Power management for wireless direct link

• US 9,002,415 B2
• Filed: 01/16/2014
• Issued: 04/07/2015
• Est. Priority Date: 06/12/2002
• 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:
  US14/157,213
• Publication Number:
  US 20140133378A1
• Time in Patent Office: 446 Days
• Field of Search: 455/127.1, 455/127.5, 455/574
• 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 disclosure 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 system comprising:

a first wireless device configured to establish a first direct wireless link with a second wireless device and to transmit from the first wireless device to the second wireless device a first frame including a first time value indicating a first time duration that both the first wireless device and second wireless device should enter a power save mode; and

the second wireless device configured to establish a second direct wireless link with the first wireless device and to receive from the first wireless device at the second wireless device a frame including a second time value indicating a second time duration that both the first wireless device and second wireless device should enter the power save mode;

wherein the first wireless device and the second wireless device are configured to enter the power save mode and suspend the first or second direct wireless link for a duration determined based on the first or second time value and to exit from the power save mode and resume the first or second direct wireless link at a time determined based on the first or second time value.

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

3. The system of claim 1, wherein the first or second 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 first or second direct wireless link.

4. The system 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 system of claim 1, wherein the frame including the first or second 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 system of claim 1, wherein, in the event that no acknowledgment of the transmitted frame including the first or second time value is received by the first wireless device, the first wireless device is configured to re-transmit the frame a limited number of times before stopping re-transmission and entering the power save mode.

7. The system of claim 1, wherein the first or second time value is a suspend period based on an end of the frame.

8. The system 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.

9. The system of claim 1, 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.

10. A system comprising:

a first wireless device; and

a second wireless device in the presence of an access point;

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

wherein the first wireless device is configured to exit the power save state and transmit a first resume-request frame to the second wireless device via the access point and to receive from the second wireless device, a second resume-request frame via the direct wireless link.

11. The system of claim 10, wherein the second wireless device is configured to suspend the direct wireless link and enter the power save state.

12. The system of claim 10, wherein the second wireless device is configured to receive a first resume-request frame from the first wireless device via the access point and to exit the power save state and wirelessly transmit a second resume-request frame to the first wireless device via the direct wireless link.

13. The system of claim 10, wherein the second wireless device is in a power save mode with the access point, and is configured to receive the first resume-request frame from the access point utilizing a power-save delivery mechanism.

14. A system comprising:

a first wireless device; and

a second wireless device;

wherein the first wireless device is configured 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, wherein the first and second wireless devices form a wireless ad hoc network or operating as clients of a same wireless infrastructure network;

wherein the first wireless device is configured to not send but instead buffer data intended for transmission to the second wireless device via the direct wireless link; and

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

15. The system of claim 14, wherein the first wireless device is configured to transmit at least a portion of the buffered data to the second wireless device within the service period.

16. The system of claim 14, 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.

17. The system of claim 14, wherein the second wireless device is configured to send notification to the first wireless device that the second wireless device is entering a power save mode.

18. The system of claim 17, wherein the second wireless device is configured to 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.

19. The system of claim 17, wherein the second wireless device is configured to receive a QoS frame via the direct wireless link indicating that the service period should end and to re-enter the power save mode.

20. The system of claim 17, 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.