KR20070075649A - Ststem, mobile apparatus and method for providing the information of a multimedia poc session clinent in poc system - Google Patents

Abstract

A multimedia PoC(PTT over Cellular) session participant information service method in a PoC system, a terminal device, and a system are provided to enable a conference server to automatically notify of supportable media types of clients participating in a session, thereby reducing an excessive signaling burden between the server and the PoC clients. A transmission PoC client(630) transmits a session invite message for requesting at least more than one receiving PoC client to participate in a session to a PoC server(650). The PoC server delivers the invite message to the receiving PoC clients, and establishes a multimedia PoC session between the PoC server and the transmission PoC client as a response message is first received from one of the receiving PoC clients(600). The PoC server transmits a message which contains session participation information included in a response message received after the first response message to the PoC clients participating in the session(602-606).

Description

Method of providing multimedia PC session participant information in PC system and terminal device and system thereof {STSTEM, MOBILE APPARATUS AND METHOD FOR PROVIDING THE INFORMATION OF A MULTIMEDIA PoC SESSION CLINENT IN PoC SYSTEM}

1 is a configuration diagram of a general PoC service system;

2 is a functional block diagram of a general PoC server;

3 is a diagram illustrating a Controlling PoC Function block and a Participating PoC Function block of a PoC server;

4 is a signal flow diagram between a PoC server and a PoC terminal device illustrating a SIP call control procedure for receiving multimedia PoC session participant information when a general PoC group session is connected;

5 is a block diagram between a PoC terminal apparatus and a PoC server according to an embodiment of the present invention;

6 is a signal flow diagram between a PoC server and a PoC terminal device for providing multimedia PoC session participant information through an MBCP message when a PoC group session is connected according to an embodiment of the present invention;

7 is a signal flow diagram illustrating a multimedia PoC group session connection process using an MBCP message according to an embodiment of the present invention;

8 illustrates an MBCP message format according to an embodiment of the present invention.

The present invention relates to a method, a terminal device, and a system for providing session participation information of PoC clients participating in a PoC group when a PoC conference session is connected to support a multimedia PTT over cellular group service. In particular, a multimedia PoC group Provided are a method, a terminal device, and a system for providing supportable media type information of PoC clients participating in a session in a communication system.

Due to the revolutionary development of mobile communication and the expansion of communication networks, more expanded and various services and applications using mobile phones are provided. In addition, the needs of users are diversified, and they are expanding from simple call services to location services, multimedia services, and push-to-talk (PTT) services. In particular, the PTT service supports various additional functions such as instant messenger and status display, as well as group calls and voice calls, which were conventionally available in radios and TRS (Trunked Radio System).

Currently, the establishment of standards for PoC services that use the PTT (Push To Talk) concept using a mobile communication network is actively discussed. One of the features of the PoC service, which is distinguished from the existing mobile communication service, is that the user belongs to a plurality of sessions, so that the user can make a call while moving between sessions as necessary. The requirement for a user to be able to make calls over multiple sessions is specified in the requirements of the Open Mobile Alliance (OMA), an organization that defines mobile communication services.

Hereinafter, the structure of a general PoC system will be described.

1 is a conceptual diagram of a general PoC service system and related network structure. As shown in FIG. 1, a general PoC system may be configured to include a PoC user equipment (UE) 100, XML Document Management Servers (XDMS) 130, 140, and a PoC server 150. have. In addition, the PoC system may further include an aggregation proxy server 160. These components may be connected via an access network 110, a SIP / IP core network 120, and a remote PoC network 170.

Each of the above-described components will be described below.

The PoC terminal 100 may include a PoC client 102 and an XML Document Management Client (XDMC) 104.

The PoC client 102 is a service requester embedded in the PoC terminal 100 and resides in the PoC terminal 100 to perform network access for providing PoC service to a PoC service subscriber. PoC service subscriber can receive PoC service through PoC terminal in which PoC client is embedded. In the following description of the present invention, the term PoC client will be used as a generic term for a terminal having a PoC client and a PoC service subscriber. In addition, reference numerals of PoC clients will be omitted later unless otherwise specified.

The main function of the PoC client is to establish a PoC session, join an existing session that has been established, or terminate the established session at the PoC service subscriber, that is, a PoC user. In addition, the PoC client performs a function of creating and transmitting a talk burst, a function of supporting Instant Personal alert, an authentication function when accessing a PoC service, and the like. The PoC client may be connected to the SIP / IP core network 120, which is a SIP / IP multimedia support core network, via the access network 110.

The SIP / IP core network 120 is connected to the PoC server 150, the XDMS 130, 140, and the like to support the PoC service to provide a service. At this time, the PoC server 150 may perform a Controlling PoC Function function for maintaining and managing a PoC session or a Participating PoC Function function for joining a PoC session established for one-to-one or multi-party calls.

