A dynamic uplink scheduling scheme for WiMAX networks

Over the past few years, there has been a rapid growth of new services such as online video games, video conferences, and multimedia services to end users. WiMAX is an emerging technology for next generation wireless networks which supports a large number of users. To achieve Quality of Service (QoS) requirements, an efficient and reliable scheduling algorithm is urgently needed. Among a large number of the proposed approaches in the literature, a variably weighted round robin scheduling algorithm (VWRR) has been proven to provide the best performance in an IP backbone network with no attempts on WiMAX networks. This paper proposes a dynamic uplink scheduling algorithm for WiMAX networks based on VWRR to allocate the bandwidth to users to maximize the throughput and ensure the constraints of delay, jitter, and load. A comparative study between the proposed scheduling algorithm and the two most famous scheduling algorithms: weighted round robin algorithm (WRR) and modified deficit round robin algorithm (MDRR) over WiMAX networks, is presented. Simulation results obtained using OPNET reveal that the proposed algorithm has a superior performance compared with WRR with respect to throughput, delay, jitter, and load. Additionally, the proposed scheduling algorithm is shown to provide an excellent level of reliability and scalability when increasing the number of served subscriber stations.