KR101407778B1 - METHOD AND SYSTEM AND PoC TERMINAL FOR ESTABLISHING PoC SESSION - Google Patents

Abstract

The present invention relates to a method for establishing a PoC session according to whether or not a participant to participate in a PoC session supports essential supplementary functions, and a system therefor and a PoC terminal. To this end, the present invention transmits a PoC session establishment request to a PoC server by including a required additional function parameter indicating an essential additional function to be used in a PoC session to be established in a session invitation request message, Message to the receiving PoC client, and if the receiving PoC client does not support the required additional function, the message is not accepted (488 Not Acceptable here) regardless of the user's intention to participate in the PoC session. And transmits it to the PoC client which is the establisher through the PoC server. By doing so, the PoC session establisher can participate in the PoC session only when the other side PoC client supports the necessary additional functions to be used in the PoC session to be established.

PoC system, INVITE, open session, required additional function

Description

METHOD AND SYSTEM AND PoC TERMINAL FOR ESTABLISHING PoC SESSION [0002]

The present invention relates to a method and system for establishing a PoC session and a PoC terminal, and more particularly, the present invention relates to a method and system for establishing a PoC session and a PoC terminal in which a participant participating in a PoC session participates in a corresponding PoC session And a PoC terminal and a system therefor.

With the breakthrough of mobile communication and the expansion of communication network, a wider variety of services and applications using mobile phones are being provided. In addition, the PTT service is widely used for a conventional radio or TRS (Trunked Radio (PTT)) service, etc. In addition, a PTT service has been extended to a location service, a multimedia service, a PTT System, etc.), as well as instant messenger and status display.

Currently, the establishment of a standard for a PoC (PTT over the Cellular) service (PoC) service that uses the PTT concept using a mobile communication network is actively being discussed. One of the requirements is that the user belongs to multiple sessions and can make calls while moving between sessions as required. The requirement that the user should be able to talk while moving a plurality of sessions, that is, Is specified in the requirements of the Open Mobile Alliance (OMA), an organization that defines mobile communications services.

On the other hand, a PoC call service among PoC services will be described. In order to use a PoC call service, a PoC user registers a PoC address of its own PoC client in a SIP / IP core. At this time, the SIP / IP core stores information about the PoC client based on the request of the PoC client. Therefore, when another PoC user tries to make a call to the PoC group, it first registers its own information in the SIP / IP core as described above, and sends a call request to its own SIP / IP core network using the group identification information transmitted from the XDMS do. At this time, the SIP / IP core performs address determination and domain positioning using the requested PoC user information, and then transmits the PoC call request to the home PoC server in which the requesting PoC user is registered. The PoC server prepares a PoC session for this 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 a call request for clients in the intra domain, the PoC server performs both PF and CF functions. The PoC server managing the requested PoC client uses the information of the PoC client transmitted to the PoC client and performs a positioning process of the SIP / IP core network, and then makes a call request to the corresponding PoC client. When a PoC client requesting a PoC call sends an OK response through its PoC client to the PoC client requesting the call, the PoC call is opened.

Referring to FIG. 4, when a PoC user A requests a PoC user B for a PoC call, the PoC user A creates a session invitation request (INVITE) message using the PoC client A of the PoC terminal of the PoC user A. At this time, the PoC user A creates a session invitation request message including service information such as a PoC service, a video service, and a queue service, to be used by the user. Then, the PoC client A transmits the created session invitation request message to the PoC server A, which is its home server, in step 400. In step 402, the PoC server A searches for a PoC server X serving as a controllable PoC function (CF) to collectively manage the PoC session, and transmits the received session invitation request message.

then. Upon receipt of the session invitation request message transmitted by the PoC client A, the PoC server X controls the PoC session based on the session invitation request message and transmits a session invitation request for transmitting the PoC service to be used by the PoC client A to the PoC client B Message to the PoC server B which is the home server of the PoC client B in step 404.

