Enhancement of WiMAX networks using OPNET modeler platform

Worldwide interoperability microwave access (WiMAX) is an 802.16 wireless standard that delivers high speed, provides a data rate of 100 Mbps and coverage area 50 km. Voice over internet protocol (VoIP) flexible offers low-cost telephony for clients IP. However, there are still many challenges must be addressed to provide stable good quality voice connection the internet. The performance various parameters such as multipath channel model bandwidth Star trajectoryWiMAX network were evaluated under scenario consisting four cells. Each cell contains one mobile base station. Network metrics throughput MOS used evaluate best VoIP codecs. Performance was analyzed via OPNET program14.5. result use (disable) better than using (ITU pedestrian A). value at 15 dB approximately 1600 packet/sec, -1 its 1300 packet/se. According data, Multipath disable type ITU Pedestrian A type.