Dynamic energy saving mechanism for access points

• US 9,288,753 B2
• Filed: 07/31/2013
• Issued: 03/15/2016
• Est. Priority Date: 05/05/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sampathkumar, Badrisrinivasan
• Primary Examiner(s): Mew, Kevin
• Application Number:
  US13/955,779
• Publication Number:
  US 20130315121A1
• Time in Patent Office: 958 Days
• US Class Current: 1/1
• 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 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Mobile access points typically run on batteries, and therefore, can operate for a limited amount of time without an external power source. However, because the access point service model requiring the access point to always be available and the access point'"'"'s limited battery capacity reduces the time that the mobile access point can be used. Functionality can be incorporated in mobile access points to implement power saving mechanisms by altering the service model that requires the access point to always be available. Configuring the access point to enter into a low powered state for a predefined period of time can conserve mobile access point power and prolong battery life. Functionality for implementing power saving mechanisms can also be incorporated on fixed access points for efficient utilization of computing resources.

Claims

1. A method for power conservation in an access point, the method comprising:

determining, at the access point, a first sleep interval of the access point based, at least in part, on a second sleep interval of a first wireless network device, wherein the access point is configured to operate in a sleep operating mode during the first sleep interval, wherein the first wireless network device is configured to operate in the sleep operating mode during the second sleep interval;

transmitting an indication of the first sleep interval from the access point to the first wireless network device to prevent the first wireless network device from initiating transmissions to the access point during the first sleep interval; and

initiating the sleep operating mode at the access point at a start of the first sleep interval.

2. The method of claim 1, wherein said transmitting the indication of the first sleep interval from the access point to the first wireless network device further comprises:

transmitting, from the access point and to the first wireless network device, at least one of a time instant at which the access point begins to operate in the sleep operating mode, a time instant at which the access point exits from the sleep operating mode, and an indication of how often the access point operates in the sleep operating mode.

3. The method of claim 1, further comprising:

determining to transmit a message from the access point to the first wireless network device;

determining whether a transmission time for transmitting the message exceeds an amount of time remaining before the start of the first sleep interval; and

determining whether to transmit the message from the access point to the first wireless network device based, at least in part, on whether the transmission time exceeds the amount of time remaining before the start of the first sleep interval.

4. The method of claim 3, further comprising:

preventing transmission of the message from the access point to the first wireless network device, in response to determining that the transmission time exceeds the amount of time remaining before the start of the first sleep interval; and

transmitting the message from the access point to the first wireless network device, in response to determining that the transmission time does not exceed the amount of time remaining before the start of the first sleep interval.

5. The method of claim 1, wherein the access point is a mobile access point or a mobile phone configured as the access point.

6. The method of claim 1, wherein said initiating the sleep operating mode at the access point at the start of the first sleep interval comprises:

initiating the first sleep interval at the access point during the second sleep interval of the first wireless network device.

7. The method of claim 1, further comprising:

determining that the access point is not communicatively coupled with any wireless network device;

determining, at the access point, a third sleep interval of the access point based, at least in part, on a beacon interval of the access point, wherein the access point is configured to periodically transmit a beacon message each beacon interval, wherein the access point is configured to operate in the sleep operating mode during the third sleep interval; and

transmitting an indication of the third sleep interval to prevent at least the first wireless network device from initiating transmissions to the access point during the third sleep interval.

8. The method of claim 1, further comprising:

initiating a normal operating mode at the access point, in response to determining that the first sleep interval has elapsed.

9. The method of claim 1, wherein said initiating the sleep operating mode at the access point is in response to:

determining that a sleep timer associated with the access point has elapsed, wherein the sleep timer indicates an amount of time that remains before the start of the first sleep interval at the access point.

10. The method of claim 1, further comprising:

receiving a message at the access point from a second wireless network device indicating a third sleep interval of the second wireless network device, wherein the second wireless network device is configured to operate in the sleep operating mode during the third sleep interval;

determining a fourth sleep interval of the access point based, at least in part, on the second sleep interval and the third sleep interval, wherein the access point is configured in the sleep operating mode during the fourth sleep interval; and

transmitting an indication of the fourth sleep interval from the access point to the first wireless network device and the second wireless network device to prevent the first wireless network device and the second wireless network device from initiating transmissions to the access point during the fourth sleep interval.

