Optical network, optical division and insertion node and recovery system from network failure

摘要

Disclosed is an optical network which has a plurality of optical division and insertion nodes and one or a plurality of hub (central) nodes which are circularly connected by using an optical transfer system where a clockwise or counterclockwise data transfer is conducted by using a plurality of optical fibers or an optical wavelength-multiplexing technique; wherein the hub (central) node and the plurality of division and insertion nodes individually use signal lights with wavelengths different from each other and are provided with a transmission system composed of two or more clockwise or counterclockwise independent paths, and the optical division and insertion node selects one of signals obtained from the two or more paths.