Adaptive Priority Scheduling for Downlink WiMAX Networks

Providing quality assurances for various services such as VoIP, FTP and Browsing remain the key interest for IEEE 802.16 WiMaX networks. A scheduling pattern which fulfils QoS constraints becomes more significant for wireless infrastructures. We present a downlink scheduling system titled as adaptive priority scheduling for Downlinks (APSD) that provides QoS assurances in WiMaX networks. APSD embraces two main modules, which are resource management and priority assignment. Diverse types of services mainly rely on its’ QoS desires to modify the priority assignments and fetch the bandwidth properties dynamically. Starvation avoidance and allocating resource are both considered. The Simulation results illustrate that APSD scheme has more substantial performance in terms of average throughput and delay than the original existed scheme. In addition, our APSD has notable advantages over FIFO and SCSA methodologies in Quality of Service satisfaction and sustaining fairness in prevention mode of starvation.