A novel QoS-supported MAC protocol for wireless network with smart antennas

A QoS (quality-of-service)-supported adaptive slot allocation multiple access protocol (QASAMA) is proposed for the wireless network with smart antennas at basestation. Time-division duplexing (TDD) is used in the QASAMA protocol. Driven by the basestation, each active mobile terminal (MT) transmits a training sequence at the beginning of each frame, so the spatial signature of the active MT can be obtained by the smart antennas. Based on the optimal signal-to-interference-plus-noise ratio (SINR) beamforming, two slot allocation algorithms, point-by-point optimizing (PPO) and global optimizing (GO), are applied. On condition that provides QoS for voice and data traffics. the basestation dynamically schedules uplink and downlink traffic transmission so that multiple packets can be transmitted simultaneously in one traffic slot. Therefore, space-division-multiple-access (SDMA) is realized. Simulation results show that the proposed protocol can support the application of smart antennas effectively and provide high channel utilization and QoS for voice and data traffics.