Improvement on LEACH by combining Adaptive Cluster Head Election and Two-hop transmission

LEACH is a popular hierarchical routing protocol which efficiently maintains the energy storage of nodes in Wireless Sensor Network (WSN). The nodes using LEACH are divided into clusters. The randomized rotation of cluster head in each cluster can save the energy consumption of nodes. However, the random election of cluster heads without considering nodes' residual energy may reduce and oscillate the lifespan of network. In this paper, we have proposed the Adaptive Cluster Head Election and Two-hop LEACH protocol (ACHTH-LEACH) to prolong the lifespan of network. It improves LEACH by using an adaptive algorithm of cluster head election and allowing multi-top transmission among cluster heads and Base Station (BS). Nodes are tagged as near nodes or far nodes according to the distances to the BS. The near nodes belong to one cluster while the far nodes are divided into different clusters by the Greedy K-means algorithm. The cluster head is shifted and the node with the maximal residual energy in each cluster is elected. During the data transmission phase, the far cluster heads may select the cluster head in the near area as the next hop or communicate directly to the BS. The simulation results have shown that ACHTH-LEACH outperforms several existing protocols in terms of network's lifespan. Especially, ACHTH-LEACH can achieve more than 2 times longer lifespan than LEACH and build a more stable routing environment.