| 摘要 |
PURPOSE:To recover communication without waiting for the recovery of fiber disconnection by inverting the transmitting direction of another transmission line paired with a disconnected transmission line by an ADM (Add-Drop Multiplex) detecting the disconnection when it is detected that the both primary and standby transmission lines are disconnected at different points. CONSTITUTION:Plural ADM #1-#4 are connected in a ring shape by two mutually reverse optical transmission lines (fibers) P and S. The fiber P is called Primary and the fiber S is called Standby. In this case, when the both fibers P and S are disconnected at different points, the ADM detecting the disconnection inverts the transmitting direction of the other fiber paired with the disconnected fiber. Thus, even when the both fibers P and S are disconnected at different points, the communication can be recovered without waiting for the recovery of fiber disconnection. |
