Wireless communication method and apparatus for optimizing access point channel selection

• US 20050119006A1
• Filed: 11/05/2004
• Published: 06/02/2005
• Est. Priority Date: 12/01/2003
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Marinier, Paul, Roy, Vincent, Cave, Christopher, Cuffaro, Angelo
• Granted Patent: US 7,454,214 B2
• Time in Patent Office: Days
• US Class Current: 455/453
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A wireless communication method and system for optimizing channel selection for an AP. The channel selection optimization process includes four sub-processes: 1) a measurement process; 2) a candidate channel determining process; 3) a channel selection process; and 4) a channel update process. Candidate channels used for supporting communication performed by the AP are determined. The candidate channels are chosen from an allowable channel set (ACS) if a detected interference of each candidate channel is less than an established maximum allowed interference.

Claims

1. A method of selecting at least an optimal channel for use by an access point (AP) in a wireless communication system, the AP having at least an operating channel, the method comprising:

(a) computing average loads of each of a plurality of neighboring base service sets (BSSs); and

(b) determining candidate channels among channel in an allowable channel set (ACS) for use by the AP; and

(c) selecting from the candidate channels a channel used for a new operation channel.

2. The method of claim 1 further comprising:

(d) recording information of the BSS of which average load is greater than a threshold.

3. The method of claim 1 wherein step (c) further comprises:

(c1) computing predicted channel utilization for all candidate channels;

(c2) selecting a channel with the lowest channel utilization;

(c3) determining if the selected channel is different from a current operating channel; and

(c4) determining whether the channel utilization of the current operating channel is greater than the channel utilization of the selected channel by at least a predefined threshold, if the selected channel is different from the current operating channel.

4. The method of claim 3 wherein step (c) further comprises:

(c5) ending the optimization channel selection process if the selected channel is the same as the current operating channel in step (c3).

5. The method of claim 4 wherein step (c) further comprises:

(c6) ending the optimization channel selection process if the channel utilization of the current operating channel is not greater than the channel utilization of the selected channel by at least a predefined threshold in step (c4).

6. The method of claim 5 further comprising:

(d) determining whether there is any wireless transmit/receive unit (WTRU) associated with the AP through the current operating channel, if the channel utilization of the current operating channel is greater than the channel utilization of the selected channel by at least a predefined threshold in step (c4); and

(e) disassociating all of the associated WTRUs determined in step (d).

7. The method of claim 6 wherein step (c) is performed if there is no associated WTRU determined in step (d) or after performing step (e).

8. An access point (AP) for automatically selecting a channel for the AP in a wireless communication system, the AP comprising:

(a) means for periodically scanning through a plurality of different channels;

(b) means for invoking a channel optimization process if the AP is operating during a period of low load, wherein a predicted channel load is calculated based on high load measurements and the AP selects and changes its operating channel to the channel with the lowest predicted channel load.

9. An access point (AP) for selecting at least an optimal channel for use by the AP in a wireless communication system, the AP having at least an operating channel, the AP comprising:

(a) means for determining candidate channels among channel in an allowable channel set (ACS) for use by the AP; and

(b) means for selecting from the candidate channels a channel used for a new AP operation channel.

10. The AP of claim 9 further comprising:

(c) means for computing average loads of each of a plurality of neighboring base service sets (BSSs); and

(d) means for recording information of the BSS of which average load is great er than a threshold.

11. An integrated circuit (IC) for communicating with a plurality of access points (APs) in a wireless communication system, the IC comprising:

(a) a measuring unit for measuring operating parameters of each channel in an allowable channel set (ACS) upon activating the IC;

(b) a power controller for controlling transmission power of the IC based on the operating parameters;

(c) a channel selector for selecting a channel used by the IC for communication based on the measured operating parameters; and

(d) a timer for setting a time period during which a beacon frame is transmitted from the IC to announce the operating parameters to the APs.

12. The IC of claim 11 wherein the beacon frame is transmitted to the APs at its maximum power during the time period.

13. The IC of claim 11 further comprising:

(e) a memory for storing the measured operating parameters.

14. The IC of claim 11 wherein the measuring unit measures an average load of each neighboring base service set (BSS) detected on a channel, and the channel selector selects candidate channels based on interference level detected on the candidate channels and selects a new channel among the candidate channels based on the average load.

15. The IC of claim 14 wherein the candidate channels are chosen from an allowable channel set (ACS) if an interference level of the candidate channels is less than a maximum allowed interference on the channel.