The Research And Improvement Of LEACH Routing Protocol In Wireless Sensor Networks

Wireless sensor networks (WSN), is a new technology about acquiring and processing information. It includes the sensor technology, embedded technology, wireless networks communication technology, distributed information processing technology and micro-elect-mechanical technology, and can be able to monitor, ap-perceive and collect the information of the environment or monitoring objects real-timely. Then the information is processed by embedded systems and sent to terminals via self-organized networks with multi-hop relay, so as to implement the "Compute Everywhere" conception. It can be forecasted that with its development and the commonly application, WSN will bring deeply influence and make a great contribution to people's life and the transformation of industry. At present, many researchers focus on the research of routing protocols, MAC protocol, QoS, network topology control, network security and so on. In this paper we will pay attention on LEACH (Low Energy Adaptive Clustering Hierarchy) routing protocol of WSN.Thinking of the insufficient in the LEACH routing protocol, this paper presents two following aspects to improve it:1. Considering the problems of the energy consumption during the cluster selection of LEACH routing protocol and its limits on compression ratio of cluster-header nodes, we improve the formula of the computing for optimal LEACH cluster-header number and prove that the network lifetime is the longest one in the new given circumstance. With the results of simulation experiments, it indicates that the network lifetime is longest if the data received by cluster-header can be totally compressed at a time and sent to the base station.2. Considering the residual energy of the nodes and the link cost, we adopt a clustering method of partitioning virtual area and introduce nodes weight to improve cluster-header selection algorithm, which ensures that the cluster-header nodes can be distributed homogeneously in the networks. So that a more optimal cluster structure is produced, this can avoid nonhomogeneous distribution of the cluster-headers and the big difference among the number of each cluster and can reduce the energy consumption of communication within clusters. Meanwhile, the way of multiple-hops among clusters reduces the communication consumption during the long distance between cluster-header nodes and base station. Then it makes sure that all the energy loads in the networks can be distributed averagely to each sensor node, which can reduce the networks energy consumption and prolong the existence of the networks effectively. With the results of simulation experiments, it indicates that there is little change of network delay within the LEACH-W algorithm and it is of more balance for the clusters and dead nodes. At the same time the number of alive nodes is increasing and the network energy consumption is reduced effectively, which is contributed to the prolongation of the network lifetime.