alt Hacker NewsCorrect me if I'm wrong, but I think I've read somewhere that it can be a SIM-less phone that abuses emergency call flow in 3GPP. GSM specs have special accomodations for 911/112 type calls that don't require a SIM(that sometimes ironically lead to normal calls working fine and just emergency calls failing).
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tengwar2 • today at 11:08 AM
The specs do have that, but I used to work at a major mobile telco which didn't implement that part of the spec. The argument was that people would use emergency calls to test phones without a SIM. That may well have changed, but you can't assume that the spec will always be implemented in the network.
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Yes, you don't (in most countries) need a SIM for 112/911, and even when you do have one, you are allowed to use other carriers for such calls, even when you ordinarily shouldn't be able to roam onto them.