An access point including a transceiver having first and second physical layers to communicate at first and second data rates, respectively. The transceiver receives a request from a first client station to reserve first or second sub-channel of a channel for transmitting data at the first or second data rate. In response to receiving the request from the first client station, the transceiver transmits a response to allow the first client station to transmit data and prevent a second client station from transmitting data while the first client station transmits data to the access point. In response to the first client station receiving the response, the first physical layer receives data from the first client station without interference from the second client station.