Meanwhile, the PoC service may be accompanied by a service for establishing a group session, such as a conference call. To this end, the OMA standard defines an XDM (XML Document Management) client 104 and an XDMS 130 and 140 for a group list service. 1 illustrates a common XDMS 130 that may be commonly used for PoC XDMS 140 and other service enablers used for PoC services. Information about the group and the group member may be input to the XDMS (130) 140 via the PoC client. The PoC client can know the information of the PoC clients that can be called through the individual or group list received from the XDMS (130) (140). Meanwhile, creation, modification and management of groups and group members for the XDMS 130 and 140 may be performed through a communication network trusted by a PoC service provider such as the Internet or an intranet. Detailed descriptions on the protocol and details of XML document management such as creating, modifying, and removing a group list will be omitted.

Also, for the group service, the aggregation proxy server 160, when receiving the group list related request from the XDM client 104, routes it to each XDM server 130, 140 according to the appropriate rules.

Next, the PoC server 150 will be described.

2 is a schematic structural diagram of a general PoC server. In terms of functionality, the PoC server is a Controlling PoC Function (hereinafter referred to as CF) that maintains and manages a PoC session as a whole, and a participating PoC Function (hereinafter referred to as PF) that manages maintenance between sessions. It can be divided into. Features of each PoC server will be described with reference to Tables 1 and 2 below.

Controlling PoC Function (CF) Provides centralized PoC session handling Provides the centralized Media distribution Provides the centralized Talk Burst Arbitration functionality including talker identification Provides SIP session handling, such as SIP session origination, termination, etc Provides policy enforcement for participation in group sessions Provides the participants information Collects and provides centralized media quality information Provides centralized charging reports May Provide transcoding between different codecs Support Talk Burst Control Protocol Negotiation

As shown in Table 1, the CF plays a role of managing the PoC session as a whole among the functions of the PoC server. Specifically, the CF accepts PoC clients' floor requests (speaks), orders and authorizes them, distributes the talk bursts requested by any client to all other clients participating in the group call, It provides information about clients attending group calls.

The PF manages sessions associated with the CF and each client in PoC sessions, as shown in Table 2 below. In particular, the PF relays when a client requests a voice or grants a client a voice in the CF. In addition, PF relays media between the CF and the client, transcoding if you are using a different codec between the two, and in the case of concurrent sessions, if you talk in one session and in another session, the PoC client's choice. It filters one by one.

Participating PoC Function (PF) Provides PoC session handling May provide the Media relay function between PoC Client and Controlling PoC server May provide user media adaptation procedures May provide the Talk Burst control message relay function PoC Client and Controlling PoC server Provides SIP session handling, such as SIP session origination, termination , etc, on behalf of the represented PoC Client Provides policy enforcement for incoming PoC session (eg access control, incoming PoC session barring, availablity status, etc) May collect and provide media quality information Provides the participant charging reports May provide filtering of the media streams in the case of simultaneous sessions May provide transcoding between different codecs May support Talk Burst Control Protocol Negotiation Stores the current Answer Mode and Incoming PoC Session Barring preferences of the PoC Client

3 is a diagram schematically illustrating a Controlling PoC Function block and a Participating PoC Function block of a PoC server.

Referring to FIG. 3, each PoC clients 102-A through 102-D establish a PoC session by accessing the CF 300 through the PFs 310-A through 310-D. Thereafter, the media for the corresponding speech of the PoC client, which has been given a talk right from the CF 300, is delivered to the respective PoC clients. At this time, the PoC client granted the right to speak may make an appropriate speech only after confirming the information of the PoC clients participating in the group session.

On the other hand, in the PoC system, the call processing technology for the call connection may be various procedures according to the request and the situation of the sender and the receiver. The characteristics of the PoC system required by the OMA according to the settings of the transmitter and the receiver are as follows.

First, the receiving side can set its own response mode according to the request of PoC client and can be classified into automatic response mode and manual response mode. The auto answer mode means that when the receiver is included in the PoC client list designated by the receiver, the response is immediately sent from the corresponding network to the sender instead of the receiver's passive response. The automatic response instead of the operation of the terminal in such a network is because the PoC server has a function of storing the response mode and the corresponding user list according to the response mode setting request of the terminal. On the other hand, the manual answer mode corresponds to the case where it is not included in the answering user list or is unclear, or when the receiver is set to the manual answer for all users, and the PoC call request is transmitted to the user's terminal through the receiving network and is transmitted to the PoC client. This means that the call will be connected by permission.

Second, the PoC system can be classified into on-demand session mode and pre-established session mode according to whether the user establishes a connection with a PoC server in the home network. Pre-established session mode is a technology in which a PoC client establishes a session in advance between a PoC client and a PoC server belonging to his home network according to his request. This pre-established session is a function required for the PoC client to negotiate with the PoC server in advance the media parameters to be used by the PoC client to proceed with the quick session establishment without having to renegotiate the media parameters between the PoC server and the clients to be used.

