KR20060131598A - Method and system for providing ptt to conference - Google Patents

Abstract

A metho for supplying a conference call during progression of a PTT(Push To Talk) service and a system therefor are provided to convert the PTT service into a conference call during the PTT service without newly initializing a conference call service after an existing PoC(Push-to-talk over Cellular) session is completed, and to make conversion into bidirectional communication between entire or some of participants possible while the PoC session is progressed. During progression of a PoC session among UEs(User Equipments)(740,750,760), a request procedure for converting a PTT service into a conference speech path is carried out(701). A conference call client invite/participate procedure is carried out to open a conference call session through a conference call server(700)(702-705c). A procedure for canceling the conference call session between a PoC server(710) and the UEs(740,750,760) is carried out(706-707c).

Description

METHOD AND SYSTEM FOR PROVIDING PTT TO CONFERENCE}

1 is a conceptual diagram of a PTT service network for a general PTT service

2 is a block diagram of a PMA service network based on OMA

3 is a diagram illustrating a call setup process of an IMS-based PTT service

4 is a block diagram of an IMS-based PTT service network

5a and 5b are diagrams illustrating a call setup process of an IMS-based PTT service network

Figure 6 is a network configuration capable of PTT vs. multi-party call in accordance with a preferred embodiment of the present invention

7 illustrates a PTT to conference call scenario according to a preferred embodiment of the present invention.

8A and 8B illustrate a call setup process according to the scenario of FIG. 7 in accordance with a preferred embodiment of the present invention.

9 is a diagram illustrating a scenario of switching a unidirectional communication mode to a bidirectional communication mode during a PTT according to another embodiment of the present invention.

10 is a diagram illustrating a call setup process according to the scenario of FIG. 9 according to another embodiment of the present invention.

FIG. 11 is a diagram illustrating a scenario of switching a unidirectional communication mode to a bidirectional communication mode during a PTT according to another embodiment of the present invention; FIG.

12 illustrates a call setup process according to the scenario of FIG. 11 according to another embodiment of the present invention.

13 is a block diagram of a terminal capable of performing a PTT versus a conference according to a preferred embodiment of the present invention.

The present invention relates to a method and a system for providing a Push to talk over Cellular (PoC) service in a cellular network, and more particularly, to a method and a system for providing a PTT-to-conference service.

Push To Talk (hereinafter referred to as "PTT") service is an instant messenger service such as a kind of radio service. As the word means, it is possible to provide a very fast communication service compared to the waiting time of the general terminal because the simple communication can be performed immediately by pressing the switch and talking. The convenience can be doubled because the PTT immediately shows whether the other party can receive on the terminal screen. PTT service is able to communicate immediately without unnecessary processes such as dialing or ringing tone, so the biggest advantage is that the PTT service is connected immediately and at high speed compared to the call waiting time of general mobile communication.

PTT service with these advantages includes one-way voice broadcasting, packetized voice over wireless data, personal and group messaging support, instant access, and simple user interface.

Push to talk over cellular (PTT) on cellular is a PTT service function implemented on an existing cellular terminal or PCS terminal. Currently, standards for PTT service are in progress centering on Open Mobile Alliance (OMA), and PTT service based on IP Multimedia Subsystem (hereinafter referred to as "IMS") in 3rd Generation Partnership Project (3GPP). I'm working on it.

1 is a conceptual diagram of a PTT service network for a general PTT service.

Referring to FIG. 1, the talker 101, one of the members of the group, performs PTT instant communication through the wireless network 109 to the talker subgroups 101, 103, 105, and 107. The situation is shown. When the talker 101 presses the switch and speaks a simple intention, the talker subgroup consisting of at least one talker receives the talker 101's voice. The talker 101 of such a general PTT service is limited to one person and may designate at least one talker group in advance and express a voice by voice, such as a kind of radio communication.

2 is a diagram illustrating an OMA-based PTT service network.

Referring to FIG. 2, the OMA-based PTT service network includes a user equipment (hereinafter referred to as "UE") 200, an XML Document Management Server (XDMS) 212, and a presence server (Presence Sever) ( 208, a PoC server 201 including a SIP proxy 206 and a packet processor 202.

The UE 200 is a terminal device capable of PTT service, the XDMS 212 is a server that manages a document in XML format, the presence server 208 and the SIP proxy 206 is defined in the SIP standard document It is an entity that mediates a PTT service by performing a predetermined role, and the PoC server 201 is a server that enables a PTT service in a cellular network.

