Selecting a wireless communication device for handoff based on active set characteristics

• US 8,457,069 B1
• Filed: 07/30/2010
• Issued: 06/04/2013
• Est. Priority Date: 07/30/2010
• Status: Expired due to Fees

• Current Assignee: Sprint Spectrum LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Vargantwar, Sachin R., Goyal, Anoop K., Oroskar, Siddharth S., Shetty, Manoj
• Primary Examiner(s): Rinehart, Mark
• Assistant Examiner(s): ANWAR, MOHAMMAD S
• Application Number:
  US12/847,198
• Time in Patent Office: 1,040 Days
• Field of Search: 370/331, 370/332, 370/333
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 72/56 based on priority criteria

Abstract

Methods and devices for a radio access network (RAN) to select a wireless communication device (WCD) for handoff to a given sector are presented. In particular, the RAN may receive resource requests from a first WCD and a second WCD, both WCDs contending for a resource of the given sector. Based on the each WCD'"'"'s active sets of sectors, the RAN may grant the resource to one of these WCDs. Preferably, the RAN grants the resource to the WCD that is more likely to benefit from use of the resource.

Claims

1. A method, performed by a radio access network (RAN), the method comprising:

the RAN receiving a first resource request from a first wireless communication device (WCD), wherein the first WCD has a first active set of sectors;

the RAN receiving a second resource request from a second WCD, wherein the second WCD has a second active set of sectors;

in response to receiving the first resource request and the second resource request, the RAN determining that the first WCD and second WCD are contending for a resource of a given sector defined by the RAN;

in response to determining that the first WCD and second WCD are contending for the resource, the RAN comparing the first active set with the second active set; and

based on a result of the comparison of the first active set with the second active set, the RAN allocating the resource to the first WCD.

2. The method of claim 1, wherein comparing the first active set with the second active set comprises comparing a size of the first active set with a size of the second active set.

3. The method of claim 2, wherein the result of the comparison of the first active set with the second active set is that the size of the first active set is smaller than the size of the second active set.

4. The method of claim 2, wherein the first WCD receives signals from the given sector at a first signal strength, wherein the second WCD receives signals from the given sector at a second signal strength, wherein signals the first WCD receives from sectors in the first active set cooperatively define a first active set measurement, and wherein signals the second WCD receives from sectors in the second active set cooperatively define a second active set measurement, and wherein comparing the first active set to the second active set comprises:

the RAN determining that the first active set and the second active set are the same size; and

in response to determining that the first active set and the second active set are the same size, the RAN (i) comparing the first signal strength with the first active set measurement to produce a first result, (ii) comparing the second signal strength with the second active set measurement to produce a second result, and (iii) comparing the first result with the second result to produce the result of the comparison of the first active set with the second active set.

5. The method of claim 4, wherein the first result is a first difference between the first signal strength and the first active set measurement, wherein the second result is a second difference between the second signal strength and the second active set measurement, and wherein the result of the comparison of the first active set with the second active set is that the first difference is greater than the second difference.

6. The method of claim 4, wherein the first result is a first ratio between the first signal strength and the first active set measurement, wherein the second result is a second ratio between the second signal strength and the second active set measurement, and wherein the result of the comparison of the first active set with the second active set is that the first ratio is greater than the second ratio.

7. The method of claim 2, wherein comparing the size of the first active set with the size of the second active set comprises comparing a count of sectors in the first active set with a count of sectors in the second active set.

8. The method of claim 1, wherein the resource comprises a code division multiple access (CDMA) code.

9. The method of claim 1, wherein the resource is the only resource of a given type available in the given sector.

10. A method, performed by a radio access network (RAN), the method comprising:

the RAN receiving a first resource request from a first wireless communication device (WCD), wherein the first WCD has a first active set of sectors, and wherein signals the first WCD receives from sectors in the first active set cooperatively define a first active set measurement;

the RAN receiving a second resource request from a second WCD, wherein the second WCD has a second active set of sectors, and wherein signals the second WCD receives from sectors in the second active set cooperatively define a second active set measurement;

in response to receiving the first resource request and the second resource request, the RAN determining that the first WCD and second WCD are contending for a resource of a given sector defined by the RAN, wherein the first WCD receives signals from the given sector at a first signal strength and the second WCD receives signals from the given sector at a second signal strength;

in response to determining that the first WCD and second WCD are contending for the resource, the RAN (i) comparing the first signal strength with the first active set measurement to produce a first result, (ii) comparing the second signal strength with the second active set measurement to produce a second result, and (iii) comparing the first result with the second result to produce a third result; and

based on the third result, the RAN allocating the resource to the first WCD.

11. The method of claim 10, wherein the first result is a first difference between the first signal strength and the first active set measurement, wherein the second result is a second difference between the second signal strength and the second active set measurement, and wherein the third result is that the first difference is greater than the second difference.

12. The method of claim 10, wherein the first result is a first ratio between the first signal strength and the first active set measurement, wherein the second result is a second ratio between the second signal strength and the second active set measurement, and wherein the third result is that the first ratio is greater than the second ratio.

13. The method of claim 10, wherein the first active set measurement based on an operation chosen from a group consisting of a minimum, a maximum, a median, and a mean.

14. The method of claim 10, wherein the resource comprises a code division multiple access (CDMA) code.

15. The method of claim 10, wherein the resource is the only resource of a given type available in the given sector.

16. A radio access network (RAN) component capable of controlling a given sector, the RAN component comprising:

a processor;

a data storage; and

program instructions, stored in the data storage and executable by the processor, to (i) receive a first resource request from a first wireless communication device (WCD), wherein the first WCD has a first active set of sectors, (ii) receive a second resource request from a second WCD, wherein the second WCD has a second active set of sectors, (iii) in response to receiving the first resource request and the second resource request, determine that the first WCD and second WCD are contending for a resource of the given sector, (iv) in response to determining that the first WCD and second WCD are contending for the resource, compare the first active set with the second active set, and (v) based on a result of the comparison of the first active set with the second active set, allocate the resource to the first WCD.

17. The RAN component of claim 16, wherein the program instructions to compare the first active set with the second active set comprise program instructions to compare a size of the first active set with a size of the second active set.

18. The RAN component of claim 17, wherein the result of the comparison is that the size of the first active set is smaller than the size of the second active set.

19. The RAN component of claim 16, wherein the first WCD receives signals from the given sector at a first signal strength, wherein the second WCD receives signals from the given sector at a second signal strength, wherein signals the first WCD receives from sectors in the first active set cooperatively define a first active set measurement, and wherein signals the second WCD receives from sectors in the second active set cooperatively define a second active set measurement, and wherein the program instructions to compare the first active set with the second active set comprise:

program instructions to (i) determine that the first active set and the second active set are the same size, and (ii) in response to determining that the first active set and the second active set are the same size, (a) compare the first signal strength with the first active set measurement to produce a first result, (b) compare the second signal strength with the second active set measurement to produce a second result, and (c) compare the first result with the second result to produce the result of the comparison of the first active set with the second active set.

20. The RAN component of claim 19, wherein the first result is a first difference between the first signal strength and the first active set measurement, wherein the second result is a second difference between the second signal strength and the second active set measurement, and wherein the result of the comparison of the first active set with the second active set is that the first difference is greater than the second difference.