Please excuse me for asking such a basic question. I was having a look at how AM radio works. So there is a carrier frequency and a higher frequency inside that that carries the data.
Does this mean that there would be two frequencies, one high and one low?
What about for stuff like 3G/GSM when stuff is sent over EM would it create noise at other frequencies, say out of their licensed spectrum?
If not how do they squeeze it all into such a tiny band of frequencies?