CN106332282A - A realization method of group call under hierarchical networking - Google Patents

Abstract

The invention discloses a method for realizing a group call in hierarchical networking. In the hierarchical networking, a cluster core network of each area is responsible for local cluster call scheduling business, and is also responsible for communicating with a superior core network system; and a superior cluster core network is responsible for the local cluster call scheduling business, and is also responsible for cluster call business control between a lower level core network and a lower level core network. A terminal initiates a group call establishment request, the core network to which the terminal belongs sends a group call establishment request to a master control server, and a group call uplink node sends a group call downlink establishment request to the current level or the lower level core network only when receiving group call uplink establishment success response returned by the master control server. By adoption of the scheme, the group call in the hierarchical networking can be realized.

Description

A realization method of group call under hierarchical networking

technical field

The present application relates to the field of mobile communication technology, in particular to trunking communication technology, and in particular to a method for implementing group calls under hierarchical networking.

Background technique

The trunking communication system is a dedicated wireless communication system developed to meet the command and dispatch needs of industry users and is oriented to specific industry applications. In the system, a large number of wireless users share a small number of wireless channels, and the command and dispatch business is the main application. It is a multi-purpose, high-efficiency wireless communication system that utilizes frequency resources. The trunking communication system has a wide range of application markets in the fields of government departments, public safety, emergency communications, electric power, civil aviation, petrochemical and military.

The TD-LTE-based broadband multimedia trunking system uses the fourth-generation mobile communication technology TD-LTE as the core technology, and combines the high speed and large bandwidth of TD-LTE with the resource sharing, fast call establishment, and command and dispatch of digital trunking technology. It is a new generation of broadband digital multimedia trunking system integrating voice, data and video.

In the actual construction process of the public safety network, it is often required to establish a network system according to the relationship between the superior and the subordinate. The network is networked according to the hierarchical relationship. On the one hand, it can ensure that the core networks of different levels of networks perform call switching and control through the upper-level core network. The entire system has high security and good controllability; on the other hand, different regions can gradually, Build the entire cluster network hierarchically. For example, the construction of a cluster communication network covering a certain province can be divided into three levels of networks: provincial, city, and county. First build the city-level network, then gradually establish and improve the county-level network, and finally realize the unified command and dispatch system for the interconnection of city and county networks in multiple regions of the province. The cluster scheduling business can not only be carried out within the same level, but also can communicate with cluster systems of other levels across levels. A certain area can build a public security broadband wireless multimedia trunking network in advance, and the internal trunking call switching control can be carried out independently. Compared with centralized deployment of multi-regional call control in a certain region, the reliability is higher. To sum up, there is an urgent need for hierarchical networking in actual network construction.

The trunking group call service is the most commonly used call service in the command and dispatch service of the trunking communication system. That is, multiple terminals form a group, and all group members share a downlink channel after the group call is established. The uplink channel is occupied by a group member who has obtained the right to speak, and other group members can receive the voice and/or video of the terminal of the right to speak. At the same time, other group members can also apply for the right to speak. When multi-regional cluster systems are interconnected, end users as group members can be distributed in different regions and belong to different regional cluster systems for management. When a group call is initiated, a dedicated and designated trunking system acts as the call service control center point of the group (ie, the group master control server) for the entire group call service to perform unified coordination on group call establishment, group call right allocation, group call Release etc. group call control process. Each group will designate a unique cluster core network as the group master server.

