Abstract

WLANs provide high speed services but the radio coverage is small and does not support good mobility performance as compared to cellular systems. In this thesis, an integrated network of GPRS and wireless LAN is presented and a handoff algorithm is proposed for the integrated network. Handoff is an important issue when considering mobility in an integrated wireless communication network. The objective of the algorithm is to achieve seamless network service coverage and maximum data transfer speed. Traditional cellular GPRS/EGPRS networks can provide good mobility performance but relatively low speed data service. In the proposed handoff algorithm, the mobile station can camp on the best serving access point based on its geographic position and moving speed. Accessing a WLAN network, if possible, has a higher priority than accessing GPRS/EGPRS cellular network. To achieve a comprehensive performance investigation, a simulation is implemented based on a large traffic load. Simulation results show the performance characteristics and functionalities of the algorithm that includes total throughput, call successful rate, call block rate, packet error rate, handoff rate and resource utilization. Simulation results demonstrate that the proposed handoff algorithm achieves higher throughput and call successful rate than the traditional cellular network. The optimization of the deployment of access points of the integrated network is also investigated.