Research On Cluster Based Routing Protocol For Mobile Ad Hoc Network

Mobile Ad hoc Network is a multi-hop,temporary self-organizing network system that provides networking and comunication in an environment lack of infrastructure support.At present,MANET is widely used in wireless sensor networks,vehicle network,drone group communication,disaster-resistant temporary networks,military command networks,etc.,its main research direction is the application in the military field,such as Tactical Internet(TI)for situational awareness and battlefield command.In MANET,the channel resources and data rate are very limited,and the high mobility of network members has a great impact on the network stability.These characteristics have brought severe challenges to the design of MANET network structure and routing protocol.However,the existing MANET routing protocols show the disadvantages of increasing routing overhead,increasing end-to-end delay,and decreasing throughput when the network scale is expanded,which can not meet the needs of large-scale MANET communication.Therefore,it is very important to propose efficient routing technology for large-scale Manet to ensure network performance.Based on the comunication subsysem of the US military tactical Internet architecture,the Wideband Network Waveform(WNW),this paper combines the clustered access control technology with the Optimized Link State Routing Protocol(OLSR)to improve routing performance,and proposed a flat multi-frequency clustered OLSR(FMC-OLSR)for large-scale MANET environment.Compared with the traditional multi-layer hierarchical structure,FMC-OLSR adopts flat multi-frequency cluster-based structure to avoid the communication bottleneck caused by traffic aggregation in the upper layer of the network,and the multi-frequency access mode can avoid the underlying channel competition;FMC-OLSR reduce the routing overhead by limiting the broadcast range of the topology control messages inside cluster,which occupies the main part of the routing overhead.Combining the lowoverhead scheme of Distance Vector Routing(DVR),the gateway nodes broadcast the distance vector information of intra cluster routing table to spread the topology information,so as to reduce the delay of inter cluster routing establishment;based on the characteristics of the access control protocol,FMC-OLSR deeply optimizes the mechanisms of MPR selection algorithm,link cost calculation,and link information diffusion to improve the service quality of broadcast service and unicast service;the gateway selection algorithm based on inter-cluster comunication performance can improve the efficiency and stability of the entire network.In order to verify the performance of FMC-OLSR protocol,OPNET simulation software is used to model and evaluate it.By comparing the routing cost,service quality and channel resource reuse rate in different scenarios with standard OLSR protocol,it is proved that FMC-OLSR can effectively reduce routing overhead,improve quality of service and network scalability in large-scale MANET.