An Adaptive Duty Cycling Mechanism for Energy Efficiency in Bluetooth Mesh Networks

The Bluetooth Mesh (BM) standard was released in 2017 to expand the application of the Bluetooth Low Energy (BLE) technology for larger-scale multi-hop Internet-of-Things (IoT) networks. To implement multi-hop data delivery, BM defines a relay feature for BLE nodes using a controlled flooding algorithm for data dissemination. By default, the relay nodes persistently scan the advertising channels to receive packets from their neighbors and broadcast. However, it has a big impact on the energy consumption and lifetime of the relay nodes, especially when they have limited energy resources. On the other hand, any constant and homogeneous setting of a duty cycle for relay nodes across the network leads to inefficient performance since the nodes can be in different spatial and temporal conditions. This paper proposes a run-time adaptive duty-cycling mechanism for relay nodes to reduce unnecessary energy consumption and yet collaboratively make a reliable end-to-end data delivery. Each relay node independently decides about its suitable duty cycle based on its local conditions. The proposed method is evaluated using a publicly available BM simulator, showing a significant reduction in energy consumption (up to 57% in the conducted experiments) while preserving the packet delivery performance of the network.