Patent ID: 8682157

Claim:
An optical communication system comprising: an optical transmission terminal comprising: a first transmitter for transmitting an optical signal, and a second transmitter for transmitting information that includes a wavelength channel service (WCS) array and a wavelength channel failure (WCF) array; and an optical receiving terminal comprising: an optical receiver for receiving the optical signal and the information transmitted from the first and second transmitter, respectively, a storage device for storing a first power value of a first optical signal of the optical signal received by the optical receiver, the first power value of the first optical signal being measured in a timing determined in accordance with the WCS and WCF arrays, and a fault detector for detecting fault of a second optical signal of the optical signal by continuously measuring a second power value of the second optical signal received by the optical receiver after the first optical signal and by comparing the second power value with a threshold value which is determined based on the first power value stored in the storage device.