Frequency hopping in 5GHz WLAN via dynamic frequency selection

• US 20040037247A1
• Filed: 08/23/2002
• Published: 02/26/2004
• Est. Priority Date: 08/23/2002
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Ngo, Chiu Y.
• Granted Patent: US 8,937,928 B2
• Time in Patent Office: Days
• 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 said AP from said plurality of MTs of said candidate channels including a received signal strength indication (RSSI) of all channels measured; and, (c) selecting one of said channels based on said channel quality report for use in communication between said AP and said 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 the steps of:

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; and

,

selecting one of the channels from the list of best available frequency channels for use in communication between the AP and the plurality of MTs.

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 comprises the steps of:

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 further comprising the steps of:

determining it a timer has expired; and

,

selecting another one of the channels from the list of best available frequency channels for use in communication between the AP and the plurality of MTs.

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

9. The method of claim 7, where the timer is based on a time period necessary to transmit a number of MAC frames.

10. The method of claim 7, further comprising the steps of:

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

,

switching to the other channel.

11. 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; and

,

means for selecting one of the channels from the list of best available frequency channels for use in communication between the AP and the plurality of MTs.

12. The apparatus of claim 11, 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.

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

14. The apparatus of claim 11, 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.

15. The apparatus of claim 14, where the threshold value is between a range of −

45 dBm to 0 dBm.

16. The apparatus of claim 11, further comprising means for updating a list of best available frequency channels based on the RSSI of each channel if a timer has not expired.

17. The apparatus of claim 11, further comprising:

means for determining if a timer has expired; and

,

means for selecting another one of the channels from the list of best available frequency channels for use in communication between the AP and the plurality of MTs.

18. The apparatus of claim 17, where means for determining if a timer has expired comprises means for determining if a counter has reached a timer threshold.

19. The apparatus of claim 17, where the timer is based on a time period necessary to transmit a number of MAC frames.

20. The apparatus of claim 17, further comprising:

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

.

means for switching to the other channel.

21. 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), the apparatus comprising:

a memory for storing a computer-readable code; and

,

a processor operatively coupled to the memory, the computer-readable code configured to allow the processor to;

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

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

,

select one of the channels from the list of best available frequency channels for use in communication between the AP and the plurality of MTs.

22. The apparatus of claim 21, 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.

23. The apparatus of claim 21, where the selection of one of the channels in the list of best available frequency channels is based on the RSSI of each channel.

24. The apparatus of claim 21, where the computer-readable code configured to allow the processor to update the list of best available frequency channels based on the RSSI of each channel is further configured to allow the processor to:

determine the RSSI of a channel; and

,

compare the RSSI of the channel with a threshold value.

25. The apparatus of claim 24, where the threshold value is between a range of −

45 dBm to 0 dBm.

26. The apparatus of claim 21, where the computer-readable code is further configured to allow the processor to update a list of best available frequency channels based on the RSSI of each channel if a timer has not expired.

27. The apparatus of claim 21, where the computer-readable code is further configured to allow the processor to:

determine if a timer has expired; and

,

select another one of the channels from the list of best available frequency channels for use in communication between the AP and the plurality of MTs.

28. The apparatus of claim 27, where the computer-readable code configured to allow the processor to determine if a timer has expired is further configured to allow the processor to determine if a counter has reached a timer threshold.

29. The apparatus of claim 27, where the timer is based on a time period necessary to transmit a number of MAC frames.

30. The apparatus of claim 27, where the computer-readable code is further configured to allow the processor to:

announce a channel switch event to the other channel from the list of best available frequency channels; and

,

switch to the other channel.