Abstract: Wireless bus system can not achieve the same performance of transmission delay and throughput when compared with the wired one. A multichannel media access control (MAC) protocol is proposed. The protocol takes advantage of the coexistence of the multiple channels provided by the wireless channel. The operation of the proposed protocol consists of the carrier sense multiple access (CSMA) session and the time division multiple access (TDMA) session in the star topology. During the CSMA session, prioritybased access greatly avoids collision. During the TDMA session, the earliest deadline first (EDF) scheduling based on the global queue achieves better channel utilization. Simulation results indicate that the proposed multichannel MAC protocol achieves better performance of transmission delay and throughput.