An effective signal strength-based wireless location estimation system for tracking indoor mobile users

Localization is an essential function for location-dependent services. Although various efficient localization methods have been proposed, many of them have not tested with practical applications. Different location-dependent applications may have very different performance and operation requirements such as the accuracy in localization and frequency of location tracking. In this paper, based on our previous works on the design of efficient localization methods, we study the important issues in the design and implementation of a location tracking system for monitoring people in an indoor environment within a large building such as in rehabit centres and schools. In estimating the current location of a mobile user, we adopt the received signal strength indicator (RSSI) approach. Enhancements are proposed to improve the accuracy in localization using RSSI. To ensure the reliability of the location results and the efficiency in location tracking, it is important to minimize the traffic of location data on the network, as well as the chance of overloading the estimation system. Various issues in the design of the system are discussed and the performance results of the system are provided to illustrate the efficiency and the limitations of the proposed methods.

► Localization based on received signal strength using wireless AP as sensor array.
► Localization without installing a client or an app, that is, server mode localization.
► Localization with signal calibrator for real-time environmental changes.
► Localization with algorithm selector to select the right algorithm for higher accuracy.