Patent attributes
An access point (AP) transmits a request-to-send (RTS) frame to a plurality of client stations. The RTS frame indicates that the plurality of client stations are requested to simultaneously transmit respective clear-to-send (CTS) frames to the AP. The AP receives at least some of the respective CTS frames from at least some of the plurality of client stations, including receiving a first CTS frame from a first client station, and receiving a second CTS frame from a second client station. The first CTS frame and the second CTS frame both span a first sub-channel, and are received simultaneously by the AP. The AP determines that the first sub-channel is available for communication with one or more client stations based on the reception of the first CTS frame and the second CTS frame.
