KR20090060649A - Method and system and poc terminal for establishing poc session - Google Patents

Abstract

A method for opening a PoC session and a system therefor and a PoC terminal are provided to request an essential addition function to be used in a PoC session that a PoC session opener wants to open when opening a PoC to a counterpart PoC client. A PoC(PTT(Push To Talk) over Cellular) client(102) generates and transmits a session invitation request message. A PoC server checks a response mode of a receiving side PoC client. If the response mode is a manual mode, the PoC server transmits the message to the receiving side PoC client. The session invitation request message includes an essential addition function parameter and invited receiving side PoC client information.

Description

Method of establishing a session and system and the PC terminal for the POC session TECHNICAL FIELD

The present invention relates to a method and system for establishing a PoC session and to a PoC terminal. Particularly, the present invention relates to a PoC session when a participant participating in a PoC session supports a mandatory additional function to be used in the corresponding PoC session. The present invention relates to a method and a system and a PoC terminal therefor.

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 beyond the simple call service, the service is expanding to location services, multimedia services, and push-to-talk (PTT) services, etc. In particular, the PTT service is a conventional radio or TRS (Trunked Radio) service. It supports various additional functions such as instant messenger and status display as well as group call and voice call.

Currently, the establishment of standards for PoC (PTT over the Cellular) service that uses this PTT concept using a mobile communication network is actively discussed. One is that a user can belong to multiple sessions so that the user can make calls while moving from session to session as needed. The requirements are specified in the requirements of the Open Mobile Alliance (OMA), an organization that defines mobile telecommunications services.

Meanwhile, referring to the PoC calling service among PoC services, the PoC user registers the PoC address of his PoC client in the SIP / IP core in order to use the PoC calling service. At this time, the SIP / IP core stores information on the PoC client based on the request of the PoC client. Therefore, when another PoC user wants to make a PoC group call, as above, his or her own information is registered in the SIP / IP core and the call request is made to his SIP / IP core network using the group identification information received from the XDMS. do. At this time, the SIP / IP core transfers the PoC call request to the home PoC server where the requesting PoC user is registered after the address determination and domain location determination process using the requesting PoC user information. The PoC server prepares to establish a PoC session for the PoC call request, obtains each client information from the XDMS server, and transmits a call request signal to the corresponding SIP / IP core network. At this time, in case of call request to clients in intra domain, PoC server performs both PF and CF functions. The PoC server managing the call request PoC client uses the information of the PoC client delivered to itself, and after making a positioning process of the SIP / IP core network, makes a call request to the corresponding PoC client. When a PoC client requesting a PoC call sends an OK response to his or her PoC client, the PoC call is opened.

Referring to FIG. 4, when PoC user A requests a PoC call from PoC user B, PoC user A creates a session invitation request (INVITE) message using PoC client A of its PoC terminal. At this time, the PoC user A creates a session invitation request message including service information such as a PoC service, for example, a video service and a queue service. Thereafter, the PoC client A transmits the session invitation request message created as described above to the PoC server A, which is its home server. Then, in step 402, the PoC server A searches for a PoC server X, which is a PoC server that plays a role of managing the PoC session as a whole (the role of Controlling PoC Function (CF)), and transmits the received session invitation request message.

then. The PoC server X, which has received the session invitation request message sent by the PoC client A, controls the PoC session based on the session invitation request message, and requests the session invitation to transmit the PoC service that the PoC client A intends to use to the PoC client B. The message is transmitted to the PoC server B, which is the home server of the PoC client B, in step 404.

Thereafter, the PoC server B receiving the session invitation request message processes the message according to the user setting of the PoC client B. For example, the received message is transmitted according to the operation of the PoC server B acting as a PF and a message transmission procedure according to a user setting such as an access policy or a reject list. Thereafter, in step 406, the PoC client B transmits a session invitation request message. The PoC Client B may respond to the PoC User B's decision after receiving the Session Invitation Request message. When PoC user B accepts a call with PoC user A, two cases may occur depending on the support services and functions of PoC client B.

