Methods for using a detector to monitor and detect channel occupancy

• US 20080095042A1
• Filed: 10/18/2006
• Published: 04/24/2008
• Est. Priority Date: 10/18/2006
• Status: Active Grant

• Current Assignee: Shared Spectrum Company
• Original Assignee: Shared Spectrum Company
• Inventors: Livsics, Jevgenijs, Steadman, Karl, Dain, Dmitry, McHenry, Mark A., Ritterbush, Olga
• Granted Patent: US 8,027,249 B2
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04B 17/14 of the whole transmission and reception path, e.g. self-test loop-back
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0647 Variable feedback rate
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 56/003 Arrangements to increase tolerance to errors in transmission or reception timing
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

Methods for using a detector to monitor and detect channel occupancy are disclosed. The detector resides on a station within a network using a framed format having a periodic time structure. When non-cooperative transmissions are detected by the network, the detector assesses the availability of a backup channel enabling migration of the network. The backup channel serves to allow the network to migrate transparently when the current channel becomes unavailable. The backup channel, however, could be occupied by another network that results in the migrating network interfering with the network already using the backup channel. Thus, the detector detects active transmission sources on the backup channel to determine whether the backup channel is occupied. Methods for using the detector include scheduling detection intervals asynchronously. The asynchronous detection uses offsets from a reference point within a frame.

Claims

1. A method for using a detector, the method comprising:

detecting non-cooperative transmissions on a current channel;

scheduling an asynchronous detection interval having a reference within a frame; and

detecting presence of transmissions on a backup channel with the detector during the detection period.

2. The method of claim 1, wherein the reference includes a transmission gap within the frame.

3. The method of claim 1, wherein the identifying of scheduling includes scheduling a start of the detection interval using an offset from the reference within the frame.

4. The method of claim 3, wherein the offset is derived in a predetermined manner.

5. The method of claim 1, wherein the scheduling includes scheduling start of detection interval within the frame using a random offset from the reference within the frame.

6. The method of claim 1, further comprising determining whether the backup channel is occupied according to the second detecting step.

7. The method of claim 1, further comprising migrating a network from the current channel to the backup channel based on the second detecting step.

8. The method of claim 1, further comprising tuning a station, including the detector, to a frequency, wherein the backup channel is within a detector window encompassing the frequency.

9. A method for using a detector, the method comprising:

detecting non-cooperative transmissions at a station participating in a network, wherein the network uses a current channel at a first frequency;

scheduling a start of a detection interval for the detector within a frame over the frequency channel; and

detecting channel occupancy on a backup channel using the detector during the scheduled detection interval, wherein the backup channel uses a second frequency different from the first frequency of the current channel.

10. The method of claim 9, further comprising detecting non-cooperative transmissions indicating the channel occupancy on the backup channel.

11. The method of claim 9, further comprising migrating the network to the backup channel based on the channel occupancy of the backup channel.

12. A method for using a detector, the method comprising:

detecting non-cooperative transmissions on a current channel;

scheduling a first start of a detection interval in a frame using a first offset from a reference point within the frame, wherein the first offset is selected from a plurality of precomputed or preselected offsets; and

detecting non-cooperative transmissions on a backup channel during the detection interval using the detector.

13. The method of claim 12, wherein the first offset is derived in a predetermined manner.

14. The method of claim 12, wherein the scheduling includes determining a second start of a detection interval using a second offset from the reference point within the frame, wherein the second offset is selected from the plurality of precomputed or preselected offsets.

15. The method of claim 14, wherein the first offset differs from the second offset.

16. A method for using a detector, the method comprising:

detecting non-cooperative transmissions on a current channel;

scheduling a start of a detection interval using a random offset within a frame; and

detecting non-cooperative transmissions on a backup channel using the detector during the detection interval.

17. The method of claim 16, further comprising randomly scheduling another start of a detection period with another random offset.

18. A method for using a detector to determine availability of a backup channel, the method comprising:

detecting non-cooperative transmissions on a current channel within a network, wherein the current channel uses a frequency within a detector window of the detector and wherein a backup channel is not at a frequency simultaneously observable by the detector;

scheduling a detection interval within a portion of the frame not used to receive network transmissions;

buffering information to be transmitted during the portion of the frame if the detection interval is scheduled during a station transmission interval;

tuning a station having the detector to a backup frequency wherein the backup channel is within the detector window; and

detecting non-cooperative transmissions on the backup channel using the detector during the detection interval.

19. The method of claim 18, further comprising indicating the backup channel is occupied based on the second detecting step.

20. The method of claim 18, wherein the scheduling step includes scheduling a start of the detection interval using an offset from a reference point within the frame.