Broadband Wireless Access (BWA) technology has developed rapidly and it has dominated the advancement of technology especially in wireless networks. This paper studies the performance evaluation of VoIP for a mobile user and how the QoS parameters vary for different speeds. The purpose of the study is to examine the effect of mobility of a user on the performance of VoIP. In the meanwhile, it is evaluating the simulation and emulation method for its validity to be used for any new upcoming technology. However, the results of the simulation need to be verified and assessed by emulation tested results, hoping that both results match closely with each other.

Today everyone is living in a gold rush of wireless communication worldwide. If we look around, we will find wireless communication happening everywhere. In our home, small routers are providing us with wireless access to the internet in offices, shopping centers, cafes, universities, and so on. In this article, a mechanism has been introduced by combining service differentiation and packet aggregation in IEEE 802.11-based WMNs. The result is IEEE802.11b is the most reliable standard among all other wireless standards. Changes required in modulation techniques so that their overhead can be decreased and data can travel in more effective and efficient way.