| 摘要 |
PURPOSE:To obtain an optical subscriber transmission system not requiring the installation of an auxiliary transmission line by inserting a multiplexer/ demultiplexer to both ends of an optical transmission line at system expansion so as to constitute the auxiliary transmission line. CONSTITUTION:The signal is transmitted as it is by connecting optical multiplexer/demultiplexers 100, 110 to both ends of an optical transmission line when the wavelength of a light source mounted to active transmitter- receivers 18, 19 is in matching with one of the wavelength of the pass band of the optical multiplexer/demultiplexers 100, 110. When other wavelength of the pass band of the optical multiplexer/demultiplexers 100, 110 is coincident with the wavelength of the light source for transmitter-receiver of an expanded system, the auxiliary line is constituted by using the light of the wavelength. Thus, it is not required to install the auxiliary transmission line in advance to constitute an economical system. |