To establish a pre-session, the PoC client provides the media parameters supported by the body, that is, the SDP Session Description Protocol Multipurpose Internet Mail Extensions (MIME) body, through the SIP INVITE method, and provides the media parameters provided by the server. It is implemented by responding to media parameters provided by the server and returns the identification information of the pre-session, which is newly set in the response message received from the server, to the PoC client including the conference URI.

When using the above-described pre-session, it is possible to pre-negotiate such as an IP address, a port number, a codec to be used, and a protocol for controlling talk bursts. On-demand session mode means that the PoC client does not set up a pre-session, and that other PoC clients do not set up a pre-session. After receiving an invitation message from another PoC client, the PoC call connection procedure is performed. Means that.

The setting of the response mode for the call request in the PoC system may be stored in both a PoC server, which is an element on the network, and a PoC client, which is a terminal on the user side.

When the response mode is set in the home network managing the PoC client, the response mode is implemented in a PoC server that performs a session participation function (PF) in the home network to which the PoC client belongs.

If a response mode is set in the network, the PF automatically responds to the call request network with a session progress message immediately when a PoC call is requested from another PoC server. Accordingly, when the auto answer mode is set, the call request procedure is simplified as compared with the case where the session setup message is delivered to the PoC client and then answered, thereby reducing initial talk time.

However, when the automatic response is performed in the network, a result different from the response intention of the user may be caused depending on the situation, and thus the response mode may be set in the PoC client. In this case, the response mode of the PoC client has priority over the response mode set on the network. This is to solve the privacy problem that occurs when the PoC client changes its response mode and requests the PoC server to update the response mode, and the response mode is not reflected in real time due to a signal delay or an error in the network.

In summary, the PoC service can set the user's response mode to both the PoC server and the PoC client, but is determined by the PoC client that most recently reflects the user's intention, and the media (such as the actual user's voice or video) is determined by this decision. Stream delivery is now implemented.

A procedure for establishing a PoC multimedia session in the PoC system as described above will be described.

The transmitting PoC client sends a multimedia invitation message using the SIP protocol to request call processing. In this case, the multimedia may include audio, video, text, and the like in various formats according to the specification of the media type. In response to the call processing request, the receiving client takes various response procedures according to the response mode setting in the corresponding PoC server and the existence of a presession. Call processing procedures for PoC calls will be described by exemplifying the procedures of the same sender network and the receiver network.

The sending PoC client sends a SIP INVITE request including the SIP address information of the receiving PoC client to which it wants to communicate to the corresponding SIP / IP core network. In this case, the SIP INVITE message may further include elements such as PoC address information of a transmitting PoC client, required media parameters, and characteristic value information indicating that the PoC service is a PoC service. Here, the "required media parameter" may include a number of characteristic values such as an encoding method, a rate, a payload type, and the like regarding audio and video when the required session is multimedia.

SIP INVITE messages are routed to a participating PoC server via a corresponding IMS server in the IMS network, i.e., P-CSPF and S-CSPF, via a route query from a Dynamic Host Configuration Protocol (DHCP) server or a Domain Name Server (DNS) server. Is passed on. In a general call request, the participating PoC server to which the PoC client is connected can be implemented separately from the controlling PoC server that manages the talk burst of the session being established, so the SIP INVITE request sent to the PF can be configured to support the SIP / IP core network of the network. It is passed to the controlling PoC server CF via.

Meanwhile, the PoC session control network including the CF transmits a SIP INVITE request message to the receiving network, and then receives a response message of the receiving network. The SIP message answered from the receiving network may be a 1xx provisional response message, a 2xx successful response message, or an error response message such as 4xx to 6xx, depending on the settings of the receiving PoC client and the PF. Can be. In the auto-answer mode, a SIP 183 'session progress' signal may be received as a response message, through which the connection between the PoC server and the client may proceed in the IMS network of the call requester. The call permission signal of the receiving PoC client is returned in SIP 183 'session progress' or SIP 200 'OK' response, and is transmitted to the PoC client via the PoC server of CF and PF. When the CF receives a 200 OK response or a 183 session progress signal from the receiving PoC server, the CF determines that the PoC call is connected and transmits a floor granted signal to the transmitting PoC client to grant the talk burst talk right. According to the above response, that is, 200 OK or 183 session progress, the granting of the burst burst authority may be divided into 'confirmed' or 'unconfirmed'. The CF needs a buffering function when it receives an 'unconfirmed' response.

Meanwhile, the transmitting PoC client receives a response signal to the SIP INVITE request signal and then receives a floor granted signal that transmits a talk burst transmission grant signal such as a ring back tone through the RTCP protocol. The talk grant signal is generated in the CF having the talk burst arbitration authority and transmitted to the PoC client through the PF managing the corresponding PoC client. In this case, since the talk grant signal uses a bearer path without using the SIP protocol, the talk grant signal may be transmitted without passing through a SIP / IP core network such as an IMS. The PoC client confirming the ring back tone transmits a media stream such as media, for example, voice, using the Real-time Transport Protocol (RTP) protocol.

