CN1960525B - A session control method and system for multi-party communication services - Google Patents

Abstract

The present invention discloses a session control method for multi-party communication services, which is applied to a system including: user equipment UE, participation function entity PF and control function entity CF. The method includes: A. During session establishment, PF is established by itself Each UE participating in the current session under its jurisdiction establishes a sub-session and sends sub-session information to the CF of the current session; B. During the media stream transmission process, the CF distributes the media stream to the PF where each sub-session is located, and then each PF sends the The received media stream is distributed to each UE corresponding to the sub-session established by itself. The invention also discloses a system, which can reduce media redundant transmission by applying the method and the system of the invention.

Description

A session control method and system for multi-party communication services

technical field

The invention relates to a technology for realizing multi-party communication services, in particular to a session control method and system for multi-party communication services.

Background technique

At present, in the communication system, various services participated by individual users or collective users have been realized, and the specific communication methods include: text, voice, video, and multimedia combination, etc. General communication services are mainly oriented to individual users, and usually only one or two user equipments (UEs) perform communication. In the communication service in which collective users participate, there are usually one or more groups of users communicating at the same time, that is to say, the communication process is not a two-party communication consisting of a calling party user and a called party user as is usually seen. There may be multiple calling party users and multiple called party users communicating, and the service in which such collective users participate is also called multi-party communication service.

In a multi-party communication service session, each communication party user UE accesses the session centralized processing server through its own access server, and the session centralized processing server centrally controls the session signaling process, and is responsible for granting each communication party the media sending right, For copying and distribution in media transmission, etc. Currently, mainstream multi-party communication services include: push-to-talk (PoC) services and conference (Conference) services in cellular systems. In the PoC service and the Conference service, the session centralized processing server is called a control function (CF, Controlling function) entity, and the access server is called a participating function (Participating function) entity, and the so-called CF and PF are in the PoC In business, it refers to controlling PoC server (Controlling PoC Server) and participating PoC server (Participating PoC Server), and in conference business, it refers to controlling Conference server (Controlling Conference Server) and participating Conference server (Participating Conference Server).

FIG. 1 is a schematic diagram of the logical relationship between processing entities in the existing session control. As shown in FIG. 1 , there are four user terminals participating in the session: UE1, UE2, UE3 and UE4. Among them, UE1 and UE2 access the session through PF1, UE3 and UE4 access the session through PF2, and the CF is responsible for centrally controlling the session and connecting PF1 and PF2. When the UE requests the PF to which it belongs to establish a session, the PF will create a user instance for the UE to process session signaling and media, such as: in Figure 1, the instance of UE1 and the instance of UE2 established by PF1, and the instance of UE3 established by PF2 An instance of and an instance of UE4. At the same time, the CF also needs to uniformly establish a session instance for the current session to centrally control the signaling and media of the current session. Here, a class for performing functional processing on UE is pre-packaged in PF. When PF wants to perform functional processing on a certain UE, it will create an object instance of this class. This article refers to the object instance for UE as user instance; The reason is that CF also pre-encapsulates a class for centralized processing of the entire session. When CF wants to establish a session, it will create an object instance of this class. In this paper, the object instance for the entire session is called a session instance. Creating an instance is a well-known software concept for those skilled in the art, therefore, the concept of an instance will not be described in detail herein.

When the session instance in CF wants to distribute media to each UE in the current session, it is aimed at the user instance of each UE, that is to say: the media data will be copied and distributed to the instance of UE1 and the instance of UE2 in PF1 by the session instance , the instance of UE3 and the instance of UE4 in PF2. In this way, a media redundant transmission will be generated between PF1 and CF, and between PF2 and CF. It can be seen that for each session media transmission, CF and PF1 and There will be two redundant transmissions between PF2. Figure 1 shows a very small session example with only four UEs participating. In actual multi-party communication service sessions such as PoC, the number of participating UEs can usually reach dozens and the PFs to which each UE belongs will be more than two as shown in Figure 1, so the amount of media redundancy transmission generated will be very considerable.

