Wi-Fi based hotspots offer mobile users broadband wireless Internet connectivity in public work spaces and corporate/ university campuses. Despite aggressive deployment of these hotspots in recent years, high-speed wireless Internet access remains restricted to a small number of geographical areas because of limited physical coverage of wireless LANs. On the other hand, despite their lower throughput, cellular networks have a significantly wider coverage and are thus much more available. Recognizing that 2.5G or 3G cellular networks can effectively complement wireless LANs, the authors set out to develop a vertical handoff system that allows mobile users to seamlessly fall back to such cellular networks as GPRS or 3G whenever wireless LAN connectivity is not available....

This paper investigates the Probability-Of-Detection 〈POD〉 performance of a novel Wireless Local Positioning System 〈WLPS〉 realized via Direct Sequence Code Division Multiple Access 〈DS-CDMA〉 and beamforming techniques. The proposed WLPS has unique signaling schemes that discriminate it from the traditional wireless systems and allows the WLPS to have many civilian and military applications. The WLPS consists of two main parts: the detecting unit, a base station carried by a mobile unit defined as Dynamic Base Station 〈DBS〉, and the being detected unit, a TRansponder 〈TRX〉 that is mounted on the targets, each assigned a unique IDentification code 〈ID code〉....