Research And Simulation Of Cluster-Based Routing Protocols For Wireless Sensor Networks

As a novel way of acquiring information,wireless sensor networks have been an attractive research hot-spot all over the world. It is a kind of late-model non-infrastructure network,and can be used for testing,sensing,collecting and processing information of monitored objects.WSNs don't need fixed infrastrucrure,and take on the strong-point of convenience and strong invulnerability.So it can be widely used in commercial and military fields.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, research 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 on LEACH.Combined with the bad aspects of LEACH about choosing cluster head and single-hop communication, this thesis suggests improving way: Taking base station as a centre, we build a wireless sensor networks environment.Nodes are randomly distributed in a rectangular domain nearby base station.Firstly, the network is divided into some fan-shaped domains.We choose parts of nodes as candidated nodes of cluster-head according to certain criterion,and choose final cluster-head according to different competition radius.Then,unequal clusters are built according to signal strength.The cluster-head choosing adopts a distributed algorithm. The above improved thought has been given the concrete implementation by the NS2 software. The results show that the improved routing protocols can be implemented and available.The new protocol is more applied to large-scale network especially. This thesis has seven 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 classic routing protocols in WSNs.Chapter 3 describes of the mechanism of LEACH protocol and the good aspects and flaws.Chapter 4 describes the simulation software of NS2.Chapter 5 carrier some simulation experiments on several classic routing protocols, then analyses simulation results and compares the performance of protocols.Chapter 6 introduces a multi-hop unequal cluster-based routing protocol scheme based on layer after describing LEACH's flaws, and we give a compare of LEACH and new protocol with simulation.Chapter 7 summarizes this paper and gives the suggestions in the future work.