Therefore, the existing session control method for multi-party communication services will waste a large amount of system processing resources, making it difficult to ensure the quality of multi-party communication services, and it is also not conducive to the realization of large-scale service networks, hindering the further expansion of multi-party communication services.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a session control method and system for multi-party communication services, which can reduce redundant transmission of session media and improve system resource utilization.

In order to achieve the above object, technical solution of the present invention is achieved in that way:

The invention discloses a session control method of a multi-party communication service, which is applied to a system including: a UE, a participation function entity (PF) and a control function entity (CF), and the method includes:

A. During the session establishment process, at least one PF of the current session establishes its own sub-session instance, and sends sub-session instance information to the CF of the current session, wherein the sub-session instance established by the PF and the participating current session under its control At least one UE of the session is associated; the CF associates the at least one sub-session instance established by the at least one PF with the session instance of the current session according to the received sub-session instance information;

B. During the media stream transmission process, the CF copies the media stream according to the number of sub-session instances associated with the session instance, and distributes the media stream to the PF where each sub-session instance is located according to the received information of each sub-session instance , each PF distributes the received media stream to at least one UE associated with the sub-session instance established by itself.

Wherein, in the step A,

Each PF in the at least one PF performs the following steps after receiving the session establishment request from the calling UE or CF:

A1. Create a sub-session instance for the current session,

A2. Associating the calling UE or the called UE of the session establishment request call with the established sub-session instance, and sending the established sub-session instance information to the CF of the current session;

After receiving the sub-session instance information from the PF, the CF establishes a session instance for the current session, and associates the established session instance with the at least one sub-session instance according to the received sub-session instance information.

Wherein, before the step A1, it further includes: establishing a user instance for the calling UE or the called UE calling for the session establishment request;

In step A2, the method for associating the calling UE or the called UE with the sub-session instance is associating the established user instance of the calling UE or the called UE with the sub-session instance.

In the step B, each PF copies the received media stream according to the number of user instances associated with the sub-session instances established by itself, and distributes the received media streams to UEs corresponding to each user instance through the user instances.

Wherein, before the step A1, it further includes: judging whether a sub-session instance has been established for the current session, and if so, performing step A2; otherwise, performing step A1.

Wherein, after the CF receives the sub-session instance information from the PF, it further includes: judging whether a session instance has been established for the current session, and if so, associating the established session instance with the received sub-session instance; otherwise, the current A session establishes a session instance and associates the established session instance with the received sub-session instance.

Wherein, when the media stream delivered by the current session includes more than one media type; in step B, more than one sub-session instance is established for the current session, and each sub-session instance corresponds to a media type; in step C, the The user instance is associated with each established sub-session instance; when the CF distributes the media stream, the method of distributing the media stream to each PF is: for each sub-session instance associated with the currently established session instance, send The media stream of the media type corresponding to the sub-session instance is sent to the PF where the sub-session instance is located; when the PF receives the media stream, the method of distributing the media stream to each UE is: for each currently established sub-session Instance, send the media stream of the media type corresponding to the sub-session instance to each UE corresponding to each user instance associated with the sub-session instance.

Wherein, the more than one media type includes: voice (Vioce), or video (Video), or message (Message), or data (Data), or any combination of these four.

In step C, the method for sending the sub-session instance information to the CF is: after the established sub-session instance is associated with the calling UE, send the sub-session instance information to the CF through a session establishment request; when the established sub-session instance After being associated with the called UE, the session establishment request response returned to the CF is sent to the CF.

Wherein, the sub-session instance information includes: a sub-session identifier, address information, information of each user instance associated with the sub-session instance, and capability information of the sub-session instance.

Wherein, the session establishment request received by the PF from the CF is: a session establishment request for one or more called UEs.

Wherein, when the method is applied to a push-to-talk (PoC) service system in a cellular system, the PF is a Participating PoC server, and the CF is a Controlling PoC server; when the method is applied to a Confernce service system, the PF is a Participating Conference server, the CF is a Controlling Conference server.

