In a communication system, an access point in communication with one or more stations identifies a first subset of wireless stations from the set of wireless stations. The first subset of wireless stations is identified based on RSSI values for radio frequency signals received from each of the stations exceeding an RSSI threshold. The first subset of wireless stations is assigned to a first reception window. The access point transmits an identifier of each of the subset of wireless stations and an identifier of the reception window via the radio frequency channel.