The existing broadband or narrowband trunking systems have not yet defined a network architecture for hierarchical networking. At present, China's narrowband digital trunking is mainly the Terrestrial Trunked Radio (TETRA) formulated by the European Communications Standards Association and the Professional Digital Trunking (PDT) standard promoted by the Ministry of Public Security of China, neither of which defines hierarchical networking Network architecture. The "Overall Technical Requirements for Broadband Trunking Communication (B-TrunC) System Based on LTE Technology (Phase 1)" issued by the Ministry of Industry and Information Technology of China in 2013 has not yet defined the network interconnection architecture for multi-regional networking. In 2014 The Ministry of Public Security of China issued the "Overall Technical Specifications for Public Security Broadband Wireless Multimedia Trunking System", although it defines the roaming architecture, it does not define the network architecture of hierarchical networking. In this specification, the network system architecture of the public security broadband wireless multimedia trunking system is proposed. System Architecture As shown in Figure 1, the network system is composed of terminals, base stations, cluster core network and cluster dispatching application platform. Among them, terminals include but not limited to multi-mode terminals, single-mode terminals, data terminals and vehicle-mounted terminals. Base stations include police Digital trunking base station (PDT Station) and T-eNB, T-eNB is the trunking system base station based on TD-LTE.Network elements in the trunking core network (TC) include: interconnection gateway (IGW), trunking control function module ( TCF), cluster media function module (TMF), evolved home subscriber server (eHSS), evolved core network gateway (eXGW), and evolved mobile management entity (eMME). The cluster scheduling application platform includes: dispatcher console (DC), Recording and video server (ReS), security encryption server (SeS), application server (ApS).

The meanings of each interface in Figure 1 are as follows:

PU - the interface between the terminal and the base station, this interface is an open interface;

PS——The interface between the base station and the cluster core network, this interface is an open interface;

PD——the interface between the cluster core network and the cluster scheduling application platform, which is an open interface;

PI - the interface between the cluster core network and the cluster core network, this interface is an open interface;

SGi——The interface between the cluster core network and the data service network. This interface should meet the requirements of 3GPP TS 23401.

PG——The interface between the cluster core network and the Internet gateway. This interface is not yet defined.

The interface between logical network elements of the cluster core network is shown in Figure 2, where,

Th - the interface between TCF and eHSS;

Mh—the interface between eMME and eHSS;

Tm—the interface between TCF and eMME;

Tt—the interface between TCF and TMF;

Tx - the interface between TMF and eXGW;

Mx - the interface between eMME and eXGW.

Note: For the definition of network element functions and interface protocol stack contained in the trunking dispatching application platform, please refer to the "General Technical Specifications for Public Security Broadband Wireless Multimedia Trunking System".

In addition, the group members are managed by core networks in different regions, and the group master server needs to know which core network management the group members belong to in some way, so that the group members can be paged when a group call is initiated. However, in existing systems, this method is mostly realized through static configuration in the system. Once the network structure changes, the related static configuration needs to be modified.

Moreover, cluster core networks in different regions under the hierarchical network are connected to each other as a network with a hierarchical relationship. The intercommunication of core network services at different levels must be exchanged and controlled through the upper-level core network. How to carry out group calling at this moment has no feasible realization method yet. In addition, after the group master server sends a group call establishment request to cluster core networks where different group members are located, communication links to multiple target cluster core networks will be established to transmit user plane media data. This causes the group master server to become the bottleneck of group call performance.

Contents of the invention

This application provides a method for implementing group calls under hierarchical networking, which can realize group calls under hierarchical networking.

The embodiment of the present application provides a method for implementing group calls under hierarchical networking. In the hierarchical networking, the trunking core network in each region is not only responsible for the trunking call scheduling service in the region, but also responsible for communicating with the upper-level core network system. To communicate. The upper-level trunking core network is not only responsible for the trunking call scheduling service in the local area, but also responsible for the trunking call service control with the lower-level core network and between the lower-level core networks; the method includes:

A. The group call calling terminal sends a group call establishment request to the nth level cluster core network to which it belongs;

B. After receiving the group call establishment request, the nth-level cluster core network judges whether it is a group master server, and if so, executes step D; otherwise, executes step C;

C. The nth level cluster core network sends a group call establishment request to the n+1st level cluster core network; let n=n+1, return to step B; wherein, the n+1st level cluster core network is located at the nth level cluster core the upper level of the network;

D. According to the pre-generated group member information and signaling routing information, the group master server sends a group call downlink to the n-1th level cluster core network to which each group member directly or indirectly belongs except the group call uplink intermediate node Establishment request; each cluster core network that receives the group call downlink establishment request acts as a transit node, and sends the group call downlink establishment request to the group members it directly manages, or to the next-level cluster core network that directly or indirectly manages the group members ;

