The worldwide interoperability for microwave access (WiMAX) is one of the newest technologies developed for broadband wireless network which offers high data rates, long coverage area and several types of quality of services to the users. In this paper, a basic simulation and performance analysis of WiMAX network in three different scenarios, using different quality of services like BLER, throughput and load, is carried out using OPNET modeler (version 14.5) which is a powerful tool used for simulation of wireless networks.