That is, the PoC client B checks whether the add-on included in the session invitation request message is supported in step 408, and indicates that the PoC client B can support the PoC service requested by the PoC client A, that is, the add-on. ) Is included in the response message (200 OK message) and transmitted to the PoC server X in steps 410 and 412. Then, PoC server X delivers the received response message to PoC client A.

 However, if the PoC client B does not support the PoC service requested by the PoC client A, that is, an add-on, the PoC client B includes an indication indicating that it is not supported, and transmits it to the PoC server X in steps 420 and 422. PoC server X then forwards the received response message to PoC client A. As a result, the PoC session is established even if the PoC client B does not support the additional function that PoC user A is essential to use in the PoC session that the PoC client A intends to establish.

As described above, when a PoC user having a PoC terminal wants to open a PoC session, if a corresponding PoC client does not support the specific add-on even though the PoC client wants to use the specific add-on in the session to be opened, the corresponding add-on is not used. PoC sessions can only be established. In other words, PoC users who have requested to open a PoC session cannot express their intention that they do not want to open a PoC session if the other client does not support the add-on they want to use in the PoC session. The session must be established first, and then the PoC session must be terminated again. Accordingly, a result of opening a session that receives a service different from the intention of the PoC session establisher may occur.

Accordingly, the present invention provides a method and system and a PoC terminal for requesting an opposite PoC client an essential additional function to be used in a PoC session to be opened by a PoC session establisher.

In addition, the present invention provides a method and system and a PoC terminal for allowing a PoC session to participate in a PoC session only when the PoC client supports an essential additional function to be used in a PoC session to be opened by a PoC session establisher.

To this end, the present invention provides a system for establishing a push to talk (PTT) over the cellular (PoTT) session, and a PoC client receiving side to invite additional functions and sessions required for a PoC session to be established when a PoC session is established. When is selected, when receiving a session invitation request message and a transmitting side PoC client for generating and sending a session invitation request message including the required additional function parameters for indicating the selected additional function and the information of the receiving PoC client, After checking the response mode of the receiving PoC client, if the response mode is set to the passive mode, a PoC server for transmitting the received session invitation request message to the receiving PoC client, and when the session invitation request message is received, If the essential additional function is not supported by checking the required additional function parameter, the Receiving side PoC client for transmitting a function support unavailable message to the PoC server to inform that the PoC session to be established does not participate.

The present invention also provides a PoC session in a system including a sending PoC client, a PoC server, and a receiving PoC client invited to the PoC session to establish a push to talk (PTT) session. In the method for establishing, the session invite request message including the required additional function parameter indicating the selected additional function and the receiving side PoC client information when the additional function to be used as essential in the PoC session is selected by the transmitting PoC client is selected. Transmitting the message to the PoC server, checking the response mode of the receiving PoC client in the received session invitation request message when the PoC server receives the session invitation request message, and manually responding to the PoC server. Mode, the received session invitation request message is sent to the receiving PoC client. When the receiving PoC client receives the session invitation request message, the receiving PoC client checks the required additional functions through the required additional function parameters included in the session invitation request message and then checks whether the supporting PoC client supports the required additional functions. And transmitting, to the PoC server, a function unsupported message for notifying that the PoC client does not participate in the PoC session if the receiving PoC client does not support the required additional function.

In addition, the present invention provides a PoC terminal for establishing a PoC session in a system including a PoC client and a PoC server for establishing a Push To Talk (PTT) session and a PoC session. When the wireless unit, the additional function to be used in the PoC session to be established when the PoC session is established, and the receiving PoC client to invite to the session are selected, the required additional function parameter and the receiving side PoC to indicate the selected additional function are selected. A session invitation request message including information of a client is generated and transmitted through the wireless unit, and when the session invitation request message is received through the wireless unit, the essential additional function parameter is checked to support the essential additional function. A feature not supported message to inform you that you are unable to join a PoC session. Characterized in that a control unit for transmitting to the PoC server via a wireless group call.

In addition, in the system of the present invention, the receiving PoC client generates a PoC service setting request message including PoC service setting information and additional function information supported by the receiving PoC client before the PoC session is established, and sets the PoC server to configure the PoC service. When the PoC service setting request message is transmitted to the PoC server and the PoC server receives the PoC service setting request message including the additional function support information, the PoC service setting is transmitted to the PoC service setting request message. And store the data corresponding to the client.

