20. REGENERATOR It mainly performs 3R function: 1R – Reamplification 2R – Retiming 3R – Reshaping It regenerates the clock and amplifies the incoming distorted and attenuated signal. It derive the clock signal from the incoming data stream. STM-N STM-N Regenerator
21. Terminal Multiplexer (TM) It combines the Plesionchronous and synchronous input signals into higher bit rate STM-N Signal. Terminal Multiplexer STM-N PDH SDH