Scalable and Energy-Efficient Broadcasting in Multi-Hop Cluster-Based Wireless Sensor Networks

In large-scale sensor networks, grouping sensor nodes into clusters has been considered as an effective way to achieve network scalability and robustness. Broadcasting over cluster heads (CHs) is often necessary for routing protocols to establish routes in cluster-based wireless sensor networks (WSNs), e.g., disseminating data to a mobile sink or flooding data centric queries sent by a sink. However, inter-cluster communication between CHs has not been sufficiently investigated in the existing literature. Specifically, most solutions either assume that CHs have longer radio ranges than ordinary nodes so that they can communicate directly, or that only one-hop clusters are constructed. In this work, we focus on scalable and energy-efficient broadcasting over CHs in multi-hop cluster-based WSNs, where a direct link between CHs is not necessarily available. We present a distributed heuristic protocol, named BOCH, to improve the scalability and energy efficiency of inter-cluster communication when performing the broadcasting service over CHs. Simulation results demonstrate the efficiency of the proposed BOCH protocol.