Study On Improved LEACH Algorithm Based On Position Information

Recently, with the rapid development of technology, various energy efficient, low-cost, multifunctional sensors have been produced widely applied to many fields. Wireless sensor networks (WSN), which is the representative of the developing trend are well welcomed by scholars, engineers and technicians. WSN is considered as the most important technologies in21st century.Location is a key technology of WSN. When the location information available, not only can people improve the efficiency of protocols, but we can develop many new applications, such as weather monitoring, environmental monitoring, package tracking, books and archives management. The location is the main content of these applications. However, the researches for WSN protocol are focus on data, little research works on the location information has been introduced. In this paper, we put forward an improved LEACH protocol on the basis of location information in order to get higher energy efficiency.We analyze the LEACH protocol and find the shortcomings of the protocol. One of the shortcomings is that the number of clusters is too random. One of the shortcomings is these are no restrictions for cluster head selection. The other is cluster heads communicate with the base station by the way of single-hop. Meanwhile, we set focus on the DV-Hop localization algorithm to get the positions of sensor nodes. The algorithm requires only a small amount of communication and simple calculation.But it roughly assumes that the distance between neighbor nodes and faraway nodes is calculated by a fixed number of hops, without considering the actual situation and the uneven distribution of nodes. So the paper combines RSSI location algorithm and analytic geometry theory to improve it. When the distance of the adjacent nodes is less than the selected threshold, it is broken down into half hop. The distance of faraway nodes is corrected by the way of Analytic Geometry. The improved algorithm has higher accuracy than the original one. For the problem of LEACH, a method combined with improved DV-Hop localization algorithm and Kmeans clustering algorithm is proposed. First of all, the protocol calculates the positions of each node by improved DV-Hop Localization Algorithm, then uses Kmeans clustering algorithm to obtain more reasonable clusters by the position information. By centralized algorithm we select every cluster head of clusters according to the energy. Finally the cluster heads send messages to the base station by multi-chain communication way. The object of the whole algorithm is to reduce energy consumption and extend the network life. Experiments have done to compare LEACH, LEACH-C, DEEAC and the improved algorithm in two different scenarios. Result shows that the improved algorithm balances the energy consumption of every sensor nodes and saves energy of the whole network.