Here, the functions of the interfaces of the entities constituting the OMA based PTT service network are as follows. The UE-XDMS interface 210 is an interface for inquiring / receiving information on a group list and a policy through the access network 211. The XDMS-PoC server interface 213 is an interface for inquiring / receiving information on the group list and the policy for the PoC service. The XDMS-Presence Server Interface 209 is an interface for inquiring / receiving information on a policy for the presence service.

In addition, the SIP proxy-presence server interface 207 has a connection standard between the SIP proxy and the presence server based on SIP, and is used to register / store / delete / view user's participation information. The UE-SIP proxy interface 204 supports SIP as an interface for transmitting signaling for a Poc session between the PoC client and the Poc server through the access network 211, provides PoC client registration, and provides authentication / Perform permissions. The UE-PoC server interface 203 is used for media transmission and talk burst control and RTP / RTCP (Real-time Transport Protocol / RTP Control Protocol) is used. The SIP proxy-PoC server interface 205 supports SIP as an interface for transmitting signaling for a PoC session between a PoC client and a PoC server, and is also used for charging and the like.

3 is a diagram illustrating a call setup process of an OMA based PTT service.

Referring to FIG. 3, the OMA-based PTT service is largely divided between a PoC Client A Home & Controlling Network 420 and a PoC Client B Home Network 430. Call flow can be distinguished. The PoC Client A Home & Controlling Network 420 is a PoC Client A 421, a SIP / IP Core (A) 422, and a PoC Server (A) (participating & controlling) ( 423). In addition, the PoC Client B Home Network 430 includes a PoC server (participating) 431, a SIP / IP core (B) 432, and a PoC Client B 430. do.

In step 301, the PoC client A 421 initiates an ad-hoc PoC group session or 1-1 PoC session by transmitting an INVITE message to the SIP / IP core (A) 422. In step 302, the SIP / IP core (A) 422 is a PoC server (participating & controlling) 423 based on the PoC client and the PoC user's Inviting PoC Address on the PoC service indication. Route the INVITE message.

In step 303, the PoC server (participating & controlling) 423 transmits an INVITE message to the SIP / IP core (A) 422. In step 304, the SIP / IP core (A) 422 routes the INVITE message to the SIP / IP core (B) 432. In step 305, the SIP / IP core (B) 432 sends the INVITE to the PoC server (participating) 431 based on the PoC address of the Invited PoC Client and the PoC service indication. Route the message.

If the PoC client B 433 automatically accepts the session in step 306, the PoC server (participating) 432 sends an AUTO-ANSWER message to the SIP / IP core (B). In step 307, the SIP / IP core (B) 432 transmits the AUTO-ANSWER message to the SIP / IP core (A).

In step 308a, the SIP / IP core (A) 422 transmits the AUTO-ANSWER message to the PoC server (A) 423. In step 308b, the PoC server (participating) 431 transmits an INVITE message requesting the PoC session establishment to the SIP / IP core (432).

When receiving the AUTO-ANSWER message in step 309a, the PoC server (A) (participating & controlling) 423 transmits an UNCONFORMED OK message to the PoC client. In step 309b, the SIP / IP core (B) 432 routes the INVITE message to the PoC client B.

In step 310a, the SIP / IP core (A) 422 delivers the UNCONFORMED OK to the PoC client A (421). In step 310b, when the PoC client B 433 receives the INVITE message, the PoC client B 433 transmits an OK message for the INVITE message.

In step 311a, the PoC server (participating & controlling) 423 transmits a talk burst confirmation message to the PoC client A 421. In step 311b, the SIP / IP core (B) 432 forwards the OK message to the PoC server (B) (participating) 431.

In step 312a, the PoC server (A) 421 transmits media to the PoC server (A) (participating & controlling) 423. In step 312b, the PoC server (participating) 431 receives an OK message. In step 313b, the SIP / IP core (B) 432 receives an OK message from the PoC server (participating) 422. In step 314b, the SIP / IP core (A) 422 transmits the OK message to the PoC server (A) (participating & controlling) 423.

In step 315, the PoC server (A) 422 transmits the received talk burst indication to the PoC server (B) 431. In step 316, the PoC server (participating) 431 relays the received talk burst message to the PoC client B 433.

4 is a configuration diagram of an IMS-based PTT service network.

Referring to FIG. 4, the IMS-based PTT service network includes a UE 400, an XML Document Management Server (XDMS) 415, a presence server 419, a PoC server 417, and a P-CSCF. An IMS core 401 including a Proxy-Call Session Control Function (411) and a Serving-Call Session Control Function (S-CSCF) 413.

