The iPhone makes calls to 911 even if you don’t have service. That’s great! It always tells me these cell phone companies are holding back the service available. I live in rural Eastern North Carolina & it’s a dead zone. With out internet service in my house I can’t make a phone call or it drops. It doesn’t matter who the carrier is they won’t put a cell tower here. A company built a tower several years ago & it sits empty. (I didn’t know this, other companies put up cell tower & usually the phone company puts their satellite or antenna on it. I honestly don’t know which.) I know the iPhone calls 911 with out service because I accidentally hit the emergency button sequence on my phone when turning it off. But I couldn’t make calls for several days because my internet was out. That’s just another way the government & companies use their power to control.