Communications methods and apparatus related to synchronization with respect to a peer to peer timing structure

• US 8,599,823 B2
• Filed: 07/06/2007
• Issued: 12/03/2013
• Est. Priority Date: 07/06/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Li, Junyi, Jovicic, Aleksandar, Richardson, Thomas, Wu, Xinzhou
• Primary Examiner(s): Ho, Huy C
• Application Number:
  US11/774,176
• Publication Number:
  US 20090010231A1
• Time in Patent Office: 2,342 Days
• Field of Search: 370/350
• US Class Current: 370/350
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

Methods and apparatus related to peer to peer communication networks are described. A peer to peer timing structure is implemented which includes recurring peer discovery intervals and traffic intervals. Some embodiments further include recurring paging intervals for peer to peer pages. A wireless communications device, supporting peer to peer communications and storing information defining the timing structure, determines a time reference point, facilitating a coarse level of synchronization with respect to the timing structure. The time reference point is determined based on a broadcast signal received from a communications device, e.g., a satellite, base station, or beacon signal transmitter. Multiple peer to peer wireless communications devices in a local vicinity thus obtain the same basic understanding as to the current relative point in time with respect to a common recurring peer to peer timing structure. Peer to peer timing synchronization is further refined based on received signals communicated between peers.

Claims

1. A method of operating a first wireless communications device, comprising:

determining a time reference point; and

accessing stored timing structure information used to determine recurring peer discovery intervals, paging intervals, and traffic intervals,

wherein said stored timing structure information indicates that multiple paging time intervals occur between peer discovery time intervals during at least one period of time for which timing structure information is stored,

wherein the method further comprises;

storing first timing structure information determined based on a first signal received from a second wireless communications device and second timing structure information determined based on a second signal received from a third wireless communications device; and

processing an additional signal based on the first timing structure information or the second timing structure information upon receiving the additional signal from the second wireless communications device or the third wireless communications device, respectively.

2. The method of claim 1, further comprising:

performing paging operations during paging intervals determined to occur at points in time relative to said time reference point.

3. The method of claim 2, further comprising:

performing peer to peer timing synchronization operations during a peer discovery time interval.

4. The method of claim 2, wherein said traffic intervals occupy more time than the time occupied by the combination of paging time intervals and peer discovery time intervals during one iteration of a communications timing structure defined by said stored timing structure information.

5. The method of claim 1, wherein determining a timing reference point includes:

receiving a broadcast signal from a device, said device being different from the first wireless communications device, said device being one of;

i) a satellite, ii) a base station in a cellular network, and iii) a beacon transmitter that doesn'"'"'t transmit user data; and

using the received broadcast signal to determine said time reference point.

6. The method of claim 5, further comprising:

determining at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing based on said time reference point.

7. The method of claim 6, further comprising:

detecting the first signal transmitted by the second wireless communications device; and

adjusting said at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing as a function of the detected first signal.

8. The method of claim 7, wherein said first signal is:

a traffic signal used to communicate user data.

9. The method of claim 7, wherein said first signal is:

a predetermined broadcast signal.

10. The method of claim 9, wherein said predetermined broadcast signal is one of a multi-tone time varying signal;

and

a predetermined time varying PN sequence signal.

11. The method of claim 9, wherein said predetermined broadcast signal is received from said second wireless communications device in one of a plurality of recurring timing synchronization intervals.

12. The method of claim 11, wherein said accessed stored timing structure information further indicates where said recurring timing synchronization intervals occur relative to said determined time reference point;

and

transmitting a second predetermined broadcast signal in a time interval having a predetermined offset from said time reference point.

13. The method of claim 1, wherein the stored timing structure information is used with respect to said time reference point to determine the recurring peer discovery intervals, the paging intervals, and the traffic intervals.

