I was in rural area, where, according to the t-mobile coverage map, should have fair LTE signal and worst case voice call and text. There was no LTE. But I got full-bar signal. When I tried to call 611 to test voice call, I got "not registered on network" on the screen and call didn't go through. When I was with AT&T, I didn't have much problem. At least I got 3G. Now I got nothing. I guess the full bar I picked up was non-t-mobile carrier, probably AT&T. But I thought we have certain roaming allowance. Do I need to do certain setup on my phone?
BTW I'm brand new t-mobile, just switched over from AT&T. The Samsung S7 is brand new to me too. I need to work quite often in that area. At least I need to be able to do voice calls. A bit bumped.
Anything helps. Thanks for your help in advance.
Best answer by stevetjr
Yes you can always make a 911 call on any available network. Even if a phone doesn't have a SIM card in it as long as it has any signal from any carrier it allows 911 calls.
As for the roaming it is complicated but a general rule of thumb is that lets say in this case if T-Mobile has a presence in a an area not only are they less inclined to sign a roaming agreement the other carrier is not legal obligated to sign one with them. However if a carrier has no spectrum in a market then the other carrier(s) that do legally have to offer a roaming agreement on "fair and reasonable terms" which especially AT&T is rotten at and often gets taken to the FCC on what they consider fair and reasonable. AT&T has a historical record of doing everything to avoid allowing other carriers to roam on their network, their latest being the whole 700 spectrum Band allocation and why there is now Band 17 and Band 12 instead of just one.
I see you have an S7 which is Band 12 capable, do you know if your market is or will be covered by T-Mobile's recent Band 12 spectrum purchases? If so Band 12 signal carries much farther and penetrates buildings and other objects much better.