After receiving the session invitation request message, the PoC server B processes the message according to the user setting of the PoC client B. For example, according to a user setting such as an access policy or a reject list, a received message is transmitted according to an operation of a PoC server B serving as a PF and a message transmission procedure. Thereafter, in step 406, a session invitation request message is transmitted to the PoC client B. After the PoC client B receives the session invitation request message, the PoC client B can respond according to the determination of the PoC user B. When the PoC user B accepts the call with the PoC user A, two cases may occur depending on the service and function that the PoC client B can support.

That is, the PoC client B checks whether the additional function included in the session invitation request message is supported in step 408. If the PoC client B supports the PoC service, i.e., the additional function requested by the PoC client A, ) To the PoC server X in steps 410 and 412, and transmits the response message (200 OK message). Then, the PoC server X forwards the received response message to the PoC client A.

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

If the PoC user having the PoC terminal attempts to use the specific additional function in the session to be opened when the PoC user having the PoC terminal attempts to open the PoC session but the corresponding PoC client does not support the specific additional function, A PoC session can not but be opened. That is, at this time, the PoC user requesting the establishment of the PoC session can not indicate that he / she does not want to open the PoC session unless the additional client supports the additional function to be used in the PoC session to be opened. The session must first be opened and then the PoC session must be terminated again. Accordingly, a session may be established in which a service other than the intention of the PoC session establisher is provided.

Accordingly, the present invention provides a PoC terminal and a method and system for requesting a counterpart PoC client for a necessary additional function to be used in a PoC session to be established by the PoC session establisher in establishing the PoC.

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

To this end, the present invention provides a system for establishing a PoC (Push To Talk) over the Cellular (PoC) session, comprising: an additional function to be used in a PoC session to be opened when a PoC session is opened; A transmitting-side PoC client for generating and transmitting a session invitation request message including an essential additional function parameter for indicating the selected additional function and information of the receiving-side PoC client, A PoC server for transmitting a received session invite request message to the receiving PoC client when the response mode is set to the passive mode after confirming a response mode of the receiving PoC client; If the necessary additional function is not supported by confirming the necessary additional function parameter, And a receiving-side PoC client for transmitting a function support-not-ready message to the PoC server to notify that it can not participate in the PoC session to be opened.

In addition, the present invention provides a PoC communication system in a system including a transmitting-side PoC client for establishing a predetermined PoC (Push To Talk) over the Cellular session, a PoC server, and a receiving-side PoC client invited to the PoC session Wherein the PoC client includes a PoC client and a PoC client, the method comprising: receiving a PoC session with the PoC client; receiving, by the PoC client, Transmitting a session invite request message to the PoC server; receiving a session invite request message from the PoC server; confirming a response mode of the receiving-side PoC client in the received session invite request message; Mode, the received session invitation request message is transmitted to the receiving-side PoC client < RTI ID = 0.0 > The PoC client receives the session invitation request message and checks the required supplementary function through the required additional function parameter included in the session invitation request message to check whether the required supplementary function is supported by the receiving side PoC client And transmitting, to the PoC server, a function incompatible message for notifying that the receiving-side PoC client does not participate in the PoC session if the essential supplementary function is not supported.

The present invention also provides a PoC terminal for establishing a PoC session in a system including a PoC (Push To Talk) over the Cellular (PoT) session and a PoC client participating in a PoC session and a PoC server, When a PoC client to be invited to a session and an additional function to be essential in a PoC session to be opened in a PoC session to be opened at the time of opening a PoC session are selected, a necessary additional function parameter for indicating the selected additional function, When the session invitation request message is received via the wireless unit, the essential additional function parameter is checked, and if the essential additional function is not supported, A message indicating that the PoC session can not participate in the desired 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-side PoC client generates a PoC service setting request message including PoC service setting information and supplementary function information that can be supported by the receiving PoC client before establishing a PoC session, And transmits the generated PoC service setup request message to the PoC server. When the PoC server receives the PoC service setup request message including the supplementary function support information, it transmits the PoC service setup to the PoC service setup request message transmitting the PoC service setup request message And stores it in association with the client.

In the system of the present invention, if the PoC client receives the session invite request message and the response mode of the PoC client of the receiving side is set to the automatic mode, The PoC client determines whether the PoC client supports the essential supplementary function, and if the support is not possible, transmits a function supportability message indicating that the PoC client can not participate in the PoC session to be established to the receiving PoC client.

