Based On Network Coding In Live P2p Data Transmission Strategy And Realization

Network coding is a new kind of revolutionary network communication technology, it enables coding before transmitting data on nodes, and makes data all equal and fungible in network, which can enhance network utilization. With the gradually mature of linear random network coding theory, the large-scale application of network coding becomes possible. On the other hand, there are plenty of peer-to-peer live streaming systems in present market, if still using the traditional idea of store-and-forward to improve their data transmission performance, technology bottleneck will be encountered inevitably. In this background, network coding technology is introduced into peer-to-peer live streaming systems in this thesis, the corresponding theoretical study and application development work are both implemented. The primary researching work is summerized below:(1) Proposing a data transmission strategy for peer-to-peer live streaming, which is based on both Network Coding and Controlled Push (NCCP). Based on the analysis of the problems of existing strategies, the NCCP strategy is proposed. This strategy combines the advantages of both network coding and push mode, it makes the decreasing of data transmission delay as the breakthrough point, and makes both the efficiently controlling of re-encoding data redundancy and the completely elimination of multi-source data redundancy as the key emphasis in work. The strategy also introduces several merits of network coding, such as high network robustness and efficiently load balancing.Furthermore, the foundation structure and mating mechanism of NCCP strategy are also designed, they include the improved Gossip network, the dual-queue streaming buffer, the choice of network coding granularity, and the playback synchronization mechanism with fixed starting delay, all of the work forms a new set of relatively complete solutions for data transmission strategy.(2) Designing and implementing a peer-to-peer live streaming prototype based on network coding. The prototype is developed according to the standard procedure of software engineering, and is designed to be simple, hierarchical and modular, it has the basic functions of a live streaming system, and provides a good platform for evaluating the actual performance of NCCP strategy in the real network environment.(3) Fully testing NCCP strategy and the prototype system. With both simulation and prototype experiments, the function and performance of both NCCP strategy and the whole system are fully tested.With the help of Distributed Peer-to-Peer Simulation System (DPS), a series of detailed comparison tests for the key performance indicators of NCCP and traditional strategies are carried out. The results shows that NCCP strategy can effectively reduce the ratio of data transmission delay to only 0.21%, and compared with the traditional one, it reaches a remarkable promotion of 60% on both node starting and load balancing performance, this illustrates the combined advantages of network coding and push mode, which includes low transmission delay, high network robustness and efficiently load balancing.And through the actual deployment of the prototype in campus network, the actual performance of both NCCP strategy and the whole system are inspected, which proves the feasibility of the strategy and indicates the practical application value of network coding.