Patent ID: 7466921
Filing Date: 2008-12-16
Classification: H04J

Abstract:
1. A drop-and-continue device provided between a signal converter which supplies data and a signal to an end user and a wavelength-division multiplexing device which comprises an optical demultiplexer separating an optical signal of a desired wavelength from an optical signal supplied from a wavelength-division multiplexing device in a head end station and an optical multiplexer supplying an optical signal to a wavelength-division multiplexing device at a subsequent stage, the drop-and-continue device comprising: an optical receiver which converts the optical signal separated by the optical demultiplexer into an electrical signal; a transmitter which transmits the electrical signal to the end user via the signal converter in the form of either an electrical signal or an optical signal; an optical transmitter which supplies an optical signal to the optical multiplexer; and a loopback processor which loops the electrical signal output from the optical receiver back to the optical transmitter.