On the other hand, in recent years, the development of the PoC 2.0 system has been in progress since the development of the specification of the PoC 1.0 evolved into a communication system suitable for a multimedia environment. Looking at the key features of the PoC 2.0 system, it supports multimedia such as video, files, images, text, and audio visuals in addition to the voices supported by PoC 1.0. In addition, PoC 2.0 supports PoC Box similar to Voice Mail Box, supports interworking with conventional commercial PTT network system, improves call setup time and network performance, improves voice control, By ensuring compatibility with the PoC 1.0 system, various technical improvements have been made to the conventional PoC 1.0 system.

According to the requirements of the PoC 2.0 specification, the media types supported by the multimedia PoC session include voice, video files, image text, etc., as described above. You can request a session. The media to be used for the call can then be answered according to the choice of the receiving client. In addition, it must support backward compatibility with PoC 1.0 system, which is a requirement of PoC 2.0 specification, and multimedia group calling function that invites multiple clients.

However, in the media type initially proposed by the PoC client to establish a multimedia group session, various modified procedures may exist depending on the contents of the media responses of the PoC clients belonging to the receiving group or the participation of legacy clients. For example, the session establishment method defined by the IETF standard is that when the PoC server receives the session request message, it generates a session request message for the group list and sends a message to the client, and simultaneously sends a 200 OK response to the session initiator. Take the procedure to send it. However, this method is not a suitable solution in consideration of the mobile wireless environment and the user's experience. Therefore, a more optimized session establishment procedure is required. To this end, the main considerations are when to connect a session between the first peer and peer and the decision of the supporting media in the session.

The above-described method of establishing a multimedia PoC group session is an additional media type to which the participating PoC clients respond if the first responder responds to voice only because the first responder is a client of PoC 1.0, or if the responding media is a subgroup of the first proposed media. You must have a way to receive information.

As described in the above description, the PoC system and its components generally use the PoC system and the component to establish the signal flow for the SIP call processing process of the PoC client to receive information on the type of the responding client and whether the media is supported. This will be described with reference to FIG. 4.

Referring to FIG. 4, the transmitting PoC client A transmits a SIP INVITE message to the PoC server X (hereinafter referred to as CF X) for requesting to open a session to PoC boxes of PoC clients B1, C, and B2. (400, 402), and thus SIP INVITE is transmitted to the client. (404, 406, 432, 434, 458, 460) Here, the initial session request message is audio, video and image (A / V / I: Audio). / Vedio / Image) is a scenario for establishing a PoC session. At this time, the CF X returns the first 200 OK response message from the PoC client C, which is the first receiving client, to initiate the PoC media session (408 to 414). Assume that you reply a 200 OK response message containing only I. On the other hand, the transmitting PoC client A requests the SIP SUBSCRIBE message to the CF X in order to obtain the participation information of the group session (424, 426). Then, upon request of the SIP SUBSCRIBE message, the CF X transmits a notification message (NOTIFY) including information of the client participating in the session, to the sending PoC client (424 to 480). As described above, in order to obtain session participation information of a PoC client, by subscribing to a conference package (SUBSCRIBE), information of a client participating in a session may be obtained through a notification message (NOTIFY) that occurs at every event. On the other hand, other session participants can also obtain the information of other clients before and after their participation and media information that can be transmitted in the session through the conference package subscription procedure.

As mentioned above, in order to obtain session participation information of PoC client that all clients participate in the session, the same conference subscription message must be generated and transmitted, and since the NOTIFY message is transmitted after every event, it is inefficient for wireline network use and wireless resource use. to be. In addition, since the content defined in the conference package is a large-capacity database related to the conference, the traffic burden is high, and since the components defined by the IETF are used, PoC Box and PoC 2.0 service elements cannot be represented.

That is, as a method for obtaining media type information that can be supported / transmitted in a multimedia PoC group session, a conference package subscription, which is a general technology of the conventional IETF, may be used. When using the method of confirming whether the responding client supports the media by using the conference subscription method, the PoC client who participated in the session uses the PoC session identification information (PoC Conference URI) transmitted after the initial session is opened. Subscribe to the event package. After that, every time other clients respond, they must perform a process that must be confirmed through a NOTIFY message. Such repeated transmission of conference information may incur a waste of cost and radio resources by involving signaling through a wireless access network.

Meanwhile, in the multimedia PoC group session, a PoC box defined in PoC 2.0 may participate in the session on behalf of a PoC client. Since the PoC Box performs a recording function of the transmission media, it may cause a privacy problem. Therefore, all clients participating in the multimedia PoC group session should be notified of the existence of PoC Box. However, the conference subscription method of the IETF does not define an event package element that can notify the PoC Box used only in the PoC 2.0 service.

Accordingly, the present invention provides a method, a terminal apparatus, and a system for reducing excessive signaling burden between PoC clients and a server by automatically notifying a media server supporting a media type of a client participating in a session in a multimedia PoC group call system. Is in.

