ktmrfs wrote:
T mobile is a GSM network as is ATT. so if T mobile allows roaming normally it will use an ATT tower if a t mobile tower is not nearby.
With the advent of 4/5 G I'm not sure if that is still the case.. However I'm also not sure it is not still the case.
I do know at one time (long ago) I had a VoIP program that could use any of the cell phone protocols. GSM was the only one that worked with my computer and connection.. Omnipoint was the only 100% GSM provider of cell service (AT&T was not using GSM then) So I went with Omnipoint which became Voicestreams and is now T-mobile.. *I'm still with 'em*
For me. the areas I travel. they work though not that well at the nearby campground.. but they do still work