Found this on the net
 

Alltel: CDMA
AT&T: GSM and TDMA*
Cingular: GSM and TDMA*
Nextel: iDEN**
Sprint PCS: CDMA
T-Mobile: GSM
U.S. Cellular: CDMA
Verizon: CDMA

Joepole, do you know if Cingular here in Shreveport TDMA? (and I'm excluding AT&T's network for the moment) I'm talking about Cingular's network. Is it purely GSM?

Although, I really don't think the issue in Shreveport is so much CDMA vs TDMA in this case with Cingular. No matter the protocol, I think Cingular just messed up and tried to pile too many users per "hertz" of radio bandwidth. A channel can only hold so many happy customers. As for AT&T, any network that is relatively "empty" should perform well IMO.

Cingular, ATTWS, TDMA, and GSM
 

Cingular owns ATTWS's TDMA network, which isn't much used anymore as they won't take new subscribers to it, they're just supporting the legacy customers because it doesn't cost much to run and they make a lot of money per user (more than they do for GSM customers because the rates haven't changed in years). In fact, they just issued a $5-10 surcharge to TDMA customers.

Cingular originally partly grew out of Bellsouth's cell network which was also (I believe) TDMA, so they may have some legacy towers, as well, but Bellsouth's cell service was TERRIBLE here, easily the worst we've ever had. I had a friend that lived in Southern Trace that got 6 or 7 hundred dollars worth of roaming charges one month from using his phone at home.