US 12,463,725 B2
Optical add/drop multiplexer and optical transmission method
Motoyoshi Kawai, Tokyo (JP)
Assigned to NEC CORPORATION, Tokyo (JP)
Appl. No. 17/431,800
Filed by NEC Corporation, Tokyo (JP)
PCT Filed Mar. 9, 2020, PCT No. PCT/JP2020/009925
§ 371(c)(1), (2) Date Aug. 18, 2021,
PCT Pub. No. WO2020/195737, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 2019-056433 (JP), filed on Mar. 25, 2019.
Prior Publication US 2022/0140907 A1, May 5, 2022
Int. Cl. H04B 10/296 (2013.01); H04B 10/03 (2013.01); H04B 10/079 (2013.01); H04J 14/02 (2006.01)
CPC H04B 10/296 (2013.01) [H04B 10/03 (2013.01); H04B 10/079 (2013.01); H04J 14/02122 (2023.08); H04J 14/02216 (2023.08)] 16 Claims
OG exemplary drawing
 
1. An optical add/drop multiplexer comprising:
a first wavelength selection switch configured to output an optical signal of each wavelength of an inputted first wavelength multiplexed signal while selecting a path for each wavelength;
a measurement circuit configured to measure optical power of an inputted optical signal;
a second wavelength selection switch including
a circuit configured to output an optical signal of each wavelength of the first wavelength multiplexed signal while selecting a path for each wavelength, in place of the first wavelength selection switch when an abnormality occurs in the first wavelength selection switch, and
a circuit configured to output an inputted second wavelength multiplexed signal for each prescribed wavelength unit to the measurement circuit when the first wavelength selection switch normally operates; and
a transmitter configured to transmit, to a terminal device connected via a transmission path, spectrum data being generated based on a measurement result of the optical power by the measurement circuit.