METHOD AND APPARATUS FOR PROTECTION SWITCHING OF OPTICAL SIGNAL IN MULTICASTING RING NETWORK

摘要

PURPOSE: An optical signal protection method and an apparatus thereof are provided to implement protection of an optical signal in multicasting transmission by extraction of a desired wavelength. CONSTITUTION: A first node device multiplexes a plurality of optical wavelength signals into an optical signal. The first node device outputs an optical signal of a multiplexed operating signal and a preliminary signal through an optical coupler(400). The adjacent second node device receives the outputted optical signal. The second node device extracts the optical signal according to a destination of the optical signal.