Ali HeidariKhoei - Islamic Azad University, Yazd, Iran
Ali Delavarkhalafi - Mathematics Department, Yazd University, Iran,

Modern networks require a sufficient degree of Quality of Service (QoS) in order to meet the requirements of next generation networks. Many researches should be carried out in this field to achieve maximum QoS. In this paper, we study QoS parameters such as throughput, packet loss, delay and maximum traffic received in WiMAX and WiFi networks. These parameters are compared in 2 different scenarios in distance increase and increase of mobile users by using OPNET 14.5 simulation in 30 minutes. Thus, 4 factors of performance are studied and analyzed in WiFi and WiMAX networks by sending data such as video traffic, file transfer and HTTP browsing.In this paper has used the pathloss model TERRAIN A which is special for the urban and suburban environments and will measure simulation according to the real environmental conditions (such as existence of hills, trees, buildings, vehicles and even people, …). Therefore, the obtained results are much closer to reality. In this paper, the maximum accessible distance in WiMAX and WiFi links were 15km and 8km, respectively. In addition, the increase in the number of users led to the decrease of efficiency in WiMAX and WiFi links; however, the decrease in WiMAX network was less than WiFi network.

QoS, Video on Demand (VoD), WiMAX, WLAN