Optical transmission system and node adding method

摘要

An object of the present invention is to simplify the addition of a node. Nodes (14-1~14-8) connect to a ring (12) through optical add/drop multiplexers (10-b 1~10-8). A new ring (20) is constructed next to the ring (12). Disposed on the ring (20) are an optical add/drop multiplexer (28) corresponding to a to-be-added node (26) and an optical add/drop multiplexer (30) to connect the ring (20) with the ring (12). The optical add/drop multiplexer (30) connects with the node (14-5) connecting the ring (12) through a connector (32). The connector (32) mediates signals between the node (14-5) and the optical add/drop multiplexer (30) bidirectionally.