| 摘要 |
PROBLEM TO BE SOLVED: To easily and surely locate a fault occurred, to improve the maintenance performance by simplifying the configuration and to reduce the cost attended with increase in number of branches of a star coupler, replacement or extension of an equipment in a terminal station. SOLUTION: A subscriber line terminator 1 and optical network terminators 5, 7, 9 are connected by a star coupler 3 and optical fiber transmission lines 2, 4, 6, 8 to conduct passive double star communication or the like by an optical signal. A forced light emission indication cell is branched by optical fiber transmission lines 2, 4, 6, 8 and a star coupler 3 and transmitted individually from the subscriber line terminator 1 to the optical network terminators 5, 7, 9. The optical network terminators 5, 7, 9 receiving the forced lighting indication cell are forcibly lighted. The subscriber line terminator 1 receives the forcibly emitted light and a fault occurrence location in the optical fiber transmission lines 2, 4, 6, 8, the star coupler 3 or the optical network terminators 5, 7, 9 is located and detected based on the reception or non-reception in this case. |