In addition, in the system of the present invention, when the session invitation request message is received and the response mode of the receiving PoC client is set to the automatic mode, the receiving side through the PoC service setting corresponding to the receiving PoC client is set. It is determined whether the PoC client supports the required additional function, and if it is not possible, a function support impossible message indicating that the PoC client cannot participate in the established PoC session is transmitted to the receiving PoC client.

In addition, in the system of the present invention, the PoC server determines whether the receiving PoC client supports the required additional function, and if necessary, indicates that the PoC server includes the required additional function support parameter to indicate that it will participate in the PoC session. The message is transmitted to the transmitting PoC client.

According to the present invention, a PoC session establisher can request a required PoC client to use a PoC session to be opened in a PoC session, and a PoC session establisher supports a mandatory additional function to be used in a PoC session to be opened by a PoC session establisher. There is an advantage to being able to only participate in PoC sessions.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

First, a PoC system to which the present invention is applied will be described with reference to FIGS. 1 to 3. 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. First, a general PoC system to which the present invention can be applied 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), and a PoC server 150. 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 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. The PoC client also creates and delivers talk bursts, supports instant personal alerts, and authenticates when accessing PoC services. 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 members may be stored in 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 XDMC 104, routes it to each XDMS 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.

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>, CF manages PoC session as a whole among PoC server's functions. Particularly, CF accepts order of floor request and grants authority. The talk burst requested by the PoC client is distributed to all other PoC clients participating in the group call, and provides information on the PoC client participating in the group call.

The PF manages sessions associated with the CF and each PoC client in the PoC session, as shown in Table 2 below. In particular, the PF plays a role in relaying when the PoC client requests a voice or grants a voice to the PoC client in the CF. PF also plays a role in media relay between CF and PoC clients, transcoding if different codecs are used between them, and in the case of concurrent sessions when talking in one session, Filters one by choice.

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

The aggregation proxy server 160 collects all messages using the XCAP protocol in the PoC system and delivers them to the corresponding entity.

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 granted the speaking right from the CF 300 is delivered to each 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.

In the PoC system configured as described above, the PoC client establishing a session notifies the counterpart PoC client of the additional function to be used in the session to be established, and if the partner PoC client supports this add-on, the session is established. The process for this will be described with reference to FIG. 5.

Referring to FIG. 5, when a PoC user A wants to use a predetermined mandatory additional function in a PoC session to be established, the mandatory additional function is selected through the PoC client A. Then, in step 500, the PoC client A converts the type of the required add-on selected by the user into a value of a required_feature parameter (P_required_feature parameter) defined in the form of Session Description Protocol (SDP) MIME extension. Include in the invitation request message. Of course, the session invitation request message also includes PoC client information to be invited to the session. At this time, the value of the mandatory additional function parameter is expressed as a decimal number, and types of additional functions are assigned to each numeric value. As shown in FIG. 6, the value of the required additional function parameter and the corresponding additional function type are mapped as shown in FIG. 6, and the additional function type definition table is stored in the PoC terminal and the PoC server.

Referring to FIG. 6, examples of additional function types allocated to each value are shown. In the present invention, it will be described based on the additional function type corresponding to the value assigned in the additional function type definition table of FIG. 6. However, in the actual implementation, the additional function type assigned to each parameter value may be different. In addition, although values for an add-on type may indicate one add-on type or may indicate two or more add-on types, one add-on type and its corresponding value may be defined, and then the required add-on type may be defined. A plurality of values may be combined and included in an essential additional function parameter. In addition, such an add-on type definition table should be stored in the same table in both PoC clients and PoC servers in order to perform the service of the present invention.

In FIG. 5, it is assumed that PoC user A has selected a video and a queuing function as essential additional functions. Then, in step 500, the PoC client A generates a session invitation request message to be transmitted to the PoC server by including 11 as an essential additional function parameter value.

