ADAPTIVE INTERFERENCE CONTROL

• US 20090052411A1
• Filed: 08/21/2007
• Published: 02/26/2009
• Est. Priority Date: 08/21/2007
• Status: Active Grant

• Current Assignee: Fimax Technology Limited
• Original Assignee: Fimax Technology Limited
• Inventors: Wong, Piu Bill, Lau, Kin Nang, Leung, Hang Ching
• Granted Patent: US 8,059,553 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]

Abstract

Systems and methods which control communications in a carrier sense multiple access environment to provide a balance between communication sensitivity and transmission availability are shown. Adaptive interference control techniques of embodiments operate to determine a media error time metric representing the time associated with receiving interfering signals. The media error time metric of embodiments is used to adjust operation of various network systems in order to adjust communication sensitivity and/or transmission availability. Desensitizing thresholds and sensitizing thresholds may be used to define operating boundaries, such that desensitizing thresholds are used to control network desensitize actions which result in decreased error times and sensitizing thresholds are used to control network sensitizing actions which result in increased error times. Error time metrics and corresponding desensitizing and sensitizing thresholds may be utilized with respect to a plurality of radios. Embodiments provide for adjustment of control parameters based upon historical operation.

Claims

1. A method comprising:

determining a communication time metric for a communication apparatus, wherein said communication time metric provides information with respect to an amount of time a communication media is unavailable for said communication apparatus to communicate via said media; and

adjusting one or more parameters of said communication apparatus to achieve a desired balance between communication sensitivity of said communication apparatus and future amounts of time said communication media is unavailable for said communication apparatus.

2. The method of claim 1, wherein said adjusting one or more parameters of said communication apparatus comprises:

reducing said communication sensitivity when said communication time metric indicates said amount of time the communication media is unavailable for said communication apparatus to communicate is greater than a predetermined threshold.

3. The method of claim 1, wherein said adjusting one or more parameters of said communication apparatus comprises:

increasing said communication sensitivity when said communication time metric indicates said amount of time the communication media is unavailable for said communication apparatus to communicate is less than a predetermined threshold.

4. The method of claim 1, wherein said communication metric comprises a good time indicating a time said media was available for communication by said communication apparatus.

5. The method of claim 1, wherein said communication metric comprises an error time indicating a time said communication apparatus received error signals.

6. The method of claim 5, wherein said determining the communication time metric comprises:

determining a receive not clear count for said communication apparatus;

7. The method of claim 6, wherein said determining the communication time metric further comprises:

determining at least one of a transmit count and a receive count for said communication apparatus; and

subtracting said at least one of said transmit count and said receive count from said receive not clear count.

8. The method of claim 7, wherein said determining at least one of said transmit count and said receive count comprises:

determining said transmit count and said receive count; and

determining a greater of said transmit count and said receive count;

wherein said subtracting said at least one of said transmit count and said receive count comprises;

subtracting said greater of said transmit count and said receive count from said receive not clear count.

9. The method of claim 1, further comprising:

comparing said communication time metric to a first threshold and, if said communication time metric is less than said first threshold said adjusting said one or more parameters of said communication apparatus comprises decreasing a future error time; and

comparing said communication time metric to a second threshold and, if said communication time metric is greater than said second threshold said adjusting said one or more parameters of said communication apparatus comprises increasing said future error time.

10. The method of claim 9, wherein said determining said communication time metric comprises:

determining a first error metric by dividing a time period associated with a first error time by said first error time.

11. The method of claim 9, wherein said adjusting said one or more parameters of said communication apparatus decreasing said future error time comprises:

decreasing a receive sensitivity of said communication apparatus; and

wherein adjusting said one or more parameters of said communication apparatus increasing said future error time comprises;

increasing a receive sensitivity of said communication apparatus.

12. The method of claim 9, further comprising:

determining a second communication time metric for said communication apparatus, wherein said second communication time metric provides information with respect to an amount of time said communication apparatus received error signals for a smaller window of time than a window of time associated with said communication time metric;

comparing said second communication time metric to a third threshold;

if said second communication time metric is less than said third threshold, adjusting said one or more parameters of said communication apparatus to achieve said desired balance between said communication sensitivity of said communication apparatus and future amounts of time said communication media is unavailable for said communication apparatus.