The present invention also provides a method, a terminal apparatus, and a system for identifying a PoC Box participating in a session on behalf of a responding client as a media storage element in a multimedia PoC group call system.

In the method for providing multimedia PoC session participant information in a PTT over Cellular (PoC) system according to an embodiment of the present invention, a session invitation message for a sending PoC client to request at least one receiving PoC client to join a session Is transmitted to the PoC server, and the PoC server delivers the session invitation message to the receiving PoC clients, and the receiving PoC client first receives the response message from one of the receiving PoC clients. Establishing a multimedia PoC session between the client and the PoC server, and transmitting, by the PoC server, a message including session participation information included in the response message received after the first message to a PoC client participating in the session. Characterized in that made.

In addition, in a system for providing multimedia PoC session participant information in a PTT over Cellular (PoC) system according to an embodiment of the present invention, a PoC server may include a session invitation message for requesting at least one receiving side PoC client to join a session. Transmits the session invitation message to the transmitting PoC client and the receiving PoC clients, and transmits the PoC client and the PoC server according to the first response message received from one of the receiving PoC clients. A multimedia PoC session is established between the PoC server, the PoC server confirms and stores session participation information included in the response message received after the first time, and transmits the message including the stored session participation information to the PoC client participating in the session. Configured to include the PoC server It is characterized by.

In addition, in a terminal apparatus for providing multimedia PoC session participant information in a PTT over Cellular (PoC) system according to an exemplary embodiment of the present invention, a data transmission unit for transmitting and receiving packet data with a PoC server and a session invitation message are received. And a control unit for transmitting a response message including a media type that can be supported in the response message to the PoC server.

The present invention described below proposes a method for efficiently providing session participant information by using user plane signaling implemented by RTCP protocol when a multimedia PoC group session is established in a PTT over Cellular (PoC) system. In particular, the multimedia PoC system can support multiple media such as video, video, image, and text in addition to voice, and support PoC system components such as PoC Box, which supports only some media or can be connected to the session according to user's preference. . The present invention thus provides a method for automatically notifying a conference server of a supported media type of a client participating in a session in a multimedia PoC group call system. It also provides a way to identify PoC system components participating in a session on behalf of responding clients as media storage elements.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the following, an example of applying the present invention to a PTT over Cellular (PoC) system, which provides a PTT service using a cellular mobile communication network, among the Push To Talk (PTT) systems, is an example. In general, the PoC system uses a Session Initiation Protocol (SIP) protocol and a SIP extension protocol to deliver session participation information of a group call, and uses an XML Configuration Access Protocol (XCAP) protocol to obtain group information. The functions of the present invention described below can be implemented by the above-described protocols, and the basic structure of the present invention can be based on the PoC Rel.1 system.

Then, the PoC server 510 and the PoC for providing multimedia PoC session participant information through a multimedia burst control signal (MBCP) message when connecting to a PoC group session according to an embodiment of the present invention with reference to FIG. 5. A block configuration of a PoC system including a terminal device 500 will be described.

First, the PoC terminal 500 processes a SIP protocol used for opening and managing a PoC session, and generates a PoC client that performs functions such as generating, processing, and transmitting user plane information related to a user. Unit 501, a display unit 502 for outputting visual media such as an image and a video received from the PoC server 510, and data for outputting the received data to the display unit 502. The control unit 503 is included. In addition, the PoC terminal apparatus 500 includes a key input unit 504 for transmitting a user input to the PoC terminal apparatus 500 and a data transmitter 505 for transmitting and receiving packet data. The data transmitter 505 may include transport protocol stacks for transmitting and receiving packet data. The data transmitter 505 may include an RTP / RTCP / FTP, UDP / TCP, IP, and Lower Layer Stack layer. Here, when the PoC client 501 receives the session invitation message (INVITE) from the PoC server 510, the PoC client 501 includes a media type that can be supported in the response message and transmits the supported media type to the corresponding PoC server 510. In addition, when the PoC client 501 is a transmitting client, media data that can be delivered to the receiving client may be transmitted according to supportable media type information of the receiving client that is received as a response message. That is, the transmitting client can transmit a media stream corresponding to the type of media that can be actually received by the receiving client.

Next, the PoC server 510 receives a data transmission unit 511 including the SIP / IP protocol stack and a SIP agent received from each PoC client, and analyzes and processes the SIP message (SIP UA (User Agent)). 513, a floor control processor 514 for PoC-specific floor management, a service policy enforcer 516 for granting a service policy, and an event package manager for storing and managing conference information. an event package manager 519 and a PoC server controller 512. At this time, the PoC server controller 512 controls the user agent 513 to store conference information in the event package manager 519 based on SIP response information received from each client. Thereafter, the PoC server controller 512 corresponds to the media information that the PoC client can support the conference information, the privacy request, the identifier information identifying the PoC Box, the PoC version information, and the PoC version. The MBCP message processed and converted into a Real-time Transport Control Protocol (RTCP) message format including client ID information is controlled to be transmitted through the data transmission unit 511. In particular, in the present invention, the PoC server 510 serving as a conference server when establishing a multimedia PoC group session performs a SIP session request and response procedure, and receives session participation information included in a response message for a session join request message from each client. Stored in the conference storage unit 520 and manages if there is an update to the session participation information. In addition, the PoC server 510 converts session participation information into a user plane message for delivery to each client and delivers it to each client.

