Bi-directional add/drop node

摘要

A bi-directional add/drop node employed in a bi-directional path-switching network linked by an optical fiber in a loop form is disclosed. The bi-directional add/drop node has a first terminal point and a second terminal point for receiving channels over the optical fiber such that odd channels are inputted through the first terminal point are outputted through the second terminal point and even channels are inputted through the second terminal point are outputted through the first terminal point. The bi-directional add/drop node comprises, a circulation section for circulating the even and odd channels in a predetermined direction, a first input-output section located between the circulation section and the first terminal point wherein the first input-output section outputs the odd channels inputted from the first terminal point to the circulation section through a first input line and outputs the even channels inputted from the circulation section to the first terminal point through a first output line, and a second input-output section positioned between the circulation section and the second terminal point, wherein the second input-output section outputs the even channels inputted from the second terminal point to the circulation section through a second input line and outputs the odd channels inputted from the circulation section to the second terminal point through a second output line.