Punctured operating channels in WLAN

1. A method for establishing an operating channel for a wireless local area network (WLAN), the method comprising:

determining, at a first communication device, an overall bandwidth of the operating channel, wherein the overall bandwidth spans a plurality of sub-channels;

determining, at the first communication device, that one or more sub-channels within the overall bandwidth will not be used for the operating channel;

generating, at the first communication device, a first packet that includes i) a first subfield that indicates the overall bandwidth of the operating channel, and ii) a second subfield that indicates the one or more sub-channels within the overall bandwidth that will not be used for the operating channel;

transmitting, by the first communication device, the first packet to inform one or more other communication devices in the WLAN of the operating channel for the WLAN, the operating channel having the overall bandwidth, wherein the indicated one or more sub-channels within the overall bandwidth are not to be used;

generating, at the first communication device, a request-to-send (RTS) frame;

after transmitting the first packet, transmitting, by the first communication device, the RTS frame to a second communication device via the operating channel, including not transmitting in the one or more sub-channels that are not used for the operating channel, wherein the second communication device is from among the one or more other communication devices;

receiving, at the first communication device, a clear-to-send (CTS) frame from the second communication device via only a subset of sub-channels via which the RTS frame was transmitted, the CTS frame responsive to the RTS frame; and

after receiving the CTS frame, transmitting, by the first communication device, a second packet to the second communication device via the only the subset of sub-channels via which the CTS frame was received.

2. The method of claim 1 , wherein transmitting the first packet informs the one or more other communication devices that the operating channel is to be used until the communication device specifies a change to the operating channel.

3. The method of claim 1 , wherein generating the first packet comprises:

generating, at the communication device, a medium access control (MAC) management frame that includes i) the first subfield that indicates the overall bandwidth of the operating channel, and ii) the second subfield that indicates the one or more sub-channels within the overall bandwidth that will not be used for the operating channel; and

generating, at the communication device, the first packet to include the MAC management frame.

4. The method of claim 3 , wherein the MAC management frame comprises one of: i) a beacon frame, ii) a probe response frame, iii) an association response frame, or iv) a reassociation response frame.

5. The method of claim 1 , wherein:

the one or more other communication devices are configured to operate according to a first communication protocol;

the operating channel is a first operating channel to be used by the one or more other communication devices;

the method further comprises: determining, at the first communication device, a bandwidth of a second operating channel that is permitted by a second legacy communication protocol and that is to be used by one or more third communication devices in the WLAN that operate according to the second legacy communication protocol, wherein the bandwidth of the second operating channel is i) contiguous in frequency, ii) within the overall bandwidth of the first operating channel, and iii) does not span any of the one or more sub-channels that will not be used for the first operating channel;

generating the first packet includes generating the first packet to include i) a third subfield that indicates the bandwidth of the second operating channel; and

transmitting the first packet also informs the one or more third communication devices in the WLAN of the second operating channel for the WLAN.

6. The method of claim 1 , wherein:

the one or more other communication devices are configured to operate according to a first communication protocol;

the operating channel is a first operating channel to be used by the one or more other communication devices; and

the method further comprises:

determining, at the first communication device, a bandwidth of a second operating channel that is permitted by a second legacy communication protocol and that is to be used by one or more third communication devices in the WLAN that operate according to the second legacy communication protocol, wherein the bandwidth of the second operating channel is i) contiguous in frequency, ii) within the overall bandwidth of the first operating channel, and iii) does not span any of the one or more sub-channels that will not be used for the first operating channel,

generating, at the first communication device, a third packet that includes a third subfield that indicates the bandwidth of the second operating channel, and

transmitting, by the first communication device, the third packet to inform the one or more third communication devices in the WLAN of the second operating channel for the WLAN.

7. The method of claim 1 , further comprising:

generating, at the communication device, a third packet; and

respectively transmitting, by the communication device, the third packet and duplicates of the third packet in the sub-channels of the operating channel, including not transmitting in the one or more sub-channels that are not used for the operating channel.

8. The method of claim 7 , wherein the first packet conforms to a first communication protocol and the third packet conforms to a second legacy communication protocol different from the first communication protocol.

