Optical communications networks utilizing frequency division multiplexing

摘要

A frequency division multiplexing (FDM) node used in optical communications networks provides add-drop multiplexing (ADM) functionality between optical high-speed channels and electrical low-speed channels. The FDM node includes a high-speed system and an ADM crosspoint. The high-speed system converts between an optical high-speed channel and its constituent electrical low-speed channels through the use of frequency division multiplexing and preferably also QAM modulation. The ADM crosspoint couples incoming low-speed channels to outgoing low-speed channels, thus implementing the ADM functionality for the FDM node.