KR20090058227A - System and method for floor control in a push to talk over cellular session - Google Patents

Abstract

A system and a method for managing the floor in a push to talk over cellular session are provided to enable a PoC client acquiring a chairman position of a corresponding PoC session to control the floor according to flow of real media contents. A PoC(Push to talk over Cellular Client) terminal(200) includes a PoC client(202) for maintaining a PoC session. And the PoC terminal is classified into a chairman PoC terminal or a general PoC terminal according to whether to acquire a chairman position. An XDMS(XML(eXensible Markup Language) Document Management Server) stores information of the PoC terminal which is connected to the PoC session and can be called and the chairman PoC terminal. A PoC server(250) generates and transmits a message by referring to information of the general and chairman PoC terminal. The message requests or controls data and the floor between the general PoC terminal and the chairman PoC terminal. The chairman PoC terminal performs control by admitting, rejecting or canceling the floor in the PoC session.

Description

SYSTEM AND METHOD FOR FLOOR CONTROL IN A PUSH TO TALK OVER CELLULAR SESSION}

The present invention relates to a system and a method in which a PoC client (Push to talk over Cellular Client) controls a talk right in a session of a PoC group in which the chairman controls a talk right. In particular, the present invention relates to a PoC client serving as a moderator. Receives the voice request message from the Push to talk over Cellular Server and controls the voice by instructing the inside of the response message to grant, reject, and revoke the voice. It relates to a method and a PoC system for implementing the same.

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 has been expanded to location services, multimedia services, and push-to-talk (PTT) services. It supports various additional functions such as instant messenger and status display as well as group call and voice call that were available in Trunked Radio System (TRS).

Currently, the establishment of standards for PoC services that service these PTT concepts using a mobile communication network is actively discussed.

Referring to FIG. 1, a process of controlling a speech by a PoC server in a general PoC session will be described. It is assumed that there is an ongoing PoC session between PoC Client A 110 and PoC Client B 140 in S110 of FIG. 1. In S120, the PoC client B 140 sends a floor request message. The voice request message typically uses a Media Burst Control Protocol (MBCP) voice request message defined in the Open Mobile Alliance (OMA) PoC standard document, and the MBCP voice request message is a real-time transmission defined in [RFC3550]. It is configured based on Real-time Transport Control Protocol Application Packets. In S120, the PoC server B (Participation PoC Function: PF) 130 transfers the received talk request message to the PoC server A (Controlling PoC Function: CF) 120 that is in charge of controlling the corresponding PoC session. PoC server A (CF) (120) after grasping the session occupancy status of the session, if the floor is idle (Idle) state or PoC client B (140) has the highest priority state, the speech giving message (S130) Floor Grant Message) is generated and delivered to PoC Client B 140 via Poc Server B (PF) 130, which is a home PoC server of PoC Client B 140. The PoC client B 140 may transmit media after obtaining a voice.

As described above, according to the conventional PoC session speaking rights management method, since the PoC server controls the speaking right, only mechanical speaking right control based on a preset criteria in the PoC server is possible.

Accordingly, in the present invention, the chairman of the PoC group controls the voice right in the session of the PoC group in which the chairman controls the voice right so that the PoC client having acquired the role of moderator of the PoC session can adjust the voice right according to the flow of the actual media content. To provide a method and a PoC system for implementing the same.

In addition, in the present invention, in the session of the PoC group in which the chairman controls the voice, the chairman or the general PoC client applies for the voice of a specific participant on behalf of the PoC session media transmission flow or a request through another PoC client's external network. It provides a method for giving a voice to the participant and a PoC system to implement it.

In order to achieve the above, the present invention is characterized by including at least one PoC client and a PoC server included in the PoC group list in which the chairman controls the voice.

In addition, the present invention provides a process for the PoC server to assign a unique ID (ID) to each PoC client included in the member list of the group whose chairman controls the voice, and to store it in a shared XML Document Management Server (Shared XDMS). It is characterized by including.

In addition, the present invention is characterized in that, in the session of the group in which the chairman controls the voice, the PoC server includes the step of identifying the PoC client acting as chairman through the group information stored in the public XDMS.

In addition, after the PoC server receives the voice request message, the present invention extracts the necessary information to generate a floor mode request message, and the message generated above to the PoC client serving as a chair recognized in the above process. Characterized in that it comprises a process of delivering.

