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; and characterized by: after transmitting the first packet, generating, at the first communication device, a request-to-send, RTS, frame; 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 in response 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. 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; and characterized by: after transmitting the first packet, generating, at the first communication device, a request-to-send, RTS, frame; 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 in response 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. after transmitting the first packet, generating, at the first communication device, a request-to-send, RTS, frame; 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 in response 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.