Thereafter, the PoC client A transmits the session invitation request message generated in step 501 to PoC server A, which is its home server. That is, the selected essential additional functions are transmitted to PoC server A, which is the home server of PoC client A, using the SDP protocol of the session invitation request message. An overview of the SDP protocol of the session invitation request message associated with the present invention will be described with reference to FIG. 7.

The portion included in the 700 block in Figure 7 is part of the SDP protocol. The contents of the entire SDP protocol include information such as connection information, address information, media information, port number, and bandwidth according to actual media transmission. In this case, since the direct connection with the present invention is small, it will be omitted. The “application / sdp” of the Content-Type indicates that the content of this content is the Session Description Protocol (sdp). The “m = application 22000 udp MBCP” contains media information. application, using the 22000 port number, and using the udp protocol. Also, “a = fmtp: MBCP queuing = 1; tb_granted = 1; P_required_feature = 11” defines additional attributes for the media, that is, the application. The format protocol uses MBCP, supports high priority when queuing is supported, and indicates that the PoC session sender wants to obtain a voice without requesting a voice when a PoC session is established. It is. In particular, in the present invention, the mandatory add-on parameter included in the session invitation request message may be included in the part where the media attribute is defined, such as 710. Since the mandatory add-on parameter value is 11, PoC user A wants to open video and queuing. It is mandatory to use in PoC session, and PoC clients that do not support PoC clients who requested to invite to PoC session cannot participate in this PoC session.

In operation 502, the PoC server A delivers the session invitation request message to the PoC server X, which is the CF, based on the characteristics of the PoC service and a routing rule.

The PoC server X then stores the required additional function parameters and their values included in the received session invitation request message and inserts the required additional function parameters in the session invitation request message for transmission to the PoC server B. In operation 504, the PoC server X transmits a session invitation request message in which an additional function parameter is inserted, to the PoC server B which is the home server of the PoC client B. Thereafter, the PoC server B determines how to process the session invitation request message according to the PoC service setting of the PoC client B. In this case, the PoC service setting may be described in various ways. However, in the embodiment of FIG. 5, it is assumed that the PoC service is set to operate in a manual answer mode among answer modes. Then, according to the response mode setting of the PoC client B, the PoC server B transmits a session invitation request message to the PoC client B in step 506.

Then, the PoC Client B checks the value of the required add-on parameter in the session invitation request message and analyzes the corresponding add-on. Here, it is assumed that the PoC client B also stores the additional function type definition table as shown in FIG. As a result of the analysis, since the value of the required additional function parameter is 11, the video and the queuing function are recognized as the required additional function.

Thereafter, the PoC client B checks whether it supports the video and queuing function set as an essential additional function in step 508. If the PoC client B supports the video and queuing functions, the PoC user B is informed that the PoC user B has been invited to the PoC session, and asks whether to participate in the PoC session. The PoC session invitation notification and the PoC session participation intention inquiry can display this content through the screen of the PoC terminal and receive a user's selection. At this time, if the PoC user B selects to join the PoC session, the PoC client B inserts 11 of the required additional function parameters into the 200 OK message as a response message, and transmits the value to the PoC server X in steps 510 and 512. do. That is, when the PoC client supports the required additional functions and receives the PoC user to participate in the PoC session, the PoC client includes the same parameter values as the received additional function parameters and transmits them.

However, if the PoC client B indicates that the PoC client B does not participate in the PoC session, even if the PoC client B supports the required additional functions in step 508, the reject message is transmitted to the PoC server X as a response message. Thereafter, in step 514 and step 516, the PoC server X transmits the PoC server A to the PoC client A with a response message including the value of the required additional function support parameter as 11.

On the other hand, if the PoC Client B does not support video and queuing functions, which are required additional functions, as a result of step 508, the PoC Client B transmits a 488 Not Acceptable here message to the PoC server X in steps 520 and 522. Notify that the features are not supported. Then, the PoC server X transmits the PoC server A to the PoC client A with a no function support message in steps 524 and 526.

That is, in the present invention, the PoC client B invited to the session cannot participate in the PoC session when the PoC client A does not support the additional functions required for the session to be opened.

