Optical transmission systems are being introduced into a subscriber loop network with a growing demand for various broadband services. A stable and high-performance maintenance method is of great significance for realizing practical optical subscriber loop systems. In particular, a fault- location method is necessary for detecting a fault occurring either in an optical cable or in a subscriber connection unit (FSU) to repair the system. An optical time-domain reflectometer (OTDR) can be used, but its length accuracy is not good enough to prove that an optical cable is connected to a FSU. This paper proposes a novel fault-location method based on a wavelength division multiplexing (WDM) technique.
© 1985 Optical Society of AmericaPDF Article