13. The method of claim 12, wherein said determining said communication time metric comprises determining a first error metric by dividing a time period associated with a first error time by said first error time, and wherein said determining said second communication time metric comprises determining a second error metric by dividing a time period associated with a second error time by said second error time.

14. The method of claim 12, wherein said communication time metric comprises a long time window metric and said second communication time metric comprises a short time window metric.

15. The method of claim 9, further comprising:

adjusting at least one of said first threshold as a function of a number of times said one or more parameters have been adjusted to decrease said future error time and said second threshold as a function of a number of times said one or more parameters have been adjusted to increase said future error time.

16. The method of claim 1, further comprising:

analyzing said adjusting the one or more parameters and a resulting communication time metric as said communication time metric approaches a first threshold in operation of said communication apparatus over time;

determining whether an overall communication time metric gain for a subsequent adjusting of said one or more parameters is smaller than a predetermined percentage of said first threshold; and

reducing said first threshold if said overall communication time metric gain is smaller than said predetermined percentage of said first threshold.

17. The method of claim 1, wherein said adjusting one or more parameters of said communication apparatus comprises:

adjusting one or more receive sensitivity parameters.

18. The method of claim 1, wherein said adjusting one or more parameters of said communication apparatus comprises:

selecting a parameter of a plurality of parameters for adjustment, wherein said plurality of parameters are selected according to a predetermined hierarchy.

19. The method of claim 1, wherein said adjusting one or more parameters of said communication apparatus comprises:

selecting a radio of a plurality of radios for which one or more said parameters are to be adjusted.

20. The method of claim 19, wherein said selecting said radio of said plurality of radios comprises:

selecting a radio having a highest individual error time.

21. The method of claim 19, wherein said selecting said radio of said plurality of radios comprises:

selecting a radio having a lowest individual error time.

22. A method comprising:

monitoring operating performance of a plurality of radios to provide receive error information;

determining an error metric for said plurality of radios using said receive error information;

analyzing said error metric to determine if at least one interference rejection parameter of at least one radio of said plurality of radios is to be adjusted;

selecting said at least one radio of said plurality of radios for interference rejection adjustment using said receive error information; and

adjusting one or more interference rejection parameter of said selected at least one radio in accordance with said error metric analysis.

23. The method of claim 22, wherein said plurality of radios operate cooperatively to provide a network node.

24. The method of claim 23, wherein said network node comprises a wireless network access point.

25. The method of claim 22, wherein said error information comprises at least two of:

receive not clear information for each radio of said plurality of radios;

transmit information for each radio of said plurality of radios; and

receive information for each radio of said plurality of radios.

26. The method of claim 25, wherein said determining said error metric for said plurality of radios comprises:

summing values of said receive not clear information associated with individual radios of said plurality of radios to provide a combined value;

subtracting a value of one of said transmit information and said receive information from a value of said combined value.

27. The method of claim 25, wherein said selecting at least one radio of said plurality of radios for interference rejection adjustment comprises:

subtracting a value of one of said transmitting information and said receive information associated with each radio of said plurality of radios from a value of a corresponding receive not clear information to provide individual radio error values; and

analyzing said individual radio error values to select said at least one radio of said plurality of radios for interference rejection adjustment.

28. The method of claim 27, wherein said analyzing said individual radio error values to select said at least one radio comprises:

identifying an individual radio value error value having a lowest value; and

wherein said adjusting said one or more interference rejection parameters comprises;

adjusting said one or more interference rejection parameters to increase receive sensitivity of said selected at least one radio.

29. The method of claim 27, wherein said analyzing said individual radio error values to select said at least one radio comprises:

identifying an individual radio value error value having a highest value; and

wherein said adjusting said one or more interference rejection parameters comprises;

adjusting said one or more interference rejection parameters to decrease receive sensitivity of said selected at least one radio.

