Patent ID: 8340521

Claim:
An optical transmission system comprising: a user side optical repeater device (ORD) to be connected with a user side optical network unit (ONU), for transmitting data in two ways, and for wavelength division multiplexing (WDM); a central office side ORD to be connected with a central office side optical line terminal (OLT), for transmitting data in two ways, and for WDM; and a wavelength multiplexing and a wavelength de-multiplexing functions (MUX/DEMUX), for relaying between the user side ORD and the central office side ORD, wherein the user side ORD includes a preamble compensating circuit that takes out a normal data signal from burst signals propagated from the user side ONU and adds a preamble signal and/or error signal to a gap between any neighboring pair of the burst signals to convert the burst signal into a continuous signal including preamble signals in front and behind the normal data signal.