Although the internal configuration of the PoC client A and the PoC client B is not illustrated in the embodiment of FIG. 5, the PoC clients A and B have a control unit and a memory unit, and the PoC client A and the PoC client B as shown in steps 500, 501, and 508. The operation of is performed by the control unit and may store the table as shown in FIG. 6 in the memory unit. In addition, PoC clients A and B have a wireless unit, and can transmit and receive messages to and from the PoC server through the wireless unit. In addition, PoC clients A and B may include a display unit to display a message or an operation state, and a key input unit may be used by the user as a predetermined selection and input means.

In FIG. 5, the response mode setting in the PoC server B's PoC service B is set to the manual response mode, and thus the session invitation request message is transmitted to the PoC client B. Hereinafter, a case in which the response mode setting of the PoC service B of the PoC client B is set to the automatic answer mode in the PoC server B will be described with reference to FIG. 8.

First, the PoC client B transmits a PoC service setting request message for setting the response mode to the auto answer mode to the PoC server B so as to set its PoC service setting to the auto answer mode. However, if the PoC server B is simply set to the auto answer mode, the PoC user B always means to participate in an incoming PoC session invitation. Therefore, when the PoC server B receives the session invitation request message to be transmitted to the PoC client B, the PoC server B responds by generating a 200 OK message as a response message without transmitting the message to the PoC client B. This can cause problems because there is no way to know whether or not PoC Client B supports the required add-ons. Therefore, in step 800 of the present invention, the PoC client B transmits to the PoC server B a message including the information for setting the response mode to the auto response mode and the additional function support information that can be supported by the PoC service configuration request message. The PoC service setting request message transmitted here may be transmitted as a PUBLISH message. Such a PoC service setting request message may be illustrated as shown in FIGS. 9A and 9B. Information contained in block 900 of FIG. 9B is additional function support information, and the PoC client which sent this message is video. It supports audio, text, queuing, media burst control schemes, and dispatcher functions. Such additional function support information may be inserted and transmitted in a PoC service setting part, such as 900 blocks of an XML MIME body of a PUBLISH message. The message including the additional function support information may be included in the 900 block written in XML in another method of transmitting the message from the PoC client to the home PoC server.

Then, the PoC server B stores PoC service setting information of the PoC client B in the PoC service setting request message received in step 802, and then transmits a response message to the PoC client B to inform that the PoC service setting is completed in step 804. do.

The PoC service setup process as in steps 800 to 804 is a procedure performed by all PoC users who want to receive PoC services for the first time through their PoC clients. Therefore, all PoC clients should send a PUBLISH message to the PoC server, including support information for additional functions that they can support when performing the process for PoC service configuration.

On the other hand, when PoC user A wants to use a certain required additional function, the PoC client A selects an essential additional function. Then, in step 810, the PoC client A converts the required add-on selected by the user into the value of the required_add_feature parameter defined in the form of SDP MIME extension and includes it in the session invitation request message. In the embodiment of FIG. 8, it is assumed that PoC user A selects a video and a queuing function as essential additional functions. Then, in step 810, the PoC client A determines that the parameter value corresponding to the additional function selected in the additional function type definition table as shown in FIG. 6 is 11 according to the selection of the required additional function of the user A, and requests the session invitation for the confirmed parameter value. It is included in the required additional function parameter value of the message to generate a session invitation request message to be sent.

Thereafter, the PoC client A transmits the session invitation request message generated in step 810 to PoC server A, which is its home server. That is, the selected essential additional functions are transmitted to PoC server A, which is the home server of PoC client A, using the SDP protocol of the session invitation request message. The session invitation request message transmitted at this time may be illustrated in FIG. 7.

PoC server A receiving the session invitation request message including the required add-on parameters in step 814, invites the session to PoC server X, which manages the PoC session as a whole based on the PoC service characteristics and routing rules. Pass the request message.

Then, the PoC server X recognizes that the home server of the receiving PoC client B of the session invitation request message is the PoC server B, and inserts the required additional function parameter into the session invitation request message for transmission to the PoC server B. Thereafter, in step 816, the PoC server X transmits a session invitation request message in which an additional function parameter is inserted, to the PoC server B which is the home server of the PoC client B.

