If there is no cellphone signal, how does the “emergency calls only” mode works?

Credit to u/billythewolf, u/goldenthrone, u/maldio

Concept

Your phone is allowed to use any network its physically capable of using for emergency call.

For example, if your phone uses Verizon and for some reason there’s no Verizon signal, but there is AT&T tower nearby, you can still and only use emergency services using signal from AT&T tower.

To fill any dead spot, sometimes, small towers are erected in remote areas. These networkless will only work for emergency calls. Plus military and private towers.

For example in Northern Ontario, companies with lumber rights have very large network areas, with many trucks, timber crews. They make their own radio towers to provide communication networks for their operation.

Application

Don’t panic and save your battery when you lost signals. Call emergency, you might need that extra battery for help to track you down.

Set your voicemail to your estimated location in case your battery dies and you lost signal. When other calls you, they will know your location and send help.

To call emergency, hold the “volume up” button and “lock” button on left and right side of your iphone.