9. The method of claim 1 , further comprising:

selecting, at the communication device, a modulation and coding scheme (MCS) to be used for a third packet to be transmitted via the operating channel, including selecting the MCS based on the overall bandwidth of the operating channel;

generating, at the communication device, the third packet according to the selected MCS; and

transmitting, by the communication device, the third packet via the operating channel.

10. The method of claim 1 , further comprising:

selecting, at the communication device, a modulation and coding scheme (MCS) to be used for a third packet to be transmitted via the operating channel, including selecting the MCS based on a number of sub-channels used in the operating channel;

generating, at the communication device, the third packet according to the selected MCS; and

transmitting, by the communication device, the third packet via the operating channel.

11. The method of claim 1 , wherein generating the first packet comprises:

generating the first packet to include an information element that includes i) the first subfield that indicates the overall bandwidth of the operating channel, and ii) the second subfield that indicates the one or more sub-channels within the overall bandwidth that will not be used for the operating channel, wherein the information element is generated to include i) an element identifier (ID) field and ii) an element ID extension field that together indicate a format of the information element.

12. The method of claim 11 , wherein generating the information element comprises:

setting, at the communication device, a third subfield of the information element to indicate that the information element includes the second subfield.

13. The method of claim 11 , wherein:

the second subfield includes a bitmap;

respective bits in the bitmap correspond to respective sub-channels within the overall bandwidth; and

values of bits in the bitmap indicate whether respective sub-channels within the overall bandwidth will be used for the operating channel.

14. The method of claim 1 , wherein the first communication device is an access point.

15. The method of claim 1 , wherein:

determining the overall bandwidth comprises determining i) a first frequency segment of the overall bandwidth and ii) a second frequency segment of the overall bandwidth, wherein the first frequency segment and the second frequency segment are separated by a gap in frequency;

generating the first packet comprises generating the first subfield to indicate that the overall bandwidth comprises two frequency segments separated by a gap in frequency; and

generating the first packet comprises generating the first packet to include i) a third subfield to indicate a first location in frequency of the first frequency segment and ii) a fourth subfield to indicate a second location in frequency of the second frequency segment.

16. A first communication device, comprising:

a network interface device having one or more integrated circuit (IC) devices, wherein the one or more IC devices are configured to:

determine an overall bandwidth of an operating channel of a wireless local area network (WLAN), wherein the overall bandwidth spans a plurality of sub-channels,

determine that one or more sub-channels within the overall bandwidth will not be used for the operating channel,

generate a first packet that includes i) a first subfield that indicates the overall bandwidth of the operating channel, and ii) a second subfield that indicates the one or more sub-channels within the overall bandwidth that will not be used for the operating channel,

transmit the first packet to inform one or more other communication devices in the WLAN of the operating channel for the WLAN, the operating channel having the overall bandwidth, wherein the indicated one or more sub-channels within the overall bandwidth are not to be used,

generate a request-to-send (RTS) frame,

after transmitting the first packet, transmit the RTS frame to a second communication device via the operating channel, including not transmitting in the one or more sub-channels that are not used for the operating channel, wherein the second communication device is from among the one or more other communication devices,

receive a clear-to-send (CTS) frame from the second communication device via only a subset of sub-channels via which the RTS frame was transmitted, the CTS frame responsive to the RTS frame, and

after receiving the CTS frame, transmit a second packet to the second communication device via the only the subset of sub-channels via which the CTS frame was received.

17. The communication device of claim 16 , wherein the one or more IC devices are configured to transmit the first packet to inform the one or more other communication devices that the operating channel is to be used until the communication device specifies a change to the operating channel.

18. The communication device of claim 16 , wherein the one or more IC devices are configured to:

generate a medium access control (MAC) management frame that includes i) the first subfield that indicates the overall bandwidth of the operating channel, and ii) the second subfield that indicates the one or more sub-channels within the overall bandwidth that will not be used for the operating channel; and

generate the first packet to include the MAC management frame.

19. The communication device of claim 18 , wherein the MAC management frame comprises one of: i) a beacon frame, ii) a probe response frame, iii) an association response frame, or iv) a reassociation response frame.