30. The method of claim 22, wherein said analyzing said error metric comprises:

comparing said error metric to a first threshold and, if said error metric is less than said first threshold said adjusting said one or more interference rejection parameters comprises decreasing receive sensitivity of said selected at least one radio; and

comparing said error metric to a second threshold and, if said error metric is greater than said second threshold said adjusting said one or more interference rejection parameters comprises increasing receive sensitivity of said selected at least one radio.

31. The method of claim 22, wherein said plurality of radios each provide communications using a plurality of communication protocols, and wherein said selecting said at least one radio of said plurality of radios for interference rejection adjustment comprises:

selecting a particular communication protocol of said plurality of communication protocols used by said selected at least one radio for said interference rejection adjustment.

32. The method of claim 31, wherein said plurality of communication protocols comprise:

a complementary code keying (CCK) modulation protocol; and

an orthogonal frequency division multiplex (OFDM) modulation protocol.

33. The method of claim 22, wherein said one or more interference rejection parameter is selected from the group consisting of:

a power detection threshold (PDT);

a carrier sense threshold (CST); and

a weak OFDM signal detection parameter.

34. The method of claim 22, wherein said one or more interference rejection parameter is selected from the group consisting of:

a finite impulse response step (FIR); and

a weak CCK signal desensitizing level.

35. A system comprising:

a plurality of radios operable together as a network node communications; and

a receive sensitivity controller coupled to the plurality of radios and operable to determine a consolidated communication metric for said plurality of radios and to control a receive sensitivity parameter of a selected radio of said plurality of radios as a function of said consolidated error metric.

36. The system of claim 35, wherein said consolidated communication metric comprises a consolidated error metric.

37. The system of claim 35, wherein said network node comprises a wireless network access point.

38. The system of claim 35, wherein said plurality of radios comprise:

two or more subscriber link radios; and

one or more backhaul link radio.

39. The system of claim 35, wherein said receive sensitivity controller comprises:

a channel status consolidation circuit coupled to each radio of said plurality of radios to receive said receive not clear information therefrom, said channel status consolidation circuit operable to provide consolidated receive not clear information from said receive not clear information;

an error time calculation circuit coupled to each radio of said plurality of radios and operable to receive said transmit information and said receive information therefrom, said error time calculation circuit also coupled to said channel status consolidation circuit to receive said consolidated receive not clear information therefrom, said error time calculation circuit operable to provide consolidated error metric from said transmit information, said receive information, and said consolidated receive not clear information; and

a threshold comparison circuit coupled to said error time circuit and operable to receive said consolidated error metric therefrom, said threshold comparison circuit operable to compare said consolidated error metric to one or more threshold to determine if a radio of said plurality of radios is to be adjusted.

40. A system comprising

a plurality of radios operable cooperatively to provide a network node, each radio of said plurality of radios operable to provide receive not clear information, transmit information, and receive information;

a channel status consolidation circuit coupled to each radio of said plurality of radios to receive said receive not clear information therefrom, said channel status consolidation circuit operable to provide consolidated receive not clear information from said receive not clear information;

an error time calculation circuit coupled to each radio of said plurality of radios and operable to receive said transmit information and said receive information therefrom, said error time calculation circuit also coupled to said channel status consolidation circuit to receive said consolidated receive not clear information therefrom, said error time calculation circuit operable to provide consolidated receive error information from said transmit information, said receive information, and said consolidated receive not clear information; and

a threshold comparison circuit coupled to said error time circuit and operable to receive said consolidated receive error information therefrom, said threshold comparison circuit operable to compare said consolidated receive error information to one or more threshold to determine if a radio of said plurality of radios is to be adjusted.

41. The system of claim 40, further comprising:

an adjustment action control circuit coupled to said threshold comparison circuit and operable to receive information with respect to a determination that said radio of said plurality of radios is to be adjusted, said adjustment action control circuit coupled to each said radio of said plurality of radios to provide control signals one or more said radios in response to said determination that said radio of said plurality of radios is to be adjusted.

42. The system of claim 40, further comprising

a threshold adjust circuit coupled to said threshold comparison circuit and operable to adaptively adjust said one or more threshold as a function of adjustment action taken with respect to said plurality of radios.