The UE 400 operates as a PTT client. When receiving the PTT service, the UE 400 transmits a SIP signaling message to the PoC server 417 to be allocated a media channel. When the PoC session is established, the UE 400 transmits and receives a packet through a bearer channel established between the PoC server 417 and the UE 400.

The PoC server 417 is responsible for signaling and bearer processing for the PTT service. The SIP message transmitted from the UE 400 is processed to establish a media channel (RTP) between the UE 400 and a PoC server (packet processor) 417. When the media session is established, the PoC server 417 copies and distributes packets for packet transmission to the UE 400. In addition, the PoC server 417 performs the flow control (floor control) during the PTT service, and generates the relevant data for billing and performs the function of reporting it to the billing server.

The XDMS 415 is a server that manages an XML document, and the presence server 208 is an entity that mediates a PTT service by performing a role defined in a SIP standard document, and the P-CSCF 411. And the S-CSCF 413 is an entity performing a call switching function in an IMS network.

The UE- (P-CSCF) interface Gm supports SIP as an interface for communication (processing related to registration and session control) between the UE 300 and the IMS core 310. The (P-CSCF)-(S-CSCF) interface (Mw) serves to perform signaling message transfer as an interface for communication between CSCFs and supports SIP. The (S-CSCF)-(Presence Server) interface (ISC) is an interface between the CSCF and the presence server, which is a SIP application server, used to provide presence services through the IMS core 310. The UE-XDMS interface Ut is an interface through which the UE 300 manages (creates / deletes / views) information related to a service in the XDMS 313 (group list and policy information).

5A and 5B are diagrams illustrating a call setup process of an IMS-based PTT service network.

5A and 5B, a network A and a PoC server (B) including a UE-A 530, a PS domain A 535, an IMS core (A) 540, and a PoC server (A) 545. 550, IMS core (B) 555, PS domain B (560) and UE-B (565) network B is divided into large.

In step 501, the user A of the UE-A 530 presses a PTT indication / button on a terminal instructing communication with the user B of the UE-B 565. In step 502, the UE-A 530 creates an SIP session for the PoC communication with the UE-B 565 as the destination address by sending an INVITE message to the IMS core (A) 540. In steps 503 to 504, the IMS core (A) 540 identifies the service indication and routes the INVITE message to the PoC server (A) 545.

In steps 505 to 506, the PoC server (A) 550 together with the IMS core (A) 540 delivers an INVITE message toward the IMS Core B 555. In steps 507-508, the IMS core (B) 555 identifies the service indication and routes the INVITE message to the PoC server (B) 550. In step 509a, the UE-B 565 automatically sends the AUTO-ANSWER to the PoC server (A) 545 by accepting the session.

In step 509b, the PoC server (B) 550 transmits an INVITE message to the UE-B 565 via the IMS core (B) 555. In steps 510a to 511a, the IMS core (B) 555 forwards the AUTO-ANSWER message to the PoC server (A) 545 via the IMS core (A) 540.

In steps 512a to 513a, the PoC server (A) 545 transmits 200 OK toward the UE-A 530 based on the AUTO-ANSWER where the PoC server (A) 545 supports media buffering, At the same time, a talk burst confirm message is transmitted to the UE-A 530. In step 514a, when a service based local policy is applied to the network of UE-A 530, IMS Core (A) 540 generates an authorization token for the session, and firstly an available and trusted SIP response. The authority token is inserted into the message and transmitted to the UE-A 530.

In steps 517a to 518a, after the UE-A 530 receives both the 200 OK and the talk burst confirmation message, the UE-A 530 may transmit the media data to the PoC server (A) 545. Do. In step 519a, the IMS core (A) 540 sends an ACK to the PoC server (A) 545. In step 520a, the PoC server (A) 545 is sent from the UE-B 565. Buffer the received media until receiving a positive response. UE-A 530 continues to transmit the media.

In steps 510b to 515b, in the case of a service-based area policy applied in the network to which the UE-B 565 belongs, the IMS core (B) 555 generates a permission token for the session, and the permission in the INVITE message. Insert the token and pass it to UE-B 565.

Typically UE-B needs to be paged before the INVITE message is translated. The INVITE message is delivered to the PS domain without any functional change.

