KR20080078181A - Method and system for providing service communication in a communication system - Google Patents

Abstract

A method and a system for providing a service in a communication system are provided to prevent misunderstanding between a terminal that talks and a terminal that cannot listen to the talk of the terminal. A PoC(Push-to-talk over Cellular) server receives a TB_REQ message for requesting talk of burst from an arbitrary terminal(201). The PoC server inserts a list of terminals that can receive RTP data, among terminals participating in a current session, into a TB_GRANT message, and transmits it to the terminal that has requested the talk of burst(203). The PoC server transmits the terminal list to the terminals on the list(205). The PoC server provides a service to an arbitrary terminal to which the terminal list-inserted TB_GRANT message was transmitted(207). The PoC server checks whether there is a terminal whose state has been changed among the terminals on the list(209). If there is a terminal whose state has been changed, the PoC server updates the terminal list according to the state information of the state-changed terminal(211).

Description

METHOD AND SYSTEM FOR PROVIDING SERVICE COMMUNICATION IN A COMMUNICATION SYSTEM}

1 is a diagram illustrating a structure of a PoC communication system according to an embodiment of the present invention;

2 is a flowchart illustrating an operation flow of a PoC server according to an embodiment of the present invention;

3 illustrates a TB_GRANT message format according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system, and more particularly, to a method and a system for providing Push To Talk (PTT) service.

In the next generation communication system, due to the revolutionary development of mobile communication and the expansion of the communication network, more expanded and various services and applications using a terminal are provided. In addition, according to various demands of the user, the terminal is expanding from a simple call service to a location service, a multimedia service, a PTT service, and the like. In particular, the PTT service supports various additional functions such as instant messenger and status display, as well as group calls and voice calls, which have been possible in a conventional radio or trunked radio system (TRS) using a terminal.

Meanwhile, the PTT service has been actively standardized for Push-to-Talk over Cellular (PoC) service which is serviced in a mobile communication network. One feature that distinguishes the PoC service from the existing mobile communication service is that a user may make a call while moving among sessions belonging to a plurality of sessions. The requirement for users to be able to make calls over multiple sessions is specified in the requirements of the Open Mobile Alliance (OMA), an organization that defines mobile communications services. have.

In addition, the PTT service based on the PoC network is a unidirectional service in which only a terminal having a voice, that is, a data transmission opportunity, can transmit data among session participant terminals. In other words, when any one of the session participant terminals requests a talk right to the PoC server to obtain a talk right, the PoC server grants a talk right to any one terminal that has requested the talk right, and the arbitrary one that has obtained the talk right. One terminal proceeds to speak. Here, the PoC server is a terminal of the terminal that can listen to the speech of any one terminal, i.e., can receive the data of any one terminal when granting a right to speak, that is, a data transmission opportunity to the any one terminal Send count information.

Accordingly, any one terminal that has received the number information of the terminal together with obtaining the data transmission opportunity can know the number of terminals that can receive their own data. However, it is not known which terminals receive their data. In addition, this problem, that is, the speaker terminal proceeding with the speech does not know which terminal listens to their speech, there is a problem that can not provide a smooth PTT service between the speaker terminal and the terminal listening to the speaker terminal. .

Accordingly, an object of the present invention is to provide a service providing method and system in a communication system.

Another object of the present invention is to provide a method and system for providing a Push To Talk (PTT) service in a communication system.

Another object of the present invention is to provide a method and system for providing a data transmission / reception service by providing information on a terminal that listens to a speaker to a speaker.

The method of the present invention for achieving the above objects; In a communication system, a method of providing a service by a server, the server receiving a service request message for data transmission from a first terminal, and the server of the first terminal among terminals included in a current session. And transmitting a list including information of a terminal capable of receiving data to the first terminal.

The system of the present invention for achieving the above objects; In a communication system, a service providing apparatus comprising: receiving a service request message for data transmission from a first terminal, and including a list including information on a terminal capable of receiving data of the first terminal among terminals included in a current session; It includes a server for transmitting to the first terminal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation of the present invention will be described, and other background art will be omitted so as not to distract from the gist of the present invention.

In the present invention, Push-To-Talk (PTT: Push-To-Talk) communication system is referred to as Push-to-talk over Cellular (PoC) communication system. We propose a method and system for providing a service. In particular, the present invention proposes a method and system for providing a PTT service by transmitting information on terminals that listen to a speaker of a speaker to the speaker. Here, the speaker terminal refers to a terminal that has obtained a speaking right in the current session.

In addition, in the present invention, for convenience of description, a service providing method and system will be described using an example of a PoC communication system, but the service providing method and system proposed by the present invention can be applied to all communication systems as well as the PoC communication system. Of course.

Next, a description will be given of the structure of the PoC communication system that is the basis of the PTT service with reference to FIG.

1 is a diagram illustrating a structure of a PoC communication system according to an embodiment of the present invention.

