Method and system for guaranteeing seamless session when replacing PoC terminal in PoC system

• US 20060189340A1
• Filed: 01/25/2006
• Published: 08/24/2006
• Est. Priority Date: 01/26/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Han, Jea-Hun, Sung, Sang-Kyung, Park, Joon-Goo
• Granted Patent: US 7,797,006 B2
• Time in Patent Office: Days
• US Class Current: 455/518
• CPC Class Codes: H04L 65/1094 Inter-user-equipment sessions transfer or sharing
• CPC Class Codes: H04L 65/4061 Push-to services, e.g. push-to-talk or push-to-video
• CPC Class Codes: H04W 4/10 Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 76/45 for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

Abstract

A method and system for guaranteeing a seamless session when replacing a PoC terminal in a PoC system is provided, in which a currently busy PoC client can be replaced in an existing busy PoC session using a PoC compliant client capable of connecting the PoC session, thereby preventing a transmitted media stream of the running PoC session from being lost when the PoC client is replaced. The method includes transmitting, by an arbitrary PoC user, a message for replacing a terminal from a user terminal to a session management server while maintaining the session; receiving, by the session management server, the replacement request message, and transmitting an INVITE message to a terminal to be replaced, or a target terminal; and receiving, by the target terminal, the INVITE message, and media through an existing session. In a situation where there is a need to replace the PoC terminal according to change of the media for the PoC call, request of mobility, etc. by the PoC user, the user is allowed to make a continuous call. Thus, it is possible to improve QoE of the user and expand the markets for the PoC terminal and its services.

Claims

1. A method for guaranteeing a seamless session when replacing a push-to-talk-over-cellular (PoC) terminal in a PoC system, the method comprising the steps of:

transmitting, by a PoC client requesting replacement of the PoC terminal, a terminal replacement request message for the replacement of the PoC terminal to a session management server while maintaining the seamless session;

receiving, by the session management server, the replacement request message, and transmitting an INVITE message to a PoC client to be replaced; and

receiving, by the terminal replacement target PoC client, the INVITE message, and media through an existing session.

2. The method according to claim 1, wherein the step of receiving, by the terminal replacement target PoC client, the media through the existing session includes terminating the session with the terminal replacement requesting PoC client.

3. The method according to claim 2, wherein the step of terminating the session is performed at a point of time after the terminal replacement target PoC client connects the session with the session management server.

4. The method according to claim 1, wherein the terminal replacement request message makes use of an SIP (Session Initiation Protocol) REFER message.

5. The method according to claim 4, wherein the SIP REFER message includes a conference URI (Uniform Resource Identifier) of the PoC session set as a Request URI, and address information of the terminal replacement target PoC client set in a Refer-To header field.

6. The method according to claim 5, wherein the address information of the terminal replacement target PoC client included in the Refer-To header field is used without discriminating from an SIP URI used in a current PoC client.

7. The method according to claim 5, wherein the PoC terminal is identified using information on a characteristic value of an SIP user agent when the address information of the terminal replacement target PoC client is used without discriminating from the SIP URI used by the terminal replacement requesting PoC client.

8. The method according to claim 7, wherein the characteristic value is one of fixed for a stationary terminal, mobile for a mobile terminal, video for a video support terminal, and explicit for a special purpose terminal.

9. The method according to claim 7, wherein the characteristic value is decided according to preference of the SIP user agent which is consistent with capability of the terminal.

10. The method according to claim 5, wherein the address information of the terminal replacement target PoC client included in the Refer-To header field makes use of the SIP URI different from a SIP URI used by the terminal replacement requesting PoC client.

11. The method according to claim 10, wherein the terminal replacement target PoC terminal and the terminal replacement requesting PoC terminal are discriminated using the SIP URI when the address information of the terminal replacement target PoC client and the SIP URI used by the terminal replacement requesting PoC client are different from each other.

12. The method according to claim 4, wherein the REFER message includes session connection information (session dialog identifier) which makes it possible to seamlessly receive content of a currently running PoC session using the terminal replacement target PoC client, and information on the terminal replacement requesting PoC terminal.

13. The method according to claim 5, wherein the Refer-To header field includes the INVITE message for connecting the session with the terminal replacement target PoC client.

14. The method according to claim 13, wherein the INVITE message includes information on one of characteristic values of an SIP user agent which include fixed for a stationary terminal, mobile for a mobile terminal, video for a video support terminal, and explicit for a special purpose terminal.

15. The method according to claim 14, wherein the characteristic value is decided according to preference of the SIP user agent which is consistent with capability of the terminal.