Next, the signal flow between the PoC server 510 and the PoC terminal device 500 for providing multimedia PoC session participant information through the MBCP message will now be described with reference to FIG. 6. 6 is a schematic flowchart of the concept of transmitting, via an MBCP message, session participation information including supportable media information for implementing the present invention.

Referring to FIG. 6, a PoC client A 630 requesting a group session first establishes a session by receiving an initial 200 OK response, and then receives a SIP response message from another client in the group, and receives the MBCP message accordingly. Send to the established session. The step of establishing a multimedia PoC session between the sending client and the PoC server according to the SIP protocol response of the first responding client may be performed between the sending client and the PoC server regardless of the media type supported by the 200 OK response originally received from the receiving client. A session may be established that supports all media types originally requested from the sending client. For example, a client-server session may be established to support all media types requested by a PoC client establishing a group session.

Thereafter, PoC server A (hereinafter referred to as CF A) 650 receives a 200 OK response message, that is, a successful response message to the session, including an additional new media type image from PoC client B1 in step 604. ), The conference information is updated in step 606. That is, CF A checks the session participation information included in the response message according to the type of the SIP protocol response message received after the initial session initiation and stores it in the conference storage unit 520. At this time, the stored session participation information includes the session support media type included in the individual SIP response message from the client invited to the conference, the identifier of the PoC Box, the ID information of the PoC client that sent the response, the privacy request information, and the PoC client version information. Etc. The above information is included in the header of the SIP message or the MIME type body part, and the PoC server can preserve this information in the form of data for the validity of the session. In addition, by using the session support media information between the CF A 650 and each client, only media streams supported afterwards may be transmitted to the corresponding client. Thereafter, the CF A 650 generates an MBCP message including session participation information included in the response message received in step 604. The MBCP message is a message including supportable media type and version information of PoC Client B, a client ID indicating session participation information for PoC Client B, and privacy request if necessary.

Thereafter, in step 608, the CF A 650 transmits the MBCP message generated by including the session participation information to the PoC client A 630, which is a PoC client participating in the session, and receives the PoC client A 630, in step 610. Sends a response message to CF A 650. In this case, the MBCP message is a message including the media type information that the PoC client can actually transmit, which is a user plane message called 'MBCP Report'. The MBCP message is a message in which the session participation information of the header and the body of the SIP response is written in the format of a user plain message in the session, and is transmitted to the PoC clients participating in the session. In this case, the CF A 650 may automatically transmit the SIP response message from the predetermined PoC clients to all clients participating in the session. In addition, when receiving a talk request message from a specific PoC client and then sending a talk grant message to the client, the PoC client can support support based on the SIP response signal received until the PoC server sends the talk grant message. It may also include media type information, PoC Box presence and related information in the conference session.

Meanwhile, in the procedure for establishing a multimedia PoC session, a session establishment request from a transmitting PoC client may be regarded as an initial talk right request message. Thus, even when CF A 650 receives the first 200 OK response from the PoC 1.0 user or the receiving PoC client responding only to a limited media type, the CF A 650 supports 200 OK supporting all media to the sending PoC client. Send a response. Subsequently, the talk right grant message is automatically transmitted, and at this time, only the limited media type that can be transmitted to the actual receiving side PoC client may include information indicating that the talk right is media. In addition, if the first 200 OK response message is received from the PoC Box, the talk right grant message may transmit a talk right grant message including a message field for notifying the PoC box in addition to the support media type information.

On the other hand, when the CF A 650 receives a successful response message from the PoC Box in step 612 to 618, the CF A 650) receives a successful response message from the PoC Box to the session in step 612. If so, the process proceeds to step 614 where the CF A 650 updates the conference information. Subsequently, in step 616, the CF A transmits an MBCP message including a PoC Box identifier (Box Indication) to the PoC client A 630. The PoC client A 630 receiving the message transmits a response message to the CF A 650 in step 618 to inform that the PoC Box, not the general PoC client, participates in the conference session.

On the other hand, if the CF A 650 receives a successful response message from some other PoC clients in step 620, if the new media type is included in the supported media type of the PoC client included in the response message, in step 622 Update conference information. Subsequently, the session participation information including the updated support media type for the corresponding PoC client is transmitted to the PoC client A 630 in step 624, and the PoC client A 630 receiving the response responds to the CF A message in step 626. Send it. In this case, if there is no update of conference information in step 622, the MBCP message in step 624 may not be transmitted.

