WiFi Indoor Positioning System Based on OpenWRT

The development of indoor positioning systems is possible thanks to the availability of wireless network infrastructure. Thus, a wireless provider can determine an accurate indoor position taking into account the existing Wifi infrastructure in buildings, malls, or offices. In this work, we develop a system for indoor positioning with the use of several libraries of OpenWRT running on three access points in an office of the CTI building. We develop a server application to retrieve the performance metrics of the WiFi signal from three wireless routers of the study area and load this information to a database. Thus, this application uses the signal strength measured and stored in the database to determine the distance between the mobile devices and each access point. Then, the position of the mobile devices is estimated by averaging the estimation of three Min-Max algorithms and updated in the database. Finally, we also implemented a mobile application that shows on a map the mobile devices position in real time and the position of mobile devices in their proximity. The results show that the mobile devices locations present an average margin error of position equal to 2.43 meters enabling the development of indoor positioning applications using the
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isting infrastructure of the wireless networks.