System and method for soft access point power reduction

• US 8,717,923 B2
• Filed: 11/02/2011
• Issued: 05/06/2014
• Est. Priority Date: 11/03/2010
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Vedantham, Ramanuja, Lu, Xiaolin, Sella, Assaf, Peery, Josef, Xhafa, Ariton, Sun, Yanjun
• Primary Examiner(s): Cho, Un C
• Assistant Examiner(s): Roudani, Oussama
• Application Number:
  US13/287,219
• Publication Number:
  US 20120106381A1
• Time in Patent Office: 916 Days
• Field of Search: 370/252, 370/338, 370/331, 370/255, 455/418, 455/78
• US Class Current: 370/252
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 4/08 User group management
• CPC Class Codes: H04W 4/50 Service provisioning or reconfiguring
• 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 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/12 Access point controller devices
• CPC Class Codes: H04W 92/18 between terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system and method for reducing power consumption of a wireless device operating as a soft access point. In one embodiment, a wireless device includes a soft access point controller that configures the wireless device to operate as a group owner in a peer-to-peer wireless local area network. The soft access point controller includes a beacon controller. The beacon controller is configured to transmit beacon frames at a first periodic interval. The beacon controller is also configured to extend a discovery interval of a wireless station by transmitting acknowledgement packets at a second periodic interval. The second periodic interval is shorter than the first periodic interval and shorter than a minimum discovery scan timeout of the wireless station.

Claims

1. A wireless device, comprising:

a soft access point controller that configures the wireless device to operate as a group owner in a peer-to-peer wireless local area network, the soft access point controller comprising;

a beacon controller configured to;

transmit beacon frames at a first periodic interval; and

extend a discovery interval of a wireless station by transmitting acknowledgement packets at a second periodic interval;

wherein the first periodic interval is shorter than a maximum discovery scan timeout of the wireless station, and the second periodic interval is shorter than the first periodic interval and shorter than a minimum discovery scan timeout of the wireless station.

2. The wireless device of claim 1, wherein the soft access point controller is configured to provide discovery only via the beacon frames.

3. The wireless device of claim 1, wherein the first periodic interval is 20-30 milliseconds in length and the second periodic interval less than 15 milliseconds in length.

4. The wireless device of claim 1, wherein the soft access point controller is configured to not activate a receiver to monitor for probe requests.

5. The wireless device of claim 1, wherein the soft access point controller is configured to:

identify a level of traffic on a co-existing wireless local area network;

schedule transmission of a message requesting exclusive use of wireless media for a time interval, wherein duration of the time interval is a function of the level of traffic on the co-existing network; and

place the wireless device in a reduced power state for the duration of the time interval.

6. The wireless device of claim 1, wherein the soft access point controller is configured to periodically place the wireless device in a reduced power state for a first time interval based on the wireless device being in an idle state.

7. The wireless device of claim 6, wherein placement of the wireless device in the reduced power state is based on all scheduled transmissions by the wireless device being at least a second time interval from initiation, and the wireless device handling no wireless traffic flows.

8. The wireless device of claim 6, wherein the soft access point controller is configured to:

monitor wireless traffic for a learning interval after establishment of a wireless traffic flow with a wireless station;

determine a level of traffic and a periodicity of traffic based on the monitored wireless traffic; and

determine the first time interval and a period at which the wireless device is to be placed in the reduced power state based on at least one of the level of traffic and the periodicity of traffic.

9. The wireless device of claim 6, wherein the soft access point controller is configured to skip a scheduled entry into the reduced power state based on either of:

detection of packet transmission by a wireless station within a second time interval prior to a scheduled reduced power state entry time; and

detection of packet transmission by a wireless station within a third time interval after exiting the reduced power state.

10. The wireless device of claim 6, wherein the soft access point controller is configured to cause the wireless device to exit the reduced power state based on any of reception of a retransmission frame and scheduling a downlink transmission.

11. The wireless device of claim 6, wherein the soft access point controller is configured to initiate periodic placement of the wireless device in the reduced power state based on detection of no non-period traffic on a wireless medium for a doze initiation time interval.