As described above, the present invention can automatically transmit the MBCP message to the PoC client participating in the session only when the new media type is included in the response message received by the CF A 650. That is, when the supported media is included in the media combination supported by the previous session, even if the CF A 650 receives the 200 OK response message, the MBCP message may not be transmitted. In this case, in the present invention, the condition for the conference server to automatically transmit the MBCP message is when the conference server receives a 200 OK response message including a media type additionally supported by the conventional session, or when the PoC Box participates. In one case, the MBCP message is automatically sent to PoC clients participating in the session.

As another embodiment of the present invention, when the PoC server CF receives the talk request message from the PoC client, the PoC server CF may deliver an MBCP message including session participation information. At this time, instead of a function of automatically transmitting an MBCP message when there is session participation or update information, the PoC server CF transmits a voice grant message for a voice request to the corresponding PoC client. It can also be transmitted by including box information, client version information, Client ID information, and privacy requests. In addition, the session participation information may be transmitted to another receiving PoC client through a media burst message. A detailed format of the MBCP message, which is a user plain message for expressing session participation information such as newly-supported media type and PoC Box identifier information, will be described with reference to FIG. 8.

Next, the multimedia PoC group session connection process using the MBCP message according to an embodiment of the present invention will be described with reference to FIG. 7 by using the concept of transmitting the multimedia PoC participation information as shown in FIG. 6 through the MBCP message.

First, when the CF X 650 receives an INVITE message requesting a group session from the PoC client A 630 (700, 702), it requests the clients to join the session (704, 706, 726, 728, 744). 746, and then first receive a response message from the PoC client C (708, 710), and then receives each response message from the PoC client B1 and PoC client B2 Box (703, 732, 748). 750)

After PoC client A 630 establishes an initial session with PoC client C 820, CF X 650 stores the session participation information included in the response message as conference information. At this time, the CF X 650 is the PoC client A 630 and the CF X 650 serving as the sending client regardless of the media type supported by the 200 OK response originally received from the PoC client C 820 serving as the receiving client. The session establishes a session supporting all media types originally requested from the PoC client A 630.

The CF X 650 then sends a 200 OK response message supporting all media types to the PoC Client A 630. (712, 714), ie, the CF X 650 is restricted from the PoC Client C 820. When receiving a response to the media type, the 200C responds to the PoC client A 630 supporting all media types. In addition, an MBCP Granted Message (MBCP Granted Message) is transmitted as a voice grant message for an implicit voice request of an initial INVITE message. In this case, the first talk right grant message includes only a media type that can be transmitted and received between actual end users in a PoC session. (716, 718) In this case, the session participation information for the PoC client C 820 is transmitted as described above. The PoC client A 630 receiving the MBCP message checks the media type supported by the PoC client C 820, and confirms that the supported media type is audio / image (A / I) to the PoC client C 820. As media for transmission, only media of audio / image (A / I) type may be transmitted.

Meanwhile, when the CF X 650 receives a response message from the PoC client B1 800, the CF X 650 transmits an MBCP message including session participation information for the PoC client B1 800 to the PoC client A 630 (736, 738). In response to this, the PoC client A 630 transmits a response message to the CF X 650. (740, 742).

In addition, when the CF X 650 receives a response message from the PoC Box 810 of the PoC client B2 (748, 750), the PoC MBC message including the session participation information for the PoC Box 810 of the PoC client B2 is PoC. The client A 630 and the PoC client B1 800 transmit (752, 754, 756, 758), and the PoC client A 630 receiving the transmission transmits a response message to the CF X 650. The PoC Box may be located at the PoC client side or may exist at the system side of the PoC server. (764, 766) Although not shown in FIG. 7, the PoC box which participates in the MBCP message for notifying the PoC Box in the session is present. Also send to client C (820). That is, when the PoC Box additionally supports a new media type or responds to a session participation response of other PoC clients, the session participation information may be transmitted in the form of a 'MBCP Report' message.

8 is a diagram illustrating an RTCP payload type representing an MBCP message of the present invention. FIG. 8 relates to a preferred embodiment of the MBCP Report message invented in the present invention to implement FIG. 6 and FIG. 7. TBCP messages are organized in RTCP APP message format according to the OMA standard for PoC Release 1.

Referring to FIG. 8, the RTCP APP packet includes general RTCP transmission related information such as version information, packet type, subtype information, packet length, and the like, and supports media type, PoC Box identifier, PoC version information, and privacy for the present invention. Request status, PoC version includes the corresponding client ID. In more detail with respect to the information fields included in the RTCP APP message for the present invention, the session support media type field may include a supported media type up to the point of generating the MBCP message, the PoC Box identifier field is a conference Whether or not PoC Box participates can be indicated in binary. In addition, the PoC version information field may distinguish whether or not a PoC 1.0 user participates. In this case, the PoC 1.0 client ID may be included in the PoC version corresponding client ID field as necessary. In addition, when privacy is requested by the SIP signal, the privacy request field may be binary-marked so as not to inform the client ID included in the MBCP message. Meanwhile, when the MBCP message is transmitted for every 200 OK response messages, the response client ID field may be selectively included for identification of the corresponding response client.

