Research And Implementation Of Routing Protocol For Maritime Broadband Wireless Ad Hoc Network

With the increasing frequency of human maritime activities,the demand for maritime broadband communications is also increasing.The current maritime wireless communication system has the problems of narrow bandwidth,low rate,and high cost,which cannot meet the needs of modern maritime Internet communication services.There is an urgent need for a maritime wireless communication system that supports broadband,high rate communication,and low cost.Based on the particularity of the maritime communication environment,this paper studies the routing protocol of the maritime broadband wireless Ad Hoc network,designs and develops the routing protocol software of the communication node of the maritime Ad Hoc network to realize the multi-hop networking function.The main contents of this paper are as follows:Routing protocols are the focus of wireless Ad Hoc networks research.Each protocol has different advantages for different application scenarios.Aiming at the maritime communication environment,the principle analysis and comparison of DSR(Dynamic Source Routing,DSR),OLSR(Optimized Link State Routing,OLSR)and AODV(Ad hoc On-Demand Distance Vector Routing,AODV)are conducted,and simulate the packet delivery rate and average end-to-end delay of the three protocols through simulation software.AODV is more suitable for maritime wireless communication.Select AODV as the routing protocol of maritime broadband wireless Ad Hoc network,combine the characteristics of maritime ships,use AIS(Automatic Identification System,AIS)message to extract the ship's location information,improve the process of AODV route discovery,reduce routing overhead,propose AIS aided AODV routing protocol(AIS-aided AODV,A-AODV).Based on the embedded software development environment,develop A-AODV routing software and design the overall architecture of the software,and divide the entire protocol function into multiple functional modules according to different message types,including RREQ processing module,RREP processing module,RERR processing module,MAC layer data processing module and transport layer data processing module.Propose solution to the design difficulties,then implement the program of the routing table and location table,design the functional modules in detail,and finally the auxiliary function design,mainly including multi-thread synchronization,ring buffer design,message flag,Ethernet communication and so on.After the program is compiled,it runs on the communication node of the maritime Ad Hoc network based on SDR(Software Defined Radio,SDR),configures the physical layer parameters,builds the experimental environment,and designs the module function verification experiment,multi-hop broadband data transmission,rediscover the routing experiment when the link is interrupted and,package delivery rate statistics.The experimental results show that the designed and implemented A-AODV routing software can realize the functions of route discovery and maintenance,multi-hop data transmission of Ad Hoc network communication nodes,which can meet the needs of modern maritime Internet services for high-speed,multi-hop transmission.It has certain practical significance for the development of maritime broadband wireless Ad Hoc network applications.