PHOTONIC GATEWAY APPARATUS

1 . An optical gateway device, comprising:

a first multiplexer-demultiplexer that includes a first port and a plurality of second ports, is configured to separate an optical signal input from the first port and to output separated optical signals from the plurality of second ports, and is configured to multiplex optical signals input from the plurality of second ports and to output a multiplexed optical signal from the first port;

a second multiplexer-demultiplexer that includes a third port and a plurality of fourth ports, is configured to separate an optical signal input from the third port and to output separated optical signals from the plurality of fourth ports, and is configured to multiplex optical signals input from the plurality of fourth ports and to output a multiplexed optical signal from the third port; and

an optical switch that includes a plurality of fifth ports and a plurality of sixth ports, the plurality of fifth ports are connected to the second ports and the fourth ports, the optical switch configured to perform switching of an optical signal between the plurality of fifth ports and the plurality of sixth ports, wherein

a direction in which a wavelength component of a first wavelength out of an optical signal passing through the first port travels and a direction in which the wavelength component of the first wavelength out of an optical signal passing through the third port travels are opposite to each other.

2 . The optical gateway device according to claim 1 , wherein

a wavelength component related to a first wavelength group including the first wavelength out of the optical signal passing through the first port travels in a first direction, and a wavelength component related to a remaining second wavelength group travels in a second direction opposite to the first direction, and

a wavelength component related to the first wavelength group out of the optical signal passing through the third port travels in the second direction, and a wavelength component related to the second wavelength group travels in the first direction.

3 . The optical gateway device according to claim 1 , wherein

all wavelength components of the optical signal passing through the first port travel in a first direction, and

all wavelength components of the optical signal passing through the third port travel in a second direction opposite to the first direction.

4 . The optical gateway device according to claim 1 , wherein

the first multiplexer-demultiplexer and the second multiplexer-demultiplexer have a wavelength cyclic characteristic,

a direction in which a wavelength component of a second wavelength in a cyclic relationship with the first wavelength out of the optical signal passing through the first port travels is a direction opposite to the direction in which the wavelength component of the first wavelength travels, and

a direction in which the wavelength component of the second wavelength out of the optical signal passing through the third port travels is a direction opposite to the direction in which the wavelength component of the first wavelength travels.

5 . The optical gateway device according to claim 1 , further comprising:

a plurality of up-down separators that includes a seventh port, an eighth port, and a ninth port, is configured to output, from the eighth port, an optical signal input from the seventh port, and is configured to output, from the seventh port, an optical signal input from the ninth port, wherein

the eighth port and the ninth port of each of the plurality of up-down separators is connected to each of the plurality of sixth ports or the eighth port of each of the plurality of up-down separators is connected to each of the plurality of fourth ports and the ninth port of each of the plurality of up-down separators is connected to each of the plurality of second ports, respectively.

6 . The optical gateway device according to claim 1 , further comprising:

an at least one processer configured to allocate a wavelength to be used for an optical signal to a service device connected to the optical gateway device, wherein

the at least one processer is configured to allocate different wavelengths to an uplink signal and a downlink signal of the service device.

7 . The optical gateway device according to claim 1 , further comprising:

a plurality of up-down separators that includes a seventh port, an eighth port, and a ninth port, is configured to output, from the seventh port, an optical signal input from the eighth port, and is configured to output, from the ninth port, an optical input from the seventh port, wherein

the seventh port of each of the plurality of up-down separators is connected to each of the plurality of sixth ports, respectively.

8 . The optical gateway device according to claim 1 , further comprising:

a first up-down separator that includes a tenth port, an eleventh port, and a twelfth port, is configured to output, from the eleventh port, an optical signal input from the tenth port, and is configured to output, from the tenth port, an optical signal input from the twelfth port; and

a second up-down separator that includes a thirteenth port, a fourteenth port, and a fifteenth port, is configured to output, from the fourteenth port, an optical signal input from the thirteenth port, and is configured to output, from the thirteenth port, an optical signal input from the fifteenth port, wherein

the tenth port is connected to the first port and the thirteenth port is connected to the third port.