Improvement of performance of heterogeneous WIMAX systems by using relay networks

Heterogeneous wireless communication systems use different wireless technologies such as WIMAX, WiFi, HSPA, 3G, etc? in providing continuous, wireless, wideband voice, video and data communication services to users. Each wireless technology is implemented for different systems with different communication network architectures. In heterogeneous systems, where different systems are used together, increasing the system capacity and coverage, improving the quality of service and the error performance at a minimum cost is of great significance. The aim of this thesis is to increase the coverage area and system capacity, improve the quality of service and the system?s performance by using relay networks in heterogeneous systems. The OPNET simulator is used in order to increase the system performance of multihop, heterogeneous systems, where various system parameters such as relay topology, queuing methods, propagation loss, network protocols, velocity, traffic, delay time, coding, multiplexing and modulation are considered in the error performance analysis of the heterogeneous systems.KEYWORDS: Heterogeneous WIMAX Systems, WLAN, multihop relay system