A Friis-based calibrated model for WiFi terminals positioning

Two types of applications use indoor positioning, services linked with mobility, such as guided tour or meeting systems, and the active security of a wireless network which locates intrusive unauthorized mobile terminals. Indoor positioning cannot be managed by a geostationary system like GPS. In fact, current researches are being conducted to conceive indoor positioning using wireless networks such as WiFi. We study such a mechanism and compare the accuracy of our results to other solutions. Our model is based on the Friis relation, which expresses signal strength as a function of distance, in a free space environment. The Friis-based model is adapted to fit the conditions of implementation. The positioning function is combined with a mobility prediction mechanism and constitutes the mobility service in a video on demand system called MoVie (mobile video).