Abstract: Implementing energy-efficient and fault tolerant routing protocols for Wireless Sensor Networks (WSNs) applications such as, seismic monitoring, battlefield surveillance and civil structural health monitoring is a great challenge due to the continuous change of the network topology. Moreover sensor nodes are prone to energy drainage and failure in WSNs because of harsh environment. Therefore, energy-efficient and fault tolerant are essential issues for WSNs. Low-Energy Adaptive Clustering Hierarchy (LEACH) protocol is one of the efficient and important protocols for routing in WSN, which maintains balanced energy consumption. ; EF-LEACH proposes vital solutions to some shortcomings of the pure LEACH. EF-LEACH provides network fault tolerant and achieves reliability and quality of service. But EF-LEACH is suffers with low energy, delay and low network lifetime. So in this paper we modified the EF-LEACH by adding two cluster heads in each cluster. The proposed approach will improve the network life as never the cluster head will die. As a cluster head will die it will be replaced by its secondary cluster head.

Keywords: Clustering, LEACH, Energy Efficient and fault-tolerant LEACH (EF-LEACH) protocol, two cluster heads, Wireless Sensor Network.