Tracking area reconfiguration based on sector load

• US 8,804,566 B1
• Filed: 07/25/2012
• Issued: 08/12/2014
• Est. Priority Date: 07/25/2012
• Status: Active Grant

• Current Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Singh, Jasinder P., Vargantwar, Sachin R., Shah, Maulik K., Rai, Deveshkumar
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US13/558,054
• Time in Patent Office: 748 Days
• Field of Search: None
• US Class Current: 370/252
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration

Abstract

A method and corresponding system is provided to help mitigate sector congestion. In one embodiment of the method, a RAN entity evaluates load among sectors of a tracking area and determines that the load is at least a threshold level of load. In response, the RAN entity enlarges the tracking area. In another embodiment of the method, when the RAN entity makes a decision to reconfigure a tracking area, it may consider one or more factors when determining how to reconfigure. In one example, the RAN entity may identify a particular border sector that has at least a threshold level of load or is a border sector in another network. Responsively, the RAN may reconfigure the tracking area such that the identified border sector is no longer a border sector. Other examples are possible.

Claims

1. In a wireless communication system in which a plurality of sectors of a radio access network (RAN) are organized into a plurality of tracking areas with each tracking area of the plurality of tracking areas having a respective size and at least one user equipment (UE) operating therein, a method comprising:

evaluating aggregate load among sectors of a given tracking area by a RAN entity;

based on the evaluating, determining that the aggregate load among sectors of the given tracking area is at least a threshold level of aggregate load by the RAN entity; and

in response to the determining, increasing the size of the given tracking area by the RAN entity.

2. The method of claim 1, wherein the aggregate load among sectors of the given tracking area comprises reverse-link congestion among sectors of the given tracking area.

3. The method of claim 1, wherein the aggregate load among sectors of the given tracking area comprises reverse-link control-channel congestion among sectors of the given tracking area.

4. The method of claim 1, wherein the aggregate load among sectors of the given tracking area comprises a number of tracking area update messages sent per unit time by UEs operating in the given tracking area.

5. The method of claim 1, wherein each tracking area of the number of tracking areas includes a respective number of sectors, and wherein increasing the size of at least one tracking area comprises increasing the respective number of sectors included in the at least one tracking area.

6. The method of claim 1, wherein each given sector of the plurality of sectors is associated with a respective base station that broadcasts over an air interface a tracking area ID that is indicative of a tracking area in which the given sector is included, and wherein increasing the size of the given tracking area comprises instructing at least one base station associated with a sector to broadcast a different tracking area ID.

7. In a wireless communication system in which a plurality of sectors of a radio access network (RAN) are organized into a plurality of tracking areas, wherein each given tracking area of the plurality of tracking areas includes (i) one or more border sectors that border at least one other tracking area, and (ii) at least one user equipment (UE) operating therein, a method comprising:

making a decision to reconfigure a given tracking area by the RAN entity;

in response to the RAN entity making the decision to reconfigure the given tracking area, evaluating by the RAN entity load at each border sector of the given tracking area;

based on the evaluating, identifying a particular border sector has at least a threshold level of load by the RAN entity; and

reconfiguring by the RAN entity of the given tracking area such that the identified border sector does not border any other tracking area.

8. The method of claim 7, wherein the RAN entity making a decision to reconfigure the given tracking area comprises the RAN entity evaluating aggregate load among sectors of the given tracking area and thereby determining that the aggregate load among sectors of the given tracking area is at least a threshold level of load.

9. The method of claim 7, wherein the RAN entity evaluating load at each border sector of the given tracking area comprises the RAN entity evaluating reverse link congestion at each border sector of the given tracking area.

10. The method of claim 7, wherein the RAN entity evaluating load at each border sector of the given tracking area comprises the RAN entity evaluating reverse-link control-channel congestion at each border sector of the given tracking area.

11. The method of claim 7, wherein the RAN entity evaluating load at each border sector of the given tracking area comprises for each given border sector of the given tracking area, the RAN entity measuring a number of tracking area update messages sent per unit time by UEs operating in the given border sector.

12. The method of claim 7, wherein the RAN entity identifying that a particular border sector has at least a threshold level of load comprises the RAN entity identifying, from among each border sector of the given tracking area, a particular border sector that has a highest level of load.

13. The method of claim 7, wherein each tracking area of the number of tracking areas includes a respective number of sectors, and wherein reconfiguring the given tracking area comprises one or more of the following:

(i) adding at least one sector to the given tracking area, and

(ii) removing at least one sector from the given tracking area.

14. The method of claim 7, wherein each given sector of the plurality of sectors is associated with a respective base station that broadcasts over an air interface a tracking area ID that is indicative of a tracking area in which the given sector is included, and wherein reconfiguring the given tracking area comprises instructing at least one base station associated with a sector to broadcast a different tracking area ID.

15. In a wireless communication system in which a plurality of sectors are shared by a first radio access network (RAN) and a second RAN, wherein each sector of the plurality of sectors is included in a respective tracking area of the first RAN and a respective tracking area of the second RAN, and wherein each tracking area of the first RAN and each tracking area of the second RAN includes (i) one or more border sectors that border at least one other tracking area, and (ii) at least one user equipment (UE) operating therein, a method comprising:

making a decision to reconfigure a given tracking area of the first RAN by a RAN entity;

in response to the RAN entity making the decision to reconfigure the given tracking area of the first RAN, identifying by the RAN entity a particular border sector in the given tracking area that is also a border sector in a tracking area of the second RAN; and

reconfiguring by the RAN entity of the given tracking area such that the identified border sector does not border any tracking area of the first RAN.

16. The method of claim 15, wherein the RAN entity making a decision to reconfigure the given tracking area of the first RAN comprises the RAN entity evaluating aggregate load among sectors of the given tracking area and thereby determining that the aggregate load among sectors of the given tracking area is at least a threshold level of load.

17. The method of claim 16, wherein the aggregate load among sectors of the given tracking area comprises reverse-link control-channel congestion among sectors of the given tracking area.

18. The method of claim 16, wherein the aggregate load among sectors of the given tracking area comprises a number of tracking area update messages sent per unit time by UEs operating in the given tracking area.

19. The method of claim 15, wherein each tracking area of the first RAN includes a respective number of sectors, and wherein reconfiguring the given tracking area comprises one or more of the following:

(i) adding at least one sector to the given tracking area, and

(ii) removing at least one sector from the given tracking area.

20. The method of claim 15, wherein each given sector of the plurality of sectors is associated with a respective base station that broadcasts over an air interface a tracking area ID that is indicative of a tracking area of the first RAN in which the given sector is included, and wherein reconfiguring the given tracking area comprises instructing at least one base station associated with a sector to broadcast a different tracking area ID.