Device-Free Passive Human Counting with Bluetooth Low Energy Beacons

The increasing availability of wireless networks inside buildings has opened up numerous opportunities for new innovative smart systems. For a lot of these systems, acquisition of context-sensitive information about attendant people has evolved to a key challenge. Especially the position and distribution of attendants significantly influence the system's service quality. To meet this challenge, several types of sensor systems have been presented over the last two decades. Most of these systems rely on an active mobile device that has to be carried by the tracked entity. Contrary to the so-called device-based active systems, device-free passive sensing systems are grounded on the idea of detecting, tracking, and identifying attendant people without carrying any active device or to actively taking part in a localization process. In order to obtain information about the position or the distribution of present people, these systems quantify the impact of the physical attendants on radio-frequency signals. Most of device-free systems rely on the existing WiFi infrastructure and device-based active concepts, but here we want to focus on a different approach. In line with our previous research on presence detection with Bluetooth Low Energy beacons, in this paper, we introduce a strategy of using those beacons for a device-free passive human counting system.