The invention also discloses a session control system for multi-party communication services. The system includes: more than one sub-session processing unit, and a session processing unit connected to each sub-session processing unit;

The sub-session processing unit is configured to establish a sub-session instance for each UE participating in the current session under the jurisdiction of the PF connected to itself and send sub-session instance information to the session processing unit connected to itself, receive the media stream from the session processing unit and pass The PF is distributed to each UE corresponding to the currently established sub-session instance;

The session processing unit is configured to receive information of each sub-session instance from the sub-session processing unit, and connect at least one sub-session instance established by the session processing unit with the session of the current session according to the received sub-session instance information The instances are associated, the media stream is received from the CF, the media stream is copied according to the number of sub-session instances associated with the session instance, and the media stream is distributed to the sub-session processing unit where each sub-session instance is located.

Wherein, each sub-session processing unit includes: a user module and a sub-session module; the user module is used to establish a user instance for each UE participating in the current session under the jurisdiction of the PF connected to itself, and send each user instance information to the sub-session A module that receives the media stream from the sub-session module and distributes it to the UE corresponding to each user instance through the PF;

The sub-session module is configured to receive user instance information from the user module, establish a sub-session instance of the current session, associate each user instance with the sub-session instance, and send the sub-session instance information to the session processing unit , receiving the media stream from the session processing unit and sending it to the user module where each user instance associated with the sub-session established by itself resides.

Wherein, the sub-session processing unit is an entity implemented independently or integrated in the PF, and the session processing unit is an entity implemented independently or integrated in the CF.

Wherein, when the system is applied to the PoC business system, the PF is the Participating PoC server, and the CF is the Controlling PoC server; when the system is applied to the Confernce business system, the PF is the Participating Conference server, and the CF is the ControllingConference server .

As can be seen from the above scheme, the key of the present invention is that in the session establishment process, each PF establishes a sub-session for each UE under its jurisdiction and participates in the current session, and sends sub-session information to the CF of the current session, and the CF will Each received sub-session is associated with the current session. During the media transmission process, the CF distributes the media stream to the PFs where the sub-sessions associated with the current session are located, and each PF distributes the received media streams to the UEs corresponding to the sub-sessions established by itself.

Therefore, the session control method and system of the multi-party communication service provided by the present invention can reduce the media redundant transmission between PF and CF during the session process, is an optimization scheme for the media transmission mechanism of the multi-party communication service, and can significantly improve the media transmission efficiency , thereby ensuring service quality.

Description of drawings

FIG. 1 is a schematic diagram of the logical relationship between processing entities in the existing session control;

Fig. 2 is a schematic diagram of the processing flow of a preferred embodiment of the session establishment process in the method of the present invention;

Fig. 3 is a schematic diagram of the processing flow of a preferred embodiment of the media sending process in the method of the present invention;

Fig. 4 is a schematic diagram of the composition and structure of a preferred embodiment of the system of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The invention discloses a session control method for a multi-party communication service, which is applied to a system including: a UE, a participating function entity (PF) and a control function entity (CF). The main processing idea is: in the session establishment process, the PF is Each UE under its jurisdiction that participates in the current session establishes a sub-session and sends sub-session information to the CF of the current session; in this way, during the media stream transmission process, the CF distributes the media stream to each sub-session according to the received sub-session information Each PF distributes the received media stream to each UE participating in the session, so as to reduce redundant media transmission between the CF and the PF. Among them, each CF may serve as a centralized processing server for multiple sessions, so each time a CF establishes a session, it needs to further associate each sub-session with the current session after receiving the information of each sub-session, so that each session in the CF Associate each sub-session corresponding to itself, and when transmitting media, the CF distributes the received media stream to the PF where each sub-session associated with the current session resides.

Based on the above-mentioned processing idea, in the actual implementation, the various functional attributes of the sub-session are usually encapsulated into a class in advance, and then the sub-session is established by creating an object instance of this class, that is, the sub-session instance described in this article, and the PF is passed to The sub-session information of the CF is also the information of the created sub-session instance. In this way, the processing of the method of the present invention specifically includes: after the PF receives the session establishment request from the calling UE or CF, it needs to establish a sub-session instance for the current session, and then sends the calling UE or each called UE called by the session establishment request Associate with the established sub-session instance, and send the established sub-session instance information to the CF of the current session; after receiving the sub-session instance information from the PF, the CF establishes a session instance for the current session, and associates the established session instances and received sub-session instances; when CF distributes media streams, it copies the media streams according to the number of sub-session instances associated with the current session instance and distributes them to the PF where each sub-session instance associated with the session instance is located, and each The PF copies the received media stream according to the number of UEs associated with the sub-session instance established by the PF and distributes it to each UE associated with the sub-session instance. In this manner, each sub-session instance established by the PF will contain the specific user information of each UE associated with the sub-session instance, so that the distribution of media streams to each UE can be realized.

