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Wireless access points are now commonplace on many university campuses [1-4]. Technologies such as IEEE 802.11 b wireless LANs (WLANs) have revolutionalized the way people think about networks, by offering users freedom from the constraints of physical wires. Mobile users are interested in exploiting the full functionality of the technology at their fingertips, as wireless networks bring closer the “anything, anytime, anywhere” promise of mobile networking. Wireless local area networks (WLANs) are spreading rapidly, their major advantage over wired ones being their easy installation. They offer many benefits to users who can access resources without being forced to stay in one place or indoors. The user base can be mobile, scalable, and create quickly-installed temporary networks. A typical campus/university mobile user (our study environment) has workstations equipped with a wireless card and the ability to access a local access point with minimal configuration required. The access point is linked to the wired network through a suitable IP gateway.

Several wireless 802.11 technologies are now available. IEEE 802.11 b is the most well known technology. Its bit rate can be up to 11 Mbps in the 2.4 GHz band. The rate 11 Mbps is the theoretical rate. Due to overhead produced by ACK and synchronization issues, the rate does not exceed 7 Mbps [5-6]. IEEE 802.11 g is an extension of 802.11 b; and works in the same 2.4 GHz band, its data rate can be up to 54 Mbps. IEEE 802.11 a operates in the 5 GHz band up to 54 Mbps. IEEE 802.11 a has the advantage of working in different band from cordless phones, microwave ovens, and …