International Journal of Computer Science Issues

More than a traditional journal...

Real-time services such as VoIP are becoming popular and are major revenue earners for network service providers. These services no longer confined to the wired domain and extended over wireless networks. Although some of the existing wireless technologies can support some low-band width applications, the bandwidth demands of many multimedia applications exceed the capacity of these technologies. The WiMAX promises to be one of the wireless access technologies capable of supporting very high bandwidth applications. However, there are still many challenges that need to be addressed to provide a steady and good quality voice connection over the best-effort WiMAX network. In This paper, we evaluate the performance of different VoIP codecs over the WiMAX network. The network performance metrics such as MOS, packet end-to-end delay, jitter and packet delay variation have been used to evaluate the performance of VoIP codecs. The results showed that, the codec G.723 provides the best results among all discussed Codecs in all presented performance metrics; the lowest delay, the highest MOS and the highest Throughput.