International Journal of Emerging Technology and Advanced Engineering (IJETAE)
Future wireless networks such as 4G system will support high data rate and multimedia services including facsimile, video teleconferencing, file transfer by consuming less bandwidth such as high-speed Internet accesses .The IEEE WiMAX/802.16 is a promising technology for broadband Wireless Metropolitan Areas Networks (WMANs) as it can provide high throughput over long distances and can support different qualities of services. The fundamental limitations of wireless communication system are limited channel bandwidth, time varying channel fading make it a difficult problem to provide a high QoS. The traditional wireless communication systems are designed to provide good quality of services at the worst channel conditions. As the result inefficient utilization of the full channel capacity.