Wireless device discovery in a wireless peer-to-peer network

• US 8,923,317 B2
• Filed: 01/10/2007
• Issued: 12/30/2014
• Est. Priority Date: 01/11/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Li, Junyi, Richardson, Tom, Wu, Xinzhou, Jovicic, Aleksandar
• Primary Examiner(s): Ng, Fan
• Application Number:
  US11/621,967
• Publication Number:
  US 20080112334A1
• Time in Patent Office: 2,911 Days
• Field of Search: None
• US Class Current: 370/431
• CPC Class Codes: H04J 3/0602 Systems characterised by the synchronising information used
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/261 Details of reference signals
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 36/16 Performing reselection for specific purposes
• CPC Class Codes: H04W 36/24 Reselection being triggered by specific parameters
• CPC Class Codes: H04W 40/24 Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 40/244 using a network of reference devices, e.g. beaconing
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 : Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/042 : Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/02 : Terminal devices
• CPC Class Codes: H04W 88/04 : adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/10 : adapted for operation in multiple networks, e.g. multi-mode access points
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

Systems and methodologies are described that facilitate detecting and/or identifying peers in a local area peer-to-peer network. Times (e.g., peer discovery intervals) for performance of mutual detection and identification between peers may be synchronized (e.g., based upon a signal broadcast to the peers). Further, within each partitioned peer discovery interval, a wireless terminal may select a portion of time to transmit (e.g., broadcast) short messages that may be employed by peers to detect and/identify the wireless terminal. Moreover, the remainder of the time within the partitioned peer discovery interval may be employed to listen to short messages received from peers.

Claims

1. A method of operating a first wireless terminal in a peer-to-peer network, comprising:

receiving a first signal from a signal source wherein the signal source is at least one of a base station, an access node, or a GPS satellite;

determining time positions of a first sequence of peer discovery intervals based upon the received first signal; and

wherein an amount of time that separates two successive peer discovery intervals in the first sequence of peer discovery intervals is at least 100 times larger than a duration of time of either of the two successive peer discovery intervals.

2. The method of claim 1, further comprising:

transitioning to an on state from a power saving state before a peer discovery interval starts; and

switching to the power saving state from the on state after the peer discovery interval ends.

3. A method of operating a first wireless terminal in a peer-to-peer network, comprising:

receiving a first signal from a signal source wherein the signal source is at least one of a base station, an access node, or a GPS satellite;

determining time positions of a first sequence of peer discovery intervals based upon the received first signal;

selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier of either the first wireless terminal or a user currently using the first wireless terminal and a time counter variable derived from the first signal;

broadcasting a second signal on each of the selected symbols; and

wherein an amount of time that separates two successive peer discovery intervals in the first sequence of peer discovery intervals is at least 5 times larger than a duration of time of either of the two successive peer discovery intervals.

4. A method of operating a first wireless terminal in a peer-to-peer network, comprising:

receiving a first signal from a signal source wherein the signal source is at least one of a base station, an access node, or a GPS satellite;

determining time positions of a first sequence of peer discovery intervals based upon the received first signal;

selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier of either the first wireless terminal or a user currently using the first wireless terminal and a time counter variable derived from the first signal;

broadcasting a second signal on each of the selected symbols;

listening during a fraction of each of the peer discovery intervals;

detecting a third broadcast signal from a peer while listening during the fraction of a current peer discovery interval; and

decoding a second identifier from the third broadcast signal if it is determined that the third broadcast signal is present.

5. The method of claim 4, wherein the second identifier is decoded based on the time counter variable.

6. The method of claim 4, wherein the at least one selected symbol is excluded from the fraction of each of the peer discovery intervals for listening.

7. The method of claim 4, wherein the at least one symbol selected for broadcasting the second signal within each of the peer discovery intervals corresponds to less than 30% of a duration of each of the peer discovery intervals and wherein the fraction for listening corresponds to at least 70% of the duration of each of the peer discovery intervals.

