METHOD AND ARRANGEMENT FOR ESTABLISHING A COMMUNICATION SESSION FOR MULTIMEDIA

• US 20100220604A1
• Filed: 12/12/2005
• Published: 09/02/2010
• Est. Priority Date: 12/12/2005
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Dahlin, Clary Hallberg, Skog, Robert, Synnergren, Per, Körling, Martin, Dahlin, Steinar
• Granted Patent: US 7,944,880 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/752 adapting media to network capabilities
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 76/12 Setup of transport tunnels
• CPC Class Codes: H04W 76/22 Manipulation of transport tunnels

Abstract

A method and arrangement for establishing a packet-switched multimedia session for a mobile terminal connected to a mobile access network. A first Radio Access Bearer RAB is obtained, and the multimedia session is started by communicating media over the first RAB. Simultaneously with the media communication, a quality of communicated media is monitored and evaluated. If the monitored quality is deemed unacceptable, a media-adapted second RAB is obtained, and the session is continued over the second RAB. Thereby, it is not necessary to delay the communication of media by waiting for the second RAB to be obtained.

Claims

1. A method of establishing a packet-switched multimedia session for a mobile terminal connected to a mobile access network for the communication of media, comprising the following steps:

obtaining a first Radio Access Bearer RAB,

starting the multimedia session by communicating said media over the first RAB,

monitoring and evaluating a quality of communicated media according to a predetermined monitoring algorithm, simultaneously with the media communication over the first RAB, and

if the monitored quality is deemed unacceptable according to said monitoring algorithm, obtaining a media-adapted second RAB based on quality requirements of the ongoing media communication, and

continuing the media communication over the second RAB.

2. The method according to claim 1, wherein the first RAB is obtained by activating a primary PDP context adapted for signalling messages.

3. The method according to claim 1, wherein the first RAB is obtained by activating a pre-established secondary PDP context adapted for media communication.

4. The method according to claim 1, wherein the first RAB is a default RAB.

5. The method according to claim 1, wherein the first RAB is initially adapted for said communicated media.

6. The method according to claim 1, wherein the session is completed over the first RAB, if the monitored quality remains acceptable throughout the session.

7. The method according to claim 1, wherein the media-adapted second RAB is obtained by activating a secondary PDP context adapted for said communicated media.

8. The method according to claim 3, wherein the media-adapted second RAB is obtained by modifying said first RAB and pre-established secondary PDP context to be adapted for said communicated media.

9. The method according to claim 7 or 8, wherein the communication of media is switched from the first RAB to the media-adapted second RAB, once the secondary PDP context has been activated or the pre-established secondary PDP context has been modified.

10. The method according to claim 1, wherein said media-adapted second RAB is obtained when at least one media stream has been added or changed during the ongoing media communication.

11. The method according to claim 1, wherein the quality of a received media stream is monitored by measuring any of the following parameters:

a packet buffer size in the terminal, a transfer bit rate, a bit error rate, a retransmission rate, and detected disturbances in the play-out or presentation of media to an end-user, as input to said monitoring algorithm.

12. The method according to claim 11, wherein the monitoring algorithm is configured such that the monitored quality is deemed acceptable as long as the measured buffer size stays above a predetermined level, and/or if the measured bit rate of the media stream stays above a predetermined level, and/or if the measured bit error rate and/or retransmission rate does not exceed a predetermined level.

13. The method according to claim 12, wherein the monitoring algorithm is configured such that the monitored quality is deemed unacceptable whenever one or more of the measured parameters stays above or does not exceed, respectively, said level(s) for a preset duration or repeatedly.

14. The method according to claim 9, wherein SIP is used for signalling and the monitoring algorithm is based on requirements derived from information in an SDP message given in an INVITE message, and/or a response thereto.

15. The method according to claim 1, wherein said quality is monitored and evaluated by the mobile terminal.

16. The method according to claim 1, wherein said quality is monitored and evaluated by a quality monitor in the mobile access network or in a multimedia service network currently controlling the session.

17. The method according to claim 16, wherein said step of obtaining a media-adapted second RAB is initiated by sending a PDP context triggering message to the mobile terminal or to a GGSN node in the mobile access network.

40. The method according to claim 7, wherein said media-adapted second RAB is obtained when at least one media stream has been added or changed during the ongoing media communication.

18. An arrangement for establishing a packet-switched multimedia session for a mobile terminal connected to a mobile access network for the communication of media, comprising:

means for obtaining a first Radio Access Bearer RAB,

means for starting the multimedia session by communicating said media over the first RAB,

means for monitoring and evaluating a quality of communicated media according to a predetermined monitoring algorithm, simultaneously with the media communication over the first RAB, and

means for obtaining a media-adapted second RAB based on quality requirements of the ongoing media communication, if the monitored quality is deemed unacceptable according to said monitoring algorithm, such that the session can continue over said second RAB.

