There's a thread about getting vzw s3 to work on T-Mobile, I'd imagine you'd need to follow a similar process. And FYI, all phones will call 911, sim, no sim service, no service, they'll call 911. My niece was playing with one of my sisters old, no longer connected phones. All of the sudden police and ambulances showed up. She had dialed 911, they tried to return the call unsuccessfully so they used the phones GPS info and showed up at the house.
Eat Play Google