Effect of Scheduling Algorithms on QoS of WiMAX

Designing a heterogeneous [1] network including systems providing different QoS, such as the emerging WiMAX, is a difficult task. The integration of a WiMAX access system with Differentiated Services (DiffServ) enhances the overall performance of the network. This paper investigates the interworking between WiMAX and DiffServ networks, by reducing the end to end delay. Scheduling improve the QoS of WiMAX. We investigated and evaluated different types of scheduling techniques aiming to determine the one that is most efficient in Wimax network. There are three different scheduling schemes viz. strictly priorty (SP), weighted round robbin (WRR) and weighed fair queuing (WFQ). These proposed schemes improves QoS to a great extend. We compared these three techniques by performing simulations using NS2. This simulation provides an intuitive model set up capability that includes core components such as animator, packet tracer analyzer, protocol designer and protocol stack. From the results of our simulation we find WF as the best scheduling algorithm when considering end to end delay and WF outperforms others for all classes of Qos Key words—QoS, DiffServ, WiMAX.