Protection switching in bidirectional WDM optical communication networks with transponders

摘要

The present invention provides a system for protection switching in a wavelength division multiplexed optical communication network including optical transponders within optical nodes. A work optical transponder receives a first work optical channel dropped by an optical add-drop multiplexer from an optical waveguide while a second work optical transponder adds a work optical channel to the optical add-drop multiplexer. Similarly, a first protect optical transponder is positioned to receive a protect optical channel dropped by the optical add-drop multiplexer while a second protect optical transponder is positioned to add a protect optical channel to the optical add-drop multiplexer. A detection element detects the strength of the optical channel received by the first work optical transponder;control means responsive to the means for detecting the strength of the optical channel received by the first optical transponder, the control means activating the second protect transponder and inactivating the second work transponder when the strength of the optical channel received by the first optical transponder falls below a preset level.