20. The communication device of claim 16 , wherein:

the one or more other communication devices are configured to operate according to a first communication protocol;

the operating channel is a first operating channel to be used by the one or more other communication devices; and

the one or more IC devices are further configured to:

determine a bandwidth of a second operating channel that is permitted by a second legacy communication protocol and that is to be used by one or more third communication devices in the WLAN that operate according to the second legacy communication protocol, wherein the bandwidth of the second operating channel is i) contiguous in frequency, ii) within the overall bandwidth of the first operating channel, and iii) does not span any of the one or more sub-channels that will not be used for the first operating channel,

generate the first packet to include i) a third subfield that indicates the bandwidth of the second operating channel, and

transmit the first packet to also inform the one or more third communication devices in the WLAN of the second operating channel for the WLAN.

21. The communication device of claim 16 , wherein:

the one or more other communication devices are configured to operate according to a first communication protocol;

the operating channel is a first operating channel to be used by the one or more other communication devices; and

the one or more IC devices are configured to:

determine a bandwidth of a second operating channel that is permitted by a second legacy communication protocol and that is to be used by one or more third communication devices in the WLAN that operate according to the second legacy communication protocol, wherein the bandwidth of the second operating channel is i) contiguous in frequency, ii) within the overall bandwidth of the first operating channel, and iii) does not span any of the one or more sub-channels that will not be used for the first operating channel,

generate a third packet that includes a third subfield that indicates the bandwidth of the second operating channel, and

transmit the third packet to inform the one or more third communication devices in the WLAN of the second operating channel for the WLAN.

22. The communication device of claim 16 , wherein the one or more IC devices are further configured to:

generate a third packet; and

respectively transmit the third packet and duplicates of the third packet in the sub-channels of the operating channel, including not transmitting in the one or more sub-channels that are not used for the operating channel.

23. The communication device of claim 22 , wherein the first packet conforms to a first communication protocol and the third packet conforms to a second legacy communication protocol different from the first communication protocol.

24. The communication device of claim 16 , wherein the one or more IC devices are further configured to:

select a modulation and coding scheme (MCS) to be used for a third packet to be transmitted via the operating channel, including selecting the MCS based on the overall bandwidth of the operating channel;

generate the third packet according to the selected MCS; and

transmit the third packet via the operating channel.

25. The communication device of claim 16 , wherein the one or more IC devices are further configured to:

select a modulation and coding scheme (MCS) to be used for a third packet to be transmitted via the operating channel, including selecting the MCS based on a number of sub-channels used in the operating channel;

generate the third packet according to the selected MCS; and

transmit the third packet via the operating channel.

26. The communication device of claim 16 , wherein the one or more IC devices are further configured to:

generate the first packet to include an information element that includes i) the first subfield that indicates the overall bandwidth of the operating channel, and ii) the second subfield that indicates the one or more sub-channels within the overall bandwidth that will not be used for the operating channel, wherein the information element is generated to include i) an element identifier (ID) field and ii) an element ID extension field that together indicate a format of the information element.

27. The communication device of claim 26 , wherein the one or more IC devices are further configured to:

set a third subfield of the information element to indicate that the information element includes the second subfield.

28. The communication device of claim 26 , wherein:

the second subfield includes a bitmap;

respective bits in the bitmap correspond to respective sub-channels within the overall bandwidth; and

values of bits in the bitmap indicate whether respective sub-channels within the overall bandwidth will be used for the operating channel.

29. The communication device of claim 16 , wherein the first communication device is an access point.

30. The communication device of claim 16 , wherein the one or more IC devices are further configured to:

determine i) a first frequency segment of the overall bandwidth and ii) a second frequency segment of the overall bandwidth, wherein the first frequency segment and the second frequency segment are separated by a gap in frequency; and

generate the first subfield to indicate that the overall bandwidth comprises two frequency segments separated by a gap in frequency; and

generate the first packet to include i) a third subfield to indicate a first location in frequency of the first frequency segment and ii) a fourth subfield to indicate a second location in frequency of the second frequency segment.

31. The communication device of claim 16 , wherein the network interface device comprises:

one or more transceivers implemented on the one or more IC devices, the one or more transceivers configured to transmit the packet.

32. The communication device of claim 31 , further comprising:

one or more antennas coupled to the one or more transceivers.