Quality of Service Evaluation of VoIP over Wireless Networks

The Voice over IP (VoIP) service demands high priority over other services and applications. Some constrains are associated with this real-time service, such as delay and throughput which need to be addressed before delivering to the customer. The mobility in IP networks is a demand that facilitates IP applications and services, especially in wireless networks. This paper demonstrates the performance of Voice over IP (VoIP) in 802.11 wireless networks and elaborates on the evaluation of voice packet end-to-end delay and throughput. Employing literature reviews and an experimental model created on OPNET that is simulated to assess the quality of service (QoS) of VoIP in 802.11g legacy and 802.11e wireless network; shows the enhancement of 802.11 reflects as enhancement in the quality of the VoIP service. The simulation results have indicated that the quality of VoIP service is influenced by the quality of the carrier which is IEEE 802.11 network. Therefore, the voice service over wireless network can be improved significantly by developing a quality of service policy that prioritizes the packet transmission based on the controlled access mechanisms. Eventually, the number of VoIP calls could be increased using the enhanced 802.11e standard rather than 802.11 standard.