Optical transmission system and optical transmission method

An optical transmission method of an optical transmission system that is configured to connect, using an optical transmission line, and aggregate a plurality of optical cross connect (OXC) devices that switches wavelength paths of optical signals between a plurality of transponder devices that relay optical signals transmitted to and from a communication device, the optical transmission method comprising:

• when optical input interruption in which an optical signal input from the optical transmission line is interrupted is detected, outputting, by an OXC device, wavelength information indicating a wavelength of the optical signal in which the optical input interruption has occurred, and path information on a path of the optical transmission line in which the optical input interruption has occurred, wherein the OXC device includes a first DB in which each piece of information stored in a second DB of one of the plurality of transponder devices is registered and stored, and
• generating, by the OXC device, an alarm signal in accordance with the output wavelength information and the output path information, the alarm signal including both pieces of information on the wavelength and the path of the optical signal relating to the optical input interruption and alarm information relating to the both pieces of information;
• and
• notifying, by a transponder device of the plurality of transponder devices, of an external failure of the transponder device based on the both pieces of information and the alarm information included in the generated alarm signal, wherein the transponder device includes the second DB storing information on a path number that is a number of a path of the optical transmission line, information on an accommodation wavelength that is a wavelength of an optical signal accommodated in the path, information on device identifications (IDs) that are unique information of a transmitting device and a destination device of a signal, and information on a transponder ID;
• determining, by the transponder device, recovery from the optical input interruption when a state is changed from a state of being unconnected to the OXC device to a state of being connected to the OXC device through the optical transmission line;
• after this determination, superimposing, by the transponder device, each piece of the information read from the second DB on a control signal that has been changed to have a unique specific wavelength;
• transmitting, by the transponder device, a resultant control signal to the OXC device;
• receiving, by the OXC device, the transmitted control signal;
• registering, by the OXC device, the received control signal;
• and
• storing, by the OXC device, the information superimposed on the received control signal in the first DB in accordance with control of the second control part.