In addition, the method of the present invention proposes another implementation mode on the basis of the implementation mode described in the preceding paragraph, that is: after the PF receives the session establishment request from the calling UE or CF, it further establishes a session for the calling UE or the session. Request the called UE to establish a user instance; then associate the established user instance of the calling UE or called UE with the sub-session instance established by itself. The number of user instances associated with each PF according to the sub-session instance established by itself Copy the received media stream and distribute it to the UE corresponding to each user instance through the user instance. In this way, the specific user information of each UE is maintained by the respective user instance, so that the user information and the sub-session instance are independent, so that in the same On the PF, the user instance is related to the UE, and the sub-session instance is related to the current session. A user instance of a UE may be associated with the sub-session instances of multiple sessions that the UE participates in. The specific processing principles of the embodiments described in this paragraph It will also be elaborated in the following paragraphs in conjunction with the accompanying drawings, and will not be further detailed here.

Among them, when the PF establishes a user instance for the calling UE or the called UE, the PF may have established a sub-session instance for the current session. The instance can be associated with the established sub-session instance. Similarly, when CF receives a sub-session instance from PF, it may have established a session instance for the current session. The session instance can be associated.

In addition, there are many specific application scenarios in which the PF receives the session establishment request from the calling UE or CF, mainly including: 1. The calling UE sends a session establishment request indicating to initiate a group session to the PF, and the session establishment request will carry Information about other multiple called UEs in the current group; 2. The calling UE sends a session establishment request indicating to join the currently established group session to the PF, and the session establishment request does not carry the information of the called UE; 3. Since the CF sends a session establishment request to the PF to which the called UE belongs after receiving the session establishment request from the calling UE, the session establishment request from the CF will carry the information of the called UE, and the PF will follow the information of the called UE. information to initiate a call to the called UE.

Taking the calling UE as an example to initiate the session establishment process to each called UE through the PF to which it belongs, the CF of the current session, and the PF to which the called UE belongs, the session establishment process in the method of the present invention will be described in detail in conjunction with FIG. 2 .

Fig. 2 is a schematic diagram of the processing flow of a preferred embodiment of the session establishment process in the method of the present invention. In this embodiment, the processing entities include: PF1 to which the calling UE belongs, CF of the current session, and PF2 to which the called UE belongs. As shown in Figure 2, the specific processing steps include:

Step 201: PF1 to which the calling UE belongs receives a session establishment request from the calling UE, and the request carries: information of the calling UE, group identifier of the current session, information of each called UE, and the like.

Step 202: PF1 described in step 201 creates a user instance for the calling UE, and judges: whether a sub-session instance has been established for the current session, and if so, associate the currently established user instance with the established sub-session instance; otherwise Create a sub-session instance of the current session, and then associate the sub-session instance with the currently established user instance. Here, the sub-session instance is used to communicate with the session instance on behalf of each user instance associated with it. Therefore, the class used for centralized communication with the session instance on behalf of each user instance associated with it can be pre-encapsulated in . After the instance is created, an object instance of this class can be created, which is referred to as a sub-session instance herein.

For multi-party communication services, each service session is based on a group identifier, and for each group, logically, there is a logical division of PF and CF for the service server. Therefore, each sub-session instance established by PF will correspond to the corresponding session group ID, so PF can determine whether there is currently a sub-session instance corresponding to the group ID according to the group ID in the current session establishment request. , it means that a sub-session instance has been established for the current session; otherwise, it means that a sub-session instance of the current session has not been established.

