
5.2 THE BASICS OF ETDM TRANSMISSION
An optical transmission system consists of a transmitter and a receiver (Figure 5.1)
and between both of them an optical fiber is used as a transmission medium. All
deployed optical transmission systems are based on ETDM, which means purely
electronic signal processing up to the final bit rate in the transmitter as well as in
the receiver, in contrast to optical time-division multiplexing (OTDM) where
signal processing, especially multiplexing and demultiplexing, involves optical
components or subsystems.
At its input, an ETDM transmitter has an interface for connecting several lower
speed data signals. These data ...