Thereafter, the PoC server B checks the PoC service setting of the PoC client B in step 818. In the embodiment of FIG. 8, since the response mode of the PoC client B is set to the auto response mode, the PoC server B processes the session invitation request message according to the auto response mode of the PoC client B.

The PoC server B checks the value of the required additional function parameter in the session invitation request message in step 818 and recognizes what additional function is required to be used in the session. Here, it is assumed that the PoC server B also stores the additional function type definition table shown in FIG. 6 like the PoC client A. As a result of the analysis, since the value of the required additional function parameter is 11, the video and the queuing function are recognized as the required additional function.

In operation 820, the PoC server B checks whether the PoC client B supports video and queuing functions in the PoC service configuration related to the PoC client B.

If the PoC client B supports video and queuing functions, the PoC client B inserts 11 of the required additional function parameters into the 200 OK message as a response message and transmits the value to the PoC server X in step 822. Then, in step 824 and 826, the PoC server X transmits a function supportable message to the PoC server A to the PoC client A.

However, if the PoC client B does not support the video and queuing function, which is an essential additional function, as a result of step 820, the PoC client B transmits a 488 Not Acceptable here message to the PoC server X in step 828. Notify not supported. Then, the PoC server X transmits the PoC server A to the PoC client A with a function unsupported message in steps 830 and 832.

Although the internal configuration of the PoC client A and the PoC client B is not illustrated in the embodiment of FIG. 8, the PoC clients A and B have a control unit and a memory unit, and the PoC client A and the PoC client B as shown in steps 810, 812, and 800. The operation of is performed by the control unit and may store the table as shown in FIG. 6 in the memory unit.

As described above, in the present invention, when a PoC is established, the PoC session establisher includes a required additional function parameter indicating a required additional function to be used in a PoC session to be opened in a session invitation request message, and transmits it to the PoC server, and the PoC server receives the received session. The invitation request message is transmitted to the corresponding PoC client. Also, if the receiving PoC client does not support the required add-on, the receiving PoC client sends a 488 Not Acceptable here message to the founding PoC client through the PoC server regardless of the user's intention to participate in the PoC session. send. By doing this, the PoC session creator can participate in the PoC session only if the other PoC client supports the necessary additional functions to be used in the PoC session to be opened.

In FIG. 8, the PoC client B stores the PoC service B of the PoC client B in the PoC server B using the PoC service B as the PoC server B. However, in another embodiment, the PoC client B can support the PoC client B. Add-on information can also be stored in a shared XDMS. At this time, if the PoC client B sets the PoC service setting for the response mode to the auto answer mode, when the PoC server B receives the session invitation request message to be transmitted to the PoC client B as in step 816, the shared XDMS If the required add-on included in the session invitation request message is included in the add-on supported by the PoC client B, the PoC client B add-on information is checked through a query. A 200 OK message can be sent to PoC Client A. However, if the required add-on included in the session invitation request message is not included in the add-on supported by the PoC client B, it may be transmitted to the PoC client A as a response message as in steps 828 to 832.

In addition, according to an embodiment of the present invention, when there are a plurality of required add-ons requested by a PoC client, which is a PoC establisher, and a corresponding PoC client supports all of the plurality of add-ons, a 200 OK message is transmitted as a response message. It was explained so that it could be opened. However, when there are a plurality of required additional functions requested by a PoC client, which is a PoC founder, and the counterpart PoC client supports at least one of the plurality of additional functions, a 200 OK message is transmitted as a response message. The PoC client, the PoC founder, can also be informed of the supported additional functions.

1 is a conceptual diagram of a general PoC service system and related network structure;

2 is a schematic structural diagram of a general PoC server;

3 is a diagram for schematically explaining a Controlling PoC Function block and a Participating PoC Function block of a PoC server;

4 is a signal flow diagram for establishing a conventional PoC session;

5 is a signal flow diagram for establishing a PoC session for requesting an essential additional function when a response mode of a receiving PoC client is a passive mode according to an embodiment of the present invention;

6 is an exemplary diagram illustrating an add-on type definition table in which a value of an essential add-on parameter and an add-on type corresponding thereto are mapped according to an embodiment of the present invention;

7 is a view showing an overview of the SDP protocol of the session invitation request message according to an embodiment of the present invention;

8 is a signal flow diagram for establishing a PoC session for requesting an essential additional function when a response mode of a receiving PoC client is an automatic mode;

9A and 9B illustrate an example of a PoC service setting request message including additional function support information according to an embodiment of the present invention.

