CHANNEL REUSE IN COMMUNICATION SYSTEMS

• US 20110014910A1
• Filed: 07/20/2009
• Published: 01/20/2011
• Est. Priority Date: 07/20/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Intellon Corporation (Qualcomm, Inc.)
• Inventors: KRISHNAM, MANJUNATH, YONGE, LAWRENCE W. III, KATAR, SRINIVAS
• Granted Patent: US 8,498,579 B2
• Time in Patent Office: Days
• US Class Current: 455/434
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 28/0231 based on communication conditions dynamic wireless traffic scheduling definition based on channel quality criteria H04W72/54
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 56/0095 estimated based on signal strength
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

Disclosed are systems and methods for communicating among stations coupled to a communication medium by receiving signals from a plurality of the stations, determining signal strength values for each of the received signals based on at least a portion of the signal, and based on the signal strength values, selecting a detection threshold such that, in response to a signal having a signal strength in excess of the detection threshold, the signal is processed according to a protocol of a subset of the stations.

Claims

1. A method of communicating among stations coupled to a communication medium, comprising:

receiving signals from a plurality of the stations,

determining signal strength values for each of the received signals based on at least a portion of the signal, and

based on the signal strength values, selecting a detection threshold such that, in response to a signal having a signal strength in excess of the detection threshold, the signal is processed according to a protocol of a subset of the stations.

2. The method of claim 1, in which determining a signal strength value for a given signal comprises detecting a preamble of the given signal.

3. The method of claim 2, in which selecting the detection threshold comprises analyzing frame control portions of the received signals.

4. The method of claim 2, in which determining the signal strength value for the given signal comprises determining the signal strength value based on at least a portion of the detected preamble.

5. The method of claim 4, in which the detection threshold is selected based on a signal strength value of a selected one of the received signals having a minimum signal strength value.

6. The method of claim 1, further comprising, if a signal strength value of a signal received after selecting the detection threshold is lower than the detection threshold, excluding the signal from further processing and proceeding with a contention process among the subset of stations.

7. The method of claim 1, further comprising, if a signal strength value of a signal received after selecting the detection threshold is in excess of the detection threshold, suspending a contention process among the subset of stations.

8. The method of claim 1, further comprising, for each station coupled to the communication medium, maintaining signal strength information.

9. The method of claim 8, in which the signal strength information is maintained at each of the stations coupled to the communication medium.

10. The method of claim 1, in which determining a signal strength value for a given signal includes determining an automatic gain control setting used for detecting the given signal.

11. The method of claim 1, in which determining a signal strength value for a given signal includes determining at least one of a correlation between different portions of the given signal and a correlation between a portion of the given signal and a stored symbol.

12. The method of claim 1, further comprising:

for each of the received signals, identifying a frame control portion of the signal, and

using the frame control portion to determine whether a signal is excluded from a contention process among the subset of stations.

13. The method of claim 1, further comprising, storing at each station coupled to the communication medium information from signals received at a given the station and not addressed to the given station.

14. The method of claim 13, in which the stored information includes at least one of a source address, network identification information, and information used to demodulate a payload.

15. The method of claim 1, further comprising, in response to detecting that the received signals are from stations that belong to different networks, selecting the detection threshold such that, in response to the received signals having a signal strength in excess of the detection threshold, the received signals are processed according to the protocol of a subset of the stations.

16. The method of claim 1, further comprising selecting the detection threshold based on information in the signals regarding the destination stations to which the signals are addressed.

17. The method of claim 1, in which the subset of the stations includes an authorized network of stations.

18. The method of claim 17, in which the signals from networks other than the authorized network are rejected.

19. A method of communicating among stations coupled to a communication medium, comprising:

sending a pending transmission from a first station in a first network to a first destination station based on whether a second destination station of an ongoing transmission is affected by the pending transmission.

20. The method of claim 19, in which sending the pending transmission from the first station to the first destination station is also based on whether the first destination station of the pending transmission is affected by the ongoing transmission.

21. The method of claim 19, in which the ongoing transmission includes a transmission from a second station within a second network to a second destination station.

22. The method of claim 19, further comprising sending the pending transmission from the first station to the first destination station if the second destination station of the ongoing transmission is not affected by the pending transmission.

23. The method of claim 19, further comprising sending the pending transmission from the first station to the first destination station if the first destination station of the pending transmission is not affected by the ongoing transmission.

24. The method of claim 19, further comprising updating transmission mechanism parameters based on at least one of whether the first destination station is affected by the ongoing transmission, and whether the second destination station is affected by the pending transmission.

25. The method of claim 19, further comprising determining whether the second destination station of the ongoing transmission will be affected by the pending transmission based on signal information stored at the first station.

26. The method of claim 19, further comprising determining whether the first destination station of the pending transmission will be affected by the ongoing transmission based on signal information stored at the first station.

27. The method of claim 26, in which the signal information includes a table having, for each signal transmitted by the stations, at least one of source address, network ID, and preamble information.

28. The method of claim 26, further comprising exchanging the signal information stored at the first station with other stations coupled to the communication medium.

29. A communication system, comprising:

a communication medium; and

multiple stations coupled to the communication medium, each station configured to

receive signals from a plurality of the stations,

determine signal strength values for each of the received signals based on at least a portion of the signal, and

based on the signal strength values, select a detection threshold such that, in response to a signal having a signal strength in excess of the detection threshold, the signal is processed according to a protocol of a subset of the stations.