Research On Planning And Protection Schemes In High Availability-oriented Long Reach Passive Optical Network

With the explosion of communication services and the expansion of communication network scale, reliability will play a more prominent role in next-generation passive optical networks (NG-PONs). Since traditional PONs have several limitations, such as low data rates, small wavelength channel counts, limited transmission distance. NG-PONs face much more challenges to provide the same level of reliability in contrast to the conventional PONs, NGPON has been considered as one of the most promising technologies to enable high-speed backbone networks. Long Reach Passive Optical Network (LRPON) is one of the most significant research fields for the evolution of NGPON. This thesis focuses on LRPON, which is the most promising technology of NG-PON. The main contributions of the thesis are summarized as follows:Firstly, the architecture and reliability of PON network topology has been studied, includes reliability into LRPON reliable network layout planning at the stage of source design and planning of network deployment. And three protection strategies for PON topology are proposed respectively according to the reliability requirements of different subscribers. But, the protection strategies with higher reliability would increase the deployment cost of the network. It means that subscribers have to afford the higher cost for protection strategies. Then, the problem formulations and mathematic models of the three protection schemes are presented in detail.Secondly, the three protection strategies are optimized by using Gurobi Optimization Solver. The deployment solutions of verification scenarios demonstrate the feasibility of the three protection strategies. And the relationship between deployment cost and the reliability of network has been analyzed by numerical results.Finally, three novel protection algorithms are proposed to reduce the high complexity of the formulation for large scale LRPON deployment problems. The deployment solutions given by the three protection algorithms may not be the optimal ones. But, the simulation results and case analysis show that the three protection algorithms could optimize the topology deployment solutions of LRPON and outperforms Gurobi in terms of efficiency. And there is only a small gap between the results of protection algorithms and Gurobi optimizer which is acceptable for practical network deployment in real world.