Performance Evaluation of VoIP QoS in WiMAX Networks

Abstract

Worldwide Interoperability for Microwave Access WiMAX is a new emerging access technology and one of 4G broadband access wireless technologies with large coverage area, low cost of deployment and high speed data rates. In parallel, transportation of voice over Internet Protocol based networks (VoIP) is a very rapid evolving communication technology. As real-time application VoIP requires packet delivery with low latency, jitter, packet loss, and sufficient bandwidth. WiMAX technology defines 5 different data delivery service classes that can be used in order to satisfy QoS requirements of different applications, such as VoIP, FTP, Web, etc. This research evaluates the performance of VoIP traffic over WiMAX networks. In particular, the study compares the performance obtained using two different QoS service classes that supported VoIP traffic, Unsolicited Grant Service (UGS) and Extended real-time Polling Service (ertPS). Through different network simulation experiments using realistic network scenarios in OPNET environment, this research provides an insight into the VoIP performance in the WiMAX networks. Parameters that indicate the Quality of Service such as end to end delay, packets delay variation, and throughput are obtained and analyzed in these scenarios. In a result of simulation, the general network QoS parameters of the two service classes that used are in the acceptable range. However, UGS has enhanced in range 4.4% to 7.7% for the delay and 21% to 47% for the throughput opposed to ertPS.