Step 203: The PF1 sends the information of the currently established sub-session instance to the CF of the current session. Since, during the session establishment process, PF1 also sends a session establishment request to the CF, a preferred method is adopted in this embodiment Send the sub-session instance information in the same way: carry the sub-session instance information in the session establishment request and send it to CF.

Wherein, the information of the sub-session instance includes: a sub-session identifier, address information, information of each user instance currently associated with the sub-session, capability information of the sub-session instance, and the like. Here, PF and CF are actually logical functional entities. In practical applications, for the same session, its PF and CF may be integrated in the same or different service servers. Therefore, the sub-session identifier can be identified by PF1 It is composed of the unique identifier in the integrated service server and the identifier of the service server. The address information may consist of an IP address and a port number; the sub-session instance capability information may be: after matching the UE capability information and user subscription data carried in the session establishment request of the calling UE with the capabilities provided by PF1 The obtained information may be used to indicate attribute information such as the media type supported by the sub-session instance.

Step 204: CF receives the sub-session instance information from PF1, determines that the session group corresponding to the sub-session instance is the corresponding service session, and judges whether a session instance has been established for the service session corresponding to the sub-session instance, if yes , associate the currently received sub-session instance with the established session instance; otherwise, establish the session instance of the current session, and then associate the received sub-session instance with the currently established session instance. Here, the CF needs to extract the sub-session instance information from the session establishment request from PF1.

Step 205: The CF analyzes the information of each called UE in the received session establishment request, and sends a session establishment request to the PF to which each called UE belongs, and the request carries the information of the called UE. It is set here that: the PF to which the called UE belongs is PF2.

After adopting the method of the present invention, the communication between the PF and the CF can be carried out in units of sub-session instances instead of communicating with each user instance, so the session establishment request sent in this step can be as follows: send a request for each called UE The session establishment request follows the existing technical mechanism; or, sends one or more session establishment requests to each PF of each PF to which each called UE belongs, and each session establishment request corresponds to multiple called UEs.

Here, there may be multiple PFs to which each called UE belongs, and the CF will at least send a session establishment request to the PF to which each called UE belongs. Figure 2 does not show the PF to which each called UE belongs, but for The processing of each PF is the same as that shown in step 205 to step 208, which will not be described in detail here, but are within the protection scope of the present invention.

Step 206: PF2 to which the called UE belongs creates a user instance for each called UE according to the information of each called UE in the received session establishment request, and judges whether a sub-session instance has been established for the current session, and if so, then Associate the currently established user instance with the established sub-session instance; otherwise, establish a sub-session instance of the current session, and then associate the sub-session instance with the currently established user instance. Here, the specific judging method is the same as that of step 202, and will not be described in detail herein.

Step 207: the PF2 sends the information of the currently established sub-session instance to the CF of the current session. Since, during the session establishment process, PF2 also returns a session establishment request response to CF, so in this embodiment, a better way is adopted to send the sub-session instance information: carry the sub-session instance information in the session establishment request response sent to CF.

Step 208: CF receives the sub-session instance information from PF2, determines that the session group corresponding to the sub-session instance is the corresponding service session, and judges whether a session instance has been established for the service session corresponding to the sub-session instance, if yes , associate the currently received sub-session instance with the established session instance; otherwise, establish the session instance of the current session, and then associate the received sub-session instance with the currently established session instance. Here, the CF needs to extract the sub-session instance information from the session establishment request response from PF2.

Although it is necessary to judge whether a session instance has been established in this step, since the judgment has been made in step 204, and the session instance of the current business session must have been established in step 204, the judgment result of this step must also be Yes, CF directly associates the received sub-session instance with the established session instance.

Using a process similar to that shown in Figure 2, it is also possible to implement the above-mentioned implementation mode in which PF only establishes sub-session instances. The sub-session instance needs to further maintain the specific user information of each associated UE. Since the processing principles and processes of the two implementations of the present invention are similar, this article will not describe in detail the way in which the PF only establishes sub-session instances, but both are within the protection scope of the present invention.

So far, the sub-session instances of the current service session have been established in PF1 and PF2, and the session instances of the current service session have been established in CF. Each sub-session instance is associated with the session instance, and the media stream transmission between PF and CF will be in the form of The sub-session instance is performed in units, so that redundant media transmission between the PF and the CF can be basically avoided.

