OPTICAL COMMUNICATION SYSTEM, OPTICAL COMMUNICATION METHOD, FAULT DETECTION DEVICE, FAULT DETECTION METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an optical communication system that is able to prevent a decline in communication quality when an active transmission path is changed due to the occurrence of a fault.SOLUTION: An optical communication system 7000 transmits data by an optical signal from a transmitter to a receiver. The optical communication system has a plurality of transmission paths from the transmitter to the receiver, sets a first transmission path as an active transmission path, and transmits data from the transmitter to the receiver via the active transmission path (7001). The optical communication system obtains a variation quality value that is a temporal variation component due to polarization mode dispersion among values indicating quality of the optical signal having passed the first transmission path (7002). The optical communication system detects that a fault will occur on the first transmission path at a time point in the future on the basis of the variation quality value (7003). The optical communication system changes the active transmission path from the first transmission path to a second transmission path when the fault occurrence is detected.