Methods and apparatus supporting adaptive decentralized traffic scheduling including a dynamic transmitter yielding threshold

• US 8,526,461 B2
• Filed: 11/10/2008
• Issued: 09/03/2013
• Est. Priority Date: 11/10/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wu, Xinzhou, Li, Junyi, Shakkottai, Sanjay, Larola, Rajiv, Tavildar, Saurabh, Richardson, Thomas, Sundararajan, Jay Kumar
• Primary Examiner(s): MATTIS, JASON E
• Application Number:
  US12/268,208
• Publication Number:
  US 20100118702A1
• Time in Patent Office: 1,758 Days
• Field of Search: 370/230, 370/278, 370/445, 370/447
• US Class Current: 370/447
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Methods and apparatus relating to scheduling of air link resources, e.g., traffic segments, in a wireless communications system are described. Various described methods and apparatus are well suited to wireless peer to peer networks in which traffic scheduling is decentralized, e.g. an ad hoc peer to peer network. An individual wireless terminal corresponding to a peer to peer connection which desires to transmit traffic signals make transmitter yielding decisions on a traffic slot by traffic slot basis. The transmitter yielding decision, in some embodiments, includes comparing a link quality estimate corresponding to a higher priority link intending to use the same traffic segment concurrently, to a dynamically generated transmitter yielding threshold. The dynamically generated transmitter yielding threshold is determined based on at least one of: quality of service information corresponding to its own link and historical link quality information corresponding to the higher priority link.

Claims

1. A method of operating a first wireless terminal in a system including a first wireless communications link from a second wireless terminal to a third wireless terminal, said first communications link having a higher priority than a second communications link from the first wireless terminal to a fourth wireless terminal, the method comprising:

transmitting a transmission request to the fourth wireless terminal;

receiving a first transmission request response from the third wireless terminal transmitted in response to a transmission request from the second wireless terminal;

receiving a second transmission request response from the fourth wireless terminal;

estimating the quality of the first communications link from the received first transmission request response signal; and

dynamically generating a yielding threshold based on at least one of;

i) historic link quality information corresponding to the first link;

or ii) quality of service information corresponding to the second communications link.

2. The method of claim 1, wherein said estimating the quality of the first communications link includes using a determined intended second link traffic signaling transmission power level.

3. The method of claim 1, wherein said estimating the quality of the first communications link is performed based on the received second transmission request response signal.

4. The method of claim 1, wherein the first and fourth wireless terminals are mobile communications devices.

5. The method of claim 1, further comprising:

determining from at least one signal received from the third wireless terminal historic link quality information corresponding to the first communications link.

6. The method of claim 5, wherein the at least one signal is a broadcast signal from the third wireless terminal which communicates said historic link quality information.

7. The method of claim 5, wherein determining from at least one signal received from the third wireless terminal includes accumulating link quality information from multiple signals sent from the third wireless terminal to the second wireless terminal, each of said multiple signals communicating link quality information corresponding to a different period of time.

8. The method of claim 7, wherein the link quality information includes at least one of link SNR information or rate information.

9. The method of claim 5, further comprising:

making a decision whether or not to transmit traffic data in a transmission segment corresponding to the received second transmission request response based on the estimated quality of the first communications link and the dynamically generated threshold.

10. The method of claim 9, wherein said making the decision comprising:

comparing the estimated quality of the first communications link to the dynamically generated threshold; and

deciding to transmit said traffic data when said comparison indicates that the estimated quality of the first communications link exceeds the dynamically generated threshold.

11. The method of claim 10, wherein said quality of service information is based on the amount of data waiting to be transmitted by the first wireless terminal to the fourth wireless terminal.

12. The method of claim 10, wherein the quality of service information indicates a quality of service level corresponding to a type of traffic waiting at said first wireless terminal to be transmitted.

13. The method of claim 9, wherein dynamically generating said threshold includes generating a lower threshold than a previous threshold when the quality of service information indicates an increase in a quality of service level corresponding to the second communications link.

14. The method of claim 9, wherein dynamically generating said threshold includes generating a higher threshold than a previous threshold when the quality of service information indicates a decrease in a quality of service level corresponding to the second communications link.

15. The method of claim 9, wherein the historic link quality information includes an average data rate supported by the first communications link during a previous time interval.

16. A first wireless terminal in a system including a first wireless communications link from a second wireless terminal to a third wireless terminal, said first communications link having a higher priority than a second communications link from the first wireless terminal to a fourth wireless terminal, the first wireless terminal comprising:

at least one processor configured to;

transmit a transmission request to the fourth wireless terminal;

receive a first transmission request response from the third wireless terminal transmitted in response to a transmission request from the second wireless terminal;

receive a second transmission request response from the fourth wireless terminal;

estimate the quality of the first communications link from the received first transmission request response signal; and

dynamically generate a yielding threshold based on at least one of;

i) historic link quality information corresponding to the first link;

or ii) quality of service information corresponding to the second communications link; and

a memory coupled to said at least one processor.

17. The first wireless terminal of claim 16, wherein said at least one processor is configured to use a determined intended second link traffic signaling transmission power level as part of being configured to estimate the quality of the first communications link.

