Design and Implementation of a Real Time Geolocation System using RSSI-based Distance Calculation

Since the inception of the Internet, society has gradually become more interconnected. This trend has surged in the past two decades due to the advent of Wi-Fi technology, which has led to the current widespread availability of wireless networks. As a result, there has been a growing interest in utilizing Wi-Fi positioning as a valuable approach for real-time location-based services. Unlike GPS, this system offers improved accuracy both indoors and outdoors while leveraging the existing Wi-Fi infrastructure, making it a cost-effective solution. The received signal strength (RSSI) of billions of wireless devices is indeed employed for accurate and real-time positioning applications. However, the exploration of this approach has been relatively less extensive compared to trilateration and fingerprinting methods, which have been widely analysed in the state of the art. Trilateration involves the use of three reference devices to triangulate the signal, while fingerprinting requires a pre-existing dataset stored in a database. In contrast, this thesis aims to investigate a solution for real-time geolocation of individuals' Wi-Fi signals on a map without relying on multiple receivers, powerful hardware devices or advanced computational algorithms. The primary focus is on designing and developing a simplified yet effective approach that provides instantaneous results. This study firstly provides a comprehensive overview of fundamental concepts such as Wi-Fi technology, Received Signal Strength Indication (RSSI), GPS, and Wi-Fi Positioning System (WPS). It then delves into an analysis of the current state of the art of three macro-areas: RSSI- based distance estimation, public Wi-Fi location databases, and the association of virtual MAC addresses to a device. The subsequent section is dedicated to the design and implementation of a positioning module capable of accurately geolocating devices in close proximity of a receiver, achieving promising results in real-world scenarios. To further validate the practicality of the approach, the module is seamlessly integrated into a commercial WiFi probe, a dedicated hardware device. Finally, the conclusion of this thesis aims to demonstrate the effectiveness of this real-time approach in comparison to the current state of the art while outlining potential avenues for enhancing scalability and performance, thereby paving the way for future advancements in the field of Wi-Fi positioning for location-based services.