REPEATING APPARATUS AND RAMAN AMPLIFICATION RELAY SYSTEM

PROBLEM TO BE SOLVED: To achieve high-quality monitoring control even if cutting/breaking faults occur in an optical fiber when performing optical amplification relay by Raman amplification. SOLUTION: There are provided a Raman excitation light generation/response signal superimposition section (41) for generating a signal for first response used by a downlink to a monitoring control command, a response signal generation section (42) for generating a signal for second response to the monitoring control command when a light signal passing through the downlink is not inputted, and a switch (43) for command response for changing the signal for first response and that for second one to the monitoring control command. By the switch (43), when the light signal passing through the downlink at a second terminal station side is inputted, the signal for first response is used as a response signal passing through the downlink at a first terminal station side to the monitoring control command. Contrarily, when the light signal passing through the downlink at the second end station side is not inputted, the signal for second response is used. COPYRIGHT: (C)2004,JPO&NCIPI