A communication circuit and protocol for a wireless local area network (WLAN) using CSMA/CA and single EDCA and/or Multiple-User (MU) EDCA. EDCA functions are configured to operate with multiple sets of operating parameters providing a range of priority levels for altering on the fly the nominal access time for a STA sending prioritized packets. The STA then must switch to a lower-priority set of parameters as recompense so that channel usage remains fair.