US 12,231,172 B2
Optical signal processing apparatus and optical signal processing method
Takuya Kanai, Musashino (JP); Shin Kaneko, Musashino (JP); Kazuaki Honda, Musashino (JP); Junichi Kani, Musashino (JP); Hiroo Suzuki, Musashino (JP); and Jun Terada, Musashino (JP)
Assigned to NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
Appl. No. 17/921,253
Filed by NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
PCT Filed May 1, 2020, PCT No. PCT/JP2020/018382
§ 371(c)(1), (2) Date Oct. 25, 2022,
PCT Pub. No. WO2021/220503, PCT Pub. Date Nov. 4, 2021.
Prior Publication US 2023/0163856 A1, May 25, 2023
Int. Cl. H04B 10/02 (2006.01); H04B 10/077 (2013.01); H04B 10/60 (2013.01)
CPC H04B 10/60 (2013.01) [H04B 10/077 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An optical communication system comprising:
a controller that controls a subscriber terminal;
an optical switch that is connected to the subscriber terminal, the controller and a communication destination of the subscriber terminal through different optical transmission paths; and
an optical signal processing apparatus that is provided between the communication destination and the optical switch,
wherein the controller is performs:
transmitting, to the subscriber terminal, a first control signal through the optical switch;
instructing, to the optical switch, after transmitting the first control signal so as to switch an output destination of an optical signal received from an optical transmission path connected to the subscriber terminal from an optical transmission path connected to the controller to an optical transmission path to an optical transmission path connected to the communication destination; and
outputting, to the optical signal processing apparatus, a second control signal addressed to the subscriber terminal,
wherein the optical signal processing apparatus comprises:
a remover that receives, from a first optical transmission path, an optical signal, addressed to the subscriber terminal from the communication destination, converted from an electrical signal, in which a first signal and a second signal having different frequencies from each other have been superimposed, and removes the second signal from the optical signal which has been input; and
a superimposer that superimposes a third signal, that is the second control signal, having a frequency different from a frequency of the first signal on the optical signal in which the second signal has been removed by the remover, and outputs the optical signal in which the third signal has been superimposed to a second optical transmission path that is the optical transmission path between the optical signal processing apparatus and the optical switch, and
wherein the optical switch outputs, to the optical transmission path between the optical signal processing apparatus and the subscriber terminal, the optical signal in which the third signal has been superimposed.