i think you'll find modulation is extremely useful if you care about bandwidth in a frequency sense
also all digital signals exist in the analog domain
lern2geeknooblar
(
GoldenFanjita whistle posse blow! horns crew i can't hear you!,
Fri 26 Dec 2008, 15:06,
archived)
also by convention
cable modems are still called modems even though they don't mo or dem.
in a related fact - MP3 codecs usually only dec, they rarely co.
(
MrChimp previously Monsieur,
Fri 26 Dec 2008, 20:35,
archived)