Patent ID: 11914191
Assignee: NEC CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 4:
5. The optical branching/coupling device according to claim 4, wherein
the second add/drop circuit
outputs, to the second line, a ninth optical signal acquired by multiplexing the fourth optical signal received from the second line with an eighth optical signal to be inserted into the second line, and outputs the fourth optical signal to the first add/drop circuit, and
the first add/drop circuit
receives the fourth optical signal from the second add/drop circuit, receives, from the first line, an eleventh optical signal acquired by wavelength-multiplexing the first optical signal with a tenth optical signal to be dropped from the first line, demultiplexes the first optical signal and the tenth optical signal, and outputs, to the first line, a twelfth optical signal acquired by multiplexing the first optical signal with the fourth optical signal.