Am I reading your info right? AT&T, which does not have enough bandwidth, frequency allocation, channels, or whatever they are crying about that is in the way of their LTE, can, and does run CDMA and GSM networks? "How can this be?", says sarcastic Blacksheep.
"If you can't beat them, buy them", says AT&T.
baa-baa for now
PS: If the store rep at my local VZW is correct, I may experience 4G in Hagerstown, MD in under 2 months. Hope so. To Viper and all other TMO customers: best wishes for a good July 4th. I may be too busy with college homework to post much for a while. 1/3 done with Associates portion of BS in IT.