Performance evaluation of transport layer protocols for video traffic over WiMax

With a variety of access technologies available, the demand for mobile multimedia applications has increased enormously. Supporting these multimedia applications with varied quality of service (QoS) requirements while maximizing the resource utilization is a challenging task. One important factor is the transport protocol that significantly affects the offered QoS and efficient utilization of network resources in the inherently varying transmission conditions due to the wireless medium. Currently most of the multimedia applications use UDP as the main transport layer protocol. However, UDP performance has not been satisfactory in meeting the varied QoS of diverse multimedia applications. A number of new protocols are being developed to meet the diverse needs of emerging multimedia applications. SCTP and DCCP are two important developments that are being considered in this regard. In this paper, through simulations, performance of UDP, SCTP and DCCP protocols has been analyzed for the transport of MPEG-4 video traffic over WiMAX as underlying access technology. Considering single cell WiMAX network, performance metrics such as throughput, delay and jitter have been determined for each of the three protocols in varying WiMAX network topologies/scenarios. On the basis of this study, it has been found that both SCTP and DCCP outperform UDP by large extent. Further, DCCP performance is better than SCTP in terms of delay and jitter.