Referring to FIG. 1, a PoC communication system includes a PoC server 101, a client, for example, a first terminal 111, a second terminal 113, a third terminal 115, The fourth terminal 117 is included.

Hereinafter, for convenience of explanation, it is assumed that any one terminal among the clients in which data to be transmitted exists is the first terminal 111. When data to be transmitted is generated, the first terminal 111 transmits a talk right request (TB_REQ: Talk Burst Request, hereinafter 'TB_REQ') message 105 to the PoC server 101.

Meanwhile, the PoC server 101 is an on-line terminal 103 managed by itself, that is, a terminal which can listen among information of terminals participating in a current session, that is, a real-time transport protocol (RTP) Terminal list capable of receiving data (hereinafter, referred to as 'listening terminal list') 109 is called TB_GRANT: Talk Burst Granted (hereinafter, referred to as 'TB_GRANT') message Inserted into 107 and transmitted to the first terminal 111. Here, the audible terminal list 109 includes terminals capable of receiving RTP data among the terminals participating in the current session, that is, the second terminal 113 and the fourth terminal 117. Accordingly, the second terminal 113 and the fourth terminal 117 may receive the RTP data transmitted by the first terminal 111.

Meanwhile, the audible terminal list 109 is also transmitted to terminals included in the list, that is, the second terminal 113 and the fourth terminal 117.

In the current session, the third terminal 115 is a hold-on state terminal and is a terminal which cannot receive RTP data. In the state in which RTP data reception is impossible, such as the hold-on state, there are an inactive state and an abnormal state. The abnormal state may be, for example, a not_permitted_send_media state and a releasing state. Can be.

First, a process of notifying the PoC server 101 that the terminal in the hold-on state, that is, the third terminal 115 is in the hold-on state in the current session, will be described.

The hold-on state terminal sets a session initialization protocol (SIP) set to "a = sendonly" indicating that only RTP data can be transmitted to a session description protocol (SDP). In the following description, an invitation (re-INVITE) message is transmitted to the PoC server 101. When the PoC server 101 receives the SIP message set to “a = sendonly”, the PoC server 101 sets the corresponding terminal, that is, the third terminal 115 to a hold-on state. Therefore, the hold-on state terminal is indicated as 'hold_on' in the online terminal 103 information managed by the PoC server 101.

Next, the process of notifying the PoC server 101 that the inactive terminal is inactive in the current session will be described as an example.

The inactive terminal transmits a SIP re-INVITE message set to “a = inactive” to the PoC server 101 indicating that transmission / reception of RTP data in the SDP is impossible. When the PoC server 101 receives the SIP message set to "a = inactive", the PoC server 101 sets the terminal to an inactive state. Accordingly, the inactive terminal is indicated as 'inactive' in the information on the online terminal 103 managed by the PoC server 101.

Next, a process of notifying the PoC server 101 that the media transmission impossible state in the abnormal state among the abnormal states in the current session is as follows.

The media non-transmission state terminal is a terminal that has obtained a voice in the current session, that is, the remaining terminals except the first terminal 111, that is, the second terminal 113, the third terminal 115, and the fourth terminal 117. Any one of the terminals transmits the RTP data to the PoC server and receives a talk rejection (TB_REVOKE: Talk Burst Revoke, hereinafter 'TB_REVOKE') message from the PoC server. When the PoC server 101 transmits the TB_REVOKE message to any one terminal, the PoC server 101 sets the terminal to a state in which no media can be transmitted. Accordingly, the media non-transmit state terminal is indicated as 'not_permitted_send_media' in the online terminal 103 information managed by the PoC server 101.

Finally, a process of notifying the PoC server 101 that the terminal in the released state is released from the current session as an example will be described below.

The release state terminal does not transmit a talk release release (TB_REALEASE: 'TB_REALEASE') message for a predetermined time even though the TB_REVOKE message is received in the media transmission impossible state. If the PoC server 101 does not receive a TB_REALEASE message from the terminal, the PoC server 101 transmits a SIP end (BYE, hereinafter referred to as 'BYE') message to the terminal until the SIP BYE message is transmitted. Set to off. Accordingly, the released state terminal is marked as 'releasing' in the information on the online terminal 103 managed by the PoC server 101.

As described above, among the terminals participating in the current list of the audible terminals, terminals that can be listened to in the current session except for a hold-on state terminal, an inactive state terminal, a media transmission impossible state terminal, a release state terminal, and the like, That is, it includes terminals capable of receiving RTP data. In addition, the PoC server 101 transmits the audible terminal list to the terminal that has the right to speak and the terminals that can receive the RTP data.

On the other hand, if the terminal that has obtained the speaking right, that is, a terminal whose state is changed in the audible terminal list 103 while the speaker terminal is transmitting RTP data, the PoC server generates the audible terminal list 103 in the changed terminal. After updating according to the state information of the retransmission to the terminals included in the speaker terminal and the audible terminal list.

