Originally Posted by D130
Respectfully I have to say that the 4th band won't help him in the US. 900 & 1800 aren't used in the US as they're reserved for other uses; those bands are used primarily in other areas of the world. Cingular & Tmobile run off of 850 & 1900, though Tmobile's 850 is primarily due to roaming agreements.
I have Tmobile & find it suits my needs, but if you need coverage in most places, I would recommend Verizon for their coverage. I don't like the way Verizon cripples the firmware on their phones, but I also don't need the sticks coverage they can provide.
You should be able to migrate from your old TDMA plan on ATT to a GSM one even though it's been taken over as a friend of mine did it a few months ago and stayed Blue; they managed to keep all the bonus minutes ATT gave them as well. They are cutting off the TDMA coverage to "encourage" people to migrate from the older technology so your reception won't be getting better.
And CDMA, the standard Verizon runs on, won't be dying anytime soon. They're gradually upgrading their network to run on one of the 3G standards CDMA2000. GSM carriers in the US will most likely be migrating to W-CDMA when they upgrade to 3G services.
You're right about 900/1800 being used elsewhere and not much here in the US. I tend to confuse 1800/1900 from time to time, but it's easy enough to look up and verify.
I do disagree though that W-CDMA will be the prevailing technology, though. The world is almost entirely GSM now and I've heard reports repeatedly that the U.S. carriers need to migrate to GSM in order to compete in the global telecommunications market. Time will tell, but I think everyone in the U.S. is sick of roaming without any coverage, and splitting back to GSM and any other number of "secondary" technologies is only going to be taking a step backwards.