In steps 513b to 514b, after receiving the INVITE message, the UE-B 565 accepts the session by returning 200 OK. UE-B 565 is capable of additional settings (traffic class streaming and bandwidth for negotiable media parameters) for media and talk burst control exchanging IP addresses and APNs.

In steps 515b to 518b, the IMS core (B) 555 delivers the 200 OK to the PoC server (B) 550, and the IMS core (B) 556 and the IMS core (A) 540. The 200 OK is forwarded to the PoC server (A) 545 via.

In steps 521 to 523, the PoC server (A) 545 transmits an ACK for the session establishment, and the ACK passes through an IMS core (A) 540 and an IMS core (B) 555 to the PoC. Forwarded to server (B) 550. The PoC server (B) 550 sends an ACK for the session.

In steps 524 to 525, the PoC server (B) 550 sends an ACK for the session to the UE-B 565 via an IMS core (B) 555. The media buffered from the UE-A 530 to the PoC server (A) 545 is transmitted from the PoC server (A) to the PoC server (B). PoC server (B) 550 sends media to UE-B 565.

In the PTT service according to the related art operating as described above, only a user who has a voice can make a call, and other users can only sign a call. That is, the PTT service is a one-way communication, and there is a limitation that several people can't make a phone call at the same time.

Accordingly, an object of the present invention is to provide a method and apparatus that enables users of a PTT service to switch to a conferencing service during a PTT service at the request of a user.

Another object of the present invention is to provide a method and apparatus capable of converting from one-way transmission to two-way transmission at the request of a user during a PTT session by supplementing one-way communication, which is a limitation of the PTT service.

A method of an embodiment of the present invention for achieving the object as described above, operating as a client in a mobile communication network having a push-to-talk over cellular (PoC) server, a conference server and a mixer to perform mixing for the conference. A method for providing a conference call during a push-to-talk (PTT) process between a plurality of terminals, the method comprising: performing a request procedure for switching to a conference call during a PoC session between the terminals; Performing a conference client invitation / participation procedure to open the conference session through the conference server; And performing a procedure for releasing the conference call session between the PoC server and the terminal.

In addition, the system of the embodiment of the present invention, a system for providing a multi-party call during the push-to-talk (PTT) process between a plurality of clients through a mobile communication network, signaling and bearer processing for the PTT service, and the multi-party call during the PTT A PoC server that performs bearer setup between the conference client and the mixer for signaling for switching and media processing for conferences; A conferencing server that handles signaling for the conferencing and interacts with a mixer to allocate media channels for clients; A mixer that performs media mixing for the conference service and allocates media resources to clients; And a terminal operating as the client.

In addition, the terminal of the embodiment of the present invention is a terminal equipped with a client that provides a multi-party call during push-to-talk (PTT) progress through a mobile communication network, the real-time operating system of the main control (main control) center of the client PTT service unit for processing a function; And components on a physical layer and a media access control layer to communicate with the PTT service unit.

According to another exemplary embodiment of the present invention, a push-to-talk (PTT) progression is performed between a plurality of terminals operating as clients in a mobile communication network having a push-to-talk over cellular (PoC) server. A method of switching a unidirectional communication mode to a bidirectional communication mode, the method comprising: transmitting a message for a bidirectional communication request to one of the plurality of terminals to the PoC server, and the PoC server uses a mixing function to bidirectionally change the unidirectional communication mode. Switching to a communication mode; and transmitting, to the terminal, each PoC client, through the preset RTP channel, the PoC server transmits an instruction for all PoC clients to speak simultaneously.

In addition, the system of another embodiment of the present invention, a system for switching the one-way communication mode to the two-way communication mode during the push-to-talk (PTT) between the plurality of clients through the mobile communication network, signaling and bearer processing for the PTT service and A push-to-talk over cellular (PoC) server performing signaling for switching from a unidirectional communication mode to a bidirectional communication mode during a PTT process; And a terminal operating as the client.

In addition, a terminal of another embodiment of the present invention is a terminal equipped with a client for switching from a unidirectional communication mode to a bidirectional communication mode during a push-to-talk (PTT) operation in a mobile communication network, the main control task of the real-time operating system (main control) PTT service unit for processing the function of the client around; And components on a physical layer and a media access control layer to communicate with the PTT service unit.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. Like reference numerals refer to the same elements as shown in the drawings, even though they may be shown on different drawings, and in the following description, detailed descriptions of related well-known functions or constructions are unnecessary. If it is determined that it can be blurred, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

In the case of a PTT service for a group, that is, one person can speak to a terminal by using several terminals, and it can be said to overcome the limitation of one-to-one communication that a telephone has. Small and medium-sized groups can be designated and talked, and one-to-one wireless calls are, of course, possible. To switch to the conference service during the service, it is configured as follows.

