Methods, computer readable media, and wireless apparatuses are disclosed. The apparatus comprising a memory and processing circuitry coupled to the memory. The processing circuitry is configured to: associate with a master station, decode a trigger frame or a multi-user request-to-send (MU-RTS) frame from the master station, where the trigger frame or the MU-RTS frame comprises a first duration and a transmitter address, and respond to the trigger frame or the MU-RTS frame if a network allocation vector (NAV) is not set, or if the NAV is set and a saved transmission opportunity (TXOP) holder address for the NAV is the same as the transmitter address of the MU-RTS or trigger frame and the trigger frame or MU-RTS indicates the station is to respond.