A wireless device comprising a transceiver configured to: transmit, over a plurality of spatial streams and a plurality of sub-channels, a Schedule frame, SCH, to a plurality of Stations, STAs (104A, 104B), to schedule an Uplink, UL, transmission; wherein each sub-channel of the plurality of sub-channels occupies a different frequency band and is allocated a spatial stream of the plurality of spatial streams; wherein the SCH includes a plurality of maps, each map scheduling a different Transmit Operation, TXOP, and associating at least one sub-channel and at least one spatial stream with an Association ID, AID; wherein each map indicates to an STA (104A, 104B) to which a respective AID was assigned, which of the at least one sub-channels and which of the at least one spatial streams are allocated to the STA (104A, 104B) during the TXOP; transmit, over the plurality of spatial streams, a Block Acknowledge, BA, to the plurality of STAs (104A, 104B), in response to receiving data from the plurality of STAs (104A, 104B); transmit, over the plurality of spatial streams and sub-channels, Downlink, DL, data to the plurality of STAs (104A, 104B) at a time indicated in the SCH; and transmit, before the UL transmission or transmitting the DL data, a map Identification, ID, frame indicating which map of the plurality of maps a next transmit operation is associated with. transmit, over a plurality of spatial streams and a plurality of sub-channels, a Schedule frame, SCH, to a plurality of Stations, STAs (104A, 104B), to schedule an Uplink, UL, transmission; wherein each sub-channel of the plurality of sub-channels occupies a different frequency band and is allocated a spatial stream of the plurality of spatial streams; wherein the SCH includes a plurality of maps, each map scheduling a different Transmit Operation, TXOP, and associating at least one sub-channel and at least one spatial stream with an Association ID, AID; wherein each map indicates to an STA (104A, 104B) to which a respective AID was assigned, which of the at least one sub-channels and which of the at least one spatial streams are allocated to the STA (104A, 104B) during the TXOP; wherein each sub-channel of the plurality of sub-channels occupies a different frequency band and is allocated a spatial stream of the plurality of spatial streams; wherein the SCH includes a plurality of maps, each map scheduling a different Transmit Operation, TXOP, and associating at least one sub-channel and at least one spatial stream with an Association ID, AID; wherein each map indicates to an STA (104A, 104B) to which a respective AID was assigned, which of the at least one sub-channels and which of the at least one spatial streams are allocated to the STA (104A, 104B) during the TXOP; transmit, over the plurality of spatial streams, a Block Acknowledge, BA, to the plurality of STAs (104A, 104B), in response to receiving data from the plurality of STAs (104A, 104B); transmit, over the plurality of spatial streams and sub-channels, Downlink, DL, data to the plurality of STAs (104A, 104B) at a time indicated in the SCH; and transmit, before the UL transmission or transmitting the DL data, a map Identification, ID, frame indicating which map of the plurality of maps a next transmit operation is associated with.