Figure 6 is a network configuration capable of PTT vs. multi-party call according to a preferred embodiment of the present invention.

Referring to FIG. 6, the PTT-to-conference network configuration includes a UE 600, a PoC server 610, a conference server 620, a mixer 630, and a SIP / IP core (IMS) ( 640).

The UE 600 operates as a PTT client. The UE 600 performs a function of transmitting SIP signaling for switching to the PoC server 610 in order to switch the PTT service to the conference call service during the PoC session. In addition, in the case of the PTT service, the PoC server 610 and the mixer 630 and the bearer channel are set in the case of the multi-call service, and the packet is transmitted and received through the set bearer channel.

The PoC server 610 is responsible for signaling and bearer processing for the PTT service. It also handles signaling for PTT versus conference. When the PoC server 610 receives a SIP message for PTT to conference switching from the UE 600, the PoC server 610 transmits a SIP message including media information about the participants to the related conference server. It also performs the function of generating relevant data for billing and reporting it to the billing server. The PoC server 610 is responsible for controlling the conference, and the PoC server (conference control logic) 610 performs bearer setup between the conference participant and the mixer for media processing (mix or bridge) for the conference. do.

The conference server 620 is responsible for signaling processing for the conference service. When the conference server 620 receives a SIP message from the PoC server including media information about all participants participating in the PoC session, the conference server 620 uses the received media information to establish a conference call with each participant. Set it. The conference server 620 interoperates with the mixer using the H.248 / Megaco protocol to allocate media channels for the participants. In addition, the multi-party server 620 generates a relevant data for billing and reports the data to the billing server.

The mixer 630 performs a media mixing function for the conference call service. In addition, the mixer 630 allocates a media resource to the UE 600 through the H.248 / Megaco interworking with the multiparty server 620. After the PoC session is established, at the request of the PTT participant, the PoC server 610 converts the PoC session into a conference call session. The following is a scenario of PTT-to-MFP conversion.

7 is a diagram illustrating a PTT to multi-party call switching scenario according to a preferred embodiment of the present invention.

Referring to FIG. 7, the PTT-to-conference switching scenario includes a PoC server 710 and a mixer 730 including a conference server 700 and a media relay server 720 (MRS). And a request procedure for PTT to conference between a plurality of UEs 740, 750, and 760, a conference participant invite / participation procedure to open a conference session, and a procedure for disconnecting an existing PoC session of a PoC server.

-Perform the request procedure for PTT to conference

In step 701, the UE1 740 transmits a SIP message (PTT to conference call indication) for PTT to conference call switching to the conference server 700. In step 702, the conference server 700 transmits a message to the PoC server 710 requesting the media information used during the existing PoC session to obtain the media information required to establish the conference session. In step 703, the PoC server 710 transmits the location (URI) and media information (RTP port, codec, etc.) for the participants used during the corresponding PoC session to the conference server 700. At this time, the PoC server 710 notifies each PTT client that the PoC session is switched to the conference call using announcement or the like. In step 704, the conference server 700 transmits the media information received from the PoC server 710 to the mixer 730 that performs the mixing for the conference, and the mixer 730 uses the information to participate in the conference. Allocate media for.

-Invite / join a conference participant to open the conference

In step 705, the conference server 700 transmits a conference invitation message (including media information assigned in the mixer) to each participant to establish a conference session. In step 706, after the invitation / participation to each participant is completed, the conference server 700 notifies the PoC server 710 that the conference session is completed. At this time, the conference server 700 notifies the participants that the conference has been set up using announcements or the like.

-Perform the procedure to terminate existing PoC session of PoC server

In step 707, after receiving notification from the conference server 700 that the conference setting is completed, the PoC server 710 performs a PoC session release procedure to terminate the existing PoC session.

8A and 8B illustrate a call setup process according to the scenario of FIG. 7 according to a preferred embodiment of the present invention.

Referring to FIGS. 8A and 8B, as in step 801 in which an RTP session for a PoC service is established, the UE-A 850 is connected to the SIP / IP core (A) 855 for INCITE for PoC to conference. Send a message. In step 802, the SIP / IP core (A) 855 forwards the INVITE message to the conference server 855. In step 803, the PoC server (A) 850 receives an INVITE message from the conference server 855. In step 804, the PoC server (A) 850 sends an OK message to the conference server 855.

