Certain aspects of the present disclosure present medium access control (MAC) protocols for uplink Spatial Division Multiple Access (SDMA) transmissions by one or more stations (STAs). An access point (AP) may receive one or more requests for uplink SDMA transmission from a plurality of stations. The access point may schedule the transmissions by sending a signal to the stations to notify them of the parameters of the uplink SDMA transmissions such as start time, duration of the transmission, spatial streams assigned to each station, and so on.