Abstract:
For the end user mobility is one of the distinctive values that wireless technology offers. One of the main mobility challenge$ is to maintain an ongoing session without interruption while on the move, even at vehicular speeds. This challenge is referred to as handoff, commonly known as Handover (HO). Performing HO well is critical to providing a good user experience. It is one of the key issues for every mobile network, whether it's GSM Network, UMTS, or Mobile WiMAX, HO is equally important. This thesis presents a new method to upgrade performance of HO in mobile WiMAX. This novel mechanism of HO follows HO recommendations in the Institute of Electrical and Electronics Engineers (IEEE) 802. l 6e system i.e. cell reselection via scanning, HO decision, initiation and network entry including synchronization and ranging with a target Base Station (BS). To make this study more interactive, it demonstrates different performance metrics of HO via simulation and the steps involved in it from one BS to other BS for successful HO. This proposed HO algorithm takes latency as a key metric to evaluate, as it has direct impact on application performance perceived by a user. Total handover latency is decomposed into other several latency elements. The system is to be modeled using 3 tier cell topology. For simplicity, 5 mobile MS and multiple fixed MSs are modeled as a basic step for the mobility simulations. The mobility related performance metrics are to be computed only for these 5 mobile terminal and the locations of all other MSs are assumed to be fixed. Handover performance metrics statistics are collected for the moving MSs only. Simulation experiments have revealed that this proposed algorithm has improved Network Entry Time, Connection Setup Time and Service Disruption Time.
