| modulation
Modulation refers to the process of
encoding digital data into analog signals for transmission. When
transferring data over phone lines, for example, a modem modulates the
data into audible tones "carried" on frequencies between 0 Hz and 4 KHz.
Once the data reaches its intended destination, another modem demodulates
the signal back into digital data. Cable TV networks also use modulation
techniques to transfer data. But instead of audible tones, cable has
sophisticated digital modulation schemes to greatly increase the amount of
data that can be sent. |