Energy-Efficient Overlay Protocol for BLE Beacon-Based Mesh Network

Bluetooth Low Energy (BLE) beacons are designed to operate for years on a coin-cell battery. However, the formation of a mesh network, overlaying on the existing Bluetooth Low Energy (BLE) beacons infrastructure, can severely degrade the lifetime of underlying beacons owing to the excessive current drawn by the scanning event. Even though we can sustain the lifetime of the underlying beacon with duty-cycle scanning, such duty-cycle scanning imposes another challenge to the overlay mesh in disseminating the packet. To this end, this paper proposes a novel overlay protocol that: 1) employs duty-cycle scanning to guarantee the lifetime of the underlying beacon, while 2) defining a set of scanning policies to increase the packet dissemination rate through the overlay mesh network. The duty-cycle scanning defines the scanning time slot based on the lowest feasible duty cycle unveiled through a comprehensive analysis of energy consumed by advertising and scanning events. The scanning policies, on the other hand, allow each node to explore all possible time slots before locking their scanning event to a particular time slot that is most likely to hear the incoming packet. Extensive experiments with practical implementation demonstrate the feasibility of our proposed overlay mesh for real-world use cases.