Delay trading between communication links

• US 20040081106A1
• Filed: 10/25/2002
• Published: 04/29/2004
• Est. Priority Date: 10/25/2002
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Bruhn, Stefan
• Granted Patent: US 7,289,451 B2
• Time in Patent Office: Days
• US Class Current: 370/276
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

In the present invention, the available delay budget for a full-duplex communication is distributed between the links depending on their activity, present and near history. By keeping track on if a link in a full-duplex communication system is active or inactive, i.e. knowing the information value of the transferred data, coding procedures having larger coding delays than normally accepted can be used for active links, if the opposite link simultaneously is inactive. Since the user sensibility for delays is as largest at the moment a link becomes active, coding procedures having smaller coding delays than normally used are assigned at the moment a link becomes active. The coding delay is subsequently increased. Preferably, the round-trip delay is controlled to be kept smaller than a requested maximum value.

Claims

1. A method for full-duplex communication, comprising the steps of:

transferring data in a full-duplex manner;

obtaining a determination of information value carried by said data; and

dynamically assigning coding delay dependent on said determination.

2. The method according to claim 1, wherein a higher coding delay is assigned for a higher information value.

3. The method according to claim 2, further comprising the steps of:

transmitting with lower allocated transmission resource when applying higher coding delay;

said transmission resource being one in the group of;

transmission power;

bit rate used for transmission;

number of packets used for transmission; and

number of allocated transmission channels.

4. The method according to claim 2, wherein said determination is a determination of whether said data corresponds to activity or inactivity, respectively, of a link carrying said data.

5. The method according to claim 4, wherein:

said transferring step in turn comprises transferring of data in a first direction and transferring of data in a second direction;

said obtaining step in turn comprises a first determination of whether said data transferred in said first direction corresponds to activity or inactivity; and

said dynamically assigning step in turn comprises dynamically assigning of coding delay in said first direction dependent on said first determination.

6. The method according to claim 5, wherein:

said assigning step in turn comprises the step of controlling said coding delay in said first direction to approach a maximum coding delay if said first determination indicates activity.

7. The method according to claim 6, wherein:

said approach is a gradual approach.

8. The method according to claim 6, wherein:

said approach takes place via a plurality of predetermined coding delay levels.

9. The method according to claim 8, wherein:

said coding delay levels are based on a set of predetermined coding schemes.

10. The method according to claim 7, wherein:

said assigning step further comprises the step of setting said coding delay in said first direction to a minimum coding delay at an onset of a period where said first determination indicates activity.

11. The method according to claim 10, further comprising the steps of:

transmitting with higher allocated transmission resource when applying lower coding delay;

said transmission resource being one in the group of;

transmission power;

bit rate used for transmission;

number of packets used for transmission; and

number of allocated transmission channels.

12. The method according to claim 10, wherein:

said gradual approach is delayed until a predetermined time after said onset.

13. The method according to claim 5, wherein:

said assigning step in turn comprises the step of controlling said coding delay in said first direction to approach a minimum coding delay if said first determination indicates inactivity.

14. The method according to claim 5, wherein:

said system having a requested maximum round-trip delay;

said obtaining step further comprises a second determination of whether said data transferred in said second direction corresponds to activity or inactivity; and

said dynamically assigning step in turn comprises dynamically assigning of coding delay in said first direction dependent on both said first determination and said second determination.

15. The method according to claim 14, wherein:

said assigning step in turn comprises the step of controlling said coding delay in said first direction to approach a maximum coding delay if said first determination indicates activity and said second determination indicates inactivity.

16. The method according to claim 15, wherein:

said assigning step further comprises the step of controlling said coding delay in said first direction to approach an intermediate coding delay if said first determination and said second determination both indicate activity.

17. The method according to claim 16, wherein:

said intermediate coding delay gives a total delay of said transfer of data in said first direction that is essentially half of said requested maximum round-trip delay.

18. The method according to claim 15, wherein:

said assigning step further comprises the step of setting said coding delay in said first direction to a minimum coding delay at an onset of a period where said first determination indicates activity.

19. The method according to claim 18, wherein:

said maximum coding delay gives a first total delay of said transfer of data in said first direction;

said minimum coding delay gives a second total delay of said transfer of data in said first direction;

a sum of said first and second total delay is essentially equal to said requested maximum round-trip delay.

20. The method according to claim 18, wherein:

said maximum coding delay gives a first total delay of said transfer of data in said first direction;

said minimum coding delay gives a second total delay of said transfer of data in said second direction;

a sum of said first and second total delay is essentially equal to said requested maximum round-trip delay.

21. The method according to claim 15, wherein:

any increase in coding delay is postponed a predetermined time period.

22. The method according to claim 4, wherein said data represents audio signals, whereby inactivity being defined as at least one of:

silence;

background noise; and

constant signal.

23. The method according to claim 4, wherein said data represents video signals, whereby inactivity being defined as at least one of:

no image;

background noise; and

still.

24. The method according to claim 18, further comprising the steps of:

measuring an actual response time for a message to be sent forward and back in said system;

adapting said minimum and maximum coding delays for making said actual response time equal to said requested maximum round-trip delay.