11. The method of claim 10, wherein said determining the fourth sleep interval of the access point comprises:

determining a least common factor between the second sleep interval and the third sleep interval; and

determining when to initiate the fourth sleep interval of the access point based, at least in part, on the least common factor between the second sleep interval and the third sleep interval.

12. The method of claim 1, further comprising:

receiving, at the access point, a request for transmitting a message from the first wireless network device;

determining that a transmission time associated with transmitting the message exceeds an amount of time remaining before the start of the first sleep interval; and

transmitting a notification from the access point to the first wireless network device to prevent transmission of the message from the first wireless network device to the access point.

13. A method comprising:

determining, at a wireless network device, that a wireless communication channel is available for transmitting a message from the wireless network device to an access point;

determining whether a transmission time associated with transmitting the message exceeds an amount of time remaining before a start of a first sleep interval of the access point, wherein the access point is configured to operate in a sleep operating mode during the first sleep interval; and

determining whether to transmit the message from the wireless network device to the access point based, at least in part, on whether the transmission time associated with transmitting the message exceeds the amount of time remaining before the start of the first sleep interval.

14. The method of claim 13, further comprising:

preventing transmission of the message from the wireless network device to the access point, in response to determining that the transmission time exceeds the amount of time remaining before the start of the first sleep interval; and

transmitting the message from the wireless network device to the access point, in response to determining that the transmission time does not exceed the amount of time remaining before the start of the first sleep interval.

15. The method of claim 13, further comprising:

transmitting an indication of a second sleep interval of the wireless network device from the wireless network device to the access point to enable the access point to determine the first sleep interval.

16. The method of claim 15, further comprising:

initiating the sleep operating mode at the wireless network device at the start of the second sleep interval; and

initiating a normal operating mode at the wireless network device, in response to determining that the second sleep interval has elapsed.

17. The method of claim 16, wherein said initiating the sleep operating mode at the wireless network device is in response to:

determining that a sleep timer associated with the wireless network device has elapsed, wherein the sleep timer indicates an amount of time that remains before the start of the second sleep interval.

18. The method of claim 13, further comprising:

determining whether to transmit the message from the wireless network device to the access point based, at least in part, on whether the transmission time exceeds an amount of time remaining before a start of a second sleep interval of the wireless network device.

19. An access point comprising:

a processor unit; and

a power saving unit coupled with the processor unit, the power saving unit configured to;

determine a first sleep interval of the access point based, at least in part, on a second sleep interval of a first wireless network device, wherein the access point is configured to operate in a sleep operating mode during the first sleep interval, wherein the first wireless network device is configured to operate in the sleep operating mode during the second sleep interval;

transmit an indication of the first sleep interval from the access point to the first wireless network device to prevent the first wireless network device from initiating transmissions to the access point during the first sleep interval; and

initiate the sleep operating mode at the access point at a start of the first sleep interval.

20. The access point of claim 19, wherein the power saving unit is configured to initiate the first sleep interval at the access point during the second sleep interval of the first wireless network device.

21. The access point of claim 19, wherein the power saving unit is further configured to:

determine that the access point is not communicatively coupled with any wireless network device;

determine a third sleep interval of the access point based, at least in part, on a beacon interval of the access point, wherein the access point is configured to periodically transmit a beacon message each beacon interval, wherein the access point is configured to operate in the sleep operating mode during the third sleep interval; and

transmit an indication of the third sleep interval to prevent at least the first wireless network device from initiating transmissions to the access point during the third sleep interval.

