Switching media converter and ring type wavelength division multiplexing passive optical network system using the same

A ring type wavelength division multiplexing passive optical network (WDM PON) system using the same wavelength for forward and backward channels, comprising:

• a central office including general media converters (MCs) each having a transmitter adapted to convert an electrical signal into an optical signal to be outputted, and a receiver adapted to receive an optical signal having the same wavelength as the output optical signal, and to convert the received optical signal into an electrical signal to be outputted, and a WDM multiplexer/demultiplexer (MUX/DEMUX) for multiplexing optical signals of different wavelengths respectively outputted from the general MCs, and externally outputting the resultant multiplexed optical signal, the WDM MUX/DEMUX also demultiplexing a multiplexed signal, externally inputted thereto, and outputting the resultant demultiplexed signals to respective general MCs;
• a coupler for transmitting the multiplexed signal outputted from the WDM MUX/DEMUX through two different optical communication lines in a distributed manner, while transmitting an optical signal received from any one of the optical communication lines to the WDM MUX/DEMUX;
• the optical communication lines constructing a ring type distribution network through bi-directional add/drop devices each coupled to the optical communication lines;
• and
• remote nodes including redundancy MCs respectively coupled to the bi-directional add/drop devices, each of the redundancy MCs functioning to detect a line breakage, and to transmit an optical signal only in a clockwise or counter-clockwise direction in accordance with the result of the detection.