| 摘要 |
PURPOSE:To reduce a transmission loss by providing a fan-out connector to build in an optical switch element part and switching the section between a call line path and a monitoring line path with the control of the optical switch element part. CONSTITUTION:At a light distribution frame (MDF) 11 in a station, a fan-out connector 12 to build in an optical switch element part 16 is provided. In the A point of the loop part of a subscriber line network 13, at the time of disconnecting, the distance from a loop end 13a up to the A point and the distance from a reverse loop end 13b up to the A point are measured by OTDR. Since the difference occurs at the level of the light to turn from the positive and negative directions in the loop due to the distance ratio, the coupling ratio of the optical switch element part 16 is changed and the signal level of respective parts after the shutting-off is made the same. The switching cycle to a monitoring line path 15 of the optical switch element part 16 is shortened and an apparent continuous monitoring function is obtained. |
