Evaluation of WIMAX network performance of baghdad city using different audio codecs

The WiMAX network in the city of Baghdad is established by “The State Company for Internet Services” (SCIS). SCIS is a subsidiary of the Ministry of Communications (MoC) in Iraq. SCIS is responsible for the installation and operation of WiMAX networks and is also the prime “Wireless Internet service provider” (WISP) in Iraq. This paper presents a simulation model of a WiMAX network for the city of Baghdad. The performance evaluation of Voice over IP (VoIP) service based on integrated Wireless “MAN/WAN” is evaluated using different encoding schemes supported by Codecs: (GSM, G729, G723 IP service, and G711). The modeling and simulation of the designed WMAN is implemented using OPNET simulator. Various parameters that indicate the “Quality of Service” (QoS) these are; “MOS, voice packet end-to-end delay, voice traffic received, voice traffic sent & voice jitter” are calculated and analyzed for the four different scenarios, to evaluate the performance “WiMAX network” that support Voice over IP service. The results obtained show that codecs G.729A delivers the best results. Therefore it is selected as the best Codecs choice for the best performance metrics of VoIP. Also, the enhancement resulted in lowest delay and the highest MOS.