Optical transmission apparatus and optical transmission method

1. An optical transmission apparatus comprising:

an optical input unit configured to input a first multiplexed signal obtained by multiplexing a plurality of optical signals having different wavelengths and a second multiplexed signal obtained by multiplexing a plurality of optical signals having different wavelengths:

a demultiplexing unit configured to demultiplex the first multiplexed signal and the second multiplexed signal by wavelength;

a processor;

a storage medium having computer program instructions stored thereon, when executed by the processor, perform to measure qualities of a plurality of optical signals obtained by the demultiplexing of the first multiplexed signal and qualities of a plurality of optical signals obtained by the demultiplexing of the second multiplexed signal; and switching between the first multiplexed signal and the second multiplexed signal to be output to a subsequent stage based on a result of measurement; and

a multiplexing unit configured to multiplex the plurality of optical signals obtained by the demultiplexing of the first multiplexed signal and outputting a multiplexed signal, and demultiplex the plurality of optical signals obtained by the demultiplexing of the second multiplexed signal and outputting demultiplexed signals.

2. The optical transmission apparatus according to claim 1 , further comprising

a branching unit configured to branch the first multiplexed signal input by the optical input unit and outputting the branched first multiplexed signal to the demultiplexing unit and the switching unit, and branching the second multiplexed signal input by the optical input unit and outputting the branched second multiplexed signal to the demultiplexing unit and the switching unit.

3. The optical transmission apparatus according to claim 1 , wherein the computer program instructions further perform to instruct the switching unit to output the second multiplexed signal when a level of any of a plurality of the optical signals obtained by the demultiplexing the first multiplexed signal by the demultiplexing unit satisfies a condition indicating deterioration in quality, and instruct the switching unit to output the first multiplexed signal when a level of any of a plurality of the optical signals obtained by the demultiplexing the second multiplexed signal by the demultiplexing unit satisfies the condition indicating deterioration in quality.

4. The optical transmission apparatus according to claim 1 , wherein the computer program instructions further perform to instruct a switching unit to output the second multiplexed signal when a level difference between the optical signals having wavelengths adjacent to each other satisfies a condition indicating deterioration in quality among a plurality of the optical signals obtained by the demultiplexing the first multiplexed signal by the demultiplexing unit, and instruct the switching unit to output the first multiplexed signal when a level difference between the optical signals having wavelengths adjacent to each other satisfies the condition indicating deterioration in quality among a plurality of the optical signals obtained by the demultiplexing the second multiplexed signal by the demultiplexing unit.

5. The optical transmission apparatus according to claim 1 , further comprising

an amplification unit configured to amplify the first multiplexed signal and the second multiplexed signal.

6. An optical transmission method comprising:

inputting a first multiplexed signal obtained by multiplexing a plurality of optical signals having different wavelengths and a second multiplexed signal obtained by multiplexing a plurality of the optical signals having different wavelengths;

demultiplexing the first multiplexed signal and the second multiplexed signal by wavelength;

measuring qualities of a plurality of optical signals obtained by the demultiplexing the first multiplexed signal and qualities of a plurality of optical signals obtained by the demultiplexing the second multiplexed signal; and

performing switching between the first multiplexed signal and the second multiplexed signal to be output to a subsequent stage based on a result of measurement by the measuring,

wherein the second multiplexed signal is output when a level difference between the optical signals having wavelengths adjacent to each other satisfies a condition indicating deterioration in quality among a plurality of the optical signals obtained by the demultiplexing the first multiplexed signal, and the first multiplexed signal is output when a level difference between the optical signals having wavelengths adjacent to each other satisfies the condition indicating deterioration in quality among a plurality of the optical signals obtained by the demultiplexing the second multiplexed signal.

7. An optical transmission apparatus comprising:

an optical input configured to input a first multiplexed signal obtained by multiplexing a plurality of optical signals having different wavelengths and a second multiplexed signal obtained by multiplexing a plurality of optical signals having different wavelengths:

a demultiplexer configured to demultiplex the first multiplexed signal and the second multiplexed signal by wavelength;

a processor; and

a storage medium having computer program instructions stored thereon, when executed by the processor, perform to measure qualities of a plurality of optical signals obtained by the demultiplexing of the first multiplexed signal and qualities of a plurality of optical signals obtained by the demultiplexing of the second multiplexed signal; and switching between the first multiplexed signal and the second multiplexed signal to be output to a subsequent stage based on a result of measurement;

wherein the computer program instructions further perform to instruct a switch to output the second multiplexed signal when a level difference between the optical signals having wavelengths adjacent to each other satisfies a condition indicating deterioration in quality among a plurality of the optical signals obtained by the demultiplexing the first multiplexed signal by the demultiplexer, and instruct the switch to output the first multiplexed signal when a level difference between the optical signals having wavelengths adjacent to each other satisfies the condition indicating deterioration in quality among a plurality of the optical signals obtained by the demultiplexing the second multiplexed signal by the demultiplexer.

8. The optical transmission apparatus according to claim 7 further comprises a multiplexer configured to multiplex the plurality of optical signals obtained by the demultiplexing of the first multiplexed signal and outputting a multiplexed signal, and demultiplex the plurality of optical signals obtained by the demultiplexing of the second multiplexed signal and outputting demultiplexed signals.

9. The optical transmission apparatus according to claim 7 , further comprises splitter configured to branch the first multiplexed signal input by the optical input and outputting the branched first multiplexed signal to the demultiplexer and the switch, and branching the second multiplexed signal input by the optical input and outputting the branched second multiplexed signal to the demultiplexer and the switch.

10. The optical transmission apparatus according to claim 7 , wherein the computer program instructions further perform to instruct the switch to output the second multiplexed signal when a level of any of a plurality of the optical signals obtained by the demultiplexing the first multiplexed signal by the demultiplexer satisfies a condition indicating deterioration in quality, and instruct the switch to output the first multiplexed signal when a level of any of a plurality of the optical signals obtained by the demultiplexing the second multiplexed signal by the demultiplexer satisfies the condition indicating deterioration in quality.