The present invention also includes a process in which the PoC server extracts necessary information after receiving a floor mode response response message for controlling the floor from a chairman and generates and delivers a floor right grant or rejection message according to the prior art. Characterized in that.

In addition, the present invention is characterized in that the PoC client includes a process for delivering a Substitution Floor Request Message (Substitution Floor Request Message) to the PoC server (CF) in order to apply for the proxy of the other PoC client.

As described above, the present invention can provide a method in which a PoC client having a chair role of a PoC session can control a speaking right according to the flow of actual media content, rather than controlling the speaking right by a mechanical determination of the PoC server. There is an advantage.

In addition, there is an advantage in that it is possible to provide a method for granting a voice to a specific PoC client according to a request for proxy voice of another PoC client.

Hereinafter, the present invention proposes a method for guaranteeing the establishment of a PoC session for handling an accident or a crisis situation by a PoC client performing an OMA PoC multimedia call service, and a system for implementing the same. First, a PoC system to which the present invention is applied will be described with reference to FIGS. 2 to 4. In the following, an example of applying the present invention to a PoC system that provides a PTT service using a cellular mobile communication network, in particular, is an example. In general, a 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 may be implemented by the above-described protocols, and the basic structure of the present invention may be based on a PoC Real.1 system. First, a general PoC system to which the present invention can be applied will be described.

2 is a conceptual diagram of a general PoC service system and related network structure.

As shown in FIG. 2, a general PoC system may be configured to include a PoC user equipment (UE) 200, a common XDMS 230, a PoC XDMS 240, and a PoC server 250. In addition, the PoC system may further include an aggregation proxy server 260. These components may be connected via an access network 210, a Session Initiation Protocol / Internet Protocol Core Network 220, and a remote PoC network 270.

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

The PoC terminal 200 may include a PoC client 202 and an XML Document Management Client (XDMC) 204.

The PoC client 202 is a service requester embedded in the PoC terminal 200 and resides in the PoC terminal 200 to perform network access for providing PoC service to a PoC service subscriber. In addition, the PoC service subscriber may receive the PoC service through the PoC terminal 200 in which the PoC client 202 is embedded. In the following description of the present invention, the term PoC client will be used as a generic term for a terminal having a PoC client and a PoC service subscriber. In addition, reference numerals of PoC clients will be omitted later unless otherwise specified.

The main function of the PoC client is to establish a PoC session, join an existing session that has been established, or terminate the established session at the PoC service subscriber, that is, a PoC user. In addition, the PoC client performs a function of creating and delivering a talk burst, a function of supporting an instant personal alert, an authentication function when accessing a PoC service, and the like. The PoC client may be connected to the SIP / IP core network 220 which is a core network supporting SIP / IP multimedia through the access network 210.

The SIP / IP core network 220 is connected to the PoC server 250, the public XDMS 230, or the PoC XDMS 240 to provide PoC services. At this time, the PoC server 250 performs an overall PoC control function (Poling Control PoC Function) that maintains and manages a PoC session, or participates in a PoC that maintains a session for joining a PoC session established for one-to-one or multi-party calls. Participating PoC Function can be performed.

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 XML Document Management (XDM) client 204, a public XDMS 230, and a PoC XDMS 240 for a group list service. 2 illustrates a common XDMS 230 that may be commonly used for PoC XDMS 240 and other service enablers used for PoC services. Information about the group and group members may be stored in the public XDMS 230 and the PoC XDMS 240 via the PoC client. The PoC client can know the information of the PoC clients that can be called through the list of individuals or groups received from the public XDMS 230 and the PoC XDMS 240. Meanwhile, creation, modification and management of groups and group members for the public XDMS 230 and the PoC XDMS 240 may be made 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.

In addition, when the proxy server 260 receives a group list related request from the XDMC 204 for the group service, the aggregation proxy server 260 routes the same to each public XDMS 230 and the PoC XDMS 240 according to a preset rule. .

Next, the PoC server will be described.

3 is a schematic structural diagram of a PoC server 250 to which the present invention is applied. The PoC server 250 is, in terms of functionality, a Controlling PoC Function (CF) 253 that maintains and manages the PoC session as a whole, and a Participating Function Server (Participating Poc Function) that is responsible for maintenance between each session. : PF) 251 and 252. As shown in FIG. 3, PoC Client A 202-A is connected to PF A 251, and PoC Client B 202-B is connected to PF B 252, so that each PF A 251 is connected. PF B 252 is responsible for session maintenance. In addition, the CF 253 is connected to the respective PFs 251 and 252 to maintain overall PoC session.

