An energy efficient clustering and relay node selection algorithm in wireless sensor networks

Wireless sensor networks utilize large numbers of sensors to perform sensing and forwarding tasks in the monitoring area. Due to the resources constraints of sensors and the energy efficiency QoS requirement, prolonging the network lifetime is a major concern in WSNs. Clustering is an efficient approach to reduce energy consumption since it can reduce data transmission of the network. In most traditional clustering protocols, the cluster heads (CHs) aggregate the coming data from their cluster members (CMs) and send the aggregated data to the remote sink node directly or visa other CHs. However, assigning a node to serve as CHs and relay nodes simultaneously may result in unbalanced energy consumption. An energy efficient overlapping clustering and relay node selection algorithm is proposed, which selects different nodes as CHs and relay node to attain the balancing of energy consumption of the network. A direction fitness metric is designed to select the proper boundary nodes in the overlapping area to serve as relay nodes. Simulation results show that the proposed algorithm significantly prolongs the network lifetime.