Abstract: Wireless Internet technology will be the next milestone for modern telecommunication technology. In order to provide Internet connectivity over a wide area it is necessary to utilize the advanced features of modern cellular systems known as 3G wireless Cellular such as UMTS and their future evolution. One problem towards such utilization is the current technological shortcomings of cellular systems that limit the data rate. One way to bypass this limitation is to use Wireless LAN in cooperation with cellular network such as GPRS/UMTS networks, an increasing number of wireless telecommunication providers are now offering both voice and data services to their users. These services and the emerging multimedia services demand higher data rates to achieve a better quality of service (QOS). So the high tier wireless systems such as UMTS provide users high mobility but less bandwidth. On the other hand wireless systems such as wireless LAN offer higher bandwidth with less mobility. To support seamless roaming between heterogeneous wireless networks is one of the key issues in the future mobile communication systems. So the 3G will dominate the future wireless Internet access, UMTS and hotspot wireless LAN. These technologies will be complement each other to provide ubiquitous high-speed wireless Internet connectivity to mobile users. In such environment it will be required to support inter technology Handoff of mobile terminals without causing disruptions to their ongoing Internet Session. Though there is a handoff technique between wireless LAN and UMTS Networks, this proposal aims to give a smooth seamless handoff between Wirelesses LAN and UMTS network by rectifying the drawbacks (like delay in latency and Packet loss) which is present in the already existing techniques.