This paper illustrates that remote fault localisation in all-optical links with concatenated fibre amplifiers can be performed by simple monitoring of the signal and the accumulated ASE noise powers at the receiver end. The method is first presented in ideal operating conditions, and second, the effect of the spontaneous emission factor variation and the EDFA non-linear behaviour are taken into account. From the analysis, the requirements of the link design for proper supervision accuracy are derived. The presented supervisory method is a simple solution for links where a fibre break or an amplifier fault is to be detected and located with the granularity of an amplifier section without local supervisory elements within the transmission sections.

Peer Reviewed