Fig. 3 is a schematic diagram of a processing flow of a preferred embodiment of the media sending process in the method of the present invention. As shown in Figure 3, PF1 is connected to UE1 and UE2, and PF2 is connected to UE3 and UE4. The user instances established in PF1 include: an instance of UE1 and an instance of UE2, and the instance of UE1 and UE2 are related to the sub-session instance established by PF1 The user instance established in PF2 includes: an instance of UE3 and an instance of UE4, and the instance of UE3 and the instance of UE4 are associated with the sub-session instance established by PF2. A session instance of the current service session is established in the CF, and the session instance is associated with the sub-session instance of PF1 and the sub-session instance of PF2. When the CF distributes the media stream, the session instance distributes the media stream to the PF1 and PF2 where the sub-session instance of PF1 associated with the session instance and the sub-session instance of FP2 are located. When PF1 receives the media stream, the instance of UE1 and the instance of UE2 associated with the sub-session instance of PF1 distribute the media stream to UE1 and UE2 corresponding to the instance of UE1 and the instance of UE2. When PF2 receives the media stream, the instance of UE3 and the instance of UE4 associated with the sub-session instance of PF2 distribute the media stream to UE3 and UE4 corresponding to the instance of UE3 and the instance of UE4. It can be seen that, after adopting the method of the present invention, redundant media transmission between PF and CF can be eliminated, and accurate distribution of media streams to each UE can be ensured.

In the embodiments shown in Fig. 2 and Fig. 3, the PF only establishes one sub-session instance for one service session. However, for a business session involving multimedia types, the media stream it transmits includes more than one media type. At this time, the PF can establish a sub-session instance for each media type. Specifically: in steps 202 and 206, more than one sub-session instance is established for the current business session, each sub-session instance corresponds to a media type, and then each established user instance is connected to each established sub-session instance. The session instances are associated; when the CF distributes the media stream, the CF sends the media stream of the media type corresponding to the sub-session instance to the PF where the sub-session instance is located for each sub-session instance associated with the currently established session instance; when the PF When receiving the media stream, the PF sends the media stream of the media type corresponding to the sub-session instance to each UE corresponding to each user instance associated with the sub-session instance for each currently established sub-session instance. Here, the more than one media type includes: voice (Vioce), or video (Video), or message (Message), or data (Data), or any combination of these four.

Based on the processing of the above method of the present invention, the present invention also proposes a session control system for multi-party communication services, which includes: more than one sub-session processing unit, and session units connected to each sub-session processing unit; each sub-session processing The unit is used to establish a sub-session for each UE participating in the current session under the jurisdiction of the PF connected to itself, and send the information of the sub-session to the session processing unit connected to itself, receive the media stream from the session processing unit and distribute it to the current session through the PF Each UE corresponding to the establishment of a sub-session; a session processing unit, configured to receive sub-session information from each sub-session processing unit, receive a media stream from a CF, and distribute the media stream to the sub-session processing unit where each sub-session is located.

Wherein, each sub-session processing unit may also include: a user module and a sub-session module. The user module is used to establish user information for each UE participating in the current session under the jurisdiction of the PF connected to itself, and send each user information to the sub-session module , receive the media stream from the sub-session module and distribute it to the UE corresponding to each user information through the PF. The sub-session module is used to receive the user information from the user module, establish a sub-session of the current session, and send the received The information is associated with the sub-session, and sends the sub-session information to the session processing unit, receives the media stream from the session processing unit and sends it to the user module where the user information associated with the sub-session established by itself is located. Here, the user information is equivalent to The specific user information maintained by the user instance described in the previous method includes: user ID, UE address information, UE media capability, subscription information, etc.

Fig. 4 is a schematic diagram of the composition and structure of a preferred embodiment of the system of the present invention. As shown in Fig. 4, the system includes: n sub-session processing units and a session processing unit. The n sub-session processing units are respectively denoted as sub-session processing unit 1, . . . , sub-session processing unit n. Each sub-session processing unit comprises user module and sub-session module, as shown in Figure 4, sub-session processing unit 1 comprises user module 1 and sub-session module 1,..., sub-session processing unit n comprises user module n and sub-session session module n.

