Research On Underwater Acoustic Communication Network Protocol And Underwater Navigation Technology Based On SDN

Ocean is one of the hot research fields in China at present.Because it is very difficult to change the nodes of underwater,this paper introduces software defined network(SDN)technology to improve the flexibility of underwater acoustic network;In the process of exploring marine resources,the perception of underwater nodes’ position and time is very important;Therefore,this paper mainly focuses on underwater acoustic communication network based on SDN and underwater navigation and positioning technology.The main work and innovations of this paper are as follows:(1)This paper describes the characteristics of underwater acoustic channel,the difficulties of underwater acoustic communication,the layered structure and topology of underwater acoustic communication network,compares it with wireless communication and wireless communication network,analyzes the research status of underwater acoustic communication network and underwater navigation and positioning technology at home and abroad,and introduces the classic MAC Protocol and routing protocol of underwater acoustic communication network.(2)This paper expounds the basic principle of SDN,introduces the concept of flow table through the combination of SDN and traditional underwater acoustic communication network,realizes the separation of control plane and data plane of underwater acoustic communication network,and improves the management ability of water surface control center for the whole underwater acoustic communication network.This paper analyzes the data flow within and between nodes in the underwater acoustic communication network based on SDN,designs the cross layer protocols of the application layer and MAC layer based on the characteristics of underwater acoustic applications,and discusses a MAC layer access scheme for underwater mobile nodes based on the characteristics of underwater mobile nodes.(3)The MAC protocol based on slot allocation and slot competition in underwater acoustic communication network is studied.Two basic MAC protocols,s-aloha protocol and TDMA protocol,are improved.Rl-tdma protocol based on reinforcement learning improves the throughput of TDMA protocol and solves the problem of low slot utilization in TDMA protocol.The increase of throughput is related to the increase of slot utilization.Simulation experiments are carried out by building the underwater acoustic communication network simulation platform unsp.(4)The time service,positioning and navigation technology based on underwater acoustic communication network is studied.This paper discusses the classic underwater clock synchronization protocol,analyzes the synchronization time and accuracy of the protocol through experimental simulation,and realizes the unification of distributed underwater node time base;The active TDOA positioning technology based on long baseline and a passive positioning technology based on relative time base are described.The propagation delay and the error of beacon node position are simulated,and the influence on the positioning accuracy of long baseline is analyzed;The common underwater navigation technologies are introduced.The integrated navigation is realized based on Kalman filter.Through the combination of strapdown inertial navigation system and long baseline positioning,the positioning accuracy of long baseline is improved,and then the strapdown inertial navigation system can be modified.