Power management for wireless direct link

• US 8,787,988 B2
• Filed: 01/14/2005
• Issued: 07/22/2014
• Est. Priority Date: 01/29/2003
• Status: Active Grant

• Current Assignee: Ozmo Licensing LLC
• Original Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Inventors: Wentink, Menzo
• Primary Examiner(s): Ajayi, Joel
• Application Number:
  US11/035,065
• Publication Number:
  US 20050122927A1
• Time in Patent Office: 3,476 Days
• Field of Search: 455/522.1, 455/552.1, 455/553.1, 455/13.4, 455571-574, 455/70, 455/343.2, 455/343.4, 455/41.2, 455/127.1, 455/127.5, 370/311
• US Class Current: 455/574
• CPC Class Codes: H04B 7/2126 using a reference station
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

Disclosed herein are exemplary techniques for managing power in a direct wireless link between two wireless devices. The present invention provides at least three direct link power management techniques: Fast Resumption Mode (FRM) wherein the direct link is resumed automatically at a specified timing synchronization function (TSF); Slow Resumption Mode (SRM) wherein the direct link may be resumed by sending a Resume-Request via the access point; and Reverse Polling (RP), wherein one peer station of the direct link is continually awake and the other peer station uses reverse polling to start a service period. Thus, a method for power management of a direct wireless link between two wireless devices is disclosed. The method comprising the steps of establishing a direct wireless link between the first wireless device and the second wireless device; transmitting, from a first wireless device, a frame having a time value; receiving, at the second wireless device, the frame from the first wireless device; suspending the direct wireless link a duration determined based on the time value; and resuming the direct wireless link at a time determined based on the time value.

Claims

1. A method for power management of a direct wireless link between a first and second wireless device, the method comprising:

at the first wireless device, establishing a direct wireless link with the second wireless device, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network;

transmitting, from the first wireless device to the second wireless device via the direct wireless link, a frame including a time value indicating a time duration that both the first wireless device and second wireless device should enter a power save mode;

at the first wireless device, entering a power save mode and suspending the direct wireless link for a duration determined based on the time value; and

exiting from the power save mode and resuming the direct wireless link at a time determined based on the time value.

2. The method of claim 1, wherein the time value is a suspend period based on an end of the frame.

3. The method of claim 1, wherein the time value is a timestamp indicating a future time at which the first and second wireless devices should exit the power save mode and resume the direct wireless link.

4. The method of claim 1, wherein the first and second wireless devices are clients of a same wireless infrastructure network, and the first wireless device is in a power save mode relative to an access point in the same wireless infrastructure network.

5. The method of claim 1, wherein the frame including the time value is transmitted from the first wireless device to the second wireless device at a transmission rate below the maximum supported transmission rate between the first and second wireless devices.

6. The method of claim 1, wherein, in the event that no acknowledgment of the transmitted frame including the time value is received by the first wireless device, the first wireless device re-transmitting the frame a limited number of times before stopping re-transmission and entering the power save mode.

7. A method for power management of a direct wireless link between a first and second wireless device, the method comprising:

at the second wireless device, establishing a direct wireless link with the first wireless device, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network;

receiving via the wireless direct link, from the first wireless device to the second wireless device, a frame including a time value indicating a time duration that both the first wireless device and second wireless device should enter a power save mode;

at the second wireless device, entering a power save mode and suspending the direct wireless link for a duration determined based on the time value; and

exiting from the power save mode and resuming the direct wireless link at a time determined based on the time value.

8. The method of claim 7, further comprising:

at the first wireless device, exiting from the power save mode and resuming the direct wireless link at a time determined based on the time value; and

at the second wireless device, exiting from the power save mode and resuming the direct wireless link at a time determined based on the time value.

34. The method of claim 7, wherein the time value is a suspend period based on an end of the frame.

35. The method of claim 7, wherein the time value is a timestamp indicating a future time at which the first and second wireless devices should exit the power save mode and resume the direct wireless link.

36. The method of claim 7, wherein the first and second wireless devices are clients of a same wireless infrastructure network, and the second wireless device is in a power save mode relative to an access point in the same wireless infrastructure network.

37. The method of claim 7, wherein the frame including a time value is transmitted from the first wireless device to the second wireless device at a transmission rate below the maximum supported transmission rate between the first and second wireless devices.