In steps 805a to 805c, the PoC server (A) 850 transmits an announcement broadcast informing that it is switching to a conference service. In step 806, the conference server 855 sends an ADD message to the mixer 860. In step 807, the conference server 855 receives an OK message from the mixer 860. In step 808, the conference server 855 sends an INVITE message to the SIP / IP core (A) 845.

In steps 809 to 810, the SIP / IP core (A) 845 sends an INVITE message to the UE-A 840 and receives an OK message. In step 811, the SIP / IP core (A) 845 sends an OK message to the conference server 855. In step 812, the SIP / IP core (A) 845 receives an INVITE message from the conference server 855.

In step 813, the SIP / IP core (A) 845 sends an INVITE message to the SIP / IP core (B) 870. In step 814, the SIP / IP core (B) 870 transmits an INVITE message to the UE-B 875. In step 815, the SIP / IP core (B) 870 receives an OK message from the UE-B 875. In step 816, the SIP / IP core (A) 845 receives an OK message to the UE-B 875. In step 817, the conference server 855 receives an OK message from the SIP / IP core (A) 845. Here, an RTP session for the conference call service is established.

In step 818, the SIP / IP core (A) 845 receives a NOTIFY message from the conference server 855. In steps 819 to 820, the SIP / IP core (A) 845 transmits a NOTIFY message to the PoC server (A) 850 and receives an OK message. In step 821, the SIP / IP core (A) 845 sends an OK message to the conference server 855.

In steps 822a to 822b, the mixer 860 transmits a guide broadcast for starting the conference. In steps 823 to 826, the UE-A 840 receives a BYE message from the PoC server (A) 850 via the SIP / IP core (A) 845, and sends an OK message to the SIP / IP core (A). 845) to the PoC server (A) 850. In steps 827 to 828, the PoC server (A) 850 sends a BYE message to the SIP / IP core (A) 845 and the SIP / IP core (B) 870.

In steps 829 to 830, the SIP / IP core (B) 870 sends a BYE message to the PoC server (B) 865 and receives an OK message. In step 831, the SIP / IP core (B) 870 transmits an OK message to the SIP / IP core (A) 845. In step 832, the SIP / IP core (A) 845 sends an OK message to the PoC server (A) 850. In steps 833 to 836, the PoC server (B) 865 transmits a BYE message to the UE-B 875 via the SIP / IP core (B) 870 and receives an OK message. The PoC session is then released.

The following describes two scenarios of switching a PoC session, which is a one-way communication, in both directions.

The outline of the procedure is as follows. After the PTT session is established, at the request of the PTT participant, the PoC server switches the PTT communication, which was performed in one direction, in both directions. The PoC server switches existing unidirectional PTT communication bidirectionally using floor control signaling, which ensures that only one participant can speak at a given time. For media processing (mixing or bridging) for bidirectional communication, the PoC server performs media mixing.

9 is a diagram illustrating a scenario of switching a unidirectional communication mode to a bidirectional communication mode during a PTT according to another embodiment of the present invention.

Referring to FIG. 9, in operation 901, the UE1 920 transmits a SIP message for requesting bidirectional communication to the PoC server 900. In steps 902a to 902c, the PoC server 900 switches from the one-way communication mode to the two-way communication mode by using a mixing function in the MRS 910 in the server. The PoC server 900 transmits an indication for all PoC clients to speak simultaneously by transmitting to each PoC client UE1 to UE3 920, 930, and 940 through a preset RTP channel. At this time, the PoC server notifies each of the PoC clients to the PoC clients UE1 to UE3 (920, 930, 940) that the announcement broadcast is possible.

10 is a diagram illustrating a call setup process according to the scenario of FIG. 9 according to another embodiment of the present invention.

Referring to FIG. 10, as in step 1001 in a state where an RTP session for a PoC service is established, the UE-A 1010 transmits an INVITE message for switching a communication mode to a SIP / IP core (A) 1020. do. In step 1002, the SIP / IP core (A) 1020 transmits an INVITE message to the PoC server (A) 1030. In steps 1003a to 1003b, the PoC server (A) 1030 receives a talk burst grant granted to the UE-2 1060 via the UE-A 1010 and the PoC server (B) 1040. send. Here, the SIP / IP core (B) 1040 only performs a general procedure.

