The Improvement And Simulation Of LEACH Clustering Routing Protocol For WSNs

Wireless Sensor Networks consist of lots of micro-sensor nodes deployed in monitored area,through wireless communication way,which build a multi-hop and self-organizationed network system.WSNs' destination is to apperceive,collect and process information of apperceived object in overlay area,then to send these information to observer.Sensor Networks are characteried by large scale,self-organizationed,dynamic and data-center and are applied to military matters,environmental monitoring and forcasting,intelligent furniture,machine monitoring and municipal traffic and so on.The routing protocols of WSNs are one of most hottest issues in related research fields.As the dynamic and variable topology,those traditional routing protocols cannot be applicable to WSNs and new routing protocols must be designed.In recent years,there are many routing protocols applicable to WSNs, researching on LEACH based on clustering structure is also an important problem in WSNs.Firstly,this thesis describes the basic characteristic of WSNs and introduces several typical routing protocols in detail.Secondly,it stresses the priciple and mechanism of LEACH and analyzes the good aspects and bad aspects of this routing protocol,moreover,gives the improvement and simulation on LEACH.Combined with the bad aspects of LEACH,this thesis suggests improving way: on cluster head's selecting,we take parts of nodes as candidate cluster-head through increasing cluster-head's probability,then setting weight and competition radius and make nodes with bigger weight become formal cluster head.At the same time,we add intra-route within cluster heads,in order to avoid remote transmission between cluster head and base station in LEACH.The above improved thought has been given the concrete implementation by the NS2 software.The results show that the improved routing protocol can be implemented and it is more effective in aspect of energy and network survival time. This thesis has six chapters as below:Chapter 1 introduces the concept,the characteristic,research hotspot and application foreground and key technology of WSNs and introduces the source and research meaning of this thesis,the working and innovation of which are given finally.Chapter 2 describes of the characteristic,the design demand,the performance index and sort of protocols in WSNs and researchs on several classic routing protocols and compares with them.Chapter 3 describes of the mechanism of LEACH protocol and the good aspects and flaws and analyses several typical improved protocols based on LEACH.Chapter 4 describes an improved LEACH protocol,called LEACH-improved.Chapter 5 describes the simulation software of NS2,and carries some simulation experiments on LEACH and LEACH-improved,then analyses simulation results and compares the performance of protocols.Chapter 6 summarizes this paper and gives the suggestions in the future work.This thesis is supported by National Natural Science Foundation of China (NO.60672137,60773211),Specialized Research Fund for the Doctoral Program Foundation of Ministry of Education of China Under Grant(No.20060497015),New Century Excellent Talent Plan Support plan(NO.NCET-08-0806).