E. The group members who receive the group call downlink establishment request return the group call downlink establishment success response to the cluster core network to which they directly belong; the cluster core network that receives the group call downlink establishment success response acts as a transit node, and the group call downlink establishment is successful The response is sent upstream to the group master server;

F. The group master control server sends a group call uplink establishment success response to the group call uplink intermediate node, and the group call uplink intermediate node sends a group call downlink establishment request to the cluster core network at the current level or a lower level; each group that receives the group call downlink establishment request The uplink intermediate node acts as a transit node, and sends the group call downlink establishment request to the group members it directly manages, or to the lower-level cluster core network that directly or indirectly manages the group members;

G. The group members who receive the group call downlink establishment request return the group call downlink establishment success response to the cluster core network to which they directly belong; the cluster core network that receives the group call downlink establishment success response acts as a transit node, and the group call downlink establishment is successful The response is sent uplink to the group call uplink intermediate node;

H. The group call uplink intermediate node sends a group call establishment success response to the group call calling terminal.

Preferably, the method further includes: in the uplink transmission link of the user plane media data from the core network of the group call calling party to the group master server, the servers at each level along the way are responsible for directly forwarding the user plane media data to other group call servers. The cluster core network where the called member is located does not need to be forwarded by the group master server.

Preferably, it is characterized in that, at the same time, the group master server and servers at all levels along the route only maintain one group call session.

Preferably, the method further includes: the user plane media data is forwarded step by step between layers; the group call uplink intermediate node is responsible for sending the group call user plane media data to the group members under its management and the group managed by the lower cluster core network. Members and the upper-level cluster core network; the group call downlink intermediate node forwards the user plane media data to the group members under its management and the group members managed by the lower-level cluster core network.

It can be seen from the above technical solutions that when a terminal initiates a group call in a hierarchical networking, the group call uplink intermediate node TCF sends the group call to the core network at the current level or the lower level only after receiving the group call uplink establishment success response returned by the group master control server. The call downlink establishment request ensures that the group master control server is the only control point for group call service control; all layers of core networks related to the group call register with the group master control server according to the group members after receiving the group call establishment success response The group member signaling routing information generated during the process initiates a group call establishment request to other group call called members. It prevents the group master control server from sending the group call establishment request to the core network nodes at each level again, and reduces the group call establishment time delay.

According to a preferred embodiment of the present application, the group master TCF and other level TCFs only maintain one group call session. Simple to implement and easy to handle;

According to a preferred embodiment of the present application, user plane media data is forwarded between layers step by step. The group call uplink intermediate node TCF is responsible for forwarding the user plane media data to the group members managed by it, the group members managed by the lower-level TCF, and the upper-level TCF. The group call downlink intermediate node TCF forwards the user plane media data to the group members managed by it and the group members managed by the lower TCF. The above method avoids the performance bottleneck problem caused by the group master server independently delivering to all layers of the core network; The servers at each level of the network are responsible for directly forwarding the user plane media data to the core network where other group members are located, which reduces the performance requirements for the user plane media data forwarding of the group master server.

Description of drawings

Figure 1 is a public security broadband wireless multimedia trunking system architecture diagram;

FIG. 2 is a schematic diagram of a logical network element interface of a cluster core network;

Figure 3 is a non-roaming two-level network architecture diagram of cities and counties under hierarchical networking;

Fig. 4 is a schematic diagram of a 3-level network model composed of multiple cluster core networks;

FIG. 5 is a schematic diagram of a group call processing flow in a hierarchical networking provided by an embodiment of the present application.

detailed description

The present application provides a method for implementing a group call under hierarchical networking. The basic design concept includes: a terminal initiates a group call establishment request, and its home core network sends a group call establishment request to the group master server. Whether the group call establishment is successful is determined by the group master server (group master TCF). The group call uplink intermediate node (in the user plane media data uplink transmission link from the core network of the group call party to the group master server, each TCF along the way, such as TCF1 and TCF2 in Figure 4) only receives the group master After the group call uplink establishment success response returned by the server, the group call downlink establishment request is sent to the core network at the current level or the lower level. A group master server can also have directly managed group members.

