A PON Monitoring Scheme for Online Fault Detection and Localization

We propose and experimentally demonstrate an online PON monitoring scheme that can simultaneously achieve the objectives of fault detection and localization. Fault detection and localization share the same transmitter module and perform in sequence. Based on a simple algorithm, one or several fiber Bragg gratings with different central reflection wavelengths are allocated to each end-user for fault detection. A large number of wavelength combinations are generated by several fiber Bragg gratings with different center wavelengths, and are finally identified in the time domain, which is very suitable for fault detection of large-capacity and high-density PON. An additional module is added before the power splitter/combiner to ensure the online troubleshooting. The model equation is established to locate the fault using two unmodulated broadband light sources. The calculated results of the fault localization method show a good agreement with the OTDR measurement results. The proposed scheme provides an integrated online troubleshooting solution for the detection and localization of PON link faults.