In wireless sensor networks, energy efficiency is an important research issue. The data transmission times could be decreased effectively to achieve energy efficiency by applying a cluster-based structure. This study proposed a level-based energy efficiency clustering approach. Each cluster replaces its cluster head and re-clusters periodically according to the established energy level. A cluster head is a node that has more residual energy and lower communication cost compared to other nodes. This level-based energy efficiency clustering approach could decrease the replacement times of cluster heads, thus avoiding the excessive energy consumption caused by frequent replacement of cluster heads. The simulation results showed that this approach has less energy consumption and can effectively extend the network lifetime.
