PURPOSE:To prevent a relay defect and the fluctuation of a light level due to the attenuation of an optical signal from occurring by switching the optical signal only by an optical switch in an optical matrix. CONSTITUTION:An optical demultiplexer and the optical switching, etc., in each bypass control part in respective light line concentrator 101 are replaced by one optical matrix 103. The optical signals inputted to the optical matrix are assumed as 0X-3X, the output optical signals of the matrix as 0Y-3Y, and also, the optical signals inputted to the light line concentrator 101 as 1X-3X, and the output optical signals of the matrix as 1y-3y. In such a case, the attenuation of the optical signal can be reduced by directly supplying the optical signal to terminal equipment 202a-202c by an optical matrix switch in the light line concentrator 101 without passing the optical demultiplexer. Furthermore, the connection of the optical switch is controlled by detecting the output optical signals of the terminal equipment 202a-202c, and the connection of the terminal equipment 202a-202c and a bypass operation, etc., are controlled. In such a way, it is possible to prevent the relay defect from occurring.
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