Transmission surveillance and self-restoration against fibre fault for time division multiplexing using passive optical network

This study proposes a practical transmission surveillance and self-protection scheme for time division multiplexing using passive optical network (TDM-PON) with centralised monitoring and self-restorable apparatus. Troubleshooting a TDM-PON involves locating and identifying the source of an optical problem in what may be a complex optical network topology that includes several optical line terminals (OLTs), optical splitters, fibres and optical network units (ONUs). Since most components in the network are passive, a large part of the issues are due to dirty/damaged/misaligned connectors or breaks/macrobends in optical fibre cables. These will affect one, some or all subscribers in the network, depending on the location of the problems. The proposed scheme is able to prevent and detect the occurrence of fibre faults in a network system through centralised monitoring and remotely operate from a central office via Ethernet connection. Even with fibre fault prevention mechanisms, failures will still occur. Therefore fibre fault detection is required in order to detect potential faults and precisely localise the exact failure location. Whenever any failure occurs on the primary entity, the proposed system can protect and switch the failure line to the protection line to ensure that traffic flows continuously. Meanwhile, the failure information will be delivered to field engineers for taking appropriate recovery action to treat the fibre fault and failure link. One suggestion in point-to-multipoint (P2PM) applications has been proposed with the experimental results as the feasibility approach. This approach has bright prospects for improving the survivability and reliability as well as increasing the efficiency and monitoring capabilities in TDM-PON.