Among them, each user module is used to receive a session establishment request from the PF, establish a user instance for the calling UE or called UE corresponding to the session establishment request, and send the information of each established user instance to its own connected Subsession module. Here, the session establishment request should be sent from the calling UE or CF to the PF, and the PF will forward the session establishment request to the user module. Each sub-session module is used to establish a sub-session instance and associate it with each received user instance, and send the information of the established sub-session instance to the session processing unit connected to itself. The session processing unit is used to establish a session instance for the current service session, and associate each received sub-session instance with the session instance established by itself. When the CF distributes the media stream, the CF forwards the media stream to the session processing unit, and the session processing unit copies the media stream according to the number of sub-session instances associated with the current session instance and distributes the media stream to each sub-session instance where each sub-session instance associated with the current session instance is located. Session module, each sub-session module copies the media stream according to the number of user instances associated with the sub-session instance through the sub-session instance created by itself and distributes it to the user module connected to itself, and then the user module passes the received media stream through Each user instance sends to the PF connected to itself, and the PF finally sends the media stream to each UE corresponding to each user instance.

In this way, in Figure 4, when the CF distributes the media stream, the media stream will start from the session processing unit and be distributed to sub-session module 1, ... sub-session module n, and then sub-session modules 1, .. ..., sub-session module n is copied and distributed to each UE through user modules 1, ..., user modules n connected to itself. Therefore, redundant transmission of media streams from the session processing unit to the sub-session processing unit can be eliminated.

In a specific implementation, each user module and its connected sub-session module, that is, the sub-session processing unit, can be an independently implemented entity, or integrated in a PF connected to itself, such as: in Figure 4, user module 1 and sub-session module 1 is integrated in PF1, user module n and sub-session module n are integrated in PFn, and the session processing unit can be integrated in the CF of the current service session.

When the method and system of the present invention are applied to a PoC business system, the PF is a ParticipatingPoC server, and the CF is a Controlling PoC server; when the method and system of the present invention are applied to a Confernce business system, the PF is a Participating Conference server , the CF is a Controlling Conference server.

To sum up, the application of the method and system of the present invention can significantly reduce the redundant transmission of media streams between PF and CF, so that the transmission of media streams is no longer based on the terminal, but on the basis of sub-sessions. Extended functions such as classified transmission of multimedia data can be further realized, which is beneficial to the further development of multi-party communication services.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (15)