After receiving the group call establishment success response, all the core networks related to the group call initiate a group call establishment request to other group call called members according to the group member signaling routing information generated in the previous group registration process. Only one group call session is maintained between the group master TCF and its directly lower-level TCF. The user plane data is forwarded level by level between levels, and the intermediate node TCF is responsible for sending the downlink user plane media data of the group call to the group members managed by it, the group members managed by the lower level TCF, and the upper level TCF. In the uplink transmission link of user plane media data from the core network of the calling party of the group call to the group master server, the servers at all levels along the way are responsible for directly forwarding the media data of the user plane to the core network of other group call members. The master server forwards.

In order to make the technical principles, features and technical effects of the technical solution of the present application clearer, the technical solution of the present application will be described in detail below in conjunction with specific embodiments.

The core of hierarchical networking is that cluster core networks in different regions are connected to each other as a network of upper and lower levels, which is mainly reflected in:

The trunking core network in each region is not only responsible for the trunking call scheduling service in the region, but also responsible for intercommunication with the upper-level core network system.

The upper-level trunking core network is not only responsible for the trunking call scheduling service in the local area, but also responsible for the trunking call service control with the lower-level core network and between the lower-level core networks.

In the hierarchical networking, the multi-region cluster core network is interconnected through the PI3 interface in the "Overall Technical Specifications for Public Security Broadband Wireless Multimedia Cluster System". The PI3 interface is an interface between different TCFs and between different TMFs. Figure 3 shows the basic city-county two-level network architecture. City C in Figure 3 contains two counties A and B. The whole trunking communication system has three sets of TD-LTE broadband multimedia trunking systems in C city, A county and B county respectively. Each network includes an independent cluster core network and application platform. The network of each region in Fig. 3 omits the base station and terminal part. Each network system independently manages the subscription data of its directly subordinate users and groups, and the basic cluster scheduling service across the core network is completed through the PI3 interface between the core networks. The core network of city C logically serves as the parent node, and the core networks of counties A and B serve as child nodes. The relationship between parent and child nodes is set through static configuration in their respective core networks. That is, the core network of the child node is configured with the only IP and port number provided by the core network of the parent node. The parent node core network configures the IP and port numbers of all child node core network services. Counties A and B are parallel cluster scheduling systems, and cannot directly perform cluster scheduling services with each other. The cluster scheduling system in city C is connected to the core networks of counties A and B through the PI3 interface. It is not only responsible for the scheduling business between cluster terminals directly under the municipality, but also for the traffic between A and B counties or between C city and A and B counties. The cluster terminal dispatches services.

The technical goals to be achieved by group members registering with the group master server include:

The group master server dynamically knows which level the group members are in for core network management;

The group master server dynamically obtains the routing information of the call signaling sent to the core network path where the group members are located;

During this process, corresponding group member information and signaling routing information are dynamically generated in all cluster core networks passing through from the cluster core network of the management group member to the group master control server.

Fig. 4 shows a three-level network model composed of multiple cluster core networks (TCF). The cluster terminals belong to the management of TCF1-TCF4 respectively. TCF1-TCF4 and group master TCF5 are deployed in a hierarchical network. TCF1 and TCF6 are child nodes of TCF2, TCF4 is a child node of TCF3, and TCF2 and TCF3 are child nodes of TCF5. The group members of the group whose group number is GDN1 include UE1-UE5, wherein UE1 and UE5 are managed by TCF1, UE2 is managed by TCF2, UE3 and UE4 are managed by TCF4, and UE5 is managed by TCF6. TCF5 acts as the group master server for the group.

After UE1 registers with TCF1, TCF1 sends a SIP (MESSAGE) registration request message to the upper group master server. The description of the registration process of other terminals UE2-UE5 is omitted. For the specific implementation process of group member registration and de-registration, please refer to another application "A Method for Group Members to Register with the Group Master Server in Hierarchical Networking" by the applicant, and will not be repeated here.

