ON-DEMAND CLUSTERING MECHANISM FOR WIRELESS SENSOR NETWORKS

Abstract

Wireless sensor networks impose strict energy efficiency requirements since the sensor nodes tend to operate with non-rechargeable batteries. The cluster-based communication structure is an attractive solution for energy efficiency, because the cluster head (CH) node gathers the messages from the sensor nodes and transmits them to the sink node. However, the CH selection is challenging due to the distributed nature of sensor networks. In this paper, we propose an energy-efficient clustering mechanism that effectively conducts the CH selection. Our proposal introduces three key contributions. First, the CH is selected on-demand, i.e., only when the residual energy is reduced by some level. Second, each sensor node maintains multiple residual energy levels in order to allow fair CH selection and gradual energy consumption. Finally, the CH node may conduct multi-hop communication to the sink to save energy. These three innovations are combined to provide an energy efficient clustering mechanism for sensor networks. Through extensive Qualnet simulations, we show that our scheme prolongs the network lifetime compared to the previous work.