Then, the characteristics of each function of the PoC server 250 will be described with reference to Tables 1 and 2 below.

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

As shown in Table 1, the CF 253 manages the PoC session as a whole among the functions of the PoC server 250. In particular, the CF 253 has the right to speak, which is the right of the PoC clients 202-A and 202-B. (Floor) Accepts a request, sets the order in which to speak, and authorizes it. The talk burst requested by any 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 251 and 252 manage sessions associated with the CF 253 and each PoC client 202 -A 202 -B in a PoC session, as shown in Table 2 below. 202-A) 202-B plays a role in requesting the right to speak, or when the CF 253 grants the right to speak to the PoC client 202-A (202-B). The PF 251 and 252 also relay media between the CF 253 and the PoC clients 202-A and 202-B, and if they use different codecs between them, transcoding In the case of concurrent sessions, if you are talking in one session and in another session, it plays a role of filtering one by the PoC user's 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

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

Referring to FIG. 4, each PoC clients 202-A through 202-D connect to the CF 400 through the PFs 410-A through 410-D to establish a PoC session. Thereafter, the media for the corresponding speech of the PoC client granted the speaking right from the CF 400 is delivered to the respective PoC clients 202-A through 202-D. 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.

First, the following describes a procedure for establishing a PoC multimedia session in a PoC system having the above-described features.

The transmitting PoC client sends a multimedia message (which may include various formats of audio, video, text, etc.) using the SIP protocol to request call processing. In response to the call processing request, the receiving client takes various response procedures according to the response mode setting in the corresponding PoC server and the existence of a presession. The call processing procedure for the PoC call will be described by exemplifying the procedures of the same sender network and the receiver network.

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

SIP invitation messages are routed to the PoC server via the corresponding IMS servers in the IMS network, i.e., P-CSPF and S-CSPF, via route queries from a Dynamic Host Configuration Protocol (DHCP) server or a Domain Name Server (DNS) server. Passed to PF.

In a general call request, the PoC server to which the PoC client is connected can be implemented separately from the CF of the PoC server that manages the talk burst of the session being established, so that the SIP invite request sent to the PF can be configured to Via CF to PoC server.

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

On the other hand, after receiving the response signal to the SIP invite request signal, the transmitting side PoC client receives the talk permission signal transmitting the talk burst transmission grant signal (for example, the ring back tone) through the RTCP protocol. The talk permission signal is generated in the CF having the talk burst arbitration authority and transmitted to the PoC client through the PF managing the PoC client. In this case, the talk permission signal may be transmitted without passing through a SIP / IP core network, such as an IMS, because it uses a path of a bearer without using a SIP protocol. After confirming the ring back tone, the PoC client transmits the media (eg, voice) stream using the Real-time Transport Protocol (RTP) protocol.

FIG. 5 is a diagram illustrating a process in which a chairman of a moderated Poc Group session in which a chairman controls a talk right in a PoC system manages a talk right according to the present invention.

S510 to S520 may be assumed to be the same as the prior art described with reference to FIG. 1. The PoC server CF collects necessary information from the talk request message received in S530, generates a talk presiding request message in S530, and delivers the requested message to the PoC client A which serves as a moderator of the corresponding PoC session. Referring to FIG. 7A as an example of the format for claiming the presence of voice, the code number indicating the request for the presence of the voice may be allocated to the 'subtype' field, and in the 'Identity of PoC Client requesting a floor', An ID, a PoC address (SIP URI or TEL URI), or a unique nickname may be included.

The PoC Client A 202-A receiving the Speaking Place Request message above decides whether to grant or deny the Speaking Request from the PoC Client B 202-B and then sends a Speaking Placement Response message. In step S530, the PoC server A (CF) 400 (410-A).

Referring to FIG. 7B as an example of the above voice announcement response message format, a code number indicating a voice presence response may be allocated to the 'subtype' field, and the PoC client A (202-) may be assigned to the 'Action Requesting for moderating a floor' field. It includes the determination of the right to speak in A). In addition, the 'Identity of PoC client to be moderated a floor' field may include an ID (ID), PoC address (SIP URI or TEL URI), or unique nickname of PoC Client B to grant or reject voice. have.

