Research On Optimization Of Mobile Ad Hoc Network Routing Protocol In Large-scale Tactical Internet

Mobile Ad Hoc Network is a multi-hop and temporary self-organizing system,which is a kind of distributed network that can provide the ability to communicate without the fixed network infrastructure.It has an extensive application prosperity in the field of military communications,and the most typical application is the Tactical Internet.In the battlefield environment,the Tactical Internet can be regarded as the Mobile Ad Hoc Network.It is the performance of the network centric warfare in the local battlefield and is the infrastructure to guarantee the transmission of information in the battlefield.In the Tactical Internet,due to the limited communication resources,channel rates and the dynamic changes of network topology,the network and routing protocols have faced new challenges.Especially in the large-scale battlefield environment,the mobility of nodes will generate a large number of network messages,which result the congestion of channel and the long delay.Therefore,the design and optimization of routing protocols play a crucial role in the construction of the large-scale Tactical Internet.The aim of this paper's research is the Wideband Network Waveform(WNW),which is the current U.S.military's new Tactical Internet technology architecture.Based on the OLSR protocol and combined with the clustering technology,cross-layer optimized technology and hazy sighted technology,this paper proposes the CH-OLSR protocol that is suitable for the large-scale battlefield environment.Compared with the OLSR protocol,network control messages are no longer broadcast over the network,but rather they only broadcast in the cluster.In the meantime,CH-OLSR adopts hazy sighted technology and cross-layer optimized technology to reduce network control overhead.In order to guarantee the performance of routing function,the network nodes are divided into cluster head nodes,gateway nodes and common nodes.The gateway nodes are responsible for the inter-cluster communication,and broadcast the abstract topology messages,which reduce the control overhead to suit a large-scale Tactical Internet.An extensible gateway selection strategy is designed to enhance the stability of the large-scale Tactical Internet.In order to verify the CH-OLSR protocol performances,this paper uses OPNET network simulation software to model and design a variety of battlefield simulation environment.Compared with the routing performance,overhead,delay and so on,the simulation results verify that the CH-OLSR protocol is more suitable for large-scale Tactical Internet.This paper is helpful to the development of routing protocols in the large-scale Tactical Internet,and has the important reference value for the development of the new generation of Tactical communication network.