摘要：Marine fishery production safety has always been a livelihood issue of high concern to government departments at all levels in China. With the construction of marine informatization, a large number of fishing vessels have entered the Vessel Monitoring System (VMS). The massive, highly concurrent, and continuous track data generated by these vessels has posed great challenges to real-time data distribution. To cope with low distribution efficiency in the original data distribution system, this paper proposed a data distribution model based on the combination of network coding and UDP, which improves both reliability and efficiency of data distribution. In order to further enhance the efficiency of data distribution, a Codeword Distance Priority Protocol based on Buffer Map (CDPPBM) was added to the proposed model for the concentration of innovative codewords in the network, thereby increasing the effectiveness of data received by nodes. Experimental results show that the protocol proposed in this paper improves the data distribution efficiency by about 75% on average, compared with the LT code. The influence of data block size on network coded data distribution system is not involved in the previous work. Therefore, this paper discusses the Block to Piece Protocol (BPP) for large files, divides large files into fixed sizes equally, and distributes n data blocks multiple times to find the optimal piece size. The experimental results show that there is an optimal n for large files of different sizes, which can maximize the efficiency of data distribution.