12. A method, comprising:

configuring a mobile wireless device to operate as a soft access point in a peer-to-peer wireless network;

transmitting, by the wireless device, at a first periodic interval, beacon frames allowing a wireless station to discover the soft access point; and

extending, by the wireless device, an access point discovery listening interval of the wireless station, by transmitting at a second periodic interval, an acknowledgement packet;

wherein the second periodic interval is shorter than the first periodic interval and shorter than a minimum discovery scan timeout of the wireless station.

13. The method of claim 12, further comprising:

identifying, by the wireless device, a level of traffic on a co-existing wireless network, and

transmitting, by the wireless device, a message requesting exclusive use of wireless media for a time interval; and

entering, by the wireless device, a reduced power state for a duration of the time interval;

wherein the duration of the time interval is based on the level of traffic on the co-existing wireless network.

14. The method of claim 12, further comprising:

determining, by the wireless device, that no transmissions from the wireless device are scheduled to occur within a first time interval, and that no wireless traffic flows are ongoing;

entering, periodically, a reduced power state based on the determining.

15. The method of claim 14, further comprising transmitting a message responsive to the determining and prior to entering the reduced power state, the message notifying a wireless station that the wireless device is unavailable for communication for a time interval corresponding to a time the wireless device is in the reduced power state.

16. The method of claim 12, further comprising:

exiting the reduced power state based on either of reception of a retransmission frame and scheduling of a downlink transmission; and

initiating, the entering periodically the reduced power state based on detection of no non-period traffic on the wireless network for a doze initiation time interval.

17. A system, comprising:

a mobile wireless device configured to operate as a group owner in a peer-to-peer wireless network, the wireless device comprising a soft access point controller configured to;

determine whether transmissions by the wireless device are scheduled to occur within a first time interval;

determine whether wireless traffic flows via the wireless device are ongoing; and

periodically transition the wireless device from an idle state to a reduced power state based on a determination of no transmissions being scheduled to occur within the first time interval and no traffic flows ongoing; and

transmit, at a first periodic interval, beacon frames allowing a wireless station to discover a soft access point; and

extend an access point discovery listening interval of the wireless station by transmitting, at a second periodic interval, an acknowledgement packet;

wherein the second periodic interval is shorter than the first periodic interval and shorter than a minimum discovery scan timeout of the wireless station.

18. The system of claim 17, further comprising a wireless station not configured to operate in the peer-to-peer wireless network wirelessly accessing the peer-to-peer wireless network via the mobile wireless device.

19. The system of claim 17, wherein the soft access point controller is further configured to transmit a message in coordination with the transition to the reduced power state, the message notifying a wireless station configured to operate in the peer-to-peer wireless network that the wireless device is unavailable for communication for a time interval corresponding to a time the wireless device is in the reduced power state.

20. The system of claim 17, wherein the soft access point controller is further configured to:

exit the reduced power state based on either of reception of retransmission frame and scheduling a downlink transmission; and

initiating, the periodic transition to the reduced power state based on detection of no traffic on the peer-to-peer wireless network for a doze initiation time interval.

21. The system of claim 17, wherein the soft access point controller is further configured to:

monitor wireless traffic for a learning interval after establishment of a wireless traffic flow with a wireless station;

determine a level of traffic and a periodicity of traffic based on the monitored wireless traffic; and

determine a duration and a period at which the mobile wireless device is to be placed in the reduced power state based on at least one of the level of traffic and the periodicity of traffic.

22. The system of claim 17, wherein the soft access point controller is further configured to initiate periodic placement of the mobile wireless device in the reduced power state based on detection of no non-period traffic on a wireless medium for a predetermined doze initiation time interval.

23. The system of claim 17, wherein the soft access point controller is configured to cause the mobile wireless device to exit the reduced power state based on any of reception of a retransmission frame and scheduling a downlink transmission.

24. The system of claim 17, wherein the soft access point controller is configured to skip a scheduled entry into the reduced power state based on either of:

detection of packet transmission by a wireless station within a second time interval prior to a scheduled reduced power state entry time; and

detection of packet transmission by a wireless station within a third time interval after exiting the reduced power state.

25. The system of claim 17, wherein the soft access point controller is further configured to transmit of a message requesting exclusive use of wireless media for a time interval corresponding to duration of the reduced power state.