Research And Simulations Of Cluster Based Routing Protocols For Ad Hoc Networks

Mobile Ad Hoc Network (MANET) is a multihop provisional autonomy system that is made up of a group of portable terminals with wireless transmitter, in which mobile nodes communicate with each other without the required intervention of any centralized access point or fixed infrastructure. It will be widely used in critical environment such as military or civilian emergency operations because it has many advantages such as it yarely, quickly and absolutely distributed etc. MANET routing protocol has to deal with the dynamic topology, unidirectional link, limited wireless bandwidth and capability-constrained of mobile nodes, etc. So, the MANET routing protocol must play a more important role than others.The architecture of Ad Hoc has two structures:plane and cluster.In the architecture of cluster,the network will be classified into several clusters,each cluster is composed of one cluster-head node and a lot of ordinary nodes.The communications between cluster-head depend on the gateway or distributed gateway nodes.The cluster-head node and gateway node can establish the high-level network which named virtual backbone.The most advantage of the cluster architecture are the nice expansibility,the unlimited scale,the smaller overhead and easier to implement the mobile management and local synchronization in network.By far, there already have much research and achievement on the cluster routing protocol.In this thesis, firstly we briefly summarize and compare the existing cluster routing protocols based on the characteristic of MANET, and give the analysis of CBRP(Cluster Based Routing Protocol) in detail.Secondly, we describe the improvement and modification about CBRP for cluster arithmetic and load-balance.One of improvement is MCBRP (Modified Cluster Based Routing Protocol) which is improved on the superiorly cluster algorithm, it optimizes the route request data packet transfer method,solves blindness "Broadcast" question in the CBRP agreement route control packets,uses route search mode which is gradually expanded to transmit broadcast packet,reduces redundant information in the network,and the routing overhead also reduces along with it;Optimize the cluster algorithm, effectively solve the cluster pitch point which can't to be replaced,energy consumption quickly,unsteadily network an so on, it optimizes a highest pitch point Cluster algorithm, alleviated the burden of the head of Cluster,obviously reduces the quantity of Cluster in the network,and then the network hastened stably; The other of improvement is MECBRP(Minimum Energy and Cluster Based Routing Protocol) which is improved on load-balance, it not only has considered the surplus energy in the path, but also had considered the dispersion of the node's energy in the path,and associates the dispersion with minimum from the formula of standard deviation. It reinforces the ability of the load-balance to some extent.Then elaborate the NS2 realization frame and the essential technology of Ad Hoc network cluster algorithm.This thesis has confirmed validity and feasible of CBRP,MCBRP and MECBRP through the simulation experiments in the NS2 simulation platform.Finally, we give the conclusion of our work and suggestions for future research direction of Ad Hoc Mobile Networks.This thesis is supported by National Natural Science Foundation of China (60672137,90304018),and the PH.D. Programs Foundation of Ministry of Education of China(20060497015).