TCF1 is the home TCF1 of the group call originator UE1. The group master server sends the group call establishment request to other group members. The group call establishment request sent to the group master server (group call uplink establishment request) is marked with a thick line, and the call establishment request sent to other group members (group call downlink establishment request) is marked with a thin line.

Figure 5 shows the group call processing flow under the hierarchical networking provided by the embodiment of the present application, including the following steps:

Step 501: The group call calling terminal UE1 sends a group call uplink establishment request to TCF1.

Step 502: TCF1 judges whether it is the group master server, if the judgment result is no, it sends a group call uplink establishment request to the superior TCF2. TCF2 returns a SIP (100 Trying) response.

Step 503: After receiving the group call uplink setup request, TCF2 sends an INVITE request to the superior TCF5. TCF5 returns a SIP (100Trying) response.

Step 504: After receiving the group call uplink setup request, the group master TCF5 sends a SIP (INVITE) group call downlink setup request to TCF3. TCF3 returns a SIP (100Trying) response.

Step 505: TCF3 sends an INVITE to TCF4 to make a group call downlink establishment request. TCF4 returns a SIP (100Trying) response.

Step 506: TCF4 sends the group call downlink establishment request to the terminal it belongs to manage. Since this process is defined in the internal implementation of the network element, the description is omitted here. TCF4 then returns a SIP (200OK) response to TCF3. TCF3 sends SIP (ACK) to TCF4.

Step 507: Since there is no group member under TCF3, directly return SIP (200 OK) to group master TCF5;

Step 508: After receiving the group call downlink establishment success response, the group master control TCF5 returns a group call uplink establishment success response SIP (200 OK) to the signaling routing node TCF2 of the group call calling party. TCF5 sends SIP (ACK) to TCF3.

Step 509: TCF2 sends a SIP (ACK) message to TCF5 after receiving the group call uplink establishment success response. At the same time, initiate a group call establishment request to the group members. Since this process is defined within the network element, the description is omitted here.

Step 510: Since UE6 is managed under TCF6, TCF2 initiates a group call downlink establishment request SIP (INVITE) to TCF6 according to the call signaling routing information generated in the previous group master server registration process. TCF6 sends a group call establishment request to the terminal under its management, and after TCF6 returns SIP (200 OK) to TCF2, TCF2 sends a SIP (ACK) message to TCF6.

Step 511: TCF2 returns a group call uplink establishment success response SIP (200 OK) to TCF1. TCF1 sends SIP (ACK) to TCF2.

Step 512: TCF1 sends a group call establishment success response to UE1, and UE1 returns a group call establishment success confirmation to TCF1.

The embodiment of this application provides the process of processing media data on the user plane of a group call in a hierarchical network as follows:

The user plane data is forwarded level by level between levels. The group call uplink intermediate node TCF is responsible for sending the group call downlink user plane media data to the group members under its management, the group members managed by the lower level TCF, and the upper level TCF; In the uplink transmission link of the user plane media data from the caller core network to the group master server, the servers at all levels along the way are responsible for directly forwarding the user plane media data to the core network of other group call called members, without forwarding by the group master server . The group call downlink intermediate node (the path for sending messages from the group master control server is the downlink path, and each TCF passing through the downlink path is the group call downlink intermediate node) forwards the user plane media data to the group members and subordinates under its management. Group members managed by TCF.

This application provides a group call implementation method under hierarchical networking, which can achieve the following technical effects:

When a terminal initiates a group call in a hierarchical networking, the group call uplink intermediate node TCF sends a group call downlink establishment request to the core network at the current level or lower level only after receiving the group call uplink establishment success response returned by the group master control server, ensuring that the group call The main control server is the only control point for group call service control;

After receiving the group call establishment success response, all layers of core networks related to the group call initiate group calls to other group call called members according to the group member signaling routing information generated when the group members register with the group master server. Create a request. It prevents the group master control server from sending the group call establishment request to the core network nodes at each level again, reducing the group call establishment delay;

The group master TCF and other level TCFs maintain only one group call session. Simple to implement and easy to handle;

