Comparative study and analysis of VoIP traffic over WiMAX using different service classes

The Worldwide Interoperability for Microwave Access (WiMAX) is a set of technical standards based on IEEE 802.16 standard, WiMAX is an alternative solution for the deployment of broadband networks in the territories, whether or not covered by other technologies such as ADSL or cable. It provides flexibility in network deployment options and service and supports point-to-multipoint (PMP) and Mesh mode. In parallel, VoIP is a technique that allows communicating by voice over IP compatible networks, one of the main advantages of VoIP is its ability to reduce costs, it becomes an alternative to public switched telephone. Voice traffic is highly delay intolerant and it needs a high priority transmission. In this paper, we investigate the performances of the most common VoIP codecs, named as G.711, G.723.1 and G.729 using Best Effort, UGS, rtPS, ertPS and nrtPS service classes and NOAH routing protocol. NS-2 simulator is used to analyze the QoS parameters. The objective is to compare different WiMAX's service classes with respect to the QoS parameters, such as, average jitter, throughput and average delay.