Multiplexing simultaneously carries two or more signals over a single
transmission channel. Combining multiple signals is possible since most transmission
media is capable of carrying much more than 8,000 samples (one conversation -
see Pulse Amplitude Modulation) per Second. For example, 8,000 samples per second at 8 bits per sample is only 64,000
bits per second. A T1 system can carry 1, 544,000 bits of data per second.
There are two types of multiplexing: Time Division and Frequency Division Multiplexing. Time Division Multiplexing weaves pieces of Digital information together into one continuous stream. Frequency Division, an older technique, stacks different frequencies on one pair of
wires (see Conductor).