WLAN having load balancing based on access point loading

• US 7,400,901 B2
• Filed: 11/12/2002
• Issued: 07/15/2008
• Est. Priority Date: 11/19/2001
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Yin, Hujun, Kostic, Zoran, Leung, Kin K
• Primary Examiner(s): Anderson; Matthew
• Assistant Examiner(s): Aminzay; Shaima Q
• Application Number:
  US10/292,862
• Publication Number:
  US 20030139197A1
• Time in Patent Office: 2,072 Days
• Field of Search: 455/525, 455/524, 455/500, 455/522, 455/450, 455/453, 455/437, 455/434, 455/141, 455/69, 370/338, 370/395.21, 370/236, 370/400
• US Class Current: 455/525
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/122 by diverting traffic away from congested entities
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/0205 at the air interface dynamic wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/0289 Congestion control load shedding arrangements in network planning H04W16/08; performing reselection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A network having distribution of access point loading includes access points to which mobile stations can associate themselves based upon access point beacon signal levels and loading levels for the various access points. A mobile station receives beacon signals from various access points and determines a signal strength for the received beacon signals. The mobile station also receives access point loading information from the access points. The mobile station associates with an access point based upon the access point beacon signal strengths and the access point loading information.

Claims

1. A method of distributing access point loading in a wireless network, comprising:

receiving beacon signals from a plurality of access points;

determining a signal strength for the received beacon signals;

receiving access point loading information from the plurality of access points, the access point loading information comprising a transmission queue length and a number of transmitted error packets; and

associating with a first one of the plurality of access points based upon the beacon signal strengths, the access point loading information, mobile station priority weighting, access point priorities, and overall network loading.

2. The method according to claim 1, further including associating with the first one of the plurality of access points when a beacon signal strength of the first one of the plurality of access points is less than a second one of the plurality of access points.

3. The method according to claim 2, wherein a loading level of the second one of the plurality of access points is greater than a loading level of the first one of the plurality of access points.

4. The method according to claim 1, further including receiving the access point loading information in a beacon frame.

5. The method according to claim 1, further including associating with the first one of the plurality of access points where at least two of the beacon signal strengths are above a predetermined level.

6. The method according to claim 5, further including associating with the first one of the plurality of access points which has a fewest number of associated mobile stations.

7. The method according to claim 1, further including associating with the first one of the plurality of access points based upon a cost function.

8. The method according to claim 7, wherein the cost function includes a parameter corresponding to the access point loading information.

9. The method according to claim 7, further including associating with the first one of the plurality of access points with the cost function using one or more parameters including one or more of access point traffic intensity and access point signal strength levels.

10. The method according to claim 1, wherein the wireless network is a 802.11 network.

11. The method according to claim 1, further including receiving the access point loading information in capability information field.

12. An access point, comprising:

a processor;

a module coupled to the processor for obtaining parameters, said parameters comprising load level information of the access point, access point priority, and overall network loading, the load level information comprising a transmission queue length and a number of transmitted error packets;

a memory coupled to the processor for storing the parameters; and

a means for transmitting the access point parameters to mobile stations.

13. The access point according to claim 12, wherein the memory stores link quality information.

14. The access point according to claim 12, wherein the access point forms a part of an 802.11 network.

15. A mobile station, comprising

a processor;

a memory coupled to the processor for storing access point loading information, access point beacon signal strength information, mobile station priority weighting, access point priorities, and overall network loading, the loading information comprising a transmission queue length and a number of transmitted error packets; and

a means for selecting to associate with a first one of a plurality of access points based upon the beacon signal strength information, the access point loading information, the mobile station priority weighting, access point priorities, and overall network loading.

16. The mobile station according to claim 15, further including means for selecting to associate with the first one of the plurality of access points when a beacon signal strength of the first one of the plurality of access points is less than a second one of the plurality of access points.

17. The mobile station according to claim 16, wherein a loading level of the second one of the plurality of access points is greater than a loading level of the first one of the plurality of access points.