Next, the operation of the PoC server will be described with reference to FIG. 2.

2 is a flowchart illustrating an operation flow of a PoC server according to an embodiment of the present invention.

In step 201, the PoC server receives a TB_REQ message requesting a talk right from any one terminal and proceeds to step 203.

In step 203, the PoC server inserts a list of terminals capable of receiving RTP data, that is, a list of audible terminals among terminals currently participating in the session, into a TB_GRANT message and transmits it to any one terminal that has requested the right to speak. Here, the audible terminal refers to a terminal capable of receiving RTP.

In step 205, the PoC server transmits a list of audible terminals inserted into the TB_GRANT message to the terminals included in the list.

In step 207, the PoC server provides a service to any one terminal that has transmitted the TB_GRANT message in which the audible terminal list is inserted in step 205, and proceeds to step 209.

In step 209, the PoC server checks whether there is a state changed terminal among terminals included in the audible terminal list. In step 209, if there is a terminal whose state is changed in the audible terminal list, the process proceeds to step 211. In step 211, the PoC server updates the audible terminal list according to the state information of the state changed terminal, and then proceeds to step 203.

As a result of the check in step 209, if there is no terminal whose state is changed in the audible terminal list, step 207 is performed.

Next, a TB_GRANT message format according to an embodiment of the present invention will be described with reference to FIG. 3.

3 illustrates a TB_GRANT message format according to an embodiment of the present invention.

Referring to FIG. 3, the TB_GRANT message format includes a subtype field, a length field, a synchronization source (SSRC) field, a name field, a speaking time duration field, and a participant field. It includes a voice expiration field and a participant application-dependent field.

 The subtype field is set to a value indicating that the message is a TB_GRANT message, that is, 01001, and the speech time duration field includes a T2-timer field, a T2-length field, and a Stop talking time value field. Herein, the T2-timer field is set to 101, and the T2-length field is set to 2. In addition, the Stop talking time value indicates the maximum time that the terminal that has obtained the right to speak, that is, the speaker terminal, may proceed to speak.

The participant field includes a P-count field, a P-count-length field, and a Participants field. Herein, the P-count field is set to 100, and the P-count-length field is set to 2. In addition, the Participants field represents the number of terminals participating in the current session.

The talk right expiration field includes an Alert-Margin field, an Alert-Margin-length field, and an Alert-Margin value field. Here, the Alert-Margin field is set to 104, and the Alert-Margin-length field is set to 2. In addition, the Alert-Margin value field represents a time for notifying the speaker terminal that the speaking right has expired within the Stop talking time value.

In addition, the SDES item CNAME in the application-dependent field represents the nickname of the requestor.

In the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, in the Push-to-talk over Cellular (PoC) communication system, the present invention provides a list of terminals that can listen to a speech among terminals participating in a current session when the server grants a voice to any one terminal. By transmitting the speaker terminal can distinguish between a terminal that can hear its own speech and a terminal that can not hear. Thus, a speaker terminal that has received a list of terminals that can listen to a speech among terminals participating in the current session can know a terminal that can listen to its contents, and thus, a speaker terminal and a terminal that cannot listen to the speech. It can reduce the possibility of misunderstanding that may exist in between.

Claims (12)

In a communication system, a method of providing a service by a server, Receiving, by the server, a service request message for data transmission from a first terminal; And transmitting, by the server, a list including information on a terminal capable of receiving data of the first terminal, among the terminals included in the current session, to the first terminal. The method of claim 1, And updating the list and retransmitting the updated list to the first terminal when a terminal whose state is changed in the list occurs. The method of claim 2, When the list is updated, And retransmitting the updated list to the terminals included in the updated list. The method of claim 1, The server further comprises the step of transmitting the list to the terminals included in the list. The method of claim 1, The list is inserted into a service grant message and the service providing method characterized in that transmitted to the first terminal. The method of claim 1, The list may include a terminal other than a speaker terminal, a hold_on state terminal, an inactive (inactive) terminal, and an abnormal state terminal among online terminals managed by the server. In a communication system, in a service providing system, Receiving a service request message for data transmission from a first terminal, And a server transmitting a list including information on a terminal capable of receiving data of the first terminal among terminals included in a current session to the first terminal. The method of claim 7, wherein The server updates the list when a terminal whose state changes in the list occurs, and retransmits the updated list to the first terminal. The method of claim 8, When the list is updated, And the server retransmits the updated list to the terminals included in the updated list. The method of claim 7, wherein The server transmits the list to the terminals included in the list. The method of claim 7, wherein The server inserts the list into a service grant message and transmits the service to the first terminal. The method of claim 7, wherein The server includes a terminal other than a speaker terminal, a hold_on state terminal, an inactive (inactive) terminal, and an abnormal state terminal among online terminals managed by the server.

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