Patent ID: 8805198

Claim:
An optical transmission and reception system including a transmitting apparatus for converting a plurality of tributary signals into a single beam of multilevel modulated light for transmission, and a receiving apparatus for receiving multilevel modulated light and converts it into a plurality of tributary signals, the transmitting apparatus comprising: a first circuitry comprising: a forward error correction coder to apply error correction coding to each individual one of the tributary signals, the error correction coding including addition of a tributary identifier for identifying a tributary; a transmitter side rate converter to perform rate conversion by adding predetermined data to the signals subjected to the error correction coding so that the signals have the same transmission rate; and a multilevel modulator to convert the signals rate-converted by the transmission-side rate converter into a single beam of multilevel modulated light, the receiving apparatus comprising: a second circuitry comprising: a multilevel modulated light receiver to receive multilevel modulated light, separate a received signal into tributary signals, and output the separated signals as received tributary signals to respective different output systems; a reception-side rate converter to perform rate conversion by deleting the predetermined data from the received tributary signals; an error correction decoder to perform error correction decoding on received tributary signals non-rate-converted by the reception-side rate converter or the received tributary signals rate-converted by the reception-side rate converter and extract the tributary identifiers from the received non-rate-converted tributary signals or the received rate-converted tributary signals in respective different output systems; a tributary detector to retain tributary identifiers defined for the respective output systems in advance as output system tributary identifiers, compare the output system tributary identifier of each output system with the tributary identifier that is extracted from the received tributary signal output to the output system, and make a notification as to a match or mismatch as a result of comparison; a tributary selector to give an instruction to change correspondence between the received tributary signals and the output systems if the result of comparison is a mismatch, and the multilevel modulated light receiver changing the correspondence between the received tributary signals to output and the output systems based on the instruction from the tributary selector.