25. The method according to claim 1, wherein said coding delay is dependent on a jitter buffer depth.

26. The method according to claim 25, wherein said dynamical assigning of coding delay in turn comprises the steps of:

setting a target jitter buffer fill level dependent on said determination; and

adjusting a jitter buffer clock to achieve an average fill level equal to said target jitter buffer fill level.

27. The method according to claim 25, wherein said dynamical assigning of coding delay in turn comprises the steps of:

setting a target jitter buffer fill level dependent on said determination; and

inserting or discarding frames to achieve an average fill level equal to said target jitter buffer fill level.

28. The method according to any of the claims 1 to 27, wherein said full-duplex communication is a multi-party communication.

29. A full-duplex communication system, comprising:

at least two terminals;

a network connecting said at least two terminals;

transferring means for transferring data in a full-duplex manner between any two of said at least two terminals;

coding/decoding means associated with said at least two terminals;

detector means for determining information value carried by said data; and

coding control means for controlling coding delay of said coding/decoding means, said coding control means being arranged to dynamically assign coding/decoding associated with a multitude of possible coding delays dependent on said determination.

30. The system according to claim 29, wherein said associated coding delay is higher for a higher value of said information value.

31. The system according to claim 30, wherein said transferring means in turn comprises means for allocating transmission resource dependent on applied coding delay;

said transmission resource being at least one in the group of;

transmission power;

bit rate used for transmission;

number of packets used for transmission; and

number of allocated transmission channels.

32. The system according to claim 30, wherein said detector means is a detector for determination of whether said data corresponds to activity or inactivity, respectively, of a link carrying said data.

33. The system according to claim 32, wherein:

said transferring means comprises means for transferring of data in a first direction between two of said at least two terminals and means for transferring of data in a second direction, opposite to said first direction;

said detector means in turn comprises a first detector for determination of whether said data carried by said data transferred in said first direction corresponds to activity or inactivity; and

said coding control means being arranged to dynamically assign coding/decoding dependent on outputs from said first detector.

34. The system according to claim 33, wherein said first detector is connected to the incoming link of at least one of said terminals, said coding control means being arranged to dynamically assign decoding dependent on outputs from said first detector.

35. The system according to claim 33, wherein:

said detector means further comprises a second detector for determination of whether said data transferred in said second direction corresponds to activity or inactivity; and

said coding control means being arranged to dynamically assign coding/decoding dependent on outputs from both said first detector and said second detector.

36. The system according to claim 35, wherein said first detector is connected to the incoming link of at least one of said terminals, said second detector is connected to the outgoing link of said at least one of said terminals, said coding control means being arranged to dynamically assign decoding dependent on outputs from both said first detector and said second detector.

37. The system according to claim 32, wherein said coding/decoding means in turn comprises a jitter buffer, said coding control means being a jitter buffer control means.

38. The system according to claim 37, wherein said jitter buffer control means is arranged to control a jitter buffer clock.

39. The system according to claim 37, wherein said jitter buffer control means is arranged to insert or discard frames.

40. The system according to claim 32, wherein said data represents audio signals, whereby said detector being sensitive to at least one of:

silence;

background noise; and

constant signal.

41. The system according to claim 32, wherein said data represents video signals, whereby said detector being sensitive to at least one of:

no image;

background noise; and

still.

42. The system according to claim 29, further comprising:

means for measuring an actual response time for a message to be sent forward and back in said system;

means for adapting minimum and maximum coding delays in response to an output of said means for measuring an actual response time.

43. The system according to any of the claims 29 to 42, further comprising:

means for supporting multi-party communication.

44. A terminal, comprising:

transferring means for transferring data in a full-duplex manner to and from said terminal;

coding means associated with an outgoing link;

decoding means associated with an incoming link;

detector means for determining information value carried by said data; and

coding control means for controlling at least one of said coding means and said decoding means, said coding control means being arranged to dynamically assign coding/decoding associated with a multitude of possible coding delays dependent on said determination.

45. The terminal according to claim 44, wherein said coding control means being arranged to dynamically assign coding/decoding associated with a plurality of predetermined coding delay levels.

46. The terminal according to claim 44, wherein said coding control means being arranged to dynamically assign coding/decoding associated with a plurality of coding delay levels based on a set of predetermined coding schemes.

47. The terminal according to claim 44, wherein said detector means is a detector for determination of whether said data corresponds to activity or inactivity, respectively, of a link carrying said data.

48. The terminal according to claim 47, wherein:

said detector means in turn comprises a first detector for determination of whether said data carried by said data transferred in said incoming link corresponds to activity or inactivity; and

said coding control means being arranged to dynamically assign decoding dependent on outputs from said first detector.

49. The terminal according to claim 48, wherein:

said detector means further comprises a second detector for determination of whether said data transferred in said outgoing link corresponds to activity or inactivity; and

said coding control means being arranged to dynamically assign decoding dependent on outputs from both said first detector and said second detector.

50. The terminal according to claim 49, wherein said decoding means comprises a jitter buffer, said coding control means being a jitter buffer control means.

51. The terminal according to claim 50, wherein said jitter buffer control means is arranged to control a jitter buffer clock.

52. The terminal according to claim 50, wherein said jitter buffer control means is arranged to insert or discard frames.