In addition, in the system of the present invention, the PoC server determines whether or not the receiving-side PoC client supports the essential supplementary function, and if it is possible to support, a response including a required supplementary function supporting parameter for indicating that the PoC client participates in the PoC session Message to the transmitting-side PoC client.

The present invention can request an essential supplementary function to be used in a PoC session to be established by a PoC session establisher at the time of establishing a PoC to the other party's PoC client and allow the other party's PoC client to support an essential additional function to be used in the PoC session to be established by the PoC session establisher The advantage is that you can only allow you to participate in a PoC session.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

First, a PoC system to which the present invention is applied will be described with reference to FIGS. 1 to 3. FIG. In the following, the present invention is applied to a PTT (Push To Talk) system, in particular, a PoC (Ptt over Cellular) system that provides a PTT service using a cellular mobile communication network. Generally, the PoC system uses a Session Initiation Protocol (SIP) protocol and a SIP extension protocol to transmit session participation information of a group call, and uses an XCAP (XML Configuration Access Protocol) protocol to acquire 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 a related network structure.

1, a general PoC system may be configured to include a PoC terminal (User Equipment; UE) 100, an XML document management server (XDMS), and a PoC server 150. In addition, the PoC system may further include an aggregation proxy server 160. These components may be connected through the access network 110, the SIP / IP core network 120, and the remote PoC network 170.

Each of the above-described components will be described as follows.

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

The PoC client 102 is a service requestor built in the PoC terminal 100. The PoC client 102 resides in the PoC terminal 100 and performs network connection for providing a PoC service to the PoC service subscriber. The PoC service subscriber can receive the PoC service through the PoC terminal having the PoC client built therein. In the following description of the present invention, the term PoC client will be used generically to refer to a terminal having a PoC client and a PoC service subscriber. Further, the reference numerals of the PoC client will be omitted hereafter unless it is particularly required to distinguish them.

The main function of the PoC client is to set up or set up a PoC session in the PoC service subscriber, i.e., the PoC user, or to terminate the established session. In addition, the PoC client performs functions such as creating and delivering a talk burst, supporting an instant personal alert, and authenticating when connected to a PoC service. The PoC client may be connected to the SIP / IP core network 120, which is a SIP / IP multimedia supporting core network, via the access network 110.

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

On the other hand, a PoC service may involve a service to open a group session, such as a conference call. To this end, the OMA specification defines XDM (XML Document Management) client 104 and XDMS 130 (140) for group list service. FIG. 1 shows a common XDMS 130 that can be used in common with PoC XDMS 140 used for PoC service and other service enablers. 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 the PoC client can call through the list of individuals or groups transmitted from the XDMS 130 (140). Meanwhile, the creation, modification, and management of group and group members for the XDMS 130 (140) may be performed over a reliable communication network of a PoC service provider such as the Internet or an intranet. The detailed description of the protocol and the specific contents of the XML document management such as generation, modification and removal of the group list will be omitted.

When the grouping-related request is received from the XDMC 104 for the group service, the aggregation proxy server 160 routes the request to each XDMS 130 (140) according to an appropriate rule.

Next, the PoC server 150 will be described.

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

The PoC server includes a Controlling PoC Function (hereinafter referred to as "CF") for maintaining and managing the PoC session as a whole and a participating PoC Function (hereinafter referred to as "PF" . Functional characteristics of the PoC server will be described with reference to Table 1 and Table 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 plays a role of managing the PoC session as a whole among the functions of the PoC server. In particular, the CF accepts and orders the rights of the PoC clients (floor) Distributes the talk burst requested by the PoC client to all other PoC clients participating in the group call and provides the information of the PoC client attending the group call.

The PF manages the CF and the sessions associated with each PoC client in the PoC session, particularly when the PoC client requests the floor or gives the floor to the PoC client in the CF, as shown in Table 2 below. In addition, PF relays media between CF and PoC clients, transcodes if they use different codecs between them, and in the case of concurrent sessions, when talking in one session, It acts as a filter for 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 the messages using the XCAP protocol in the PoC system and transmits the messages to the corresponding entities.

