Optimizing a neighbor list of access points

Patent metadata

Field	Value
Publication number	US-9253693-B2
Application number	US-201313772896-A
Country	US
Kind code	B2
Filing date	Feb 21, 2013
Priority date	Dec 18, 2012
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

In an example embodiment, a neighbor radio/access point (AP) list is obtained. The neighbor AP list is optimized for a client that is associated with a current access point. The list may be optimized based on any one or combination of techniques, including but not limited to roaming patterns of previous clients that were associated with the current access point, radio frequency metrics, bandwidth requirements for the client, and/or any other suitable criteria. In particular embodiments, requests from the client to associate with an access point that is not on the optimized neighbor AP list may be denied.

First claim

The invention claimed is:

1. Logic encoded in a non-transitory, tangible, computer readable medium for execution by a processor, and when executed, configured to:
obtain a neighbor access point list;
maintain statistics for a current access point a client is currently associated with, the statistics comprising previous access points previous clients have roamed from prior to associating with the current access point, and next access points the previous clients associated with;
optimize the neighbor access point list for the client, comprising:
determining one or more previous clients that associated with a same previous access point as the client; and
prioritizing access points in the optimized neighbor access point list, based on the next access points the one or more previous clients associated with;

send the optimized neighbor access point list to the client; and
control roaming of the client based on the optimized neighbor access point list by denying a request from the client to associate with an access point that is not on the optimized neighbor access point list during a first period of time, wherein the client is allowed to associate with the access point that is not on the optimized neighbor access point list during a second period of time responsive to at least one of (i) a predetermined number of denials to associate with the access point not on the optimized neighbor access point list and (ii) a predetermined time period having elapsed during which the client does not associate with the access point that is on the optimized neighbor access point list.

2. The logic set forth in claim 1 , wherein load balancing is a criteria employed to optimize the neighbor access point list.

3. The logic set forth in claim 1 , wherein radio frequency metrics of neighboring access points are obtained; and
wherein the radio frequency metrics are employed to optimize the neighbor access point list.

4. The logic set forth in claim 1 , wherein the neighboring access point list is optimized by prioritizing neighboring access points that are on the same band that the client is currently using for communications.

5. The logic set forth in claim 1 , further configured to:
upon determining that the client is a multi-band client, prioritizing neighbor access points in a predetermined, preferred band in the optimized neighbor access point list.

6. The logic set forth in claim 5 , wherein determining that the client is the multi-band client further comprises reviewing probe requests and association history for the client.

7. The logic set forth in claim 1 , wherein optimizing the neighbor access point list is further based on locations where previous clients of the current access point roamed.

8. The logic set forth in claim 1 , wherein access points on a same floor as the current access point associated with the client are prioritized in the optimized neighbor access point list.

9. The logic set forth in claim 1 , further configured to maintain a traffic history for the client to determine a traffic requirement for the client; and
wherein access points capable of handling the traffic requirement for the client are prioritized in the optimized neighbor access point list.

10. The logic set forth in claim 1 , further configured to determine a bandwidth requirement for an application the client is executing; and
wherein access points capable of meeting the bandwidth requirement for the application the client is executing are prioritized in the optimized neighbor access point list.

11. An apparatus, comprising:
an interface for sending and receiving data;
neighbor list logic coupled with the interface and configured to communicate via the interface by performing an operation, comprising;
obtaining a neighbor access point list;
maintaining statistics for a current access point a client is currently associated with, the statistics comprising previous access points previous clients have roamed from prior to associating with the current access point, and next access points the previous clients associated with;
optimizing the neighbor access point list for the client, comprising:
determining one or more previous clients that associated with a same previous access point as the client; and
prioritizing access points in the optimized neighbor access point list, based on the next access points the one or more previous clients associated with;

sending the optimized neighbor access point list to the client via the interface; and
controlling roaming of the client based on the optimized neighbor access point list by denying a request from the client to associate with an access point that is not on the optimized neighbor access point list during a first period of time, wherein the client is allowed to associate with the access point that is not on the optimized neighbor access point list during a second period of time responsive to at least one of (i) a predetermined number of denials to associate with the access point not on the optimized neighbor access point list and (ii) a predetermined time period having elapsed during which the client does not associate with the access point that is not on the optimized neighbor access point list.

12. The apparatus set forth in claim 11 , wherein load balancing is a criteria employed to optimize the neighbor access point list.

13. The apparatus set forth in claim 11 , wherein radio frequency metrics of neighboring access points are obtained; and
wherein the radio frequency metrics are employed to optimize the neighbor access point list.

14. A method, comprising:
obtaining a neighbor access point list; and
optimizing the neighbor access point list for a client associated with a current access point, comprising:
maintaining statistics for a current access point the client is currently associated with, the statistics comprising previous access points previous clients have roamed from prior to associating with the current access point, and next access points the previous clients associated with;
maintaining counters associated with access points where previous clients that associated with the current access point associated with the client have roamed;
reducing the counters in a manner that preserves the proportion of the counters when a predefined threshold is exceeded; and
upon determining a direction of travel of the client based on the maintained counters and statistics, prioritizing neighboring access points within the neighbor access point list based on the determined direction of travel;

wherein neighboring access points are prioritized in the optimized neighbor access point list based on the next access points previous clients associated with that also associated with the same previous access point as the client.

15. The method according to claim 14 , wherein optimizing the neighbor access point list further comprises:
upon determining that the client is a multi-band client, prioritizing neighbor access points in a predetermined, preferred band in the optimized neighbor access point list.

16. The method according to claim 15 , wherein determining that the client is the multi-band client further comprises reviewing probe requests and association history for the client.

17. The method according to claim 14 , wherein optimizing the neighbor access point list further comprises prioritizing access points on a same floor as the current access point associated with the client in the optimized neighbor access point list.

18. Logic encoded in a non-transitory, tangible, computer readable medium for execution by a proce

Assignees

• Cisco Tech Inc

Inventors

• Pang Tak Ming Francis
• Stephenson David S
• Pandey Santosh
• Desai Vishal Satyendra

Classifications

• H04W72/56

  based on priority criteria · CPC title

• H04W36/0083 Primary

  Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists · CPC title

• H04W36/00835 Primary

  Determination of neighbour cell lists · CPC title

• H04W24/02 Primary

  Arrangements for optimising operational condition · CPC title