| As the rise of social networks and P2P services, the trend of local traffic is increasing, putting forward higher requirements to the ability to exchange local equipment. More traffic through the local exchange is completed, and the network also reduces the pressure on other areas. As an important technology on the last mile access network, PON network has the tree structure which is low connectivity. To some extent, it limits the efficiency and scope of the network. Network coding function effectively reduces the pressure on local traffic, making the original network throughput be increased by half, while it provides a new encryption method as a very meaningful design.In this study, the integration of passive optical networks and network coding techniques is the study objective. The aspects of DBA algorithm, security performance and system design for network coding passive optical network are the main purpose. Then an efficient, safe, and practical network coding passive optical network system is achieved.This paper’s mainly innovations and research results are as follows:The main innovations:(1) Combination with network coding and passive optical networks. An important trend in the current business network development is localization. It puts forward higher requirements to the capacity of local exchange networks, but also is an important business driver. Fortunately network coding passive optical network system can exactly solve a problem.(2) The DBA algorithm using graph theory. Network encoding PON system introduces the relationship between ONU and brings many new properties. Especially the relationship between networking encoded data, existing DBA algorithm does not take it into account. The new DBA algorithm, fully taking the network coding data into account, can reduce data delay, release OLT storage, improve network coding efficiency, and at last improve PON system transmission efficiency.(3) The simple XOR encryption. Traditional encryption algorithm can ensure security on a certain degree, and because of the constraints of hardware conditions, advanced encryption algorithm needs large cost, low encryption algorithm makes low security. But network coding passive optical network theoretically achieve the highest standards of data security, encrypting with one-time key, which is the conventional network system cannot achieve.Main research achievements:(1) Design and realization of passive optical network device supporting network encoding is completed. Key technologies for convergence of network coding and PON have been studied. The network coding passive optical network system platform is built.(2) The mathematical model for network coding dynamic bandwidth allocation algorithm is established. Effective network coding dynamic bandwidth allocation algorithm is proposed, and has been tested and verified through simulation.(3) In-depth research for passive optical network encryption algorithm is made. Possible risks of the triple-churning encryption algorithm are found. The paper shows the improvement of passive optical network system security performance through network coding.In this study, in order to achieve innovation and engineering applications, by the system control layer, data layer design, and innovative research for equipment realization, we develop a complete NC-PON system and equipments. Then we propose some network coding dynamic bandwidth allocation algorithm, and introduce graph theory and related theoretical system. At last we research changes to passive optical network system security performance for network coding, and find that combination with network coding and encryption algorithms can improve network security significantly. |
