| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical access network that avoids effects exerted on a user to the utmost, due to faults or deterioration in a transmission line or the like, enabling quick recovery of the line. SOLUTION: The optical access network is provided with a subordinate node unit with an access system optical branch circuit connected to a subscriber side unit via a subscriber fiber, a host node unit having an access system subscriber unit, and a relay fiber transmission line that interconnects the access system optical branch circuit with the access system subscriber unit. The relay fiber transmission line comprises an active system relay fiber transmission line, and a plurality of standby system relay fiber transmission lines, whose paths differ from that of the active system relay fiber transmission line, the active system relay fiber transmission line or a plurality of the standby system relay fiber transmission lines are connected to the access system optical branch circuit via a 1st optical switch, and to the access system subscriber unit via a 2nd optical switch. |
