Design and Implementation of an Efficient Scheduling Algorithm for QoS Management in WiMAX

Due to the costly spectrum and ever growing demand for multimedia services, it thus become important to optimise and design appropriate scheduling algorithms and channel management techniques to maximise throughput and QoS. In this paper, the IEEE 802.16e standard based Mobile WiMAX (Worldwide Interoperability for Microwave Access) system is explored for the purpose of Quality of Service provisioning. Since the standard does not specify a specific scheduling algorithm for polling services, hence a well thought out algorithm will be of great contribution to the area under investigation. An in-depth study of the Modified Deficit Round Robin (MDRR) scheduling algorithm has been provided. Modifications have been made to the existing scheduler and the refined new MDRR scheduler is implemented in OPNET Modeler. Results from the simulations obtained show that the designed algorithm works well with latency and throughput constraints as well as with the Quality of Service demands of the WiMAX standard. Keywords— IEEE 802.16, MAC, OFDMA, OPNET, QoS, WiMAX