Research On Clustering Algorithm For Wireless Sensor Network Based On LEACH Protocol

With the characteristics of scalability, high reliability and easy deployment, wirelesssensor network（WSN） integrates sensor technology, embedded computer technology,microelectronic technology, wireless communication technology and so on. WSN is anemerging field of cross-over study. It has broad application prospects in the military andnational defense, environmental monitoring, medical and rescue, as well as commercialapplications. Wireless sensor network is data-centric, which acquaints and processes theinformation of the monitoring region via the node. Then it transfers the information to theterminal. At the same time, the sensor nodes have the disadvantage of using battery supplyingpower and cannot add when energy exhausted. Therefore, how to efficiently utilize the limitedenergy of nodes is the focus and difficulty in the field of WSN.In this paper, on the basis of systemic analysis the LEACH protocol in clustering routingprotocol, deeply study of the advantages and disadvantages of the protocol, a routingalgorithm ECHNL based on the probability of hierarchical cluster head is presented to makebetter improvement of LEACH and gets a better result. The organization is as follows:Firstly, an overview of the research background and the main work are summarized, andthe architecture of wireless sensor network is introduced, which includes communicationsarchitecture, the sensor nodes structure and the protocol structure of WSN. Moreover, thewireless sensor network is compared with the traditional networks and Ad-hoc network.Then, the routing protocol of WSN is systematically studied and makes correspondingclassification for different environmental requirements. The typical routing protocol of WSNis introduced and that routing algorithm in the WSN is evaluated. The main factor of design arouting protocol with excellent performance is summarized, and the dual-homed fault-tolerantrouting technology is thoroughly studied.The thesis focuses on the study of LEACH protocol, analyzes the advantages anddisadvantages of the agreement. According to three problems of random election in theprocess of establishment of cluster head, not considering the residual energy in the election ofthe threshold T（n） and limited own fault-tolerant mechanism of LEACH protocol, thispaper combined1:1dual-homed fault-tolerant routing technology, and introduced the thoughtof the main cluster head and the alternative cluster head, adopting the probability ofhierarchical cluster head election, improve the electoral threshold. And then, an improvedapproach based on energy and hierarchical cluster head election probability is presented, analgorithm called ECHNL is proposed in the thesis. This paper describes cluster headestablishment phase and data stable transfer phase of the algorithm ECHNL in detailed, which including the initialization of the network nodes, the cluster head election, the inter-clusterand intra-cluster routing structure. Both the theoretical analysis and the simulation indicatethat ECHNL algorithm is better than LEACH protocol in terms of energy consumption of thenetwork nodes.Finally, the simulation environment of improved algorithm ECHN is built through thesoftware platform of NS2. The performance of the algorithm ECHNL is compared withLEACH and RPUCDH. The simulation results show that ECHNL has a relatively highoptimize cluster head election, better-balanced network node energy consumption, andeffectively extending the network lifetime, comparing with LEACH and RPUCDH.