22. The access point of claim 19, wherein the power saving unit is further configured to:

receive a message from a second wireless network device indicating a third sleep interval of the second wireless network device, wherein the second wireless network device is configured to operate in the sleep operating mode during the third sleep interval;

determine a fourth sleep interval of the access point based, at least in part, on the second sleep interval and the third sleep interval, wherein the access point is configured in the sleep operating mode during the fourth sleep interval; and

transmit an indication of the fourth sleep interval from the access point to the first wireless network device and the second wireless network device to prevent the first wireless network device and the second wireless network device from initiating transmissions to the access point during the fourth sleep interval.

23. A wireless network device comprising:

a processor unit; and

a power saving unit coupled with the processor unit, the power saving unit configured to;

determine that a wireless communication channel is available for transmitting a message from the wireless network device to an access point;

determine whether a transmission time associated with transmitting the message exceeds an amount of time remaining before a start of a first sleep interval of the access point, wherein the access point is configured to operate in a sleep operating mode during the first sleep interval; and

determine whether to transmit the message from the wireless network device to the access point based, at least in part, on whether the transmission time associated with transmitting the message exceeds the amount of time remaining before the start of the first sleep interval of the access point.

24. The wireless network device of claim 23, wherein the power saving unit is further configured to:

transmit an indication of a second sleep interval of the wireless network device to the access point to enable the access point to determine the first sleep interval.

25. The wireless network device of claim 23, wherein the power saving unit is further configured to:

determine whether to transmit the message from the wireless network device to the access point based, at least in part, on whether the transmission time exceeds the amount of time remaining before a start of a second sleep interval of the wireless network device.

26. A non-transitory machine-readable storage medium having machine executable instructions stored therein, the machine executable instructions comprising instructions to:

determine, at an access point, a first sleep interval of the access point based, at least in part, on a second sleep interval of a first wireless network device, wherein the access point is configured to operate in a sleep operating mode during the first sleep interval, wherein the first wireless network device is configured to operate in the sleep operating mode during the second sleep interval;

transmit an indication of the first sleep interval from the access point to the first wireless network device to prevent the first wireless network device from initiating transmissions to the access point during the first sleep interval; and

initiate the sleep operating mode at the access point at a start of the first sleep interval.

27. The non-transitory machine-readable storage medium of claim 26, wherein said instructions further comprise instructions to:

determine that the access point is not communicatively coupled with any wireless network device;

determine, at the access point, a third sleep interval of the access point based, at least in part, on a beacon interval of the access point, wherein the access point is configured to periodically transmit a beacon message each beacon interval, wherein the access point is configured to operate in the sleep operating mode during the third sleep interval; and

transmit an indication of the third sleep interval to prevent at least the first wireless network device from initiating transmissions to the access point during the third sleep interval.

28. The non-transitory machine-readable storage medium of claim 26,

wherein said instructions further comprise instructions to:

receive a message at the access point from a second wireless network device indicating a third sleep interval of the second wireless network device, wherein the second wireless network device is configured to operate in the sleep operating mode during the third sleep interval;

determine a fourth sleep interval of the access point based, at least in part, on the second sleep interval and the third sleep interval, wherein the access point is configured in the sleep operating mode during the fourth sleep interval; and

transmit an indication of the fourth sleep interval from the access point to the first wireless network device and the second wireless network device to prevent the first wireless network device and the second wireless network device from initiating transmissions to the access point during the fourth sleep interval.

29. A non-transitory machine-readable storage medium having machine executable instructions stored therein, the machine executable instructions comprising instructions to:

determine that a wireless communication channel is available for transmitting a message from a wireless network device to an access point;

determine whether a transmission time associated with transmitting the message exceeds an amount of time remaining before a start of a first sleep interval of the access point, wherein the access point is configured to operate in a sleep operating mode during the first sleep interval; and

determine whether to transmit the message from the wireless network device to the access point based, at least in part, on whether the transmission time associated with transmitting the message exceeds the amount of time remaining before the start of the first sleep interval of the access point.

30. The non-transitory machine-readable storage medium of claim 29,

wherein said instructions further comprise instructions to:

determine whether to transmit the message from the wireless network device to the access point based, at least in part, on whether the transmission time exceeds the amount of time remaining before a start of a second sleep interval of the wireless network device.