Well, except your short and simple answer isn't correct.
Modern mobile phones almost invariably include the ability for the phone to act as a modem. It doesn't make a whit of difference that in a digital phone system the bandwidth is filtered to those used by the human voice - because that's precisely what landline systems do, as well.
Go reread the posts leading up to this. Understand them. Think about it again.
We were talking about using GSM voice services for data. And when it comes to that, my statement holds 100% true, I'm afraid.
Voice circuits in GSM are not just 'filtered'. Go read up on low-bitrate voice codecs and how they work. You won't get high-speed FSK/PSK/<insert favourite V.xx modulation here> across them. Period.
If and when data is transmitted in digital cellular such as GSM, it's flagged as such and in fact sent more or less verbatim across the digital link. Technically the phone doesn't really act as a 'classic' modem, even though it represents itself as such (much the same as, say, external ISDN TAs) to the DTE.
When I was with Sprint, I used my digital cell phone to dial up modems with the phone's internal modem all the time. Now that I'm on Verizon, I use their 1xrtt system on my phone to get 144Kbps net connectivity, as well as being able to dial into terminal servers that have standard 56K analog modems on them, on a regular basis, when I'm out in the field. And it all works perfectly well.[div align=\"right\"][a href=\"index.php?act=findpost&pid=88330\"][{POST_SNAPBACK}][/a][/div]
Obviously it works perfectly well. But this has to do with the fact you are using
data services.
As for connecting to standard analog modems -- what happens is that the data is in fact sent digitally using data services to an outgoing modem pool at your cellular provider, from where an actual analog modem connection is initiated into POTS over which your data is sent. Again, no magic there either. And no GSM voice circuit as well.
Best regards,
Chris.
