The Research And Improvement On Leach Algorithm For Wireless Sensor Networks

Wireless Sensor Network (WSN) is a latest model wireless network of fewer infrastructures less network and can be used for testing, sensing, collecting and processing information of monitored objects. WSN has intensive potential applications on military and other civil fields for its unique advantages. More attention has been paid to WSN and the research on each aspect of WSN is also an active field in current academe. Due to the limitation of power and memory size, the router protocol of wireless sensor networks must maintain small router information and reduce the power usage as much as possible. So, it is most important to improve the overall performance of Wireless Sensor Network by improve the existing router protocol effectively.The dissertation mainly studies and analyzes LEACH protocol, then brought forward some improvements to LEACH protocol based on analyzing the shortages of it. Firstly, this study concluded the best number of cluster-head node by analyzing the formulas. Secondly, the distributing of cluster-head nodes are improved by resetting up the probability parameter, so there is the problem of unbalanced distributing. This study gives the new probability to each node by scaling the distance between the sink node and it. This can resolve the unbalanced distributing problem. Finally, there brought forward the new communication mode, muti-hop instead of the intrinsic single-hop, it is more advantages on the energy saving that can prolong the lifetime of the whole network.Then the proposed routing algorithm in this paper was implemented in NS. The improved algorithm was compared with the existing Leach algorithms. Through the simulation results, it is proved that the improved algorithms can achieve good performance in terms of the system lifetime and energy cost. It can reduce the average energy cost of the network so effectively that can increase the continuous time for working and prolong the lifetime of the whole network. However, the improved algorithms still has a limitation that the transmission delay is a bit longer than Leach.