METHODS AND APPARATUS FOR TIMING SYNCHRONIZATION USING MULTIPLE DIFFERENT TIMING SIGNAL SOURCES

• US 20120008618A1
• Filed: 07/08/2010
• Published: 01/12/2012
• Est. Priority Date: 07/09/2007
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wang, Hua, Wu, Xinzhou, Li, Junyi, Jovicic, Aleksandar
• Application Number:
  US12/832,758
• Publication Number:
  US 20120008618A1
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04W 56/002 Mutual synchronization

Abstract

A wireless terminal detects timing signals from different local timing signal sources. The wireless terminal selects from the plurality of detected timing signal sources two timing signal sources in accordance with a predetermined timing signal source priority ordering. In some embodiments, the wireless terminal intentionally selects two timing signal sources which are not synchronized with respect to one another. The wireless terminal determines a first set of peer communications time intervals corresponding to a first selected timing signal source and a second set of peer communications time intervals corresponding to a second selected timing signal source. The wireless terminal transmits a peer to peer signal, e.g., a peer discovery signal, during at least one of the first set of peer communications time intervals. The wireless terminal transmits a peer to peer signal, e.g., a peer discovery signal, during at least one of the second set of peer communications time intervals.

Claims

1. A method of operating a wireless terminal, the method comprising:

detecting timing signal sources which may be used for synchronizing peer to peer communications;

determining a first set of peer communications time intervals based on a first detected timing signal and a second set of peer communications time intervals based on a second detected timing signal, said first and second timing signals corresponding to different timing signal sources;

transmitting a first peer to peer signal during at least one of the first set of time intervals; and

transmitting a second peer to peer signal during at least one of the second set of time intervals.

2. The method of claim 1, further comprising:

selecting from a plurality of detected timing signal sources in accordance with a predetermined timing signal source priority ordering which ones of said plurality of detected timing signal sources are to be used as the source of said first and second timing signals.

3. The method of claim 2, wherein said selected timing signal sources correspond to different communications technologies.

4. The method of claim 2, wherein said first timing signal is from a first timing signal source which is a TV transmitter and wherein the second timing signal is from a second timing signal source which is a cellular base station.

5. The method of claim 2, wherein said first timing signal is from a first timing signal source;

wherein said second timing signal is from a second timing signals source; and

wherein said first and second timing signal sources are different base stations which are not time synchronized.

6. The method of claim 1, wherein said first and second sets of time intervals are unsynchronized with respect to one another.

7. The method of claim 2, wherein timing signal sources with a larger coverage area are treated as having a higher priority than timing signal sources with a smaller coverage area.

8. The method of claim 1, further comprising:

receiving a third peer to peer signal during at least one of the first set of time intervals; and

receiving a fourth peer to peer signal during at least one of the second set of time intervals.

9. A wireless terminal comprising:

means for detecting timing signal sources which may be used for synchronizing peer to peer communications;

means for determining a first set of peer communications time intervals based on a first detected timing signal and a second set of peer communications time intervals based on a second detected timing signal, said first and second timing signals corresponding to different timing signal sources;

means for transmitting a first peer to peer signal during at least one of the first set of time intervals; and

means for transmitting a second peer to peer signal during at least one of the second set of time intervals.

10. The wireless terminal of claim 9, further comprising:

means for selecting from a plurality of detected timing signal sources in accordance with a predetermined timing signal source priority ordering which ones of said plurality of detected timing signal sources are to be used as the source of said first and second timing signals.

11. The wireless terminal of claim 10, wherein said selected timing signal sources correspond to different communications technologies.

12. The wireless terminal of claim 10, wherein said first timing signal is from a first timing signal source which is a TV transmitter and wherein the second timing signal is from a second timing signal source which is a cellular base station.

13. The wireless terminal of claim 10, wherein said first timing signal is from a first timing signal source;

wherein said second timing signal is from a second timing signals source; and

wherein said first and second timing signal sources are different base stations which are not timing synchronized.

14. The wireless terminal of claim 9, wherein said first and second sets of time intervals are unsynchronized with respect to one another.

15. A computer program product for use in a wireless terminal, the computer program product comprising:

a non-transitory computer readable medium comprising;

code for causing at least one computer to detect timing signal sources which may be used for synchronizing peer to peer communications;

code for causing said at least one processor to determine a first set of peer communications time intervals based on a first detected timing signal and a second set of peer communications time intervals based on a second detected timing signal, said first and second timing signals corresponding to different timing signal sources;

code for causing said at least one processor to transmit a first peer to peer signal during at least one of the first set of time intervals; and

code for causing said at least one processor to transmitting a second peer to peer signal during at least one of the second set of time intervals.

16. A wireless terminal comprising:

at least one processor configured to;

detect timing signal sources which may be used for synchronizing peer to peer communications;

determine a first set of peer communications time intervals based on a first detected timing signal and a second set of peer communications time intervals based on a second detected timing signal, said first and second timing signals corresponding to different timing signal sources;

transmit a first peer to peer signal during at least one of the first set of time intervals; and

transmit a second peer to peer signal during at least one of the second set of time intervals; and

memory coupled to said at least one processor.

17. The wireless terminal of claim 16, wherein said at least one processor is further configured to:

select from a plurality of detected timing signal sources in accordance with a predetermined timing signal source priority ordering which ones of said plurality of detected timing signal sources are to be used as the source of said first and second timing signals.

18. The wireless terminal of claim 17, wherein said selected timing signal sources correspond to different communications technologies.

19. The wireless terminal of claim 17, wherein said first timing signal is from a first timing signal source which is a TV transmitter and wherein the second timing signal is from a second timing signal source which is a cellular base station.

20. The wireless terminal of claim 17, wherein said first timing signal is from a first timing signal source;

wherein said second timing signal is from a second timing signals source; and

wherein said first and second timing signal sources are different base stations which are not timing synchronized.