FAVORING ACCESS POINTS IN WIRELESS COMMUNICATIONS

• US 20090137249A1
• Filed: 11/12/2008
• Published: 05/28/2009
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Agashe, Parag A., Deshpande, Manoj M., Nanda, Sanjiv, Ulupinar, Fatih, Tenny, Nathan E., Prakash, Rajat, Chen, Jen Mei, Pica, Francesco, Horn, Gavin B.
• Granted Patent: US 8,902,867 B2
• Time in Patent Office: Days
• US Class Current: 455/435.200
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

Systems and methodologies are described that facilitate applying offsets and/or selectable hysteresis values to favor access points in cell reselection. In measuring and ranking surrounding access points in reselection, offsets can be applied to favorable access points to facilitate cell reselection thereto. The offset can positively affect measurements, and thus ranking as well, in some cases. Negative offsets can also be applied to lower measurements (and thus ranking) of some access points. Moreover, hysteresis values can be applied in measuring current cells to prevent frequent reselection. The hysteresis values can be selected based on a type of the current cell or related access point to expand the coverage area where desired. Thus, where the current access point is favorable, a larger hysteresis can be added to measurements related to the current access point.

Claims

1. A method for cell reselection in a wireless communication network, comprising:

receiving wireless communication service from a first access point;

determining a type and signal strength of a second access point; and

applying an offset to the signal strength of the second access point in ranking the second access point for cell reselection from the first access point, the offset is selected based at least in part on the type of the second access point.

2. The method of claim 1, wherein the type of the second access point relates to whether the second access point is included in a maintained list of preferred access points.

3. The method of claim 2, wherein the second access point is included in the maintained list of preferred access points and the offset is a positive number.

4. The method of claim 1, further comprising applying a hysteresis value to a signal strength of the first access point based at least in part on a type of the first access point.

5. The method of claim 4, wherein the type of the first access point relates to whether the first access point is included in a maintained list of preferred access points.

6. The method of claim 4, further comprising receiving the hysteresis value from the first access point, the second access point, and/or a prior visited access point.

7. The method of claim 4, further comprising performing cell reselection to the second access point where the signal strength of the second access point modified by the offset is beyond the signal strength of the first access point modified by the hysteresis value.

8. The method of claim 7, wherein the cell reselection is performed while in an idle communication mode with respect to the wireless communication network.

9. The method of claim 4, further comprising performing cell reselection to a third access point where the signal strength of the second access point modified by the offset is beyond the signal strength of the first access point modified by the hysteresis value.

10. The method of claim 9, wherein the third access point is on a different frequency band from the second access point.

11. The method of claim 1, further comprising receiving the offset from the first access point, the second access point, and/or a prior visited access point.

12. The method of claim 1, wherein the determined type of the second access point includes a femtocell or a macrocell.

13. The method of claim 1, wherein the determined type of the second access point includes whether the second access point implements restricted or non-restricted association.

14. The method of claim 1, wherein the signal strength of the second access point is determined by tuning away from the first access point.

15. A wireless communications apparatus, comprising:

at least one processor configured to;

receive wireless communication service from a first access point;

receive a type and signal strength for each of the first access point and a second access point;

apply an offset to the signal strength of the second access point in ranking the second access point for cell reselection from the first access point, the offset is applied based at least in part on the type of the second access point; and

apply a hysteresis to the signal strength of the first access point in ranking the second access point for reselection from the first access point, the hysteresis is selected based at least in part on a type of the first access point; and

a memory coupled to the at least one processor.

16. A wireless communications apparatus that facilitates performing cell reselection to one or more access points, comprising:

means for receiving service from a first access point;

means for determining a type and signal strength of a second access point; and

means for applying an offset to the signal strength of the second access point in ranking the second access point for reselection from the first access point, the offset is selected based at least in part on the type of the second access point.

17. A computer program product, comprising:

a computer-readable medium comprising;

code for causing at least one computer to receive wireless communication service from a first access point;

code for causing the at least one computer to determine a type and signal strength of a second access point; and

code for causing the at least one computer to apply an offset to the signal strength of the second access point in ranking the second access point for cell reselection from the first access point, the offset is selected based at least in part on the type of the second access point.

18. An apparatus, comprising:

a sector parameters measurer that measures a signal strength of one or more surrounding access points;

an access point offset specifier that applies an offset to the signal strength of the one or more surrounding access points based at least in part on a type thereof; and

a cell reselector that establishes communication with the one or more surrounding access points based at least in part on a ranking of the offset applied signal strength with respect to a current access point.

19. The apparatus of claim 18, further comprising an access list controller that determines the type of the one or more surrounding access points based at least in part on presence of the one or more surrounding access points in a maintained list of preferred access points and/or related groups.

20. The apparatus of claim 19, wherein the one or more surrounding access points are included in the maintained list of preferred access points and the offset is a positive number.

21. The apparatus of claim 18, further comprising an access point hysteresis specifier that applies a hysteresis value to a signal strength of the current access point based at least in part on a type of the current access point.

22. The apparatus of claim 21, wherein the type of the current access point relates to whether the current access point is included in a maintained list of preferred access points and/or related groups.

23. The apparatus of claim 21, wherein the access point hysteresis specifier receives the hysteresis value from the current access point, the one or more surrounding access points, and/or a prior visited access point.

24. The apparatus of claim 18, wherein the access point offset specifier receives the offset from the current access point, the one or more surrounding access points, and/or a prior visited access point.

25. The apparatus of claim 18, wherein the cell reselector establishes communication with the one or more surrounding access points while in an idle communication mode with respect to the current access point.

26. The apparatus of claim 18, wherein the cell reselector establishes communication with a disparate access point where the communication establishment is denied by the one or more surrounding access points.

27. The apparatus of claim 26, wherein the disparate access point is on a different frequency band from the one or more surrounding access points.

28. The apparatus of claim 18, wherein the type of the one or more surrounding access points includes a femtocell or a macrocell.

29. The apparatus of claim 18, wherein the type of the one or more surrounding access points includes whether the one or more surrounding access points have restricted or non-restricted association.

30. The apparatus of claim 18, wherein the signal strength of the one or more surrounding access points is determined by tuning away from the current access point.