Systems and methods for coordinating power save operations in an ad hoc network

• US 9,485,715 B2
• Filed: 05/13/2014
• Issued: 11/01/2016
• Est. Priority Date: 05/13/2014
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kella, Leela Prasad, Ansari, Imran
• Primary Examiner(s): Kassim, Khaled
• Assistant Examiner(s): BELETE, BERHANU D
• Application Number:
  US14/276,674
• Publication Number:
  US 20150334648A1
• Time in Patent Office: 903 Days
• Field of Search: 370/310, 370/311, 340/7.32, 340/7.38, 4553431-3436
• US Class Current: 1/1
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 8/245 from a network towards a terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Systems and methods are disclosed for facilitating coordination among member stations in an IBSS to allow members to remain in a power save mode of operation for extended periods of time without awakening to transmit or receive beacons at each scheduled TBTT. A power save initiator may establish a power save period during which all nodes in the network may enter a power save mode. Correspondingly, beacons may not be sent during the extended power save period and any traffic to be exchanged between members of the IBSS WLAN may be buffered for delivery after the extended power save period ends.

Claims

1. A method for operating an independent basic service set (IBSS) for a plurality of stations, the method being performed by a power save initiator within the IBSS and comprising:

determining scheduled target beacon transmission times (TBTTs) at which one or more of the plurality of stations are scheduled to transmit beacons;

detecting a trigger condition for entering an extended power save period, wherein a duration of the extended power save period is greater than a TBTT period;

upon detecting the trigger condition, signaling the extended power save period to the plurality of stations to prevent the stations from transmitting beacons during one or more of the scheduled TBTTs;

operating in a power save mode for the extended power save period, wherein the extended power save period causes the power save initiator to remain in the power save mode during the one or more scheduled TBTTs; and

returning to an active mode after the extended power save period has elapsed.

2. The method of claim 1, further comprising determining that other stations within the IBSS have extended power save capabilities by receiving a beacon frame having extended power save period information from the other stations.

3. The method of claim 2, wherein the power save initiator is to signal the extended power save period after receiving a beacon frame having extended power save period information from each of the plurality of stations.

4. The method of claim 1, wherein the signaling comprises:

broadcasting a first beacon frame upon determining that the trigger condition is met, wherein the first beacon frame includes an information element (IE) indicating the extended power save period.

5. The method of claim 4, wherein the trigger condition corresponds to a period of inactivity.

6. The method of claim 4, wherein the first beacon frame specifies the duration of the extended power save period.

7. The method of claim 4, further comprising broadcasting at least one additional beacon frame, wherein each beacon frame provides relative timing information regarding a start time for the extended power save period.

8. The method of claim 7, wherein the timing information comprises a decrementing count.

9. The method of claim 8, wherein the power save initiator is operated in a power save mode after the decrementing count reaches a minimum value.

10. The method of claim 4, wherein the first beacon frame causes each of the plurality of stations within the IBSS to operate in the power save mode for the duration of the extended power save period.

11. A wireless communications device comprising a transceiver and a power save controller, the wireless communications device being configured to:

determine scheduled target beacon transmission times (TBTTs) at which one or more of a plurality of stations of an independent basic service set (IBSS) are scheduled to transmit beacons;

detect a trigger condition for entering an extended power save period, wherein a duration of the extended power saving period is greater than a TBTT period;

upon detecting the trigger condition, signal the extended power save period to the plurality of stations to prevent the stations from transmitting beacons during one or more of the scheduled TBTTs;

operate in a power save mode for the extended power save period, wherein the extended power save period causes the wireless communications device to remain in the power save mode during the one or more scheduled TBTTs; and

return to an active mode after the extended power save period has elapsed.

12. The wireless communications device of claim 11, wherein the power save controller is to further determine that others of the plurality of stations within the IBSS have extended power save capabilities if the transceiver receives a beacon frame having extended power save period information from the other stations.

13. The wireless communications device of claim 12, wherein the transceiver is to signal the extended power save period after the power save controller determines that each of the plurality of stations has extended power save capabilities.

14. The wireless communications device of claim 11, wherein the wireless communications device is to signal the extended power save period by:

broadcasting a first beacon frame upon determining that the trigger condition is met, wherein the first beacon frame includes an information element (IE) indicating the extended power save period.

15. The wireless communications device of claim 14, wherein the trigger condition corresponds to a period of inactivity.

16. The wireless communications device of claim 14, wherein the first beacon frame specifies the duration of the extended power save period.

17. The wireless communications device of claim 14, wherein the transceiver is to further broadcast at least one additional beacon frame, wherein each beacon frame provides relative timing information regarding a start time for the extended power save period.

18. The wireless communications device of claim 17, wherein the timing information comprises a decrementing count.

19. The wireless communications device of claim 18, wherein the power save controller is to operate the transceiver in a power save mode after the decrementing count reaches a minimum value.

20. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors of a wireless communications device, cause the wireless communications device to:

determine scheduled target beacon transmission times (TBTTs) at which one or more of a plurality of stations of an independent basic service set (IBSS) are scheduled to transmit beacons;

detect a trigger condition for entering an extended power save period, wherein a duration of the extended power save period is greater than a TBTT period;

upon detecting the trigger condition, signal the extended power save period to the plurality of stations to prevent the stations from transmitting beacons during one or more of the scheduled TBTTs;

operate in a power save mode for the extended power save period, wherein the extended power save period causes the wireless communications device to remain in the power save mode during the one or more scheduled TBTTs; and

return to an active mode after the extended power save period has elapsed.