The Research Of Transmission Mechanism Based On Network Coding And Multipath Routing In Underwater Acoustic Networks

As the development and utilization of ocean, underwater acoustic networks gradually become one of the key technology of underwater acoustic engineering. As acoustics channels have the characters of low transmission rate, complexity environment noise, high path loss and multi-path action, which make underwater acoustic networks have the characteristics of long transmission delay, low bandwidth, high error rate, and low reliability. These characters determine the transmission in the acoustic environment is hard to balance transmission reliability and efficiency. Since the theory of the existing terrestrial wireless sensor network can't be directly applied to the underwater acoustic sensor network, the transmission strategies for the underwater acoustic sensor network need be deeply researched. The research of this thesis is based on the project of the National Science Foundation. On the basis of the existing research on network coding technology and multipath transmission technology, this paper studies the transmission mechanism for underwater acoustic sensor network, the main contents include:1. The basic theory, classification and application of network coding algorithm are introduced, and the random linear network coding is analyzed emphatically. Then the paper summarizes the multipath transmission mechanism based on network coding (MNC), studies the network model that applies network coding and discusses the problems in applying MNC to underwater acoustic networks.2. A network coding and multi-path transmission mechanism based on multi-hop acknowledgment technique (MHA-MNC) is put forward for underwater acoustic networks,and the performances of proposed algorithm are tested and analyzed through the simulation experiment.3. This paper studies the transmission mechanism based on routing protocol and MNC,and analyses the problem of the transmission redundancy. To solve this problem,a transmission mechanism based on dynamic redundancy control mechanism (DRC-NCMR) is proposed to promote the transmission efficiency effectively.4. An underwater acoustic network model based on acoustic channel models is established with the help of OPNET modeler. Taking the successful deliver ratio, normalized redundancy and energy efficiency as the evaluation parameters, the transmission mechanism combining MHA-MNC and DRC-NCMR is compared with network coding multipath routing strategy (NCMR). Simulation results demonstrate that the optimal transmission strategy performs better than NCMR.