Development of Web Services for WLAN-based Indoor Positioning and Floor Map Repositories

Abstract

Indoor location based service (ILBS) is one of the current hottest research issues. ILBS cannot be realized without indoor positioning solutions. Among the many existing indoor positioning methods, the Wireless Local Area Network (WLAN) based trilateration is one of the most economic and easiest methods to be installed. The WLAN-based trilateration estimates the distance between an access point (AP) and a mobile device with the signal strength of the signal from the AP. Then, the WLAN-based trilateration estimates the location of the mobile device with the estimated distances and the coordinates of the APs. The first contribution of this paper is to propose a floor map repository that allows users to upload floor map files (AutoCAD files) and register coordinates of APs so that any software developer can use them after getting authorization. One of the drawbacks of the trilateration is its inaccuracy. The RF (radio frequency) signals between APs and a mobile device are very sensitive to the noise and the estimated distances are very inaccurate. The second contribution of this paper is that after discussing the pros and cons of various modified versions of trilateration, we find our own solution for indoor positioning and implement and publish our solution as a web service so that any software developer can use it.