Research On Reliable Transmission And Routing Protocol Of UASNs Based On DTN

Underwater Acoustic Sensor Networks(UASNs),as an important means to obtain large-scale marine information,have been widely used in marine monitoring,resource exploration,disaster prevention,tactical surveillance and other fields.Due to the characteristics of underwater acoustic channel,such as long transmission delay,high bit error rate and frequent link interruption,underwater acoustic communication has been faced with great challenges in data transmission reliability.Traditional Transmission Control Protocol/Internet Protocol(TCP/IP)architecture deteriorates sharply in this communication scenario and cannot be fully applicable.Therefore,this paper studies the Delay Tolerant Network(DTN)protocol architecture that can overcome the communication problems of intermittent connections,large delays,and high bit error rates,including its reliable transmission technology and routing technology.Specifically,in order to build high-reliability UASNs,the research of this paper is specifically carried out around the following contents.Firstly,the basic principles of UASNs topology classification,DTN architecture and reliable transmission technology are introduced in detail.The network topology of UASNs is divided into three types: centralized,distributed and multi-hop.The DTN and TCP/IP protocol systems are compared,the differences between the two in terms of system structure and communication problem handling are introduced,and the functions of the bundle layer and convergence layer in the DTN system are explained in detail.For reliable transmission technology,the principles,advantages and disadvantages of different methods are specifically introduced from the two categories of error control and multipath transmission.The above content is the necessary theoretical basis for subsequent research.Secondly,this paper designs a reliable transmission method combining erasure coding technology and multipath routing technology.In view of the low transmission success rate caused by the traditional method that does not consider the path allocation of coded packets in different link states,this method is based on the mathematical derivation of the underwater acoustic attenuation model,and the allocation mechanism of erasure coding packets transmitted on multiple paths based on Bayes theorem is designed to improve the success rate of receiving data at the destination node.In this paper,a simulation comparison between the allocation mechanism and the reliable transmission method is carried out.The results show that,compared with the traditional method,the method proposed in this paper has a higher rate of successful data delivery.Finally,this paper designs and simulates the DTN architecture and routing protocol for UASNs.This paper is oriented to the application of marine environment monitoring network with multi-hop hierarchical topology.Aiming at the characteristics of long propagation delay of underwater acoustic channel,it studies the operating mechanism and frame format design of Delay Tolerant Link State Routing(DTLSR)protocol.The link weight calculation method of DTLSR is modified,and the underwater acoustic DTLSR protocol is obtained.Then for the need of reliable transmission,a multipath routing algorithm based on the underwater acoustic DTLSR protocol is proposed.Compared with the traditional link state routing protocol,the underwater acoustic DTLSR routing protocol has advantages in reducing routing overhead and quickly establishing routing tables.Moreover,facing the actual application requirements of the marine environment monitoring network,the simulation realization of the DTN full-architecture network including the underwater acoustic DTLSR routing protocol was completed,and the verification was carried out by the OPNET software simulation platform and the multi-node hardware platform based on the channel simulator.It proves that the DTN full-architecture protocol stack is achievable and has advantages in reliable transmission.