Claims (20)

In the system for establishing a PoC (Push To Talk) over the Cellular (PTT) session, A sending PoC client generating and sending a session invitation request message; At least one receiving PoC client, Receiving the session invitation request message, checking a response mode of the receiving PoC client and if the response mode is set to a passive mode, a PoC server for transmitting the received session invitation request message to the receiving PoC client; , The session invitation request message includes a mandatory add-on parameter and invited PoC client information invited, and the mandatory add-on parameter is information indicating an add-on selected for use in a mandatory PoC session. When the receiving PoC client receives the session invitation request message, the receiving PoC client checks the required additional function parameter to determine whether to support the required additional function, and if not, supports the function notifying that the PoC client cannot participate in the opened PoC session. PoC session establishment system, characterized in that for transmitting the impossible message to the PoC server. The method of claim 1, wherein the transmitting PoC client, After storing the add-on type definition table consisting of at least one add-on type and a value corresponding to each add-on type, and after confirming the value for the type of the selected add-on to be mandatory to use in the PoC session, PoC session establishment system, characterized in that to include the identified value in the required additional function parameter. The method of claim 2, wherein the receiving PoC client, After checking the required additional function parameter, if the user supports the required additional function, the PoC user is informed to select whether to participate in the PoC session, and if the user is selected to participate in the PoC session, the user is allowed to participate in the PoC session. The PoC session establishment system, characterized in that for transmitting a response message including the required additional function support parameters to indicate that the PoC server. The method of claim 3, wherein the receiving PoC client, If the mandatory add-on is supported and the PoC session participation is selected from the user, a response message including a value equal to the value of the mandatory add-on parameter included in the received session invitation request message is included in the mandatory add-on support parameter. PoC session establishment system, characterized in that for transmitting to the PoC server. The method of claim 1, The receiving PoC client generates a PoC service setting request message including PoC service setting information and additional function information that can be supported before the PoC session is established, and then the generated PoC service setting request for PoC service setting to the PoC server. Send the old message to the PoC server, And when the PoC server receives a PoC service setting request message including the additional function support information, stores the PoC service setting in correspondence with a PoC client that has transmitted the PoC service setting request message. The method of claim 5, wherein the PoC server, If the session invitation request message is received and the response mode of the receiving PoC client is set to the automatic mode, whether the receiving PoC client supports the required additional function through the PoC service setting corresponding to the receiving PoC client. And determining whether to support the PoC session to the receiving side PoC client. The method of claim 6, wherein the PoC server, Determining whether the receiving PoC client supports the required additional function, and if possible, sending a response message including the required additional function support parameter to indicate that the receiving PoC client will participate in the PoC session. Featured PoC session establishment system. The method of claim 7, wherein the PoC server, If the mandatory add-on is supported, the response message includes a value equal to the value of the mandatory add-on parameter included in the received session invitation request message in the mandatory add-on support parameter and is transmitted to the transmitting side PoC client. PoC session establishment system. The PoC session is established in a system including a transmitting PoC client, a PoC server, and at least one receiving PoC client invited to the PoC session, to establish a predetermined PoC PoC (Push To Talk) session. In the method for opening, Transmitting, by the transmitting PoC client, a session invitation request message including the required additional function parameter indicating the additional function selected for the essential use in the PoC session and the receiving PoC client information to the PoC server; Checking, by the PoC server, a response mode of the receiving PoC client in the received session invitation request message; If the response mode is set to the passive mode, transmitting the received session invitation request message to the receiving PoC client; When the receiving PoC client receives the session invitation request message, checking the essential additional functions through the required additional function parameters included in the session invitation request message, and then checking whether the PoC client supports the required additional functions; When the receiving PoC client receives the session invitation request message, the receiving PoC client checks the required additional function parameter to determine whether to support the required additional function, and if not, supports the function notifying that the PoC client cannot participate in the opened PoC session. PoC session establishment method comprising the step of transmitting a non-access message to the PoC server. The method of claim 9, wherein the transmitting of the session invitation request message