Precise Failure Location and Protection Mechanism in Long-Reach Passive Optical Network

In this paper, optical code domain reflectometer (OCDR) and optical time domain reflectometer (OTDR) are used for centralized monitoring and troubleshooting any fault occurring in the network. It combines the advantages of the OTDR scheme and the optical coding scheme, which can supervise the whole long-reach passive optical network in a cost-effective manner. Network management system in the central office can initialize monitoring, locating failure, and protection process by monitoring information. The scheme can locate the faulty point precisely by OTDR after determining the failed optical fiber link by the optical coding technique. The OTDR precise positioning and protection scheme can be carried out simultaneously, thus saving recovery time. Furthermore, network performance of OCDR and OTDR, recovery time, loss, cost, bit error rate of data signal transmission are also studied. The results obtained prove the feasibility and efficiency of the proposed network, and that it can support high network capacity.