In steps 1005a to 1005b, the PoC server (A) 1030 transmits an announcement to the UE-2A 1060 via the UE-A 1010 and the PoC server (B) 1040 indicating that the PoC server 1030 is switching to the bidirectional mode. do. In step 1006, the PoC server (A) 1030 transmits an OK message to the SIP / IP core (A) 1020. In step 1007, the SIP / IP core (A) 1020 transmits an OK message to the UE-A 1010.

FIG. 11 is a diagram illustrating a scenario of switching a unidirectional communication mode to a bidirectional communication mode during a PTT according to another embodiment of the present invention. FIG.

Referring to FIG. 11, in step 1101, the UE1 1120 transmits an RTCP message for a bidirectional communication request to the PoC server 1100. In step 1102, the PoC server 1100 switches the unidirectional communication mode to the bidirectional communication mode using a mixing function in the MRS 1110 in the server. The PoC server 1100 transmits an indication that all PoC clients can speak at the same time by transmitting to the PoC clients UE1 to UE3 1120, 1130, and 1140 through preset RTP channels. At this time, the PoC server 1100 notifies each of the PoC clients UE1 to UE3 1120, 1130, and 1140 through bidirectional communication that two-way communication is enabled.

12 is a diagram illustrating a call setup process according to the scenario of FIG. 11 according to another embodiment of the present invention.

Referring to FIG. 12, in a state in which an RTP session for a PoC service is established, as in step 1201, the UE-A 1210 requests a talk burst request for switching a communication mode to the PoC server (A) 1230. Request) Send a message. In step 1202a to 1202b, the PoC server (A) 1230 transmits a talk burst grant granted to the UE-2 1260 via the UE-A 1210 and the PoC server (B) 1240. do. Here, the SIP / IP core (B) 1240 performs a general procedure of the PTT service.

In steps 1003a to 1003b, the PoC server (A) 1030 transmits an announcement to the UE-2A 1060 via the UE-A 1010 and the PoC server (B) 1040 indicating that the PoC server 1030 is switching to the bidirectional mode. do. In step 1006, the PoC server (A) 1030 transmits an OK message to the SIP / IP core (A) 1020. In step 1007, the SIP / IP core (A) 1020 transmits an OK message to the UE-A 1010.

13 is a block diagram of a terminal capable of performing PTT versus conference according to an embodiment of the present invention.

Referring to FIG. 13, the terminal includes a PTT service unit 1300, a modem 1310, a codec 1320, a BBA 1330, and an RF processor 1340. The PTT service unit 1300 software-processes the PTT-to-conference call function described in FIGS. 6 to 12 based on a main control task in a real-time operating system.

In addition, the modem 1310, the codec 1320, the BBA 1330, and the RF processor 1340 follow a general communication procedure of the terminal, and introduce only their characteristic functions as follows. The modem 1310 handles protocols defined in standards such as IS-95A. The codec 1320 is generally adopted from 8 kbps Qualcomm Code Excited Linear Prediction (QCELP) and 8 kbps Enhanced Variable Rate Codec (EVRC). The baseband analog (BBA) 1330 is composed of an integrated circuit and includes a second intermediate frequency processor, a second intermediate frequency, an analog to digital (A / D) or a digital to analog (D / A) converter, and the like. This is included. The RF processor 1340 processes high and intermediate frequencies.

Although the present invention has been described in detail so far, it should be apparent that the embodiments mentioned in the process are only illustrative, and not restrictive, and the present invention is provided by the following claims. Within the scope not departing from the scope of the present invention, component changes to the extent that they can be equivalently substituted from the present invention will fall within the scope of the present invention.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The present invention has the effect of switching to a conference call during the PTT service without initializing the conference service newly after terminating the existing PoC session.

In addition, the present invention has the effect that it is possible to switch to two-way communication between all or some participants during the PoC session, which is a one-way communication method.

In addition, the present invention has an effect that can be converted from one-way transmission to two-way transmission at the request of the user during the PTT session by supplementing the one-way communication that is a limitation of the PTT service.

