On the fingerprints dynamics in WLAN indoor localization

Location Based Services require seamless tracking of human or object outdoor/indoor anywhere, everywhere. Based on its location and availability, it should make use of the underlying wireless system it has access to or it could process. In terms of vehicular system also, it requires seamless tracking also in the indoor parking or places where it lacks clear LOS and has to depend upon the widely accessed Wireless Local Area Network based localization. This paper focuses on Received Signal Strength measurements dynamics in WLAN indoor localization. Real-field measurement data taken 3 year apart in the same university building (situated in Tampere, Finland) are used for this analysis. The building AP network has undergone a substantial structural change in between the two sets of measurements, in such a way that most WLAN emitters were replaced and renewed. We study here the variability and dynamics of the indoor channel and accuracy of the positioning results when emitter configuration is changed, but the indoor scenario remains the same (same building structure, same rooms and furniture).