Optical communication systems, and, optical communication method

PROBLEM TO BE SOLVED: To reduce the number of function parts which process a signal to be transmitted through optical communication.SOLUTION: An optical communication system includes: first and second network side devices 20 and 30 connected to a communication network for performing optical communication; and first and second end side devices 40 and 50. The first and second end side devices 40 and 50 are connected via first and second communication cables C11 and C22 to the first and second network side devices 20 and 30 such that optical communication is performed between the first and second end side devices 40 and 50 and the first and second network side devices 20 and 30. The first network side device 20 is connected via a communication network, the second network side device 30 and a third communication cable C21 to the first end side device 40 such that optical communication is performed between the first network side device 20 and the first end side device 40. The third communication cable C21 connects the second network side device 30 to the first end side device 40.SELECTED DRAWING: Figure 2