^ urm dial up is frequency based as well ... the thing is that it operates on one frequency, a single band, that is why the speed is so slow ... by wi-fi i assume you mean broadband, fast connections ? those operate the same as dial up but on multiple frequencies at the same time, thus giving it extra speed ... old school copper telephone lines were not meant to carry multiple signals frequencies all at the same time and often ended up with too much data error ...

but anyway, back to the subject ... yes total BS ... radio frequency will not carry over a telephone receiver ...