Abstract
While WiMAX handoff characteristics and quality of service (QoS) provisioning have been explored by many network researchers, the effect of traffic type, node mobility and network size on WiMAX has not been fully explored yet. This paper therefore reports on a study of the impact of traffic type and node mobility on the performance of a typical mobile 802.16 WiMAX for varying network sizes. We consider small, medium and large network scenarios under four different traffic types (FTP, HTTP, VoIP and Videoconferencing) with node speeds of up to 90 km/hour. We develope an extensive simulation model using OPNET Modeler to measure network throughputs, FTP response times, HTTP object and page response times, VIOP jitter, and Video conferencing end-to-end delays. Results obtained show that packet delays of less than one second are maintained regardless of increased node speeds. Packet loss ratios for VoIP and video conferencing are irregularly high and increase with network traffic. Another observation is that the average throughput of video conferencing and m-VoIP is decreased and packet loss ratio is irregularly increased causing loss of connection. As expected, both FTP and HTTP traffic are transmitted well over WiMAX because they can tolerate a certain amount of delays. However, the transmission of both m-VoIP and video conferencing packets suffered high packet losses. The results reported in this paper provide some insights into the performance of 802.16 WiMAX with respect to the traffic type, network size and node mobility on system performance.