3 is a diagram for explaining a Controlling PoC Function Block and a Participating PoC Function Block of a PoC server.

Referring to FIG. 3, each of the PoC clients 102-A to 102-D establishes a PoC session by accessing the CF 300 through the PFs 310-A to 310-D. Thereafter, the media for the corresponding utterance of the PoC client that has been given the voice from the CF 300 is transmitted to each PoC client. At this time, the PoC client that has been granted the voice can only make an appropriate remark after confirming the information of the PoC clients participating in the group session.

In the PoC system configured as described above, the PoC client that opens the session informs the PoC client of the supplementary function that it intends to use as essential in the session to be opened, and when the corresponding PoC client supports the additional function, Will be described with reference to FIG.

Referring to FIG. 5, when the PoC user A intends to use a predetermined essential additional function in a PoC session to be established, the essential additional function is selected through the PoC client A. In step 500, the PoC client A converts the type of the mandatory additional function selected by the user into the value of the mandatory additional function parameter (P_required_feature parameter) defined in the form of SDP (Session Description Protocol) MIME extension, Include in invitation request message. Needless to say, the session invitation request message includes the PoC client information to be invited to the session. At this time, the value of the mandatory additional function parameter is represented by a decimal number, and the type of the feature is assigned to each numerical value. The additional function type definition table in which the values of the required additional function parameters and the corresponding additional function types are mapped as described above is shown in FIG. 6, and the additional function type definition tables are stored in the PoC terminal and the PoC server.

Referring to FIG. 6, there are shown examples of additional function types assigned to each value. The present invention will be described based on the additional function type corresponding to the value assigned in the additional function type definition table of FIG. However, it goes without saying that the additional function types allocated to each parameter value may vary in actual implementation. The values for the additional function type may represent one additional function type or may represent more than two additional function types. However, after defining one additional function type and its corresponding value, A plurality of values may be combined and included in the required additional function parameter. In order to perform the service according to the present invention, such additional function type definition table should be stored in the same table in both PoC clients and PoC servers.

Hereinafter, it is assumed in FIG. 5 that the PoC user A has selected video and queuing functions as essential supplementary 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 parameter value.

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

The portion included in 700 blocks in FIG. 7 is a part of the SDP protocol. The contents of the entire SDP protocol include information such as connection information, address information, media information to be used, a port number, and a bandwidth according to actual media transmission Here, the description is omitted because it is directly related to the present invention. &Quot; m = application 22000 udp MBCP " includes media information. This media is used as an application (" application / sdp " application, that it uses a port number of 22000, and that it is called MBCP using the udp protocol. Further, "a = fmtp: MBCP queuing = 1; tb_granted = 1; P_required_feature = 11" defines additional attributes for the media or application. The format protocol uses MBCP, supports high priority when queuing is supported, and when the PoC session is established, the sender of the PoC session tries to obtain the voice without requesting the floor . In particular, the mandatory additional function parameters included in the session invitation request message according to the present invention may be included in a portion where media attributes are defined, such as 710. Since the mandatory additional function parameter value is 11, PoC user A desires to open video and queuing PoC clients that do not support it will be able to attend this PoC session.

On the other hand, the PoC server A having received the session invitation request message including the required additional function parameters delivers the session invitation request message to the PoC server X, which is CF by the characteristic of the PoC service and the routing rule in step 502.

Then, the PoC server X stores the required additional function parameters and their values included in the received session invitation request message, and inserts the required additional function parameters into the session invitation request message for transmission to the PoC server B. Then, in step 504, the PoC server X transmits a session invitation request message to the PoC server B, which is the home server of the PoC client B, with the additional function parameter inserted therein. Thereafter, the PoC server B determines the processing method of the session invitation request message according to the PoC service setting (service setting) of the PoC client B. [ At this time, although the PoC service setting can be variously described, it is assumed that the embodiment of FIG. 5 is set to operate as a manual answer mode in the answer mode. The PoC server B transmits a session invitation request message to the PoC client B in step 506 according to the response mode setting of the PoC client B. [

Then, the PoC client B checks the value of the required additional function parameter in the session invitation request message, and analyzes what additional function corresponds to the value. Here, it is assumed that the PoC client B also stores the additional function type definition table as shown in FIG. Then, since the value of the mandatory additional function parameter is 11 as a result of the analysis, it is recognized that video and queuing functions are mandatory additional functions.

