IEEE 802.11 WLAN Based Real-Time Location Tracking in Indoor and Outdoor Environments

In this paper we propose an IEEE 802.11 wireless LAN (WLAN) based location tracking system for indoor and outdoor environments. The system is implemented using the received signal strength indication (RSSI) measurements and training-data based estimation techniques. Methods for acquiring, filtering and interpreting wireless data are discussed with emphasis on how they will be applied to wireless tracking. Training-data based estimation is performed by taking a series of RSSI measurements at known training points and then approximating the current location using the nearest neighbor algorithm. Propagation-based distance estimation is based on the Log-distance path loss model. Experiments are conducted for both training and propagation models to estimate the distance of the user from a known access point in indoor and outdoor locations. The experimental results that show the indoor and outdoor location estimation using the propagation model and training data are presented.