Wireless mobile user’s location in an indoor environment - an overview

This century is experiencing an unprecedented growth in the number of mobile wireless users, applications, and wireless network access technologies. The future technology will provide communications and computing, where the users have network access, anytime, anywhere, and these applications shall be location-sensitive. To realize this vision, the network connectivity of private networks is required to be extended to public places like airports, malls, hotels, parks, and so on, where individuals spend a considerable amount of their time. Although the 2n generation cellular networks are undoubtedly playing a vital role in providing wide-area long-range service, advances in indoor short-range wireless communication technology and the proliferation of lightweight handheld devices with built-in high-speed radio access have made wireless LAN deployments increasingly common. The WLANs operating at 2.4 GHz and 5.8 GHz are generally used for indoor applications and for such an environments, location of mobile users is an essential requirement. Indoor location science is very vital for the implementation of the 4th generation wireless networks. The 4th generation wireless networks are expected to provide geo-location service to locate the mobile/static users and important portable equipment and support multi-media services, which include commercial, public safety and military applications. The proliferation of mobile computing devices and local area wireless networks has fostered a growing interest in location-aware systems and services. The central to each location-aware application is the ability to determine user locations with a useful degree of accuracy. Efficient location and coordination of mobile users in any office, factory, hospital, library, and other similar categories of large buildings is difficult and recurring problem. In case of emergencies in any hospital, the location of doctors, nurses and patients is extremely important.