Originally Posted by benjamin
Not quite. Modems convert data into sound (called an "analog carrier signal") and back. The word "modem" is actually a shortened version of modulator-demodulator.
Radio frequency is, by definition, outside of the spectrum that is audible to humans. If you generate a wave within the audible spectrum, it isn't RF.
couldn't have said it better myself
RF is pretty much any frequency from ~100KHz to just short of infrared at ~100GHz.
Originally Posted by click sidious
Phones don't have a very wide frequency spectrum...
The Cellular frequency range or at least the PCS range is 1850-1990Mhz. That's 140MHz of bandwidth total and about 120MHz of usable bandwidth. not a bad chunk of spectrum for simple CDMA voice and light data applications. Especially since uncompressed voice can be almost flawlessly recreated on a 64k line.