Then, in step 508, the PoC client B confirms whether the video and queuing functions set as the mandatory additional functions are supported. If the PoC client B supports the video and the queuing functions, the PoC client B informs the PoC user B that the PoC client B is invited to the PoC session, and performs an operation for asking the user whether or not to participate in the PoC session. The PoC session invitation notification and PoC session participation inquiry can display this content on the screen of the PoC terminal and receive the user's selection. At this time, if the PoC user B has selected to participate in the PoC session, the PoC client B inserts the value of the mandatory additional function parameter into the 200 OK message as the response message as 11, and transmits it to the PoC server X through steps 510 and 512 do. That is, when the PoC client is selected to participate in the PoC session by the PoC user while supporting the necessary additional function, the PoC client transmits the additional parameter including the parameter value same as the received additional parameter.

However, if the PoC client B supports the mandatory additional function as a result of step 508 and the PoC user B indicates that the PoC user B does not participate in the PoC session, it sends a reject message to the PoC server X as a response message. In step 514 and step 516, the PoC server X transmits a response message including the value of the essential supplementary function supporting parameter 11 to the PoC server A to the PoC client A.

On the other hand, if it is determined in step 508 that the PoC client B does not support the video and queuing function, which is an essential supplementary function, the PoC client B transmits a message 488 Not Acceptable here to the PoC server X in steps 520 and 522 Functions are not supported. Then, in step 524 and step 526, the PoC server X transmits a function supportability message to the PoC server A to the PoC client A.

That is, in the present invention, if the PoC client B invited to the session does not support the additional function that the PoC client A intends to use in the session to be opened, the PoC client B can not participate in the PoC session.

Although not shown in the internal configuration of the PoC client A and the PoC client B 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 Is performed by the control unit, and the table as shown in FIG. 6 can be stored in the memory unit. Also, the PoC clients A and B have wireless units and can transmit and receive messages to and from the PoC server through the wireless unit. In addition, the PoC clients A and B can display a message or an operation state by providing a display unit, and the PoC clients A and B can use a key input unit as a predetermined selection and input means.

In FIG. 5, the case where the response mode setting of the PoC client B in the PoC client B is set to the manual response mode and the session invitation request message is transmitted to the PoC client B has been described with reference to FIG. Hereinafter, a case where a response mode setting is set to an automatic answer mode during PoC service setting of the PoC client B in the PoC server B will be described with reference to FIG.

First, the PoC client B sends a PoC service setup request message for setting the response mode to the automatic answering mode to the PoC server B, and sets the PoC service setting of the PoC client B in the automatic response mode. However, if the PoC server B is simply set to the automatic response mode, the PoC user B will always participate in the received 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 generates a 200 OK message in response to the response message and does not send it to the PoC client B. At this time, there is no way to know whether the PoC client B supports the necessary supplementary functions, which may cause problems. Therefore, in step 800, the PoC client B transmits to the PoC server B information for setting the response mode to the automatic response mode in the PoC service setup request message, and additional function support information that the PoC client B can support. The PoC service setup request message transmitted here may be transmitted in the PUBLISH message. Such a PoC service setup request message can be shown in FIGS. 9A and 9B. The information included in the 900 block of Fig. 9B is supplementary function support information, and the PoC client that transmitted this message is video (vedio). Audio, text, queuing, a media burst control scheme, and a dispatcher function. Such additional function support information can be inserted and transmitted in the PoC service setting part as in the 900 block of the XML MIME body of the PUBLISH message. Another method in which a message including additional function support information is transmitted from a PoC client to a home PoC server may include 900 blocks written in XML.