18. The first wireless terminal of claim 16, wherein said at least one processor is configured to use the received second transmission request response signal as part of being configured to estimate the quality of the first communications link.

19. The first wireless terminal of claim 16, wherein the first and fourth wireless terminals are mobile communications devices.

20. The first wireless terminal of claim 16, wherein said at least one processor is further configured to determine, from at least one signal received from the third wireless terminal, historic link quality information corresponding to the first communications link.

21. The first wireless terminal of claim 20, wherein the at least one signal is a broadcast signal from the third wireless terminal which communicates said historic link quality information.

22. The first wireless terminal of claim 20, wherein said at least one processor is further configured to accumulate link quality information from multiple signals sent from the third wireless terminal to the second wireless terminal, each of said multiple signals communicating link quality information corresponding to a different period of time, as part of being configured to determine from at least one signal received from the third wireless terminal historic link quality information corresponding to the first communications link.

23. The first wireless terminal of claim 22, wherein the link quality information includes at least one of link SNR information or rate information.

24. The first wireless terminal of claim 20, wherein said at least one processor is further configured to make a decision whether or not to transmit traffic data in a transmission segment corresponding to the received second transmission request response based on the estimated quality of the first communications link and the dynamically generated threshold.

25. The first wireless terminal of claim 24, wherein said at least one processor is configured to:

compare the estimated quality of the first communications link to the dynamically generated threshold; and

decide to transmit said traffic data when said comparison indicates that the estimated quality of the first communications link exceeds the dynamically generated threshold,

as part of being configured to make said decision.

26. The first wireless terminal of claim 25, wherein said quality of service information is based on the amount of data waiting to be transmitted by the first wireless terminal to the fourth wireless terminal.

27. The first wireless terminal of claim 25, wherein the quality of service information indicates a quality of service level corresponding to a type of traffic waiting at said first wireless terminal to be transmitted.

28. A first wireless terminal in a system including a first wireless communications link from a second wireless terminal to a third wireless terminal, said first communications link having a higher priority than a second communications link from the first wireless terminal to a fourth wireless terminal, the first wireless terminal comprising:

means for transmitting a transmission request to the fourth wireless terminal;

means for receiving a first transmission request response from the third wireless terminal transmitted in response to a transmission request from the second wireless terminal;

means for receiving a second transmission request response from the fourth wireless terminal;

means for estimating the quality of the first communications link from the received first transmission request response signal; and

means for dynamically generating a yielding threshold based on at least one of;

i) historic link quality information corresponding to the first link;

or ii) quality of service information corresponding to the second communications link.

29. The first wireless terminal of claim 28, wherein said means for estimating the quality of the first communications link includes means for using a determined intended second link traffic signaling transmission power level.

30. The first wireless terminal of claim 28, wherein said means for estimating the quality of the first communications link includes means for performing the estimating based on the received second transmission request response signal.

31. The first wireless terminal of claim 28, wherein the first and fourth wireless terminals are mobile communications devices.

32. The first wireless terminal of claim 28, further comprising:

means for determining from at least one signal received from the third wireless terminal historic link quality information corresponding to the first communications link.

33. The first wireless terminal of claim 32, wherein the at least one signal is a broadcast signal from the third wireless terminal which communicates said historic link quality information.

34. The first wireless terminal of claim 32, wherein said means for determining from at least one signal received from the third wireless terminal includes means for accumulating link quality information from multiple signals sent from the third wireless terminal to the second wireless terminal, each of said multiple signals communicating link quality information corresponding to a different period of time.

35. The first wireless terminal of claim 34, wherein the link quality information includes at least one of link SNR information or rate information.

36. The first wireless terminal of claim 34, further comprising:

means for making a decision whether or not to transmit traffic data in a transmission segment corresponding to the received second transmission request response based on the estimated quality of the first communications link and the dynamically generated threshold.

37. The first wireless terminal of claim 36, wherein said means for making the decision comprising:

means for comparing the estimated quality of the first communications link to the dynamically generated threshold; and

means for deciding to transmit said traffic data when said comparison indicates that the estimated quality of the first communications link exceeds the dynamically generated threshold.

38. The first wireless terminal of claim 37, wherein said quality of service information is based on the amount of data waiting to be transmitted by the first wireless terminal to the fourth wireless terminal.

39. The first wireless terminal of claim 37, wherein the quality of service information indicates a quality of service level corresponding to a type of traffic waiting at said first wireless terminal to be transmitted.

40. A computer program product for use in a first wireless terminal in a system including a first wireless communications link from a second wireless terminal to a third wireless terminal, said first communications link having a higher priority than a second communications link from the first wireless terminal to a fourth wireless terminal, the computer program product comprising:

a non-transitory computer readable medium comprising;

code for causing at least one computer to;

transmit a transmission request to the fourth wireless terminal;

receive a first transmission request response from the third wireless terminal transmitted in response to a transmission request from the second wireless terminal;

receive a second transmission request response from the fourth wireless terminal;

estimate the quality of the first communications link from the received first transmission request response signal; and

dynamically generate a yielding threshold based on at least one of;

i) historic link quality information corresponding to the first link;

or ii) quality of service information corresponding to the second communications link.