Location aware background access point scanning for WLAN

• US 8,331,335 B2
• Filed: 10/16/2008
• Issued: 12/11/2012
• Est. Priority Date: 10/22/2007
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell World Trade Limited (Marvell Technology Group Limited)
• Inventors: Chhabra, Kapil
• Primary Examiner(s): PHUNKULH, BOB A
• Application Number:
  US12/252,965
• Publication Number:
  US 20090103503A1
• Time in Patent Office: 1,517 Days
• Field of Search: None
• US Class Current: 370/338
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Respective distances between a communication device and a plurality of wireless local area network (WLAN) access points are determined. One of the plurality of WLAN access points with which the communication device is to associate is selected based on the determined distances.

Claims

1. A method, comprising:

determining, with a communication device, respective distances between the communication device and a plurality of wireless local area network (WLAN) access points, wherein determining the respective distances is based on position information corresponding to the plurality of WLAN access points and position information corresponding to the communication device;

determining, with the communication device, whether a distance between (i) the communication device and (ii) a current WLAN access point with which the communication device is currently associated is greater than a threshold;

when it is determined that the distance between (i) the communication device and (ii) the current WLAN access point is greater than the threshold, initiating, with the communication device, a background scanning process that includes;

selecting, with the communication device, one of the plurality of WLAN access points with which the communication device is to associate based on the determined distances, including;

evaluating the plurality of WLAN access points in an order, wherein the order is based on the determined distances, wherein evaluating each WLAN access point includes determining if the WLAN access point is acceptable, and

stopping evaluating the plurality of WLAN access points before all of the plurality of WLAN access points have been evaluated if an acceptable WLAN access point is determined.

2. The method of claim 1, further comprising receiving the position information corresponding to the plurality of WLAN access points.

3. The method of claim 2, wherein the position information corresponding to the plurality of WLAN access points is received from the current WLAN access point with which the communication device is currently associated.

4. The method of claim 1, wherein selecting one of the plurality of WLAN access points with which the communication device is to associate is further based on respective received signal strength indicators corresponding to the plurality of WLAN access points.

5. The method of claim 1, wherein selecting one of the plurality of WLAN access points with which the communication device is to associate is further based on respective channel load indicators corresponding to the plurality of WLAN access points.

6. The method of claim 1, wherein evaluating the plurality of WLAN access points is based on a plurality of received signal strength indicators associated with the plurality of WLAN access points.

7. The method of claim 1, wherein evaluating the plurality of WLAN access points is based on a plurality of channel load indicators associated with the plurality of WLAN access points.

8. The method of claim 1, further comprising:

determining velocity information corresponding to the communication device; and

initiating the acts of determining respective distances and selecting one of the plurality of WLAN access points based on the velocity information.

9. The method of claim 1, further comprising:

comparing a velocity of the communication device to a second threshold;

disabling the background scanning process based on comparing the velocity the second threshold; and

causing a WLAN interface of the communication device to go into a sleep mode based on comparing the velocity to the second threshold.

10. The method of claim 9, wherein disabling the background scanning process comprises not starting the background scanning process.

11. The method of claim 9, wherein disabling the background scanning process comprises disabling the background scanning process after it has already started.

12. The method of claim 9, further comprising receiving the velocity information from a positioning system.

13. The method of claim 9, further comprising calculating the velocity information based on position information indicating a position of the communication device.

14. The method of claim 13, further comprising receiving the position information indicating the position of the communication device from a positioning system.

15. The method of claim 1, wherein determining if each WLAN access point is acceptable is based on direction information indicating a direction in which the communication device is traveling.

16. The method of claim 15, further comprising determining the direction information based on position information corresponding to the communication device.

17. An apparatus, comprising:

a wireless local area network (WLAN) channel scanning control unit configured to;

determine, based on position information corresponding to a plurality of WLAN access points and position information corresponding to a communication device, respective distances between the communication device and the plurality of WLAN access points,

determining whether a distance between (i) the communication device and (ii) a current WLAN access point with which the communication device is currently associated is greater than a threshold,

when it is determined that the distance between (i) the communication device and (ii) the current WLAN access point is greater than the threshold, initiate a background scanning process that includes;

evaluating the plurality of WLAN access points in an order, wherein the order is based on the determined distances, wherein when evaluating each of the plurality of WLAN access points, the WLAN channel scanning control unit is configured to determine if the WLAN access point is acceptable,

stopping evaluating the plurality of WLAN access points if the WLAN channel scanning control unit determines an acceptable WLAN access point before the WLAN channel scanning control unit evaluates all of the plurality of WLAN access points, and

selecting one of the plurality of WLAN access points with which the communication device is to associate based on evaluating the plurality of WLAN access points.

18. The apparatus of claim 17, further comprising a positioning system to generate the position information corresponding to the communication device.

19. The apparatus of claim 18, further comprising a WLAN interface.

20. The apparatus of claim 17, further comprising a WLAN interface.

21. The apparatus of claim 20, wherein the position information corresponding to the plurality of WLAN access points is received using the WLAN interface.

22. The apparatus of claim 20, wherein the WLAN channel scanning control unit is a component of the WLAN interface.

23. The apparatus of claim 20, wherein the WLAN channel scanning control unit is coupled to the WLAN interface.

24. The apparatus of claim 17, wherein the WLAN channel scanning control unit is configured to determine if each WLAN access point is acceptable based on a received signal strength indicator corresponding to the WLAN access point.

25. The apparatus of claim 17, wherein the WLAN channel scanning control unit is configured to determine if each WLAN access point is acceptable based on a channel load indicator corresponding to the WLAN access point.

26. The apparatus of claim 17, wherein the WLAN channel scanning control unit is configured to:

compare a velocity of the communication device to a second threshold;

disable the background scanning process based on comparing the velocity to the second threshold; and

cause a WLAN interface of the communication device to go into a sleep mode based on comparing the velocity to the second threshold, by signaling from the WLAN scanning control unit to the WLAN interface.

27. The apparatus of claim 26, further comprising the WLAN interface.

28. The apparatus of claim 27, wherein the WLAN interface includes the WLAN channel scanning control unit.

29. The apparatus of claim 27, wherein the WLAN interface is coupled to the WLAN channel scanning control unit.

30. The apparatus of claim 27, further comprising a positioning system to generate the velocity information.

31. The apparatus of claim 27, further comprising a positioning system to generate position information indicating a position of the communication device;

wherein the WLAN channel scanning control unit is configured to calculate the velocity information based on the position information indicating the position of the communication device.

32. The apparatus of claim 17, wherein the WLAN channel scanning control unit is configured to determine if each WLAN access point is acceptable based on direction information indicating a direction in which the communication device is traveling.

33. The apparatus of claim 32, further comprising a positioning system to generate position information corresponding to the communication device;

wherein the WLAN channel scanning control unit is configured to determine the direction information based on the position information corresponding to the communication device.