This paper proposes a Service Differentiated-Dynamic Slotted Multiple Access （SD-DSMA） protocol with QoS guarantee. The Media Access Control （MAC） frame format is variable according to the traffic of uplink and downlink and the traffic of control and data. In addition, the services are divided into two categories, Guaranteed Bandwidth （GB） and Best Effort （BE）. Uplink control message slots are designed for the GB users to reduce contention. Taking into consideration the techniques in physical layer, a two-Dimensional Radio Resource Allocation （2-D RRA） method is proposed. The 2-D RRA is an efficient way to allocate radio resources for multi-cell, multi-user OFDM/TDMA system as it takes into consideration both the channel condition and the co-channel interference. The piggyback mechanism and fair scheduling algorithm are adopted for GB services, and the max C/I scheduling algorithm is used for BE services. The simulation results show that the proposed MAC protocol has better performance in terms of delay, probability of successful access request.