comprises: If the sending side PoC client is selected as an essential function to be used in the PoC session, the selected PoC client includes the at least one additional function type and a value corresponding to each type. Checking the value for the type of add-on, And generating a session invitation request message including the checked value and the receiving side PoC client information in the required additional function parameter and transmitting the generated session invitation request message to the PoC server. The method of claim 10, wherein after performing the inspection process, If the receiving PoC client supports the required additional function, informing the PoC user of the receiving PoC client to select whether to participate in the PoC session; If the PoC user is selected to participate in the PoC session, further comprising the step of transmitting a response message including the required additional function support parameters to the PoC server. The method of claim 11, wherein the transmitting of the response message including the required additional function support parameter to the PoC server comprises: And transmitting a response message including a value equal to a value of a required additional function parameter included in the received session invitation request message to the PoC server. 10. The method of claim 9, If the PoC server receives a PoC service setting request message including additional function support information before transmitting a session invitation request message to the PoC server, the PoC service setting request message to the PoC service setting request message; And storing the corresponding PoC client in correspondence with the transmitted PoC client. If the response mode of the receiving PoC client is set to the automatic mode after performing the response mode checking procedure of the receiving PoC client, the receiving PoC client is added to the required PoC client through the service setting corresponding to the receiving PoC client. Verify that the feature is supported, And transmitting a function unsupported message to the receiving PoC client to inform that the PoC session cannot participate in the PoC session if the required additional function is not supported. The method of claim 13, wherein after performing the process of checking whether the receiving PoC client supports the required additional function, The PoC server further includes a step of transmitting a response message including the required additional function support parameter to the transmitting PoC client to indicate that the PoC server will participate in the PoC session if the required additional function is supported. How to open. The method of claim 14, wherein the transmitting of the response message to the transmitting PoC client comprises: The PoC server is a process of transmitting a response message including a value equal to a value of a required additional function parameter included in the received session invitation request message to the transmitting side PoC client. How to open a PoC session. In the PoC terminal for establishing a PoC session in a system including a PoC terminal and a PoC server for establishing a PoC PoC (PTT (Push To Talk) over the Cellular) session and participating in the PoC session, Wireless unit for sending and receiving messages, Generate and send a session invitation request message including the required add-on parameter indicating the selected add-on to be used in a PoC session and the invited PoC client information through the wireless unit, and send a predetermined session invitation through the wireless unit. When the request message is received, it is determined whether the essential additional function is supported by checking the required additional function parameter, and if the support is not available, a function support unavailable message indicating that the user cannot participate in the PoC session to be established is transmitted through the wireless unit. PoC terminal comprising a control unit for transmitting to the server. The method of claim 16, And a memory unit configured to store an additional function type definition table including at least one additional function type and a value corresponding to each additional function type. The controller checks the value of the type of the additional function selected for the essential use in the PoC session through the memory unit, and then includes the checked value in the required additional function parameter. The method of claim 17, wherein the control unit, After checking the required additional function parameter, if the user supports the required additional function, the PoC user is informed to select whether to participate in the PoC session, and if the user is selected to participate in the PoC session, PoC terminal, characterized in that for transmitting a response message including the necessary additional function support parameter to indicate that the to the PoC server through the wireless unit. The method of claim 18, wherein the control unit, If the mandatory add-on is supported and the PoC session participation is selected from the user, a response message including a value equal to the value of the mandatory add-on parameter included in the received session invitation request message is included in the mandatory add-on support parameter. PoC terminal, characterized in that for transmitting to the PoC server via the wireless unit. The method of claim 16, wherein the control unit, If there is a request from the user for PoC service setting before the PoC session is established, a PoC service setting request message including input PoC service setting and additional function information supported by the user is generated, and then the PoC server is configured for PoC service setting. PoC terminal, characterized in that for transmitting the generated PoC service setting request message via a wireless unit.

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