Occupancy Detection by Multi-Power Bluetooth Low Energy Beaconing

Indoor environments are becoming more and more sensorized. Technologies such as Bluetooth, Wi-Fi and RFID are commonly used to provide connectivity to people living in such spaces. However, these technologies can also be exploited to automatically detect empty/occupied indoor areas and who is occupying that area. Our work goes toward such direction proposing an occupancy detection strategy based on the Bluetooth Low Energy (BLE) stack. We designed our solution by considering two fundamental challenges: costs and power-efficiency. We tested our system in several offices of our research institute by deploying few Bluetooth receivers and assigning to people a Bluetooth tag integrated with the institute's badge. We analyzed the performance of our solution with Bluetooth tags emitting at one single power first, and then we further refined our solution by considering the possibility of using beacons emitting simultaneously at different powers. The obtained results show a high accuracy without significantly affecting the energy consumption of the tags.