A novel Multiple Access Control (MAC) protocol - User-dependent Perfect-scheduling Multiple Access (UPMA) protocol, which supports joint transmission of voice and data packets, is proposed. By this protocol, the bandwidth can be allocated dynamically to the uplink and downlink traffic with on-demand assignment and the transmission of Mobile Terminals (MTs) can be perfectly scheduled by means of polling. Meanwhile, a unique frame structure is designed to guarantee Quality of Service (QoS) in voice traffic supporting. An effective collision resolution algorithm is also proposed to guarantee rapid channel access for activated MTs. Finally, performance of UPMA protocol is evaluated by simulation and compared with MPRMA protocol. Simulation results show that UPMA protocol has better performance. A novel Multiple Access Control (MAC) protocol - User-dependent Perfect-scheduling Multiple Access (UPMA) protocol, which supports joint transmission of voice and data packets, is proposed. By this protocol, the bandwidth can be allocated dynamically to the uplink and downlink traffic with on-demand assignment and the transmission of Mobile Terminals (MTs) can be perfectly scheduled by means of polling. Meanwhile, a unique frame structure is designed to guarantee Quality of Service (QoS) in voice traffic supporting. An effective collision resolution Finally, the performance of UPMA protocol is evaluated by simulation and compared with MPRMA protocol. Simulation results show that UPMA protocol has better performance.