Claims (22)

A method for providing a conference call during a push-to-talk (PTT) process between a plurality of terminals operating as clients in a mobile communication network having a push-to-talk over cellular (PoC) server, a conference server, and a mixer for mixing for conferences. In Performing a request procedure for switching to a conference call during a PoC session between the terminals; Performing a conference client invitation / participation procedure to open the conference session through the conference server; And And performing a procedure for releasing the conference call session between the PoC server and the terminal. The method of claim 1, The process of performing a request procedure for switching to a conference call during the PoC session between the terminals, Transmitting, by the terminal desiring the conference of the terminals, a conference call switching instruction message to the conference server; Sending, by the conference server, a media information request message used during the PoC session to establish a conference session to the PoC server;  Sending, by the PoC server, location (URI) and media information for clients used during the PoC session to the conference server; And And transmitting, by the conference server, the media information received from the PoC server to the mixer, and the mixer allocates media for a conference client using the media information. The method of claim 2, The media information includes a real-time transport protocol (RTP) port and a codec. The method of claim 2, The PoC server transmits the location and media information about the clients used during the PoC session to the conference server, and notifies each of the clients that the PoC session is converted to the conference. Way. The method of claim 1, The process of performing a conference client invitation / participation procedure to open the conference session through the conference server may include: Sending, by the conference server, a conference invitation message including media information assigned in the mixer to each client to establish a conference session; And And notifying the PoC server that the conference server has completed a conference call. The method of claim 5, And the multi-party server notifies the PoC server that the multi-party session is completed, and then notifies the plurality of clients that the multi-party call has been set up. The method of claim 1, The performing of the procedure for releasing the conference call session may include the PoC server releasing the PoC session after receiving notification from the conference server that the conference setting is completed. In a system for providing a conference call during a push-to-talk (PTT) process between a plurality of clients through a mobile communication network, Push-to-talk over cellular (PoC) server that performs signaling and bearer processing for PTT service, signaling for conference switching during PTT, and bearer setup between the client and mixer for media processing for conference ; A mixer that performs a media mixing function for a multiparty call service and allocates media resources to the client; A conferencing server that handles signaling for conferencing and interacts with the mixer to allocate a media channel for the client; And And a terminal operating as said client. The method of claim 8, The PoC server includes a function for generating and reporting related data for billing. The method of claim 8, The conference server includes a function for generating and reporting related data for billing. In a terminal equipped with a client that provides a conference call during push-to-talk (PTT) in a mobile communication network, A PTT service unit processing a function of the client based on a main control task of a real-time operating system; And And a component on a physical layer and a media access control layer to communicate with the PTT service unit. A method of switching a unidirectional communication mode to a bidirectional communication mode during a PTT progress between a plurality of terminals operating as clients in a mobile communication network having a push-to-talk over cellular (PoC) server, Transmitting, by one of a plurality of terminals, a message for a bidirectional communication request to the PoC server; The PoC server converts a unidirectional communication mode into a bidirectional communication mode by using a mixing function; And transmitting, by the PoC server, an instruction for all PoC clients to speak simultaneously to the terminal, each PoC client, through a preset RTP channel. The method of claim 12, The message for the bidirectional communication request is a SIP message. The method of claim 12, And the message for the bidirectional communication request is an RTCP message. The method of claim 12, And the mixing function is performed at a media relay server in the PoC server. The method of claim 12, The PoC server, each of the PoC client characterized in that it informs the terminal of the announcement broadcast that the two-way communication is possible. In the system for switching the unidirectional communication mode to the bidirectional communication mode during the push-to-talk (PTT) between the plurality of clients through the mobile communication network, A push-to-talk over cellular (PoC) server that performs signaling and bearer processing for the PTT service and signaling for switching from the unidirectional communication mode to the bidirectional communication mode during the PTT process; And And a terminal operating as said client. The method of claim 17, And the PoC server uses floor control signaling as signaling for switching to the bidirectional communication mode. The method of claim 17, And the PoC server performs a media mixing function for media processing for bidirectional communication. The method of claim 19, And wherein said media processing is a mix or a bridge. The method of claim 19 And the mixing function is performed at a media relay server in the PoC server. A terminal equipped with a client for switching from a one-way communication mode to a two-way communication mode during a push-to-talk (PTT) operation in a mobile communication network, A PTT service unit processing a function of the client based on a main control task of a real-time operating system; And And a component on a physical layer and a media access control layer to communicate with the PTT service unit. A method of switching a unidirectional communication mode to a bidirectional communication mode during a PTT progress between a plurality of terminals operating as clients in a mobile communication network having a push-to-talk over cellular (PoC) server, Transmitting, by one of a plurality of terminals, a message for a bidirectional communication request to the PoC server; The PoC server converts a unidirectional communication mode into a bidirectional communication mode by using a mixing function; And transmitting, by the PoC server, an instruction for all PoC clients to speak simultaneously to the terminal, which is a PoC client, through a preset RTP channel.

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