16. The method according to claim 13, wherein the INVITE message discriminates between the terminal replacement target PoC terminal and the terminal replacement requesting PoC terminal using a SIP URI when the address information of the terminal replacement target PoC client and the SIP URI used by the terminal replacement requesting PoC client are different from each other.

17. The method according to claim 13, wherein the INVITE message includes session dialog information in a Replaces header field so as to enable the terminal replacement target PoC client to receive media through the same session dialog with respect to a currently running session.

18. The method according to claim 14, wherein the characteristic value is registered using a SIP REGISTER message.

19. A method for guaranteeing a seamless session when replacing a push-to-talk-over-cellular (PoC) terminal in a PoC system, the method comprising the steps of:

transmitting, by a PoC client requesting replacement of the PoC terminal, a terminal replacement request message for the replacement of the PoC terminal to a PoC client to be replaced while maintaining the seamless session;

receiving, by the terminal replacement target PoC client, the terminal replacement request message, and transmitting an INVITE message including information on an existing session to a session management server; and

transmitting, by the session management server receiving the INVITE message, media to the terminal replacement target PoC client.

20. The method according to claim 19, further comprising, by the session management server,

receiving the INVITE message, and transmitting the media through the existing session;

and

terminating the session with an arbitrary terminal transmitting the terminal replacement request message.

21. The method according to claim 19, wherein the terminal replacement target PoC client has the same address information as that of the terminal replacement requesting PoC client.

22. The method according to claim 19, wherein the PoC terminal is identified using information on a characteristic value of an SIP user agent when the address information of the terminal replacement target PoC client is different from the address information used by a current PoC client.

23. The method according to claim 22, wherein the characteristic value is one of fixed for a stationary terminal, mobile for a mobile terminal, video for a video support terminal, and explicit for a special purpose terminal.

24. The method according to claim 19, wherein address information of the terminal replacement target PoC client is different from address information used by the terminal replacement requesting PoC client.

25. The method according to claim 19, wherein the INVITE message additionally includes information on a characteristic value of a user agent which is set up by request of a user.

26. The method according to claim 25, wherein the characteristic value is one of fixed for a stationary terminal, mobile for a mobile terminal, video for a video support terminal, and explicit for a special purpose terminal.

27. A push-to-talk-over-cellular (PoC) system for guaranteeing a seamless session when replacing a push-to-talk-over-cellular (PoC) terminal, the PoC system comprising:

a terminal replacement requesting PoC client that makes a request to replace the PoC terminal;

a terminal replacement target PoC client that becomes a replacement target of the PoC terminal; and

a session management server that receives a terminal replacement request message from the terminal replacement requesting PoC client, transmits an INVITE message to the terminal replacement target PoC client with reference to information on the terminal replacement target PoC client included in the terminal replacement request message, and transmits media to the terminal replacement target PoC client while maintaining an existing session.

28. The PoC system according to claim 27, wherein the terminal replacement request message includes information on the session and the terminal replacement target PoC client.

29. The PoC system according to claim 27, wherein the session management server transmits the INVITE message to the terminal replacement target PoC client with reference to information included in the terminal replacement request message.

30. A push-to-talk-over-cellular (PoC) system for guaranteeing a seamless session when replacing a PoC terminal, the PoC system comprising:

a terminal replacement requesting PoC client that makes a request to replace the PoC terminal;

a terminal replacement target PoC client that receives a terminal replacement request message from the terminal replacement requesting PoC client, refers to information on an existing session, and transmits an INVITE message including the existing session information; and

a session management server that receives the INVITE message, and transmits media to the terminal replacement target PoC client while maintaining the existing session.

31. The PoC system according to claim 30, wherein the session management server terminates the session with the terminal replacement requesting PoC client after transmitting the media to the terminal replacement target PoC client.

32. A push-to-talk-over-cellular (PoC) terminal for maintaining a seamless session when the PoC terminal is replaced in a PoC system, comprising means for transmitting to a session management server a terminal replacement request message including a session identity and information on a PoC terminal to be replaced, and means for receiving a session termination message to terminate the session when a process of replacing the terminal is terminated by the session management server.

33. A push-to-talk-over-cellular (PoC) terminal for maintaining a seamless session when the PoC terminal is replaced in a PoC system, comprising means for directly transmitting a terminal replacement request message, that includes a session identity and information on a PoC terminal to be replaced, to a replacement target PoC terminal through a SIP/IP core network, and means for receiving a session termination message from a session management server to terminate the session.

34. A push-to-talk-over-cellular (PoC) terminal for maintaining a seamless session when the PoC terminal is replaced in a PoC system, comprising means for receiving a terminal replacement request message from a replacement requesting PoC terminal, means for transmitting an INVITE message to a session management server according to information on an existing session received from the replacement requesting PoC terminal, and means for receiving media from the session management server.