User plane media data is forwarded step by step between layers. The group call uplink intermediate node TCF is responsible for forwarding the user plane media data to the group members managed by it, the group members managed by the lower-level TCF, and the upper-level TCF. The group call downlink intermediate node TCF forwards the user plane media data to the group members managed by it and the group members managed by the lower TCF. The above method avoids the performance bottleneck problem caused by the group master server independently delivering to all layers of the core network;

In the uplink transmission link of user plane media data from the core network of the calling party of the group call to the group master server, the servers at all levels along the way are responsible for directly forwarding the user plane media data to the core network of other group members, reducing the burden on the group master. The performance requirements of media data forwarding on the user plane of the control server.

The above descriptions are only preferred embodiments of the application, and are not intended to limit the scope of protection of the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the technical solutions of the application are It should be included within the protection scope of this application.

Claims (4)

1. an implementation method for the group call that rank groups is off the net, in described classification networking, the cluster core in each area This area trunked call scheduling business had both been responsible for by heart net, also was responsible for carrying out intercommunication with upper core net system；Higher level's cluster Core net had both been responsible for this area trunked call scheduling business, also was responsible between subordinate's core net and subordinate's core net Trunked call service controls；It is characterized in that, the method includes:

A, group exhale calling terminal transmission group to exhale foundation request to its affiliated n-th grade of cluster core net；

B, n-th grade of cluster core net receive after group exhales foundation request, it is judged that whether self is group main control server, If so, step D is performed；Otherwise, step C is performed；

C, n-th grade of cluster core net transmission group exhale foundation request to (n+1)th grade of cluster core net；Make n=n+1, return Step B；Wherein, (n+1)th grade of cluster core net is positioned at the upper level of n-th grade of cluster core net；

D, group main control server, according to the group membership's information previously generated and the information of signalling route, are exhaled to except group (n-1)th grade of cluster core net transmission group that each group membership outside up intermediate node directly or indirectly belongs to is exhaled descending Set up request；Receiving group exhales descending each cluster core net of request of setting up as transit node, and group is exhaled descending building Vertical request sends the group membership directly managed to it, or sends to the next stage cluster directly or indirectly managing group membership Core net；

E, receive group and exhale the descending group membership setting up request to exhale descending foundation to cluster core net return group of its direct ownership Success response；Receiving group exhales the descending cluster core net of response that is successfully established as transit node, and group is exhaled descending foundation The up transmission of success response is to organizing main control server；

F, group main control server send group call uplink to group call uplink intermediate node and are successfully established response, in the middle of group call uplink Node exhales descending foundation to ask to this level or subordinate's cluster core net transmission group；Receive group and exhale each of descending foundation request Group, as transit node, is exhaled the descending request of setting up to send the group membership directly managed to it by individual group call uplink intermediate node, Or send to the next stage cluster core net directly or indirectly managing group membership；

G, receive group and exhale the descending group membership setting up request to exhale descending building to cluster core net return group of its direct ownership Vertical success response；Receiving group exhales the descending cluster core net of response that is successfully established as transit node, and group is exhaled descending building The vertical up transmission of success response is to group call uplink intermediate node；

H, group call uplink intermediate node are exhaled calling terminal transmission group to exhale to group and are successfully established response.

Method the most according to claim 1, it is characterised in that the method farther includes: exhale calling party from group Core net to group main control server user face media data uplink link in, each level server on the way be responsible for User face media data is forwarded directly to other groups and exhales called member place cluster core net, it is not necessary to group main control server Forward.

Method the most according to claim 2, it is characterised in that at synchronization, group main control server and on the way Each level server only safeguards that a group exhales dialogue.

Method the most according to claim 1, it is characterised in that the method farther includes: user face media number Forward step by step according between level；Group call uplink intermediate node is responsible for group is exhaled user face media data be sent to belong to it The group membership of management, the group membership of subordinate's cluster core net management and higher level's cluster core net；Group exhales descending middle node User face media data is forwarded to belong to the group membership of its management, the group membership of subordinate's cluster core net management by point.