| 摘要 |
PURPOSE:To reduce the state that a line link is interrupted depending on a fault state by monitoring the link while taking the fault takes place at a stage before an optical repeater resident just before when an alarm signal is received. CONSTITUTION:When a reception fault takes place, an active optical transmission section W and a standby optical transmission section P of each equipment send an alarm signal while the alarm signal is included in a main signal. When either one of the active optical transmission section W and the standby optical transmission section P in each equipment receives the alarm signal, it is regarded that the fault takes place in a stage before an optical repeater REG resident just before, and link monitor is implemented from an overhead signal of an optical signal of the equipment receiving the alarm signal, then each optical terminal station equipment LTE accesses an intermediate optical repeater REG. Since a RINGDWN signal representing a line interrupt state and the alarm signal are discriminated from each other, a priority path is given to the line and remote monitor/control in the inside of the equipment is continued. |
