STANDBY TIME IMPROVEMENTS FOR STATIONS IN A WIRELESS NETWORK

• US 20070297438A1
• Filed: 02/28/2007
• Published: 12/27/2007
• Est. Priority Date: 03/03/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Meylan, Arnaud, Nanda, Sanjiv, Deshpande, Manoj
• Granted Patent: US 8,880,104 B2
• Time in Patent Office: Days
• US Class Current: 370/445
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Techniques to improve the standby time of a station in a wireless network are described. An access point may advertise or convey a maximum listen interval and/or an association timeout supported by that access point. A station may operate in a power-save mode and may wake up every listen interval to receive a beacon and any potential traffic for the station. The station may select a suitable listen interval based on the maximum listen interval. The station may be dormant for a longer duration than the listen interval and may become active at least once in every association timeout in order to keep the association with the access point alive. The access point may also send broadcast and multicast traffic that might be of interest to stations in the power-save mode less frequently and using a special indication message.

Claims

1. An apparatus comprising:

a processor configured to determine a maximum listen interval supported by an access point, to select a listen interval based on the maximum listen interval, and to send the selected listen interval to the access point; and

a memory coupled to the processor.

2. The apparatus of claim 1, wherein the processor is configured to receive a beacon sent by the access point and to obtain the maximum listen interval from the beacon.

3. The apparatus of claim 1, wherein the processor is configured to send a probe request to the access point and to receive a probe response with the maximum listen interval from the access point.

4. The apparatus of claim 1, wherein the processor is configured to select an initial listen interval, to send an association request with the initial listen interval to the access point, and to receive an association response with the maximum listen interval from the access point.

5. The apparatus of claim 1, wherein the processor is configured to receive data from the access point at time instances determined based on the selected listen interval and to sleep between the time instances.

6. The apparatus of claim 1, wherein the selected listen interval is equal to the maximum listen interval.

7. A method comprising:

determining a maximum listen interval supported by an access point;

selecting a listen interval based on the maximum listen interval; and

sending the selected listen interval to the access point.

8. The method of claim 7, wherein the determining the maximum listen interval comprises

receiving a beacon sent by the access point, and

obtaining the maximum listen interval from the beacon.

9. The method of claim 7, further comprising:

receiving data from the access point at time instances determined based on the selected listen interval and

sleeping between the time instances.

10. An apparatus comprising:

means for determining a maximum listen interval supported by an access point;

means for selecting a listen interval based on the maximum listen interval; and

means for sending the selected listen interval to the access point.

11. A processor-readable medium including instructions stored thereon, comprising:

a first instruction set for determining a maximum listen interval supported by an access point;

a second instruction set for selecting a listen interval based on the maximum listen interval; and

a third instruction set for sending the selected listen interval to the access point.

12. An apparatus comprising:

a processor configured to send a plurality of requests for a plurality of listen interval values, to receive a response accepting one of the plurality of requests, to receive another response denying another one of the plurality of requests, and to determine a listen interval for use based on the received responses; and

a memory coupled to the processor.

13. The apparatus of claim 12, wherein the processor is configured to send one request for one listen interval value at a time until the response accepting one of the plurality of requests and the response denying another one of the plurality of requests are both received.

14. The apparatus of claim 12, wherein the processor is configured to send one request for one listen interval value at a time, starting with a request for a largest listen interval value and concluding with a request for a smallest listen interval value, until the response accepting one of the plurality of requests is received.

15. The apparatus of claim 12, wherein the processor is configured to send one request for one listen interval value at a time, starting with a request for a smallest listen interval value and concluding with a request for a largest listen interval value, until the response denying another one of the plurality of requests is received.

16. An apparatus comprising:

a processor configured to send a maximum listen interval supported by an access point, to receive from a station a listen interval selected based on the maximum listen interval, and to send data to the station based on the listen interval; and

a memory coupled to the processor.

17. The apparatus of claim 16, wherein the processor is configured to send the maximum listen interval in a beacon or a frame to the station.