Although a preferred embodiment of the present invention has been described in detail above, those skilled in the art to which the present invention pertains may make various changes without departing from the spirit and scope of the invention as defined in the appended claims. It will be appreciated that modifications or variations may be made. Therefore, changes in the future embodiments of the present invention will not depart from the technology of the present invention.

The present invention automatically delivers the actual supported media and session information to the sender PoC client when the initial session is established by the PoC client responding to the media type of the PoC 1.0 terminal or subgroup. By doing so, the efficiency of radio resources, traffic burden reduction, and optimized setup procedure of multimedia PoC session can be induced. In addition, there is an effect that the PoC Box, which may cause privacy problems, can be delivered to the PoC clients participating in the session in real time.

Claims (13)

In the method for providing multimedia PoC session participant information in a PTT over Cellular (PoC) system, Transmitting, by the sending PoC client, a session invitation message for requesting at least one receiving PoC client to join the session, to the PoC server; The PoC server delivers the session invitation message to the receiving PoC clients, and establishes a multimedia PoC session between the transmitting PoC client and the PoC server according to the first response message received from one of the receiving PoC clients. Opening process, The PoC server provides a multimedia PoC session participant information in the PoC system comprising the step of transmitting a message including the session participation information included in the response message received after the first to the PoC client participating in the session. How to. The process of claim 1, wherein the PoC server transmits a message including the session participation information. Checking session participation information included in the response message when receiving a successful response message for the session connection by the receiving PoC client; If there is updated information of the session participation information, updating the corresponding session participation information, and generating a MBCP (Media Burst Control Protocol) message including the updated session participation information; The method for providing multimedia PoC session participant information in the PoC system, characterized in that further comprising the step of transmitting the generated MBCP message to the PoC client participating in the session. The method as claimed in claim 2, wherein the media burst control protocol (MBCP) message is provided in the form of a real-time transport control protocol (RTCP) payload. . The media burst control protocol (MBCP) message includes at least one of a supported media type field, a PoC box identifier field, a PoC version information, a privacy request field, and a PoC version corresponding client ID field. Method for providing a multimedia PoC session participant information in a PoC system characterized in that the. The method of claim 1, further comprising: when the PoC server receives the talk request message from the receiving PoC client, includes the session participation information in a talk grant message and transmits the session participation information to the requesting talk PoC client. A method for providing multimedia PoC session participant information in a PoC system characterized by the above-mentioned. The method of claim 1, wherein the establishing of the multimedia PoC session between the transmitting PoC client and the PoC server comprises: The PoC system for providing multimedia PoC session participant information in the PoC system, characterized in that the transmitting PoC client establishes a session supporting all media types requested for the first time. In the system for providing multimedia PoC session participant information in a PTT over Cellular (PoC) system, A sending PoC client transmitting a session invitation message to the PoC server for requesting at least one receiving PoC client to join the session; Deliver the session invitation message to the receiving PoC clients, and establish a multimedia PoC session between the transmitting PoC client and the PoC server according to the first response message received from one of the receiving PoC clients. The PoC server includes the PoC server that checks and stores the session participation information included in the response message received after the first time, and transmits the message including the stored session participation information to the PoC client participating in the session. System for providing multimedia PoC session participant information in a PoC system, characterized in that. The method of claim 7, wherein the PoC server, Upon receiving a successful response message for the session connection by the receiving PoC client, check the session participation information included in the response message, and if there is an updated information of the session participation information, update the corresponding session participation information. And generating a Media Burst Control Protocol (MBCP) message including the updated session participation information, and then transmitting the generated MBCP message to a PoC client participating in the session. System for providing PoC session participant information. 10. The system of claim 8, wherein the Media Burst Control Protocol (MBCP) message is provided in the form of a Real-time Transport Control Protocol (RTCP) payload. . 10. The method of claim 9, wherein the MBCP message includes at least one of a supported media type field, a PoC box identifier field, a PoC version information, a privacy request field, and a PoC version corresponding client ID field. System for providing multimedia PoC session participant information in a PoC system, characterized in that. The method of claim 7, wherein the PoC server, Upon receiving the talk right request message from the receiving PoC client, the PoC system includes the session participation information in the talk right grant message and transmits it to the receiving PoC client requesting the speaking right. System for Providing. A terminal device for providing multimedia PoC session participant information in a PTT over cellular system, A data transmission unit for transmitting and receiving packet data with the PoC server, And a controller for transmitting a response message including a media type that can be supported in the response message to the PoC server upon receiving the session invitation message. The method of claim 1, wherein the control unit, Upon receiving the response message for the session invitation request, the multimedia data in the PoC system is transmitted according to the supportable media type information of the receiving PoC client included in the response message. Terminal device for providing PoC session participant information.

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