8. The method of claim 4, further comprising:

adding the decoded second identifier to a first list of identifiers wherein the first list of identifiers represents detected terminals.

9. The method of claim 4, further comprising:

storing a second list of buddy identifiers;

comparing the decoded second identifier with buddy identifiers in the second list of buddy identifiers; and

marking the decoded second identifier as a particular one of the buddy identifiers if the comparison result indicates that the decoded second identifier is substantially similar to the particular one of the buddy identifiers in the second list of buddy identifiers.

10. The method of claim 9, further comprising:

transmitting a signal to the peer associated with the decoded second identifier; and

informing the peer that it has been identified.

11. A method of operating a first wireless terminal in a peer-to-peer network, comprising:

receiving a first signal from a signal source wherein the signal source is at least one of a base station, an access node, or a GPS satellite;

determining time positions of a first sequence of peer discovery intervals based upon the received first signal;

selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier of either the first wireless terminal or a user currently using the first wireless terminal and a time counter variable derived from the first signal;

broadcasting a second signal on each of the selected symbols; and

wherein the value of the time counter variable varies from one peer discovery interval to another in the first sequence of peer discovery intervals and a position of the at least one selected symbol within each of the peer discovery intervals varies from one peer discovery interval to another.

12. The method of claim 11, wherein the second signal includes a tone.

13. The method of claim 12, wherein a frequency location of the tone is selected based on the first identifier and the time counter variable and the frequency location of the tone varies from one peer discovery interval to another in the first sequence of peer discovery intervals.

14. The method of claim 12, wherein a transmission power of the tone is at least 10 times higher than a transmission power of any other tone in the same symbol.

15. A wireless communications apparatus, comprising:

a memory that retains instructions related to obtaining a first signal from a signal source and identifying time positions of a first sequence of peer discovery intervals based upon the obtained first signal;

a processor, coupled to the memory, configured to execute the instructions retained in the memory; and

wherein the memory further retains instructions for separating two successive peer discovery intervals in the first sequence by an amount of time at least 100 times a length of time of either of the two successive peer discovery intervals.

16. The wireless communications apparatus of claim 15, wherein the memory further retains instructions for transitioning to and from an on state before a start of a peer discovery interval and after an end of the peer discovery interval, respectively.

17. A wireless communications apparatus, comprising:

a memory that retains instructions related to;

obtaining a first signal from a signal source;

identifying time positions of a first sequence of peer discovery intervals based upon the obtained first signal;

separating two successive peer discovery intervals in the first sequence by an amount of time at least 5 times a length of time of either of the two successive peer discovery intervals; and

selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier and a time counter variable derived from the first signal, and broadcasting a second signal on each of the selected symbols; and

a processor, coupled to the memory, configured to execute the instructions retained in the memory.

18. The wireless communications apparatus of claim 17, wherein the memory further retains instructions for varying the time counter variable between peer discovery intervals in the first sequence and varying a position of the at least one selected symbol within each of the peer discovery intervals from one peer discovery interval to another.

19. A wireless communications apparatus, comprising:

a memory that retains instructions related to obtaining a first signal from a signal source and identifying time positions of a first sequence of peer discovery intervals based upon the obtained first signal;

a processor, coupled to the memory, configured to execute the instructions retained in the memory;

wherein the memory further retains instructions for selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier and a time counter variable derived from the first signal, and broadcasting a second signal on each of the selected symbols; and

wherein the memory further retains instructions for listening during a fraction of each of the peer discovery intervals, detecting a third broadcast signal from a peer during the fraction of a current peer discovery interval employed for listening, and decoding a second identifier from the third broadcast signal when detected.

20. The wireless communications apparatus of claim 19, wherein the memory further retains instructions for decoding the second identifier based on the time counter variable.

21. The wireless communications apparatus of claim 19, wherein the memory further retains instructions for excluding the at least one selected symbol from the listening related fraction of each of the peer discovery intervals.