19. The arrangement according to claim 18, wherein said means for obtaining a first RAB is configured to obtain the first RAB by activating a primary PDP context adapted for signalling messages.

20. The arrangement according to claim 18, wherein said means for obtaining a first RAB is configured to obtain the, first RAB by activating a pre-established secondary PDP context adapted for media communication.

21. The arrangement according to claim 18, wherein the first RAB is a default RAB.

22. The arrangement according to claim 18, wherein the first RAB is initially adapted for said communicated media.

23. The arrangement according to claim 18, further comprising means for completing the session over the first RAB, if the monitored quality remains acceptable throughout the session.

24. The arrangement according to claim 18, wherein said means for obtaining a media-adapted second RAB is configured to obtain the second RAE by activating a secondary PDP context adapted for said communicated media.

25. The arrangement according to claim 20, wherein said means for obtaining a media-adapted second RAB is configured to obtain the second RAE by modifying said first RAB and pre-established secondary PDP context to be adapted for said communicated media.

26. The arrangement according to claim 25, further comprising means for switching the communicated media from the first RAB to the second RAB, once the secondary PDP context has been activated or the pre-established secondary PDP context has been modified.

27. The arrangement according to any claim 18, wherein said means for obtaining a media-adapted second RAB is configured to obtain a media-adapted second RAB when at least one media stream has been added or changed during the ongoing media communication.

28. The arrangement according to claim 18, wherein the monitoring and evaluating means is configured to obtain measurements of any of the following parameters:

a packet buffer size in the terminal, a transfer bit rate, a bit error rate, a retransmission rate, and detected disturbances in the play-out or presentation of media to an end-user, and to provide said measurements to the processor as input to said monitoring algorithm to indicate the quality of a received media stream.

29. The arrangement according to claim 28, wherein the monitoring algorithm is configured such that the quality is deemed acceptable as long as the measured buffer size stays above a predetermined level, and/or if the measured bit rate of the media stream stays above a predetermined level, and/or if the measured bit error rate and/or retransmission rate does not exceed a predetermined level.

30. The arrangement according to claim 29, wherein the monitoring algorithm is configured such that the monitored quality is deemed unacceptable whenever one or more of the measured parameters stays above or does not exceed, respectively, said level(s) for a preset duration or repeatedly.

31. The arrangement according to claim 26, wherein SIP is used for signalling and the monitoring algorithm is based on requirements derived from information in an SDP message given in an INVITE message, and/or a response thereto.

32. The arrangement according to claim 18, wherein the monitoring and evaluating means is implemented in the mobile terminal.

33. The arrangement according to claim 18, wherein the monitoring and evaluating means is implemented as a quality monitor in the mobile access network or in a multimedia service network currently controlling the session.

34. The arrangement according to claim 33, wherein said means for obtaining a media-adapted second RAB is configured to send a PDP context triggering message to the mobile terminal or to a GGSN node in the mobile access network.

41. The arrangement according to any claim 24, wherein said means for obtaining a media-adapted second RAB is configured to obtain a media-adapted second RAB when at least one media stream has been added or changed during the ongoing media communication.

35. An arrangement in a mobile terminal, when connected to a mobile access network, for establishing a packet-switched multimedia session for the communication of media, comprising:

a communication unit configured to obtain a first Radio Access Bearer RAB, and to start the multimedia session by communicating media over the first RAB, and

a processor configured to monitor and evaluate a quality of communicated media according to a predetermined monitoring algorithm, simultaneously with the media communication over the first RAB, and to trigger the communication unit to obtain a media-adapted second RAB based on quality requirements of the ongoing media communication, if the monitored quality is deemed unacceptable according to said monitoring algorithm, such that the session can continue over said second RAB.

36. The arrangement according to claim 35, further comprising a measuring unit configured to provide measurements to the processor from at least one of:

a data buffer, a decoder and a media play-out unit.

37. A quality monitor for monitoring and evaluating a quality of communicated media, comprising:

—

a measurement receiver for receiving quality measurements regarding an ongoing multimedia session for a mobile terminal using a first RAB,

a processor for evaluating the quality measurements and for determining whether a media-adapted second RAB is needed to fulfill quality requirements of the ongoing multimedia session, and

a PDP context triggering unit configured to send a message to the mobile terminal or to a GGSN node in the access network, if said quality is deemed unacceptable according to a predetermined monitoring algorithm, said message triggering a media-adapted second RAB based on quality requirements of the ongoing media communication, such that the session can continue over said second RAB.

38. The quality monitor according to claim 37, configured to be implemented in a mobile access network to which the mobile terminal is currently connected, or in a multimedia service network currently controlling the session.

39. The quality monitor according to claim 37, configured to receive said quality measurements from at least one of:

a mobile access network to which the mobile terminal is currently connected, a multimedia service network currently controlling the session, and the mobile terminal.