Urban Wi-Fi RSSI Analysis along a Public Transport Route for Kinematic Localization

Abstract

Wireless Fidelity (Wi- Fi) location fingerprinting is a method of finding a mobile device/person's location based on the measurement of the Received Signal Strength Indicator (RSSI) of Wi-Fi networks. Due to growing Wi-Fi coverage this method is becoming increasingly useful in areas where GNSS signals do not reach, such as underground or within the built-up city area, such as in urban canyons. In the course of this study, the operability and performance of Wi-Fi fingerprinting is investigated at a set number of reference points, referred to as Intelligent Check Points (iCPs), along a tramway route. The route leads from a residential neighborhood to an University building in downtown of the city of Vienna, Austria. Of particular interest in this study are the mobile Access Points (APs) installed on the trains of the tramway line. From our point of view, an analysis of how they can contribute to the confirmation and validation of the user localization determination along the route is a main goal. A SLAM approach is proposed for a combined and integrated solution for user localization. From a first analyses of the availability, visibility and RSSI stability of the APs on the tram and in the surrounding environment an approach is derived for continuous user localization integrating the smartphone inertial sensors in addition.