Medium access control for multi-channel OFDM in a wireless local area network

A first communication device, comprising:

• a network interface configured to:
• allocate respective sub-channels of an orthogonal frequency division multiplexing (OFDM) channel to two or more second communication devices for uplink orthogonal frequency division multiple access (OFDMA) transmission from the two or more second communication devices, including:
• (i) allocating non-contiguous sub-channels by skipping a particular sub-channel of the OFDM channel, when the particular sub-channel is determined to be unavailable for transmission, and (ii) allocating a first sub-channel to a first one of the two or more second communication devices and a second sub-channel to a second one of the two or more communication devices;
• provide, to the two or more second communication devices, i) indications of the respective sub-channels allocated for uplink transmission from the two or more second communication devices, including indications of the non-contiguous sub-channel allocation, and ii) an indication of a length of the uplink OFDMA transmission from the two or more second communication devices;
• and
• receive an uplink OFDMA data unit that includes at least a first OFDM data unit from the first one of the two or more second communication devices and a second OFDM data unit from the second one of the two or more second communication devices, wherein the first OFDM data unit i) has a duration in accordance with the indication of the length provided by the first communication device and ii) is transmitted from the first one of the two or more second communication devices via the first sub-channel allocated to the first one of the two or more second communication devices and the second OFDM data unit i) has the duration in accordance with the indication of the length provided by the first communication device and ii) is transmitted from the second one of the two or more second communication devices via the second sub-channel allocated to the second one of the two or more second communication devices.

A method for simultaneously communication with multiple communication devices in a wireless local area network, the method comprising:

• allocating, by a first communication device, respective sub-channels of an orthogonal frequency division multiplexing (OFDM) channel to two or more second communication devices for downlink orthogonal frequency division multiple access (OFDMA) transmission to the two or more second communication devices, including:
• (i) allocating non-contiguous sub-channels by skipping a particular sub-channel of the OFDM channel, when the particular sub-channel is determined to be unavailable for transmission, and (ii) allocating a first sub-channel to a first one of the two or more second communication devices and a second sub-channel to a second one of the two or more communication devices;
• generating a signal field of an OFDMA data unit to include indications of the respective sub-channels allocated for downlink OFDMA transmission to the two or more second communication devices, including indications of the non-contiguous sub-channel allocation;
• generating the OFDMA data unit to include (i) the signal field, (ii) a first OFDM data unit directed to the first one of the two or more second communication devices and (iii) a second OFDM data unit directed to the second one of the two or more second communication devices, wherein the first OFDM data unit is to be transmitted in the first sub-channel and the second OFDM data unit is to be transmitted in the second sub-channel;
• and
• transmitting the OFDMA data unit to the two or more second communication devices.

A first communication device, comprising:

• a network interface configured to:
• allocate respective sub-channels of an orthogonal frequency division multiplexing (OFDM) channel to two or more second communication devices for downlink orthogonal frequency division multiple access (OFDMA) transmission to the two or more second communication devices, including:
• (i) allocating non-contiguous sub-channels by skipping a particular sub-channel of the OFDM channel, when the particular sub-channel is determined to be unavailable for transmission, and (ii) allocating a first sub-channel to a first one of the two or more second communication devices and a second sub-channel to a second one of the two or more communication devices;
• generate a signal field of an OFDMA data unit to include indications of the respective sub-channels allocated for downlink OFDMA transmission from the two or more second communication devices, including indications of the non-contiguous sub-channel allocation;
• generate the OFDMA data unit to include (i) the signal field, (ii) a first OFDM data unit directed to the first one of the two or more second communication devices and (iii) a second OFDM data unit directed to the second one of the two or more second communication devices, wherein the first OFDM data unit is to be transmitted in the first sub-channel and the second OFDM data unit is to be transmitted in the second sub-channel;
• and
• transmit the OFDMA data unit to the two or more second communication devices.