9. A first wireless device adapted to manage the power of a direct wireless link with a second wireless device, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network, the first wireless device comprising a processor adapted to:

establish a direct wireless link with the second wireless device;

generate and transmit a frame via the direct wireless link including a time value to the second wireless device, the time value indicating a time duration that both the first wireless device and second wireless device should enter a power save mode;

enter a power save mode and suspend the direct wireless link for a duration determined based on the time value; and

exit the power save mode and resume the direct wireless link at a time determined based on the time value.

10. The first wireless device of claim 9, wherein the time value is a suspend period based on an end of the frame.

11. The first wireless device of claim 9, wherein the time value is a timestamp indicating a future time at which the first and second wireless devices should exit the power save mode and resume the direct wireless link.

12. The first wireless device of claim 9, wherein the first and second wireless devices are clients of a same wireless infrastructure network, and the first wireless device is in a power save mode relative to an access point in the same wireless infrastructure network.

13. The first wireless device of claim 9, wherein the processor is adapted to transmit the frame including the time value from the first wireless device to the second wireless device at a transmission rate below the maximum supported transmission rate between the first and second wireless devices.

14. The first wireless device of claim 9, wherein in the event that no acknowledgment of the transmitted frame including the time value is received by the first wireless device, the processor is configured to re-transmit the frame a limited number of times before stopping re-transmission and entering the power save mode.

15. A second wireless device adapted to manage the power of a direct wireless link with a first wireless device, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network, the second wireless device comprising a processor adapted to:

establish a direct wireless link with the first wireless device;

receive a frame via the direct wireless link including a time value from the first wireless device, the time value indicating a time duration that both the first wireless device and second wireless device should enter a power save mode;

enter a power save mode and suspend the direct wireless link for a duration determined based on the time value; and

exit the power save mode and resume the direct wireless link at a time determined based on the time value.

16. The second wireless device of claim 15, wherein the time value is a suspend period based on an end of the frame.

17. The second wireless device of claim 15, wherein the time value is a timestamp indicating a future time at which the first and second wireless devices should exit the power save mode and resume the direct wireless link.

18. The second wireless device of claim 15, wherein the first and second wireless devices are clients of a same wireless infrastructure network, and the second wireless device is in a power save mode relative to an access point in the same wireless infrastructure network.

19. A method for power management of a direct wireless link between a first wireless device and a second wireless device in the presence of an access point, the method comprising:

at the first wireless device, establishing a direct wireless link with the second wireless device;

transmitting from the first wireless device to the second wireless device via the direct wireless link, or receiving at the first wireless device from the second wireless device via the direct wireless link, a first frame including a power management bit set indicating that the direct wireless link should be suspended and that the first and second wireless devices should enter a power save state;

at the first wireless device, suspending the direct wireless link and entering the power save state;

at the first wireless device, exiting the power save state and transmitting a first resume-request frame to the second wireless device via the access point; and

receiving, at the first wireless device from the second wireless device, a second resume-request frame via the direct wireless link.

20. A method for power management of a direct wireless link between a first wireless device and a second wireless device in the presence of an access point, the method comprising:

at the second wireless device, establishing a direct wireless link with the first wireless device;

transmitting from the second wireless device to the first wireless device via the direct wireless link, or receiving at the second wireless device from the first wireless device via the direct wireless link, a first frame including a power management bit set indicating that the direct wireless link should be suspended and that the first and second wireless devices should enter a power save state;

at the second wireless device, suspending the direct wireless link and entering the power save state;

at the second wireless device, receiving a first resume-request frame from the first wireless device via the access point; and

exiting the power save state and wirelessly transmitting a second resume-request frame to the first wireless device via the direct wireless link.

21. The method of claim 20, wherein the second wireless device is in a power save mode with the access point, and receives the first resume-request frame from the access point utilizing a power-save delivery mechanism.

22. A first wireless device adapted to manage the power of a direct wireless link with a second wireless device in the presence of an access point, the first wireless device comprising a processor adapted to:

establish a direct wireless link with the second wireless device;

transmit to the second wireless device via the direct wireless link, or receive from the second wireless device via the direct wireless link, a first frame including a power management bit set indicating that the direct wireless link should be suspended and that the first and second wireless devices should enter a power save state;

suspend the direct wireless link and enter a power save state;

exit the power save state and transmit a first resume-request frame to the second wireless device via the access point; and

receive from the second wireless device a second resume-request frame via the direct wireless link.

