Wireless technology is becoming an integral part of our everyday lives. Most students have a cellular phone or a personal digital assistant (PDA) used for voice communications, checking emails, or organizing personal information [1]. This is the technology of the 21st century, which has incredible opportunities and various applications. Recent advances in networking technology have enabled portable computing devices to link up with servers through wireless networks, such as IEEE802.11b and Bluetooth, to access information from them, and to delegate heavy tasks to them [2]. A typical IEEE802.11b wireless LAN consists of more than one base station (i.e. access point), whose typical radio area is within at most a few hundred meters, connected through a local area network [3]. The data flows and interactions between mobile users, sensors and their supporting computing infrastructure are clearly very different from those of today’s popular Internet applications such as email, instant messaging or the world-wide web [4]. When a user moves from location to location, his/her mobile computing device may be disconnected from the current network and reconnected to another network. Several researchers has explored mechanisms to transparently mask variations in mobility at the network or system level, such as Mobile-IP and host mobility.