Methods and apparatus to perform dynamic channel management and dynamic bandwidth changes in wireless local area networks

• US 7,796,566 B2
• Filed: 06/14/2006
• Issued: 09/14/2010
• Est. Priority Date: 06/22/2005
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Airy, Manish, Chhaya, Harshal Shantanu, Xhafa, Ariton E.
• Primary Examiner(s): Eng; George
• Assistant Examiner(s): FARAGALLA, MICHAEL A
• Application Number:
  US11/452,842
• Publication Number:
  US 20060291432A1
• Time in Patent Office: 1,553 Days
• Field of Search: 370/336, 370/465, 370/229, 370/329, 370/338, 370/389, 455/574, 455/418
• US Class Current: 370/336
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Methods and apparatus to perform dynamic channel management and dynamic bandwidth changes in wireless local area networks are disclosed. A disclosed example method comprises deciding at an access point to initiate at least one of a bandwidth change or a channel assignment change; and sending a frame to initiate the at least one of the bandwidth change or the channel assignment change from the access point to one or more stations of a wireless network, the frame including a first field to identify a first channel and a second field to identify a second channel.

Claims

1. A method for dynamic channel switching comprising:

during a first contention-free interval of a wireless network, deciding at an access point to configure a dynamic bandwidth change for the wireless network from a first data transmission bandwidth to a second data transmission bandwidth for a subsequent contention-free interval of the wireless network, wherein stations of the wireless network are to transmit during the subsequent contention-free interval using the second data transmission bandwidth, and the second data transmission bandwidth differs from the first data transmission bandwidth;

transmitting from the access point to the stations of the wireless network during the first contention-free interval a first frame at the first data transmission bandwidth to initiate the dynamic bandwidth configuration change, the first frame including a first field to identify a first channel and a second field to identify a second channel;

transmitting from the access point to the stations of the wireless network a second frame at the second data transmission bandwidth to end the first contention-free interval and to activate the initiated dynamic bandwidth configuration change of the wireless network to the second data transmission bandwidth; and

sending a clear-to-send frame on the first channel when the first channel was not previously being used by the wireless network after waiting a time duration that is at least a short interframe spacing plus a switching time.

2. A method as defined in claim 1, wherein the first frame is comprises a dynamic channel switch frame including a receiver address field containing a broadcast address of the access point.

3. A method as defined in claim 1, wherein the bandwidth change is at least one of a change from 20 MHz operation to 40 MHz operation or from 40 MHz operation to 20 MHz operation.

4. A method as defined in claim 1, further comprising, at least one of omitting or leaving blank the second field.

5. A method for dynamic channel switching comprising:

during a first contention-free interval of a wireless network, deciding at an access point to configure a dynamic bandwidth change for the wireless network from a first data transmission bandwidth to a second data transmission bandwidth for a subsequent contention-free interval of the wireless network, wherein stations of the wireless network are to transmit during the subsequent contention-free interval using the second data transmission bandwidth, and the second data transmission bandwidth differs from the first data transmission bandwidth;

transmitting from the access point to the stations of the wireless network during the first contention-free interval a first frame at the first data transmission bandwidth to initiate the dynamic bandwidth configuration change, the first frame including a first field to identify a first channel and a second field to identify a second channel; and

transmitting from the access point to the stations of the wireless network a second frame at the second data transmission bandwidth to end the first contention-free interval and to activate the initiated dynamic bandwidth configuration change of the wireless network to the second data transmission bandwidth, wherein the second frame comprises a contention-free end frame transmitted on at least one of the first channel, the second channel, or a third channel being replaced by at least one of the first or the second channel.

6. A method as defined in claim 5, further comprising waiting a time duration of at least a short interframe spacing before sending the contention-free end frame.

7. A method for dynamic bandwidth change comprising:

during a first contention-free interval of a wireless network, deciding at an access point to configure a dynamic bandwidth change for the wireless network from a first data transmission bandwidth to a second data transmission bandwidth for a subsequent contention-free interval of the wireless network, wherein stations of the wireless network are to transmit during the subsequent contention-free interval using the second data transmission bandwidth, and the second data transmission bandwidth differs from the first data transmission bandwidth;

transmitting from the access point to the stations of the wireless network during the first contention-free interval a first frame at the first data transmission bandwidth to initiate the dynamic bandwidth configuration change, the first frame including a first field to identify a first channel and a second field to identify a second channel;

transmitting from the access point to the stations of the wireless network a second frame at the second data transmission bandwidth to end the first contention-free interval and to activate the initiated dynamic bandwidth configuration change of the wireless network to the second data transmission bandwidth;

receiving the frame at a first station of the wireless network; and

configuring at least one of a receiver or a transmitter of the first station based upon the first field and the second field.

8. A method as defined in claim 7, further comprising:

waiting to receive free end the second frame at the first station; and

resuming normal operation of the first station at the second data transmission bandwidth after the second frame is received.