Patent ID: 11916589
Assignee: NEC CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A submarine device monitoring method comprising:
branching, by a first branching unit of a submarine device, an optical signal, and outputting first branched light;
processing, by a processing unit of the submarine device, the first branched light as an input optical signal, and outputting an output optical signal;
branching, by a second branching unit of the submarine device, the output optical signal output from the processing unit, and outputting second branched light;
selecting, by a selecting unit of the submarine device, branched light from the first branched light and the second branched light, and outputting the branched light; and
monitoring, by a monitoring unit of the submarine device, the selected branched light, wherein
the selecting unit includes an N×N variable optical attenuator having a plurality of port pairs, each port pair including an input port and an output port,
the method further comprises attenuating, by the attenuator and for each of the plurality of port pairs, a port optical signal at the input port of the port pair according to a control, and outputting the attenuated port optical signal at the output port of the port pair.