| 摘要 |
<p>The present invention dynamically performs a fault location that is partway along a pathway in real time without modifying an optical access system. In an optical path system configured from a plurality of pathways comprising a plurality of branch lines and an optical path resulting from a single optical fiber, the optical path resulting from a single optical fiber being branched into the plurality of branch lines by means of a passive optical branching means, and the plurality of branch lines being configured from optical fibers having a distance difference of at least the distance resolution of the OTDR that is used, this optical path monitoring method monitors loss characteristic changes partway along each pathway by means of an OTDR. The current reflection impulse response waveform and the reflection impulse response waveform from a set period of time prior are continuously compared and monitored, and when a decreased response is detected, the pathway in which loss has arisen is identified by means of the fall position of the waveform of the decreased response, and the location at which loss has arisen is identified by means of the rise position of the waveform of the decreased response. A digital OTDR that uses a pseudorandom code correlation method is used.</p> |