23. A second wireless device adapted to manage the power of a direct wireless link with a first wireless device in the presence of an access point, the second wireless device comprising a processor adapted to:

establish a direct wireless link with the first wireless device;

receive from the first wireless device via the direct wireless link, or transmit to the first wireless device via the direct wireless link, a first frame including a power management bit set indicating that the direct wireless link should be suspended and that the first and second wireless devices should enter a power save state;

suspend the direct wireless link and enter a power save state;

receive a first resume-request frame from the first wireless device via the access point; and

exit the power save state and transmit a second resume-request frame to the first wireless device via the direct wireless link.

24. The second wireless device of claim 23, wherein the second wireless device is in a power save mode with the access point, and receives the first resume-request frame from the access point utilizing a power-save delivery mechanism.

25. A method for power management of a direct wireless link between a first wireless device and a second wireless device, the method comprising:

at the first wireless device, establishing a direct wireless link between the first wireless device and the second wireless device in which the first wireless device indicates to the second wireless device that it is a continuously awake node, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network;

at the first wireless device, not sending but instead buffering data intended for transmission to the second wireless device via the direct wireless link;

receiving a QoS-Null frame at the first wireless device from the second wireless device indicating the start of a service period in which the second wireless device is not in power save mode;

the first wireless transmitting at least a portion of the buffered data to the second wireless device within the service period.

26. The method of claim 25, wherein the first wireless device transmits all of the buffered data to the second wireless device, and sets an End Of Service Period (EOSP) bit in a QoS frame to indicate that no more data will be transmitted in the service period.

27. A method for power management of a direct wireless link between a first wireless device and a second wireless device, the method comprising:

at the second wireless device, establishing a direct wireless link between the first wireless device and the second wireless device in which the first wireless device indicates to the second wireless device that it is a continuously awake node, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network;

at the second wireless device, sending notification to the first wireless device that the second wireless device is entering a power save mode;

at the second wireless device, exiting the power save mode and sending a QoS-Null frame to the first wireless device to indicate the start of a service period in which the second wireless device is not in the power save mode and is available to receive data via the direct wireless link;

at the second wireless device, receiving a QoS frame via the direct wireless link indicating that the service period should end; and

re-entering the power save mode.

28. The method of claim 27, wherein the second wireless device exits power save mode and transmits the QoS-Null frame to the first wireless device at a regular periodic interval.

29. The method of claim 28, wherein the regular periodic interval is substantially every 10 msec.

30. A first wireless device adapted to manage the power of a direct wireless link with a second wireless device, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network, the first wireless device comprising a processor adapted to:

establish a direct wireless link with the second wireless device in which the first wireless device indicates to the second wireless device that it is a continuously awake node;

not send but instead buffer data intended for transmission to the second wireless device via the direct wireless link;

receive a QoS-Null frame at the first wireless device from the second wireless device indicating the start of a service period in which the second wireless device is not in a power save mode;

transmit at least a portion of the buffered data to the second wireless device within the service period.

31. The first wireless device of claim 30, wherein the processor is further adapted to:

transmit all of the buffered data to the second wireless device, and set an End Of Service Period (EOSP) bit in a QoS frame to indicate that no more data will be transmitted in the service period.

32. A second wireless device adapted to manage the power of a direct wireless link with a first wireless device, the first and second wireless devices forming a wireless ad hoc network or operating as clients of a same wireless infrastructure network, the first wireless device comprising a processor adapted to:

establish a direct wireless link between the first wireless device and the second wireless device in which the first wireless device indicates to the second wireless device that it is a continuously awake node;

send notification to the first wireless device that the second wireless device is entering a power save mode;

exit the power save mode and send a QoS-Null frame to the first wireless device to indicate the start of a service period in which the second wireless device is not in the power save mode and is available to receive data via the direct wireless link;

receive a QoS frame from the first wireless device via the direct wireless link indicating that the service period should end; and

re-entering the power save mode.

33. The second wireless device of claim 32, wherein the QoS frame includes an End Of Service Period (EOSP) bit set to indicate that no more data will be transmitted in the service period.