METHODS AND APPARATUS FOR IMPROVING POWER EFFICIENCY AND LATENCY OF MOBILE DEVICES USING AN EXTERNAL TIMING SOURCE

• US 20110019601A1
• Filed: 07/22/2009
• Published: 01/27/2011
• Est. Priority Date: 07/22/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Li, Junyi, Tavildar, Saurabh, Jovicic, Aleksandar, Richardson, Thomas
• Granted Patent: US 8,848,622 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and apparatus for increasing power efficiency and decreasing latency of communication of a mobile device operating in an unlicensed spectrum using global timing data are disclosed. The method includes receiving, at the mobile device, the global timing data from an external timing source, the mobile device communicating in the unlicensed spectrum, obtaining, at the mobile device, a time from the global timing data, and determining, at the mobile device, a wake time to switch the mobile device from a sleep state to an active state based on the time obtained from the global timing data.

Claims

1. A method of increasing power efficiency and decreasing latency of communication of a mobile device operating in an unlicensed spectrum using global timing data, the method comprising:

receiving, at the mobile device, the global timing data from an external timing source, the mobile device communicating in the unlicensed spectrum;

obtaining, at the mobile device, a time from the global timing data; and

determining, at the mobile device, a wake time to switch the mobile device from a sleep state to an active state based on the time obtained from the global timing data.

2. The method of claim 1 further comprising:

receiving, at the mobile device during the active state, signals from other devices communicating in the unlicensed spectrum; and

determining, at the mobile device, a sleep time occurring after the wake time to switch the mobile device from the active state to the sleep state based on the signals received during the active state from the other devices communicating in the unlicensed spectrum.

3. The method of claim 2 further comprising decoding the signals received during the active state from the other devices communicating in the unlicensed spectrum.

4. The method of claim 3 wherein determining a sleep time occurring after the wake time to switch the mobile device from the active state to the sleep state comprises at least one of matching information in the decoded signals with a stored list of peer devices or determining whether a traffic request signal was received at the mobile device or sent from the mobile device.

5. The method of claim 1 further comprising transmitting information in the unlicensed spectrum during the active state.

6. The method of claim 5 wherein the information is selected from a group consisting of peer discovery information, routing information, timing information, traffic information, and combinations thereof.

7. The method of claim 1 further comprising updating an internal clock on the mobile device to be synchronized with the time obtained from the global timing data.

8. The method of claim 1 wherein the sleep state is when the mobile device is not transmitting or receiving information.

9. The method of claim 1 wherein the active state is when the mobile device is transmitting or receiving information.

10. An apparatus for increasing power efficiency and decreasing latency of communication and configured to operate in an unlicensed spectrum, the apparatus comprising:

a processor configured to;

receive the global timing data from an external timing source;

obtain a time from the global timing data; and

determine a wake time to switch from a sleep state to an active state based on the time obtained from the global timing data.

11. The apparatus of claim 10 wherein the processor is further configured to:

receive, during the active state, signals from other devices communicating in the unlicensed spectrum; and

determine a sleep time occurring after the wake time to switch from the active state to the sleep state based on the signals received during the active state from the other devices communicating in the unlicensed spectrum.

12. The apparatus of claim 11 wherein the processor is further configured to decode the signals received during the active state from the other devices communicating in the unlicensed spectrum.

13. The apparatus of claim 12 wherein to determine a sleep time occurring after the wake time to switch from the active state to the sleep state comprises at least one of match information in the decoded signals with a stored list of peer devices or determine whether a traffic request signal was received at the processor or sent from the processor.

14. The apparatus of claim 10 wherein the processor is further configured to transmit information in the unlicensed spectrum during the active state.

15. The apparatus of claim 14 wherein the information is selected from a group consisting of peer discovery information, routing information, timing information, traffic information, and combinations thereof.

16. The apparatus of claim 10 wherein the processor is further configured to update an internal clock to be synchronized with the time obtained from the global timing data.

17. The apparatus of claim 10 wherein the sleep state is when the processor is not transmitting or receiving information.

18. The apparatus of claim 10 wherein the active state is when the processor is transmitting or receiving information.

19. An apparatus for increasing power efficiency and decreasing latency of communication and configured to operate in an unlicensed spectrum, the apparatus comprising:

means for receiving the global timing data from an external timing source;

means for obtaining a time from the global timing data; and

means for determining a wake time to switch from a sleep state to an active state based on the time obtained from the global timing data.

20. The apparatus of claim 19 further comprising:

means for receiving, during the active state, signals from other devices communicating in the unlicensed spectrum; and

means for determining a sleep time occurring after the wake time to switch from the active state to the sleep state based on the signals received during the active state from the other devices communicating in the unlicensed spectrum.

21. The apparatus of claim 20 further comprising means for decoding the signals received during the active state from the other devices communicating in the unlicensed spectrum.

22. The apparatus of claim 21 wherein the means for determining a sleep time occurring after the wake time to switch from the active state to the sleep state comprises at least one of means for matching information in the decoded signals with a stored list of peer devices or means for determining whether a traffic request signal was received or sent.

23. The apparatus of claim 19 further comprising means for transmitting information in the unlicensed spectrum during the active state.

24. The apparatus of claim 23 wherein the information is selected from a group consisting of peer discovery information, routing information, timing information, traffic information, and combinations thereof.

25. The apparatus of claim 19 further comprising means for updating an internal clock to be synchronized with the time obtained from the global timing data.

26. The apparatus of claim 19 wherein the sleep state is when the apparatus is not transmitting or receiving information.

27. The apparatus of claim 19 wherein the active state is when the apparatus is transmitting or receiving information.

28. A machine readable medium embodying machine executable instructions to implement a method of increasing power efficiency and decreasing latency of communication of a mobile device operating in an unlicensed spectrum using global timing data, the method comprising:

receiving, at the mobile device, the global timing data from an external timing source, the mobile device communicating in the unlicensed spectrum;

obtaining, at the mobile device, a time from the global timing data; and

determining, at the mobile device, a wake time to switch the mobile device from a sleep state to an active state based on the time obtained from the global timing data.

29. The machine readable medium of claim 28 further comprising instructions for:

receiving, at the mobile device during the active state, signals from other devices communicating in the unlicensed spectrum; and

determining, at the mobile device, a sleep time occurring after the wake time to switch the mobile device from the active state to the sleep state based on the signals received during the active state from the other devices communicating in the unlicensed spectrum.

30. The machine readable medium of claim 29 further comprising instructions for decoding the signals received during the active state from the other devices communicating in the unlicensed spectrum.

31. The machine readable medium of claim 30 wherein the instructions for determining a sleep time occurring after the wake time to switch the mobile device from the active state to the sleep state comprises at least one of instructions for matching information in the decoded signals with a stored list of peer devices or instructions for determining whether a traffic request signal was received at the mobile device or sent from the mobile device.

32. The machine readable medium of claim 28 further comprising instructions for transmitting information in the unlicensed spectrum during the active state.

33. The machine readable medium of claim 32 wherein the information is selected from a group consisting of peer discovery information, routing information, timing information, traffic information, and combinations thereof.

34. The machine readable medium of claim 28 further comprising instructions for updating an internal clock on the mobile device to be synchronized with the time obtained from the global timing data.

35. The machine readable medium of claim 28 wherein the sleep state is when the mobile device is not transmitting or receiving information.

36. The machine readable medium of claim 28 wherein the active state is when the mobile device is transmitting or receiving information.