Frequency hopping in 5GHz WLAN via dynamic frequency selection

• US 8,937,928 B2
• Filed: 08/23/2002
• Issued: 01/20/2015
• Est. Priority Date: 08/23/2002
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Ngo, Chiu Y.
• Primary Examiner(s): MURPHY, RHONDA L
• Application Number:
  US10/227,201
• Publication Number:
  US 20040037247A1
• Time in Patent Office: 4,533 Days
• Field of Search: None
• US Class Current: 370/332
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Disclosed is a method and system for dynamically selecting a communication channel between an access point (AP) and a plurality of mobile terminals (MTs) in a wireless local area network (WLAN), the method having the steps of (a) measuring a channel quality of a plurality of frequency channels, (b) reporting to the AP from the plurality of MTs of the candidate channels including a received signal strength indication (RSSI) of all channels measured and, (c) selecting one of the channels based on the channel quality report for use in communication between the AP and the plurality of MTs.

Claims

1. A method for dynamically selecting a communication channel between an access point (AP) and at least one mobile terminal (MT) located within the coverage area of a cell in a wireless local area network (WLAN), the method comprising:

measuring a channel quality of a plurality of frequency channels, including a received signal strength indicator (RSSI) for each channel measured;

updating a list of best available frequency channels based on the RSSI of each channel;

upon expiration of a timer, selecting one of the channels from the list of best available frequency channels, other than a currently used channel, for use in communication between the AP and the at least one mobile terminal; and

switching to the selected channel.

2. The method of claim 1, where the list of best available frequency channels is sorted based on the RSSI of each channel, and the selection of one of the channels is sequential through the list.

3. The method of claim 1, where the selection of one of the channels in the list of best available frequency channels is based on the RSSI of each channel.

4. The method of claim 1, where updating a list of best available frequency channels based on the RSSI of each channel comprising:

determining the RSSI of a channel; and

,

comparing the RSSI of the channel with a threshold value.

5. The method of claim 4, where the threshold value is between a range of −

45 dBm to 0 dBm.

6. The method of claim 1, further comprising the step of updating a list of best available frequency channels based on the RSSI of each channel if a timer has not expired.

7. The method of claim 1, where determining if a timer has expired comprises the step of determining if a counter has reached a timer threshold.

8. The method of claim 7, further comprising:

announcing a channel switch event to the other channel from the list of best available frequency channels.

9. An apparatus for dynamically selecting a communication channel between an access point (AP) and at least one mobile terminal (MT) located within the coverage area of a cell in a wireless local area network (WLAN), comprising:

means for measuring a channel quality of a plurality of frequency channels, including a received signal strength indicator (RSSI) for each channel measured;

means for updating a list of best available frequency channels based on the RSSI of each channel;

means for determining if a timer has expired; and

means for, upon detecting expiration of the timer, selecting one of the channels from the list of best available frequency channels, other than a currently used channel, for use in communication between the AP and the at least one mobile terminal and for switching to the selected channel.

10. The apparatus of claim 9, where the list of best available frequency channels is sorted based on the RSSI of each channel, and the selection of one of the channels is sequential through the list.

11. The apparatus of claim 9, where the selection of one of the channels in the list of best available frequency channels is based on the RSSI of each channel.

12. The apparatus of claim 9, where means for updating the list of best available frequency channels based on the RSSI of each channel comprises:

means for determining the RSSI of a channel; and

,

means for comparing the RSSI of the channel with a threshold value.

13. The apparatus of claim 12, where the threshold value is between a range of −

45 dBm to 0 dBm.

14. The apparatus of claim 9, further comprising means for updating a list of best available frequency channels based on the RSSI of each channel at a known rate.

15. The apparatus of claim 9, where means for determination of expiration of said time comprises means for determining if a counter has reached a timer threshold.

16. The apparatus of claim 9, further comprising:

means for announcing a channel switch event to the other channel from the list of best available frequency channels.