Energy-Efficient Hybrid Clustering Protocol for WSN-Based Smart City on 5G Infrastructure

Nowadays, clustering protocols have become the most popular technique to save energy consumption in WSN-based smart cities. However, to balance the energy load between cluster heads and other nodes in such protocols, global re-clustering has to be performed periodically, which incurs excessive energy consumption. In this paper, we propose an Energy-Efficient Hybrid Clustering (EEHC) protocol to enhance the energy efficiency of WSNs. In the proposed protocol, the whole network is divided into logically segregated sub-networks with the help of 5G base stations. In each sub-network, the nodes with close physical locations form a cluster, and the unique base station maintains the status information of the clusters with low-cost residual energy prediction algorithm. During each sub-network operation, the base station balances residual energy of clusters with the help of inter-cluster node reassigning algorithm, while the intracluster cluster head rotation mechanism ensures the nodes in each cluster have the same energy level. Based on the above two schemes, the residual energy of nodes in the network can be well balanced. Each base station also calculates optimal intercluster routes for all clusters in the local sub-network to avoid the high energy consumption for distributed inter-cluster routing discovery. Simulation results demonstrate that our EEHC protocol outperforms the latest clustering protocols in terms of energy efficiency, quality of service, and scalability.