Toplogy based modeling and simulation of UMTS-WLAN Wireless Heterogeneous Network

Wireless Heterogeneous Networks (WHN) have become one of the deployment scenarios for the Fourth Generation Mobile Communications Networks (4G). In recent trends, heterogeneous service models integrating between Wireless LANs (WLANs) and cellular networks have attracted the most attention. This is due to the increasing demand for broadband services, causing cellular network providers to consider the complementary use of WLAN in hot spot areas and indoor locations in a cooperative context. Cooperative approaches in integration are characterized by mutual investments and/or ownership of both access technologies, opening up the possibilities for centralized coordination between them to optimize the design parameters and hence the performance of the integrated network. In this paper, we propose an architecture for deploying a service model combining UMTS and WLAN hotspots into an integrated cooperative heterogeneous network. Through modeling and simulation, we investigate the effect of certain network topology parameters on the over-all network performance. We present a WLAN-first based vertical handoff (VHO) scheme to use in our proposed model. Simulation results show that the topology parameters of the integrated network, specifically the positioning of the WLAN hotspots, can be used as design variables to enhance the overall network performance through minimizing call blocking probability.