14. The method of claim 1, further comprising:

receiving the additional signal from one of the second wireless communications device or the third wireless communications device; and

retrieving the first timing structure information if the additional signal is received from the second wireless communications device and the second timing structure information if the additional signal is received from the third wireless communications device,

wherein the processing the additional signal comprises using the retrieved timing structure information to process the additional signal.

15. A first wireless communications device, comprising:

a timing reference point determination module for determining a time reference point;

a memory for storing timing structure information used to determine recurring peer discovery intervals, paging intervals, and traffic intervals; and

an interval determination module for accessing stored timing structure information and determining a type of interval corresponding to a point in time,

wherein said stored timing structure information indicates that multiple paging time intervals occur between peer discovery time intervals during at least one period of time for which timing structure information is stored,

wherein the memory is for storing first timing structure information determined based on a first signal received from a second wireless communications device and second timing structure information determined based on a second signal received from a third wireless communications device, and

wherein the device further comprises a receive and processing module for processing an additional signal based on the first timing structure information or the second timing structure information upon receiving the additional signal from the second wireless communications device or the third wireless communications device, respectively.

16. The first wireless communications device of claim 15, further comprising:

a paging module for performing paging operations during paging intervals determined to occur at points in time relative to said time reference point.

17. The first wireless communications device of claim 16, further comprising:

a peer to peer timing synchronization module for performing peer to peer timing synchronization operations during a peer discovery time interval.

18. The first wireless communications device of claim 16, wherein said traffic intervals occupy more time than the time occupied by the combination of paging time intervals and peer discovery time intervals during one iteration of a communications timing structure defined by said stored timing structure information.

19. The first wireless communications device of claim 15, further comprising:

a wireless receiver module for receiving a broadcast signal from a device, said device being different from the first wireless communications device, said device being one of;

i) a satellite, ii) a base station in a cellular network, and iii) a beacon transmitter that doesn'"'"'t transmit user data; and

wherein said timing reference point determination module uses the received broadcast signal to determine said time reference point.

20. The first wireless communications device of claim 19, further comprising at least two of:

a satellite broadcast signal processing module;

a base station broadcast signal processing module; and

a beacon signal transmitter signal processing module.

21. The first wireless communications device of claim 19, further comprising:

a peer to peer timing synchronization module for determining at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing based on said time reference point.

22. The first wireless communications device of claim 21, further comprising:

a peer node signal detection module for detecting the first signal transmitted by the second wireless communications device; and

a timing adjustment module for adjusting said at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing as a function of the detected first signal.

23. The first wireless communications device of claim 22, wherein said first signal transmitted by said second communications device is:

a traffic signal used to communicate user data.

24. The first wireless communications device of claim 22, wherein said first signal transmitted by said second communications device is:

a predetermined broadcast signal.

25. The first wireless communications device of claim 24, wherein said predetermined broadcast signal is one of:

a multi-tone time varying signal; and

a predetermined time varying PN sequence signal.

26. The first wireless communications device of claim 24, wherein said predetermined broadcast signal is received from said second wireless communications device in one of a plurality of recurring timing synchronization intervals.

27. The first wireless communications device of claim 26, wherein said stored timing structure information further indicates where said recurring timing synchronization intervals occur relative to said determined time reference point;

the first wireless communications device further comprising;

a broadcast signal generation module for generating a second predetermined broadcast signal; and

a wireless transmitter for transmitting said generated second predetermined broadcast signal in a time interval having a predetermined offset from said time reference point.

28. A first wireless communications device, comprising:

timing reference point determination means for determining a time reference point;

means for determining recurring peer discovery intervals, paging intervals, and traffic intervals; and

means for accessing stored timing structure information and determining a type of interval corresponding to a point in time,

wherein said stored timing structure information indicates that multiple paging time intervals occur between peer discovery time intervals during at least one period of time for which timing structure information is stored,

wherein said device further comprises;

means for storing first timing structure information determined based on a first signal received from a second wireless communications device and second timing structure information determined based on a second signal received from a third wireless communications device; and

means for processing an additional signal based on the first timing structure information or the second timing structure information upon receiving the additional signal from the second wireless communications device or the third wireless communications device, respectively.

