Estimation of Mobile Point Distance based on the Signal Strength of Wireless Network Routers

Abstract

The necessity to obtain the localization on the terrestrial globe surface allowed the expansion and emergence of primordial technologies to contemporary engineering, especially in the context of Intelligent Transportation Systems. Several systems have been based on the information obtained by GNSS (Global Navigation Satellite System) for localization. However, these kind of systems demonstrate structural limitations, which prevent users from obtaining more accurate positions, especially in closed environments such as underground parking lots, environments where satellite signals are not possible or where interference occurs. In this sense, positioning systems based on rssi (received signal strength indication) function is a support for traditional localization. The strategy used in this work consists of using signals provided by wireless network routers, available in the infrastructure of domestic, corporate or public networks, to estimate the position based the of signal power received by wireless receivers of mobile devices. Moreover, different models were studied and evaluated that equate the distance relation as a function of the power of the rssi signal received. In order to evaluate the models from desired external scenarios, an optimization was applied using the Particle Swarm Optimization (PSO) algorithm to obtain the optimum parameters of each model, conducting to an accurate position estimation. Experiments in real environment were performed to evaluate these different models with reference to a GPS-RTK system.