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

The PoC service setting process as in steps 800 to 804 is a procedure performed by all the PoC users who wish to receive the PoC service through their own PoC clients. Therefore, all PoC clients must send a PUBLISH message to the PoC server, including supplementary support information that can be supported by the PoC clients during the process of setting up the PoC service.

On the other hand, when the PoC user A wishes to use a predetermined essential additional function, the essential additional function is selected through the PoC client A. Then, in step 810, the PoC client A converts the required additional function selected by the user into a value of a required additional function parameter (P_required_feature parameter) defined in the form of an SDP MIME extension, and includes it in the session invitation request message. In this case, it is assumed that the PoC user A has selected video and queuing functions as essential supplementary functions in the embodiment of FIG. In step 810, the PoC client A confirms 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 mandatory additional function of the user A, And generates a session invitation request message to be included in the mandatory additional function parameter value of the message.

Then, the PoC client A transmits the session invitation request message generated in step 810 to the PoC server A as its home server in step 812. That is, the selected required additional functions are transmitted to the PoC server A, which is the home server of the PoC client A, using the SDP protocol of the session invitation request message. The session invitation request message transmitted at this time can be shown in FIG.

Upon receipt of the session invitation request message including the necessary additional function parameters, the PoC server A sends to the PoC server X, which plays a role of collectively managing the PoC session according to the characteristics of the PoC service and the routing rule, It forwards the request message.

Then, the PoC server X recognizes that the home server of the receiving-side PoC client B of the session invitation request message is the PoC server B, and inserts the necessary additional function parameters into the session invitation request message for transmission to the PoC server B. In step 816, the PoC server X transmits a session invitation request message to the PoC server B, which is the home server of the PoC client B, with the additional function parameter inserted therein.

Then, the PoC server B confirms 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 automatic response mode, the PoC server B processes the session invitation request message according to the automatic response mode setting of the PoC client B.

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

Then, in step 820, the PoC server B confirms whether the PoC client B supports the video and queuing functions in the PoC service configuration related to the PoC client B.

If the PoC client B supports the video and the queuing function, the value of the mandatory additional function parameter is inserted as 11 in the 200 OK message as a response message, and is transmitted to the PoC server X in step 822. In step 824 and step 826, the PoC server X transmits the function supportable message to the PoC server A to the PoC client A.

However, if it is determined in step 820 that the PoC client B does not support the video / queuing function, which is a mandatory additional function, the PoC client B transmits a function not supported (488 Not Acceptable here) message to the PoC server X in step 828, Notification is not supported. In step 830 and step 832, the PoC server X transmits a function supportability message to the PoC server A to the PoC client A.

Although not shown in the internal configuration of the PoC client A and the PoC client B 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 Is performed by the control unit, and the table as shown in FIG. 6 can be stored in the memory unit.

As described above, according to the present invention, the PoC session establisher transmits a session invitation request message to the PoC server, including essential supplementary function parameters indicating essential supplementary functions to be used in the PoC session to be opened in the session invitation request message, And transmits an invitation request message to the corresponding receiving-side PoC client. If the receiving-side PoC client does not support the required additional function, the receiving-side PoC client transmits a function not supported (488 Not Acceptable here) message to the PoC client which is the originator through the PoC server regardless of the user's intention to participate in the PoC session send. By doing so, the PoC session establisher can participate in the PoC session only when the other side PoC client supports the necessary additional functions to be used in the PoC session to be established.

In FIG. 8, the PoC client B stores the PoC service configuration of the PoC client B in the PoC server B as the PoC server B, but in another embodiment, the PoC client B can support the PoC client B Additional feature information may also be stored in the Shared XDMS. When the PoC server B sets the PoC service setting for the response mode to the automatic response mode, the PoC server B receives the session invitation request message to be transmitted to the PoC client B as in step 816, If the essential additional function included in the session invitation request message is included in the additional function that can be supported by the PoC client B, a response message is generated as in steps 822 to 826 200 OK message to the PoC client A. However, if the required additional function included in the session invitation request message is not included in the supplementary function that can be supported by the PoC client B, the response message may be transmitted to the PoC client A in steps 828 through 832.

