Research On The MAC Protocolsof Underwater Acoustic Networks

With the rapid decrease of resources in the world,the competition of the ocean resource has become more and more fierce.The technology of ocean engineering has achieved big progress in our country.To achieve thisgoala deep study is made in MAC layer protocol.Firstly,a platform that can perform simulation and emulation of MAC layer protocol is built.Then the advantages and disadvantages of different MAC layer protocols are compared,and suitable MAC layer protocol is selected.This article is based on this demand to carry out the related research.Firstly,this article analyzesthe frame structure of NS2 and its extended softwarefor network simulation and experiment.Secondly,according to the requirements of the application,this article focuses on the theories of ALOHA,T-Lohi,and DACAP MAC layer protocol.Based on the pre-built underwater acoustic communication network development environment,ALOHA,T-Lohi,and DACAP MAC protocol are simulated in the conditions of different periods and different length of packets.The network throughput,end to end delay,and the packet loss rate,as functions of the packet length or the periods are investigated through the study,respectively.This result providesthe important reference basis for optimizing periods and the packet length for the field trial.Thirdly,T-Lohi MAC layer protocols are implementedbased on the theory of T-Lohi MAC layer protocols in the pre-built underwater acoustic communication network development environment.And then,in order to improve the efficiency in real system,the algorithm in routing layer is modified.Finally,using the integrated software system and MAC layer based on different periods and different lengths of packets,field testsshow that verifying the relationship between ALOHA,T-Lohi,andDACAP MAC layer protocol with network throughput,end to end delay and the packet loss rate of underwater acoustic communication network are completed.The tests prove that T-Lohi and DACAP MAC layer protocols are transplantedsuccessfully and can be apply in field test.The results are analyzed anda standard to select MAC layer protocol is provided.