Favoring access points in wireless communications

• US 8,902,867 B2
• Filed: 11/12/2008
• Issued: 12/02/2014
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Horn, Gavin B., Ulupinar, Fatih, Agashe, Parag A., Prakash, Rajat, Deshpande, Manoj M., Nanda, Sanjiv, Chen, Jen Mei, Pica, Francesco, Tenny, Nathan E.
• Primary Examiner(s): VU, HOANG-CHUONG Q
• Application Number:
  US12/269,619
• Publication Number:
  US 20090137249A1
• Time in Patent Office: 2,211 Days
• Field of Search: 370/338, 370/331, 455/435.2, 455/436, 455/437
• US Class Current: 370/338
• 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, by a mobile device, wireless communication service from a first access point;

determining, by the mobile device, a type and signal strength of a second access point, 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;

verifying, by the mobile device, association of the second access point with the list;

selecting, by the mobile device, an offset based at least in part on whether the second access point is included in the maintained list of preferred access points; and

applying, by the mobile device, the selected offset to the signal strength of the second access point in affecting a ranking of the second access point for cell reselection from the first access point.

2. 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.

3. The method of claim 2, 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.

4. The method of claim 2, further comprising receiving the hysteresis value from the first access point, the second access point, or a prior visited access point.

5. The method of claim 2, further comprising performing cell reselection to the second access point where the signal strength of the second access point modified by the offset exceeds the signal strength of the first access point modified by the hysteresis value.

6. The method of claim 5, wherein the cell reselection is performed while in an idle communication mode with respect to the wireless communication network.

7. The method of claim 2, further comprising performing cell reselection to a third access point where the signal strength of the second access point modified by the offset exceeds the signal strength of the first access point modified by the hysteresis value.

8. The method of claim 7, wherein the third access point is on a different frequency band from the second access point.

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

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

11. 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.

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

22. The mobile device of claim 6, 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.

23. The mobile device of claim 22, wherein the disparate access point is on a different frequency band from the one or more surrounding access points.

13. A mobile device, comprising:

at least one processor of the mobile device 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, 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;

verify association of the second access point with the list;

select an offset based at least in part on whether the second access point is included in the maintained list of preferred access points;

apply the selected offset to the signal strength of the second access point in affecting a ranking of the second access point for cell reselection from the first 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.

14. A mobile device that facilitates performing cell reselection by the mobile device 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, 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;

means for verifying association of the second access point with the list;

means for selecting an offset based at least in part on whether the second access point is included in the maintained list of preferred access points; and

means for applying the selected offset to the signal strength of the second access point in affecting a ranking of the second access point for reselection from the first access point.

15. A computer program product, comprising:

a non-transitory computer-readable medium of a mobile device 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 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;

code for causing the at least one computer to verify association of the second access point with the list;

code for causing the at least one computer to select an offset based at least in part on whether the second access point is included in the maintained list of preferred access points; and

code for causing the at least one computer to apply the selected offset to the signal strength of the second access point in affecting a ranking of the second access point for cell reselection from the first access point.

16. A mobile device, comprising:

a sector parameters measurer of the mobile device that measures a signal strength of one or more surrounding access points,

an access list controller of the mobile device 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 or related groups, and verifies association of the one or more surrounding access points with the list;

an access point offset specifier of the mobile device that selects and applies an offset to the signal strength of the one or more surrounding access points based at least in part on whether the second access point is included in the maintained list of preferred access points; and

a cell reselector of the mobile device 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.

17. The mobile device of claim 16, 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.

18. The mobile device of claim 17, 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 or related groups.

19. The mobile device of claim 17, wherein the access point hysteresis specifier receives the hysteresis value from the current access point, the one or more surrounding access points, or a prior visited access point.

20. The mobile device of claim 16, wherein the access point offset specifier receives the offset from the current access point, the one or more surrounding access points, or a prior visited access point.

21. The mobile device of claim 16, 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.

24. The mobile device of claim 16, wherein the type of the one or more surrounding access points includes a femtocell or a macrocell.

25. The mobile device of claim 16, 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.

26. The mobile device of claim 16, wherein the signal strength of the one or more surrounding access points is determined by tuning away from the current access point.