Intruder tracking in WSNs using binary detection sensors and mobile sinks

Powered by digital transmission advances in recent years, wireless sensor networks (WSNs) are beginning to experience a boom in different areas. Of special interest are those applications offering real-time tracking and monitoring of objects in motion, both indoors and outdoors. A WSN can have a large number of nodes, each with multiple neighbor nodes. These nodes work together to create a self-configuring mesh that can efficiently achieve a common objective. In this paper, we focus on the accuracy of intruder tracking and monitoring, when relying on low-cost binary detection sensing mechanisms. To overcome the limitations imposed by this kind of sensors, we propose an intruder tracking algorithm to estimate the intruder location. In our study, we adopted the IEEE 802.15.4 standard for radio communications, and the MRLG (Mobile-sink Routing for Large Grids) protocol to route data to a mobile sink. Experimental results based on a grid sensor deployment show that the tracking error, measured as the mean euclidean distance between the estimated and the real intruder locations, is typically maintained below 10 meters, validating the applicability of the proposed solution.