Entity tracking within a Zigbee based smart home

Abstract

Modern Smart Home Automation (SMA) systems are predominantly based on wireless communication standards. New home automation setups can often include dozens of devices ranging from thermostats, humidity sensors, light switches, digital locks and cooling systems, all communicating on a common network. In this paper we focus on how SMA systems built on one of the most common standards (Zigbee), could be leveraged to provide a secondary benefit in the form of an Indoor Positioning System (IPS). IPS can be implemented in the form of Device Free Localization (DfL), Active tracking or as a combination of both techniques. A system containing a DfL implementation can detect and track moving entities by monitoring the changes in received signal strength (RSSI) values between nodes within a wireless network. DfL does not require the entity that is being tracked to carry an electronic device and actively contribute to the localization process. In Active tracking, the tracked entity contributes to the tracking process. In this paper both techniques are implemented individually, and a combination of both techniques is explored. Having implemented DfL and Active tracking, we were able to localize a person within a 3m × 3m quadrant with DfL with 80% accuracy. Active tracking resulted in a higher resolution of tracking compared to DfL, being able to localize a person within a 2m × 2m area with 95% accuracy. The accuracy of Active Tracking was then further increased to 98%, by coupling Active Tracking with DfL measurements.