29. The first wireless communications device of claim 28, further comprising:

means for performing paging operations during paging intervals determined to occur at points in time relative to said time reference point.

30. The first wireless communications device of claim 28, further comprising:

wireless receiver means for receiving a broadcast signal from a device, said device being different from the first wireless communications device, said device being one of;

i) a satellite, ii) a base station in a cellular network, and iii) a beacon transmitter that doesn'"'"'t transmit user data; and

wherein said timing reference point determination means uses the received broadcast signal to determine said time reference point.

31. The first wireless communications device of claim 30, further comprising:

means for determining at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing based on said time reference point.

32. The first wireless communications device of claim 31, further comprising:

means for detecting the first signal transmitted by the second wireless communications device; and

means for adjusting said at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing as a function of the detected first signal.

33. A non-transitory computer readable medium embodying machine executable instructions for operating a first wireless communications device, the method comprising:

determining a time reference point; and

accessing stored timing structure information used to determine recurring peer discovery intervals, paging intervals, and traffic intervals,

wherein said stored timing structure information indicates that multiple paging time intervals occur between peer discovery time intervals during at least one period of time for which timing structure information is stored,

wherein the computer readable medium further embodies machine instructions for;

storing first timing structure information determined based on a first signal received from a second wireless communications device and second timing structure information determined based on a second signal received from a third wireless communications device; and

processing an additional signal based on the first timing structure information or the second timing structure information upon receiving the additional signal from the second wireless communications device or the third wireless communications device, respectively.

34. The computer readable medium of claim 33, further embodying machine executable instructions for:

performing paging operations during paging intervals determined to occur at points in time relative to said time reference point.

35. The computer readable medium of claim 33, wherein determining a timing reference point includes:

receiving a broadcast signal from a device, said device being different from the first wireless communications device, said device being one of;

i) a satellite, ii) a base station in a cellular network, and iii) a beacon transmitter that doesn'"'"'t transmit user data; and

using the received broadcast signal to determine said time reference point.

36. The computer readable medium of claim 35, further embodying machine executable instructions for:

determining at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing based on said time reference point.

37. The computer readable medium of claim 36, further embodying machine executable instructions for:

detecting the first signal transmitted by the second wireless communications device; and

adjusting said at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing as a function of the detected first signal.

38. An apparatus comprising:

a processor configured to;

determine a time reference point; and

access stored timing structure information used to determine recurring peer discovery intervals, paging intervals, and traffic intervals,

wherein said stored timing structure information indicates that multiple paging time intervals occur between peer discovery time intervals during at least one period of time for which timing structure information is stored,

wherein said processor is further configured to;

store first timing structure information determined based on a first signal received from a second wireless communications device and second timing structure information determined based on a second signal received from a third wireless communications device; and

process an additional signal based on the first timing structure information or the second timing structure information upon receiving the additional signal from the second wireless communications device or the third wireless communications device, respectively.

39. The apparatus of claim 38, wherein said processor is further configured to:

perform paging operations during paging intervals determined to occur at points in time relative to said time reference point.

40. The apparatus of claim 38, wherein determining a timing reference point includes:

receiving a broadcast signal from a device, said device being different from the first wireless communications device, said device being one of;

i) a satellite, ii) a base station in a cellular network, and iii) a beacon transmitter that doesn'"'"'t transmit user data; and

using the received broadcast signal to determine said time reference point.

41. The apparatus of claim 40, wherein said processor is further configured to:

determine at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing based on said time reference point.

42. The apparatus of claim 41, wherein said processor is further configured to:

detect the first signal transmitted by the second wireless communications device; and

adjust said at least one of peer to peer receive symbol timing and peer to peer transmit symbol timing as a function of the detected first signal.