Also, in the embodiment of the present invention, when a plurality of required additional functions requested by a PoC client as a PoC establisher are supported, and when the relative PoC client supports all of the plurality of additional functions, a 200 OK message is transmitted as a response message, To be opened. However, when there are a plurality of required additional functions requested by the PoC client that is a PoC establisher, and the relative PoC client supports at least one of the plurality of additional functions, a 200 OK message is transmitted as a response message, It is possible to notify the PoC client which is the PoC establisher.

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

FIG. 2 is a schematic 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 requesting an essential supplementary function when the response mode of the receiving-side PoC client is the passive mode according to the embodiment of the present invention;

6 is an exemplary diagram showing an additional function type definition table to which values of essential additional function parameters and corresponding supplementary function types are mapped according to an embodiment of the present invention;

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

8 is a signal flow diagram for establishing a PoC session requesting an essential supplementary function when the response mode of the receiving-side PoC client is the automatic mode,

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

Claims (20)

1. A system for establishing a PoC (Push To Talk) over the Cellular (PTT) session, Upon receipt of the session invitation request message from the transmitting-side PoC client, the receiving-side PoC client checks the response mode of the receiving-side PoC client, and if the response mode is set to the manual mode, transmits the received session invite request message to the receiving- Server, Wherein the session invitation request message includes an essential supplementary function parameter and invited recipient-side PoC client information, the essential supplementary function parameter is information indicating an additional function selected for use in the PoC session, Wherein the PoC server receives from the receiving-side PoC client a function not supporting message indicating that the PoC client can not participate in the PoC session or a response message including an essential supporting function parameter indicating that the PoC client participates in the PoC session. Session opening system. 2. The PoC client according to claim 1, An additional function type definition table including at least one additional function type and a value corresponding to each additional function type is stored and a value of a type of the selected additional function is confirmed for use in the PoC session, And the identified value is included in the additional function parameter. 3. The PoC client according to claim 2, After confirming the necessary additional function parameters and informing the PoC user to select whether or not to participate in the PoC session, if he or she desires to participate in the PoC session, he / she can participate in the PoC session And transmits a response message to the PoC server, the response message including a required additional function support parameter for indicating that the PoC session is established. 4. The PoC client according to claim 3, When the participation of the PoC session is selected by the user, a response message including the same value as the value of the essential supplementary function parameter included in the received session invitation request message is included in the essential supplementary function supporting parameter To the PoC server. The method according to claim 1, The receiving-side PoC client generates a PoC service setting request message including PoC service setting information and supplementary function information that the PoC service setting information can support before establishing a PoC session, and then transmits the created PoC service setting message to the PoC server Transmits an old message to the PoC server, And when the PoC server receives the PoC service setup request message including the supplementary function support information, stores the PoC service setup in association with the PoC client that transmitted the PoC service setup request message. 6. The PoC server according to claim 5, If the session invite request message is received and the response mode of the receiving PoC client is set to the automatic mode, the receiving-side PoC client determines whether the receiving-side PoC client supports the required additional function through the PoC service setting corresponding to the receiving- And transmits a function incompatible message to the receiving PoC client to inform the PoC client that it can not participate in the PoC session if it can not support the PoC session. 7. The PoC server according to claim 6, Determining whether the receiving-side PoC client supports the required additional function, and transmitting, to the transmitting-side PoC client, a response message including an essential supporting function parameter for indicating that the PoC client is to participate in the PoC session if supported PoC session establishment system characterized by. 8. The PoC server according to claim 7, If it is possible to support the essential supplementary function, a value equal to the value of the essential supplementary function parameter included in the received session invitation request message is included in the essential supplementary function supporting parameter and is transmitted to the transmitting-side PoC client PoC session establishment system. A PoC server for sending a PoC (Push To Talk) over the Cellular (PoT) session, a PoC server, and at least one receiving PoC client invited to the PoC session. In the method, Receiving, by the PoC server, a session invitation request message including an essential additional function parameter indicating an additional function selected for use in the PoC session from the transmitting-side PoC client and the receiving-side PoC client information; Confirming a response mode of the receiver-side PoC client