Locating faults in optical transmission paths - by feeding output of regenerator back via adjacent opposite-direction regenerator

摘要

The method involves passing the signal from a selected regenerator via a monitor loop to the input of the adjacent regenerator operating in the opposite direction and then back to the selected loop input. All circuit elements of the regenerators connected by the monitor loop are tested without the use of expensive optical loop switching or loading the transmission paths with additional damping. The light signal produced by the optical source (LD) at the output of the selected regenerator is converted into an electrical signal. The electrical signal is passed along a conductor (9) contg. a loop switch (4) and is converted back into an optical signal. The optical signal is fed to the optical receiver (OE) at the input to the adjacent regenerator.