18. An apparatus comprising:

a processor configured to establish an association with an access point, to receive data based on a first listen interval negotiated with the access point during establishment of the association, to renegotiate with the access point for a second listen interval without disassociating with the access point, and to receive data based on the second listen interval after the renegotiation; and

a memory coupled to the processor.

19. The apparatus of claim 18, wherein the processor is configured to establish states during the establishment of the association and to retain the states during the renegotiation for the second listen interval.

20. The apparatus of claim 18, wherein the processor is configured to send a control frame with the second listen interval to the access point and to receive an indication of acceptance of the second listen interval from the access point.

21. The apparatus of claim 18, wherein the processor is configured to wake up for beacon frames determined by the first or second listen interval and to sleep between the beacon frames when no data is sent to the apparatus.

22. A method comprising:

establishing an association with an access point;

receiving data based on a first listen interval negotiated with the access point during establishment of the association;

renegotiating with the access point for a second listen interval without disassociating with the access point; and

receiving data based on the second listen interval after the renegotiation.

23. The method of claim 22, further comprising:

establishing states during establishment of the association; and

retaining the states during the renegotiation for the second listen interval.

24. An apparatus comprising:

means for establishing an association with an access point;

means for receiving data based on a first listen interval negotiated with the access point during establishment of the association;

means for renegotiating with the access point for a second listen interval without disassociating with the access point; and

means for receiving data based on the second listen interval after the renegotiation.

25. A processor-readable medium including instructions stored thereon, comprising:

a first instruction set for establishing an association with an access point;

a second instruction set for receiving data based on a first listen interval negotiated with the access point during establishment of the association;

a third instruction set for renegotiating with the access point for a second listen interval without disassociating with the access point; and

a fourth instruction set for receiving data based on the second listen interval after the renegotiation.

26. An apparatus comprising:

a processor configured to establish an association for a station, to send data to the station based on a first listen interval negotiated with the station during establishment of the association, to renegotiate with the station for a second listen interval without disassociating the station, and to send data to the station based on the second listen interval after the renegotiation; and

a memory coupled to the processor.

27. The apparatus of claim 26, wherein the processor is configured to establish states for the station during the establishment of the association and to retain the states for the station during the renegotiation for the second listen interval.

28. An apparatus comprising:

a processor configured to establish an association with an access point, to determine an association timeout for the access point, and to become active at least once in every association timeout to keep the association with the access point alive; and

a memory coupled to the processor.

29. The apparatus of claim 28, wherein the processor is configured to receive a beacon sent by the access point and to obtain the association timeout from the beacon.

30. The apparatus of claim 28, wherein the processor is configured to receive a frame from the access point and to obtain the association timeout from the received frame.

31. The apparatus of claim 28, wherein the processor is configured to negotiate with the access point for a listen interval during the establishment of the association and to sleep for a period longer than the listen interval.

32. The apparatus of claim 28, wherein the processor is configured to negotiate with the access point for a listen interval during the establishment of the association and to sleep for a period longer than the listen interval without informing the access point.

33. A method comprising:

establishing an association with an access point;

determining an association timeout for the access point; and

becoming active at least once in every association timeout to keep the association with the access point alive.

34. The method of claim 33, wherein the determining the association timeout comprises

receiving a beacon sent by the access point, and

obtaining the association timeout from the beacon.

35. The method of claim 33, further comprising:

negotiating with the access point for a listen interval during the establishment of the association; and

sleeping for a period longer than the listen interval.

36. An apparatus comprising:

means for establishing an association with an access point;

means for determining an association timeout for the access point; and

means for becoming active at least once in every association timeout to keep the association with the access point alive.

37. A processor-readable medium including instructions stored thereon, comprising:

a first instruction set for establishing an association with an access point;

a second instruction set for determining an association timeout for the access point; and

a third instruction set for becoming active at least once in every association timeout to keep the association with the access point alive.

38. An apparatus comprising:

a processor configured to establish an association for a station, to send an association timeout supported by an access point, and to receive from the station at least one transmission in every association timeout to keep the association alive; and

a memory coupled to the processor.

39. The apparatus of claim 38, wherein the processor is configured to send the association timeout in a beacon or a frame to the station.