Branch identification in point to multipoint passive optical networks using distinct pusle shapes

Popular data networks in the last mile are Time Division Multiplexed (TDM) point-to-multipoint (P2MP) Passive Optical Networks (PON)s networks. Wherever there is provision to deploy fiber cables, it is the most preferred transmission medium as these networks are able to meet the growing bandwidth demands. For reliable transmission and to meet the service level agreements and we need to monitor the PONs constantly. Service disruption is mainly caused due to fiber cuts and Optical Network Unit (ONU) failures. When the ONUs are located at different distances from the Central Office (CO), then the simple time-based OTDR measurement is sufficient to identify the branches based on the time of travel of the reflected pulses from the fiber ends. As fault isolation becomes ambiguous when two or more reflected pulses from different branches overlap at the Optical Line Terminal (OLT), monitoring by OTDR method cannot be adopted [1]. We propose a novel method, which overcomes the above drawback of OTDR method of monitoring P2MP networks, where the branches can be identified even when the reflected pules overlap.