COMMUNICATIONS NETWORK TRANSPORT NODE, OPTICAL ADD-DROP MULTIPLEXER AND METHOD OF ROUTING COMMUNICATIONS TRAFFIC

摘要

A communications network transport node 10 comprising an optical add-drop multiplexer (OADM) 12,comprising optical signal processing apparatus 16 and electrical signal routing apparatus 18, and a packet switch 14. Each optical signal processing apparatus 16 comprises an optical input 20, an optical output 22, optical-to-electrical (O-E) signal conversion apparatus 24, arranged to receive input optical channel signals and to convert each into an input radio frequency (RF) modulated electrical channel signal,and electrical to optical(E-O) signal conversion apparatus 26, arranged to receive output RF modulated electrical channel signals and to convert each into an output optical channel signal. The electrical signal routing apparatus 18 determines which input RF modulated electrical channel signals are to be dropped, and routes these to the electrical drop outputs, and which are to be transmitted, and routes these to a selected E-O apparatus 26. The routing apparatus 18 receives further electrical channel signals and routes these to a selected E-O apparatus 26. The packet switch 14 receives the input RF modulated electrical channel signals to be dropped and delivers further RF modulated electrical channel signals to the OADM 12.