1. A method for session control of a multi-party communication service, applied to a system comprising: user equipment UE, participation function entity PF and control function entity CF, characterized in that the method comprises: A. During the session establishment process, at least one PF of the current session establishes its own sub-session instance, and sends sub-session instance information to the CF of the current session, wherein the sub-session instance established by the PF and the participating current session under its control At least one UE of the session is associated; the CF associates the at least one sub-session instance established by the at least one PF with the session instance of the current session according to the received sub-session instance information; B. During the media stream transmission process, the CF copies the media stream according to the number of sub-session instances associated with the session instance, and distributes the media stream to the PF where each sub-session instance is located according to the received information of each sub-session instance , each PF distributes the received media stream to at least one UE associated with the sub-session instance established by itself. 2. The method according to claim 1, characterized in that, in the step A, Each PF in the at least one PF performs the following steps after receiving the session establishment request from the calling UE or CF: A1. Create a sub-session instance for the current session, A2. Associating the calling UE or the called UE of the session establishment request call with the established sub-session instance, and sending the established sub-session instance information to the CF of the current session; After receiving the sub-session instance information from the PF, the CF establishes a session instance for the current session, and associates the established session instance with the at least one sub-session instance according to the received sub-session instance information. 3. The method according to claim 2, characterized in that before the step A1, it further comprises: establishing a user instance for the calling UE or the called UE calling for the session establishment request; In step A2, the method for associating the calling UE or the called UE with the sub-session instance is associating the established user instance of the calling UE or the called UE with the sub-session instance. In the step B, each PF copies the received media stream according to the number of user instances associated with the sub-session instances established by itself, and distributes the received media streams to UEs corresponding to each user instance through the user instances. 4. The method according to claim 2 or 3, characterized in that, before the step A1, further comprising: judging whether a sub-session instance has been established for the current session, if yes, performing step A2; otherwise, performing step A1 . 5. The method according to claim 2 or 3, wherein after receiving the sub-session instance information from the PF, the CF further includes: judging whether a session instance has been established for the current session, and if so, associating the sub-session instance information The established session instance and the received sub-session instance; otherwise, establish a session instance for the current session and associate the established session instance with the received sub-session instance. 6. The method according to claim 3, wherein, when the media stream delivered by the current session includes more than one media type; in step B, more than one sub-session instance is set up for the current session, and each sub-session instance Corresponding to a media type; in step C, associate the user instance with each established sub-session instance; When the CF distributes the media stream, the method of distributing the media stream to each PF is: for each sub-session instance associated with the currently established session instance, sending the media stream of the media type corresponding to the sub-session instance to the sub-session instance PF where the session instance is located; When the PF receives the media stream, the method for distributing the media stream to each UE is: for each currently established sub-session instance, send the media stream of the media type corresponding to the sub-session instance to the sub-session instance for association Each UE corresponding to each user instance of . 7. The method according to claim 6, wherein the more than one media type comprises: Voice, or Video, or Message, or Data, or any combination of these four. 8. The method according to claim 2 or 3, characterized in that, in step C, the method for sending sub-session instance information to CF is: After the established sub-session instance is associated with the calling UE, send the sub-session instance information to the CF through a session establishment request; After the established sub-session instance is associated with the called UE, it is sent to the CF through the session establishment request response returned to the CF. 9. The method according to claim 2 or 3, wherein the sub-session instance information includes: sub-session identifier, address information, information of each user instance associated with the sub-session instance, and capability information of the sub-session instance . 10. The method according to claim 2 or 3, wherein the session establishment request received by the PF from the CF is: a session establishment request for one or more called UEs. 11. The method according to claim 1, wherein, when the method is applied to a push-to-talk PoC service system in a cellular system, the PF is to participate in the Participating PoC server, and the CF is to control the Controlling PoC server; the method When applied to a conference business system, the PF is a Participating Conference server, and the CF is a ControllingConference server. 12. A session control system for multi-party communication services, characterized in that the system comprises: more than one sub-session processing unit, and a session processing unit connected to each sub-session processing unit; The sub-session processing unit is configured to establish a sub-session instance for each UE participating in the current session under the jurisdiction of the PF connected to itself and send sub-session instance information to the session processing unit connected to itself, receive the media stream from the session processing unit and pass The PF is distributed to each UE corresponding to the currently established sub-session instance; The session processing unit is configured to receive each sub-session instance information from the sub-session processing unit, and combine at least one sub-session instance established by the session processing unit with the session instance of the current session according to the received sub-session instance information Associating, receiving the media stream from the CF copies the media stream according to the number of sub-session instances associated with the session instance, and distributes the media stream to the sub-session processing unit where each sub-session instance is located. 13. The system according to claim 12, wherein each sub-session processing unit comprises: a user module and a sub-session module; The user module is used to establish a user instance for each UE participating in the current session under the jurisdiction of the PF connected to itself, and send the information of each user instance to the sub-session module, receive the media stream from the sub-session module and distribute it through the PF To the UE corresponding to each user instance; The sub-session module is configured to receive user instance information from the user module, establish a sub-session instance of the current session, associate each user instance with the sub-session instance, and send the sub-session instance information to the session processing unit , receiving the media stream from the session processing unit and sending it to the user module where each user instance associated with the sub-session established by itself resides. 14. The system according to claim 12, wherein the sub-session processing unit is an independently implemented entity or integrated in the PF, and the session processing unit is an independently implemented entity or integrated in the CF middle. 15. The system according to any one of claims 12 to 14, wherein when the system is applied to a PoC business system, the PF is a Participating PoC server, and the CF is a Controlling PoC server; the system is applied to a Conference In the business system, the PF is the Participating Conference server, and the CF is the Controlling Conference server.

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