Here, referring to FIG. 8, the PoC server assigns a unique ID to each of the PoC clients listed in the group in which the chairman controls the floor, and stores it in a public XDMS in advance. Can be reduced.

It is possible to include a revoke in the 'Action Requesting for moderating a floor' field of the above voice message response message, to revoke the voice of the specific PoC client who is speaking.

Assuming that the PoC client B 202-B grants the right to speak, the PoC server A (CF) 400, 410-A, which has received the above voice message response message, speaks according to the prior art of FIG. 1 in S530. The authorization message is transmitted to the PoC server B 410-B. The PoC server B (PF) 410-B forwards the above permission permission message to the PoC client B 202-B in S540. Accordingly, the PoC client B 202-B is granted a voice and is able to transmit media. It becomes a state.

 FIG. 6 illustrates an example of a process in which a right to speak is given to a specific participant by a proxy speaking application of a PoC client or a general PoC client in which a chairman acquires a chairman role in a session of a group in which a chairman controls a speaking right according to an embodiment of the present invention. to be.

Assuming that there is an ongoing PoC session in S610, the PoC client A 202-A requests a proxy floor message in S620 according to a need in a PoC session media transmission flow or a request through an external network of another PoC client. The request message) may be transmitted to the PoC server A (CF) 400 (410-A) to apply for a voice of a specific participant. The PoC client A 202-A may be a PoC client B 202-B that is a PoC client having acquired a chairman role or a general PoC client.

Referring to FIG. 7C as an example of the above-mentioned proxy right request message format, a code number indicating a request for proxy representation may be allocated to the 'subtype' field, and the PoC server A 400 may be assigned to the 'Action Request for granting a floor' field. 410-A), the ID (ID) or PoC address (SIP URI or TEL URI) of the PoC Client B to obtain the actual voice in the 'Identity of PoC Client to granted a floor' field, or unique Nicknames may be included.

If the PoC client that has requested to speak by sending the above proxy request message is a PoC client who has acquired the role of chairman of the PoC session, the PoC server may be in the current state of the queuing queue or the priority of the PoC client. Regardless of the grade, in the S630, the talk right permission message according to the prior art is transmitted to the PoC server B 410-B, which is the home PoC server in charge of the PoC client B 202-B.

On the other hand, if the PoC client who sends the proxy voice request message in S620 above is an ordinary participant, the S630 is determined by mechanical judgment based on conditions such as the queue status of the PoC server and the priority level of the PoC client. A voice permission message or a voice rejection message may be sent.

If the PoC server B 410-B transmits the above voice grant message to the PoC client B 202-B in S630, the PoC client B 202-B is in a state capable of media transmission.

1 is a signal flow diagram illustrating a process in which a PoC server controls a voice after opening a PoC session according to the related art.

2 is a block diagram of a PoC service system to which an embodiment of the present invention is applied

3 is a functional block diagram of a typical PoC server

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

5 is a signal flow diagram illustrating a process in which a PoC client that acquires a chairman role according to a participant's request to speak in a session of a group in which the chairman controls the floor according to an embodiment of the present invention controls the floor.

FIG. 6 is a signal flow diagram illustrating a process in which a right to speak is given to a specific participant by a proxy speaking application of a PoC client or a general PoC client in which a chairman acquires a chairman role in a session of a group in which a chairman controls a speaking right according to an embodiment of the present invention.

7A to 7C are exemplary views illustrating a format of a voice control message proposed in an embodiment of the present invention (FIGS. 5 and 6).

8 is an exemplary diagram illustrating a state in which an ID is assigned to a member list of a group in which a chairman who can be stored in a public XDMS controls a voice.