in the received session invitation request message when the PoC server receives the session invitation request message; Transmitting the received session invitation request message to the receiving-side PoC client when the response mode is set to the passive mode; Receiving a function incompatible message indicating that the PoC server can not participate in the PoC session from the receiving PoC client or a response message including an essential supplementary function supporting parameter for indicating participation in the PoC session And a PoC session establishment method. [11] The method of claim 9, When the sender-side PoC client selects an add-on function to be essential in the PoC session, the sender-side PoC client adds the at least one add- Checking the value of the type of the additional function; And generating a session invitation request message including the confirmed value and the receiving-side PoC client information in the essential additional function parameter, and transmitting the session invitation request message to the PoC server. The method of claim 10, wherein the step of receiving the response message comprises: A step of informing the PoC user of the receiving-side PoC client to select whether to participate in the PoC session if the receiving-side PoC client supports the essential additional function; And transmitting a response message including the essential supplementary function supporting parameter to the PoC server if the PoC user is selected to participate in the PoC session. The method as claimed in claim 11, wherein the step of transmitting a response message including the essential supplementary function supporting parameter to the PoC server comprises: And transmitting a response message including the same value as the value of the essential supplementary function parameter included in the received session invitation request message to the essential supplementary function supporting parameter to the PoC server. The method as claimed in claim 9, further comprising, before the PoC server receives the PoC service setup request message including the supplementary function support information, The method comprising the steps of: If the response mode of the receiving-side PoC client is set to the automatic mode after performing the acknowledgment mode check of the receiving-side PoC client, the receiving-side PoC client notifies the receiving- Checking whether the function is supported, Further comprising the step of transmitting, to the receiving-side PoC client, a function-not-supporting message for notifying the failure to participate in the PoC session if the essential supplementary function is not supported. 14. The method according to claim 13, further comprising: after confirming whether the receiving-side PoC client supports the essential additional function, Wherein the PoC server further includes a step of transmitting, to the transmitting-side PoC client, a response message including an essential supplementary function supporting parameter for indicating that the PoC server is to participate in the PoC session if the essential supplementary function is supported. How to open. The method of claim 14, wherein the step of transmitting the response message to the sending PoC client comprises: Wherein the PoC server transmits a response message including the same value as the value of the essential supplementary function parameter included in the received session invitation request message to the essential PoC function supporting parameter to the transmitting PoC client How to set up a PoC session. A PoC terminal for establishing a PoC session in a system including a PoC terminal (PTT (Push To Talk) over the Cellular) session and a PoC terminal participating in a PoC session and a PoC server, A wireless unit for sending and receiving a message, Generates a session invitation request message including a required additional function parameter indicating an additional function selected for use in a PoC session and invited receiver side PoC client information, transmits the session invitation request message through the wireless unit, When the request message is received, determines whether the essential supplementary function is supported by checking the essential supplementary function parameter, and if it is not supported, transmits a function not supporting message indicating that the user can not participate in the opened PoC session, And transmitting the PoC terminal to the PoC terminal. 17. The method of claim 16, Further comprising a memory unit for storing an additional function type definition table including at least one additional function type and a value corresponding to each additional function type, Wherein the control unit confirms a value of a type of the selected additional function for use in the PoC session through the memory unit and then includes the identified value in the required additional function parameter. 18. The apparatus of claim 17, After confirming the necessary additional function parameters and informing the PoC user to select whether or not to participate in the PoC session, if he or she desires to participate in the PoC session, he / she can participate in the PoC session To the PoC server via the radio unit, a response message including the required supplementary function support parameter for indicating that the supplementary function supporting parameter is present. 19. The apparatus of claim 18, When the participation of the PoC session is selected by the user, a response message including the same value as the value of the essential supplementary function parameter included in the received session invitation request message is included in the essential supplementary function supporting parameter To the PoC server through the wireless unit. 17. The apparatus of claim 16, If there is a request for setting a PoC service from the user before the establishment of the PoC session, a PoC service setup request message including the input PoC service configuration and the supportable supplementary function information can be generated, And transmits the generated PoC service setup request message through a radio unit.

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