Abstract:
Handover has a great significance to accomplish seamless connectivity in heterogeneous wireless networks. When existing connections in the Wi-Fi or UMTS network is deteriorated gradually or may not enhance service quality. In case of weak signal level, or unavailable network. Using a vertical handover to select the best network based on required service, application, and location. In this research, our main objective is to evaluate the Vertical handover between Wi-Fi and UMTS networks Using OPNET Modeler software, to know and understand more about the handover process. In this thesis Wi-Fi and UMTS networks different statistics are calculated based on several parameters such as throughput, delay, traffic received and sent, end to end delay for application such as VOICE and HTTP. With regard to this evaluation it found that in Global statistics the delay for UMTS network is decrease by the rate of 18% and throughput value for Wi-Fi network is increase by the rate of 10% the with-handover scenario was improved significantly compare to without-handover scenario. In Node statistics; the delay has decreased for user Wi-Fi by the rate of -63% and -55% for user UMTS, thus the user has been connected to the better network and improved Qos when user moves between Wi-Fi and UMTS.