Claims (20)

In the voice management system in the PoC session, A plurality of PoC terminals including a PoC client for maintaining the PoC session, divided into a chair PoC terminal or a general PoC terminal according to whether the chair role is obtained; An XDM server connected to the PoC session to store information of a PoC terminal that is currently callable and information of a chairman PoC terminal; A PoC server generating and transmitting a message for requesting or controlling data and the right to speak between the general PoC terminal and the chairman PoC terminal with reference to the information of the general PoC terminal and the information of the chairman PoC terminal stored in the XDM server; A floor management system in a PoC session. The method of claim 1, wherein the chairman PoC terminal, A floor control system in a PoC session, characterized in that the control by granting, rejecting or canceling the right to speak in the PoC session. The method of claim 1, wherein the data, A voice management system in a PoC session, characterized in that the data on the media of voice, text or video. The method of claim 2, wherein the chairman PoC terminal, And a speech control system in a Poc session, wherein a general Poc terminal that wants to obtain the speech right grants or rejects the speech right in response to requesting permission of the speech right. The method of claim 4, wherein the PoC server, When receiving a voice request message from the predetermined general PoC terminal, after confirming with reference to the information on the chairman PoC terminal of the XDM server, generates and transmits a voice control command to the chairman PoC terminal, And a utterance authority response message generated from the chairman Poc terminal receiving the utterance authority request message, generating and transmitting a utterance permission message to the predetermined general PoC terminal. The method of claim 2, wherein the chairman Poc terminal, And a spokesperson for a PoC session, wherein a general PoC terminal grants or rejects the speaking right in response to a request for a specific PoC terminal to grant the speaking right. The method of claim 6, wherein the PoC server, When receiving a proxy talk request message from the predetermined PoC terminal, after confirming with reference to the information on the chairman PoC terminal of the XDM server, and generates and transmits a proxy talk request message to the chairman PoC terminal, And a utterance permission message sent from the chairman Poc terminal receiving the proxy utterance request message, to generate and transmit a utterance permission message to the specific PoC terminal. The method of claim 2, wherein the chairman Poc terminal, And a spoken authority management system in a PoC session, characterized in that the speaking authority is granted to a specific PoC terminal. The method of claim 8, wherein the PoC server, And a speech permission permission message is generated and transmitted to the specific PoC terminal when the proxy voice presence request message is received from the chairman PoC terminal. The system of claim 1, wherein the information of the general PoC terminal and the information of the chairman PoC terminal stored in the XDM server are predetermined IDs composed of binary codes. The method according to claim 10, wherein the predetermined ID, A floor management system in a PoC session, characterized in that included in the message about the request or control of the floor. In the voice management method in the PoC session, Setting up the PoC session between a plurality of general PoC terminals and a chairman PoC terminal having acquired a chair role; Controlling, by the chairman PoC terminal, the speaking right to a predetermined general PoC terminal among the general PoC terminals through a PoC server; And a method of transmitting data by the chairman PoC terminal or the predetermined general PoC terminal through the PoC session. The method of claim 12, wherein the controlling of the right to speak is performed. A control method of a talk right in a PoC session, characterized in that the process of controlling by granting, rejecting or canceling the talk. The method of claim 12, wherein the data, A voice management method in a PoC session, characterized in that the data on the media of the voice, text or video. The method of claim 12, wherein the controlling of the right to speak is performed. And a step of granting or rejecting the right to speak as the predetermined general Poc terminal seeking to obtain the right to speak requests the permission of the right to speak. The method of claim 15, wherein the process of granting or rejecting the right to speak, When receiving a talk request message from the predetermined PoC terminal, after confirming with reference to the information on the chairman PoC terminal of the XDM server, generates and sends a talk presidency request message to the chairman PcC terminal, And receiving a speaking authority response message from the chairman Poc terminal having received the speaking authority request message, generating and transmitting a speaking right permission message to the predetermined PoC terminal. The method of claim 12, wherein the controlling of the right to speak is performed. And a method for granting or rejecting the right to speak in response to a general PoC terminal requesting a specific PoC terminal to grant the right to speak. The method of claim 17, wherein the process of granting or rejecting the right to speak, When receiving the proxy talk request message from the predetermined general PoC terminal, after confirming with reference to the information on the chairman PoC terminal of the XDM server, generates and sends a proxy talk request message to the chairman PoC terminal, And receiving a proxy speaking right request message from the chairman Poc terminal that has received the proxy speaking right request message, generating and transmitting a speaking right permission message to the specific PoC terminal. The method of claim 12, wherein the controlling of the right to speak is performed. And a request for a surrogate to speak a specific PoC terminal. The method of claim 19, wherein the process of authorizing the right to speak, And a method for generating a voice permission message to the specific PoC terminal when receiving a proxy voice presence request message from the chairman PoC terminal.

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