22. The wireless communications apparatus of claim 19, wherein the memory further retains instructions for broadcasting less than 30% of a duration of each of the peer discovery intervals and listening for the remainder of each duration.

23. The wireless communications apparatus of claim 19, wherein the memory further retains instructions for adding the decoded second identifier to a first list of identifiers that represents detected terminals.

24. The wireless communications apparatus of claim 19, wherein the memory further retains a second list of buddy identifiers and instructions for comparing the decoded second identifier with buddy identifiers in the second list and identifying the decoded second identifier as a particular one of the buddy identifiers when the decoded second identifier is substantially similar to the particular one of the buddy identifiers in the second list.

25. A wireless communications apparatus, comprising:

a memory that retains instructions related to obtaining a first signal from a signal source and identifying time positions of a first sequence of peer discovery intervals based upon the obtained first signal;

a processor, coupled to the memory, configured to execute the instructions retained in the memory;

wherein the memory further retains instructions for selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier and a time counter variable derived from the first signal, and broadcasting a second signal on each of the selected symbols;

wherein the memory further retains instructions for varying the time counter variable between peer discovery intervals in the first sequence and varying a position of the at least one selected symbol within each of the peer discovery intervals from one peer discovery interval to another; and

wherein the memory further retains instructions for choosing a frequency location of a tone included in the second signal on a per peer discovery interval basis as a function of the first identifier and the time counter variable.

26. A wireless communications apparatus that enables synchronizing a time period for discovery of peers in a peer-to-peer network, comprising:

a memory device including a communication routine;

means for receiving a first signal from a signal source;

means for locating time positions of a first sequence of peer discovery intervals based upon the first signal; and

means for separating successive peer discovery intervals in the first sequence by a time that is at least 100 times as long as a duration of each of the successive peer discovery intervals.

27. The wireless communications apparatus of claim 26, further comprising means for switching to and from a power saving state after an end of or before a beginning of a peer discovery interval, respectively.

28. A wireless communications apparatus that enables synchronizing a time period for discovery of peers in a peer-to-peer network, comprising:

a memory device including a communication routine;

means for receiving a first signal from a signal source;

means for locating time positions of a first sequence of peer discovery intervals based upon the first signal;

means for separating successive peer discovery intervals in the first sequence by a time that is at least 5 times as long as a duration of each of the successive peer discovery intervals;

means for selecting at least one symbol within each of the peer discovery intervals of the first sequence based on a first identifier and a time counter variable derived from the first signal; and

means for transmitting a broadcast of a second signal on each of the selected symbols.

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

means for listening during a fraction of each of the peer discovery intervals;

means for detecting a third broadcast signal from a peer during the fraction of a present peer discovery interval employed for listening; and

means for decoding a second identifier from the third broadcast signal when detected based on the time counter variable.

30. The wireless communications apparatus of claim 29, further comprising means for enforcing a maximum percentage of a duration of each of the peer discovery intervals utilized for transmitting the broadcast on the selected symbols.

31. The wireless communications apparatus of claim 28, further comprising:

means for varying the time counter variable from one peer discovery interval to the next;

means for varying a position of the at least one selected symbol within each of the peer discovery intervals from one peer discovery interval to another; and

means for selecting a frequency location of a tone included in the second signal on a per peer discovery interval basis as a function of the first identifier and the varying time counter variable.

32. In a wireless communication system, an apparatus comprising:

a processor configured to;

obtain a periodic signal from a base station;

determine time positions of a sequence of peer discovery intervals based upon the obtained periodic signal, wherein the sequence of peer discovery intervals is synchronized between peers of a peer-to-peer network;

select at least one symbol within each of the peer discovery intervals of the sequence based on a first identifier and a time counter variable derived from the first signal, and broadcast a second signal on each of the selected symbols;

listen during a fraction of each of the peer discovery intervals;

detect a third broadcast signal from a peer during the fraction of a current peer discovery interval employed for listening; and

decode a second identifier from the third broadcast signal when the third broadcast signal is detected.