transmitted through the call channel, the BM-SC, and the MBMS-GW and the destination terminal 603. ;

The application server 604 is configured to establish a call channel between the source terminal 602 and the destination terminal 603 for the source terminal 602 through the base station 601 core network and the IMS domain, so that the source terminal 602 is in the call channel and the BM-SC and the destination terminal 603 perform voice. Delivery of data;

The destination terminal 603 is configured to receive the voice data sent by the source terminal 602 through the call channel and the BM-SC.

Further, the source terminal 602 is further configured to send an RRC connection request to the base station 601. The RRC connection is sent; the service request carrying the point-to-multipoint cluster call identifier is sent to the base station 601, and the base station 601 forwards the service request to the core network, and simultaneously performs security authentication of the IMS domain; establishes a radio bearer with the base station 601, and Updating the bearer information by using the MME, the SGW, and the PDN-GW in the core network; sending a session establishment request message to the application server 604; and receiving the call permission message fed back by the application server 604 according to the session establishment request message, establishing a relationship with the destination terminal 603 Call channel

The application server 604 is further configured to receive the session establishment request message sent by the source terminal 602, and feed back the call permission message to the source terminal 602 according to the session establishment request message.

Further, the source terminal 602 is further configured to send voice data to the application server 604 through the call channel;

The application server 604 is further configured to forward the voice data to the PDN-GW in the core network. When the PDN-GW determines that the bearer where the voice data is located is a point-to-multipoint type, the PDN-GW forwards the voice data to the BM-SC. After the session is started by the BM-SC through the MBMS-GW and the MME, the voice data is forwarded to the destination terminal 603 through the MBMS-GW and the base station 601.

In this embodiment, the application server 604 is a PoC-based cluster application server. Similarly, the application server 604 in this embodiment may also be a Gota-based cluster application server and other types of cluster application servers, when using a Gota-based cluster application server and other types of cluster application servers, due to a Gota-based cluster application. The server contains IMS functionality and does not need to go through the IMS domain.

The point-to-multipoint calling method, the terminal and the system in the cluster system based on the LTE technology in the embodiment of the present invention complete the point-to-multipoint by performing function expansion on the basis of the existing air interface protocol and not changing as much as possible or as small as possible. The cluster communication mechanism uses the IMS+PoC architecture and performs functional expansion on some network elements in the existing network architecture, and specifically establishes a communication channel between the source terminal and the destination terminal through the base station, the core network, the IMS domain, and the application server. Passing the voice channel through the call channel and the BM-SC and the destination terminal to realize the point pair of the cluster system in the LTE network Multi-point services, more leverage the compatibility and convergence of cluster systems with existing LTE networks.

The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and equivalent structural or process changes made by the present specification and drawings may be directly or indirectly applied to other related technical fields. The same is included in the scope of patent protection of the present invention.

Claims

Claim

The method according to claim 1, wherein the process of establishing a call channel between the source terminal and the destination terminal by using the base station, the core network, the IMS domain, and the application server includes:

The method according to claim 1 or 2, wherein the process of transmitting voice data to the destination terminal through the call channel, the BM-SC, and the MBMS-GW includes:

The source terminal sends voice data to the application server through the call channel, and the application server forwards the voice data to the PDN-GW in the core network;

4. A point-to-multipoint calling terminal in a cluster system, the terminal comprising: a call channel establishing module, configured to establish a call channel with the destination terminal through the base station, the core network, the IMS domain, and the application server;

The terminal according to claim 4, wherein the call channel establishing module comprises: an RRC connection establishing unit, configured to establish an RRC connection by sending an RRC connection request to the base station;

The terminal according to claim 4 or 5, wherein the voice data delivery module is further configured to:

Transmitting the voice data to the application server by using the call channel, triggering the application server to forward the voice data to the PDN-GW in the core network; triggering the PDN-GW to determine that the bearer where the voice data is located is a point-to-multipoint When the type is forwarded, the voice data is forwarded to the BM-SC. After the BM-SC is enabled to open the session through the MBMS-GW and the MME, the voice data is forwarded to the destination terminal through the MBMS-GW and the base station.

A point-to-multipoint calling system in a cluster system, the system comprising: a source terminal and a destination terminal capable of communicating with a base station, and an application server connected to the base station through the core network, wherein:

The source terminal is configured to be established by using a base station, a core network, an IMS domain, and an application server. a call channel between the destination terminals; and the voice data is transmitted to the destination terminal through the call channel, the BM-SC, and the MBMS-GW;

The system according to claim 7, wherein the source terminal is further configured to: establish an RRC connection by sending an RRC connection request to the base station; and send a service request carrying the point-to-multipoint cluster call identifier to the base station, triggering The base station forwards the service request to the core network, and performs security authentication of the IMS domain at the same time; and establishes a radio bearer with the base station, and performs update of the bearer information by using the MME, the SGW, and the PDN-GW in the core network; The application server sends a session establishment request message; the receiving application server establishes a call channel with the destination terminal according to the call permission message fed back by the session establishment request message;

9. The system according to claim 7 or 8, wherein

The application server is further configured to forward the voice data to a PDN-GW in the core network, and trigger the PDN-GW to forward the voice data when determining that the bearer where the voice data is located is a point-to-multipoint type To the BM-SC; after the BM-SC is enabled to open the session through the MBMS-GW and the MME, the voice data is forwarded to the destination terminal through the MBMS-GW and the base station.

10. The system according to claim 9, wherein the application server is a push-to-talk over PoC-based cluster application server.