Patent ID: 6222653
Filing Date: 2001-04-24
Classification: H04J

Abstract:
An optical node comprising:a clockwise primary optical transmission line input terminal and a clockwise primary optical transmission line output terminal,a counter-clockwise primary optical transmission line input terminal and a counter-clockwise primary optical transmission line output terminal,a clockwise stand-by optical transmission line input terminal and a clockwise stand-by optical transmission line output terminal,a counter-clockwise stand-by optical transmission line input terminal and a counter-clockwise stand-by optical transmission line output terminal,a first terminal section including a first reception unit that converts a first reception optical signal inputted from one of the clockwise primary optical transmission line input terminal, the counter-clockwise primary optical transmission line input terminal, the clockwise stand-by optical transmission line input terminal, and the counter-clockwise stand-by optical transmission line input terminal, to a first electrical signal, and a first transmission unit that converts the first electrical signal to a first optical signal, and that outputs the first optical signal through one of the clockwise primary optical transmission line output terminal, the counter-clockwise primary optical transmission line output terminal, the clockwise stand-by optical transmission line output terminal, and the counter-clockwise stand-by optical transmission line output terminal,a second terminal section including a second reception unit that converts a second reception optical signal inputted from one of the clockwise primary optical transmission line input terminal, the counter-clockwise primary optical transmission line input terminal, the clockwise stand-by optical transmission line input terminal, and the counter-clockwise stand-by optical transmission line input terminal, to a second electrical signal, and a second transmission unit that converts the second electrical signal to a second optical signal, and that outputs the second optical signal through one of the clockwise primary optical transmission line output terminal, the counter-clockwise primary optical transmission line output terminal, the clockwise stand-by optical transmission line output terminal, and the counter-clockwise stand-by optical transmission line output terminal,a first stand-by path and second stand-by path each having an input terminal and an output terminal,a first optical path switching unit having first through fourth input ports and first through fourth output ports, the first optical path switching unit configured to switch a path of the first reception optical signal received on any one of the first through fourth input ports to any one of the first through fourth output ports,the first input Port being connected to the output terminal of the first stand-by path, the second input port being connected to the clockwise primary optical transmission line input terminal, the third input port being connected to an output terminal of the second terminal section, the fourth input port being connected to the counter-clockwise stand-by optical transmission line input terminal,the first output port being connected to the clockwise stand-by optical transmission line output terminal, the second output port being connected to an input terminal of the first terminal section, the third output port being connected to the clockwise primary optical transmission line output terminal, and the fourth output port being connected to the input terminal of the second stand-by path,a second optical path switching unit having first through fourth input ports and first through fourth output ports, the second optical path switching unit configured to switch a Path of the second reception optical signal received on any one of the first through fourth input ports of the second optical path switching unit to any one of said first through fourth output ports of the second optical path switching unit,the first input port of the second optical path switching unit being connected to the clockwise stand-by optical transmission line input terminal, the second input port of the second optical path switching unit being connected to an output terminal of the first terminal section, the third input port of the second optical path switching unit being connected to the clockwise primary optical transmission line input terminal, and the fourth input port of the second optical path switching unit being connected to the output terminal of the second stand-by path,the first output port of the second optical path switching unit being connected to the input terminal of the first stand-by path, the second output port of the second optical path switching unit being connected to the counter-clockwise primary optical transmission line output terminal, the third output port of the second optical path switching unit being connected to an input terminal of the second terminal section, and the fourth output port of the second optical path switching unit being connected to the counter-clockwise stand-by optical transmission line output terminal.