Study On The Cooperative Ad Hoc Technique For Unmanned Surface Vehicle

With the proposal of "Building a Maritime Power" and "Maritime Silk Road",marine activities such as marine production,monitoring,safety and emergency response have become more frequent Marine activities have increasingly higher requirements for maritime information transmission,making the research on marine communications more and more urgent.Combining the characteristics of maneuverability and intelligence of unmanned surface vehicle and other unmanned systems with the characteristics of decentralization,selforganization,and strong robustness of mobile Ad Hoc networks to form a maritime unmanned surface vehicle cooperative Ad Hoc network,which is applied various military and civilian activities.Medium Access Control protocol has the functions of controlling node access channel,sharing channel resources,supporting service priority and so on,which has become the research focus of Ad Hoc network.Aiming at the multiple priority services that need to access the channel in cooperative Ad Hoc network to ensure the quality of high priority services in communication,the following contents are studied.Firstly,a new random access protocol based on channel awareness is proposed to solve the problem of prioritizing multiple services and guaranteeing the quality of service of high priority services in Marine emergency communication or observation.The protocol uses a priority mechanism and controls the sending of packets with different priorities through the size of channel occupancy statistics.The OPNET simulation software was used to simulate performance indicators such as throughput,average end-to-end delay,and packet access success rate.Compared with CSMA,it is found that the proposed protocol can improve the network throughput,reduce the average end-to-end delay of high-priority services,improve the success rate of packet access in the network,and guarantee the quality of service of high-priority services in the network.Secondly,in order to guarantee the quality of service of high-priority services in the airsea interface cooperative observation system,the slotted ALOHA protocol based on business priority is proposed.The channels are divided into data channels and ACK channels,and different priorities are controlled through the number of retransmissions,and the transmission of high-priority data packets is guaranteed first when the low-priority queue backs off.The OPNET simulation software is used to simulate slotted ALOHA protocol,slotted ALOHA protocol based on retransmission and slotted ALOHA protocol based on service priority,and the performance indexes such as packet access success rate and throughput are analyzed.The results show that the proposed time-slot ALOHA protocol based on service priority effectively improves the network throughput and packet access success rate under low load conditions,and improves the throughput and packet access success rate of high-priority services.Guarantee the quality of service for high-priority businesses.The simulation results show that the research contents can effectively guarantee the quality of service in terms of delay,throughput and success rate of high-priority business in cooperative Ad Hoc networks.The two proposed MAC protocols for Ad Hoc networks are of great significance to the research of MAC protocols supporting multi-service priority in maritime unmanned surface vehicle cooperative Ad Hoc networks.