Mobile station dynamic power saving control

• US 20050221869A1
• Filed: 03/31/2004
• Published: 10/06/2005
• Est. Priority Date: 03/31/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Liu, Jiewen, Tsien, Chih C.
• Granted Patent: US 7,295,827 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: G06F 1/3209 Monitoring remote activity, e.g. over telephone lines or network connections
• CPC Class Codes: H04W 52/0232 according to average transmission signal activity
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile station in a wireless network dynamically adjusts its sleeping time for power saving based on its data traffic activity.

Claims

1. A method comprising determining a power savings level for a mobile station based on an amount of data traffic.

2. The method of claim 1 further comprising determining the amount of data traffic as a percentage of traffic activity within a time interval.

3. The method of claim 1 wherein determining a power savings level comprises determining a time interval for the mobile station to sleep.

4. The method of claim 3 wherein determining a time interval for the mobile station to sleep comprises comparing a desired sleep interval and a required wake-up time to receive broadcast and multicast packets.

5. The method of claim 3 wherein the time interval for the mobile station to sleep is expressed as a number of 802.11 compliant beacon intervals.

6. The method of claim 5 wherein the method is performed within a beacon monitor task run in response to an interrupt caused by a Target Beacon Transmission Times (TBTT) timer.

7. The method of claim 5 wherein determining a time interval for the mobile station to sleep comprises comparing a Delivery Traffic Indication Message (DTIM) count within a received beacon with a time interval associated with the power saving level.

8. A method comprising:

determining a desired sleep interval to sleep to save power;

determining a broadcast time to wake up to receive packets from an access point; and

setting a wake-up time based on the desired sleep interval and the broadcast time.

9. The method of claim 8 wherein determining a desired sleep interval comprises determining a desired number of beacon intervals to sleep.

10. The method of claim 8 wherein determining a desired sleep interval comprises determining a desired number of beacon intervals to sleep based, at least in part, on a volume of data traffic.

11. The method of claim 10 wherein determining a desired sleep interval further comprises selecting one of a plurality of power savings levels based on the volume of data traffic.

12. The method of claim 8 wherein determining a broadcast time comprises examining a Traffic Indication Map (TIM) element within an 802.11 compliant beacon.

13. The method of claim 8 wherein setting a wake-up time comprises setting the wake-up time to the end of one desired sleep interval when the broadcast time is more than two desired sleep intervals in the future.

14. The method of claim 8 wherein setting a wake-up time comprises setting the wake-up time to the broadcast time when the broadcast time is less than two desired sleep intervals in the future.

15. An apparatus having a machine-readable medium with instructions stored thereon that when accessed, result in a machine performing:

waking up a mobile station to receive a beacon;

evaluating traffic activity; and

setting a power savings level for the mobile station based on the traffic activity.

16. The apparatus of claim 15 wherein evaluating traffic activity comprises determining a percentage of traffic time over a time interval.

17. The apparatus of claim 16 wherein the power savings level may be set differently each time the traffic activity is evaluated.

18. The apparatus of claim 15 further comprising setting a sleep time associated the power savings level.

19. The apparatus of claim 15 wherein setting a power savings level comprises determining a number of beacon intervals for the mobile station to sleep.

20. The apparatus of claim 19 wherein determining a number of beacon intervals for the mobile station to sleep comprises comparing a desired number of beacon intervals with a Delivery Traffic Indication Message (DTIM) count.

21. An apparatus configured to communicate in an 802.11 wireless network, and configured to sleep for a number of beacon intervals based on traffic volume.

22. The apparatus of claim 21 comprising a network interface card.

23. The apparatus of claim 21 comprising a mobile computer.

24. An electronic system comprising:

a plurality of antennas;

a radio interface coupled to the plurality of antennas;

a processor coupled to the radio interface; and

a static random access memory with instructions stored thereon that when accessed, result in the processor performing;

waking up an apparatus to receive a beacon, evaluating traffic activity, and setting a power savings level for the apparatus based on the traffic activity.

25. The electronic system of claim 24 wherein setting a power savings level comprises determining a time interval for the apparatus to sleep.

26. The electronic system of claim 25 wherein determining a time interval for the apparatus to sleep comprises comparing a desired sleep interval and a required wake-up time to receive multicast packets.

27. The electronic system of claim 25 wherein the time interval for the apparatus to sleep is expressed as a number of beacon intervals.