How do cellphones make calls when there's no network signal?

Engineering Technology
1

I have seen in my phone that there is an EMERGENCY CALL button, and it works even when there is no network bars on the phone. How does that work?

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2

I know for emergency numbers like 911, a cellphone manufacturer has to make sure that their cellphone hops on any network available to make the call. It doesn’t have to be the NATIVE network of that phone.

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So, if you’re stuck in a place where there are very few to no network towers of any kind, the emergency call wouldn’t work?

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Could it be linked to satellites? I suppose certain cellphones might come with built-in satellite communication features.

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When there is no network coverage, emergency calls can still be made by using another service provider’s network. Emergency communication is possible through satellite phones or radios if network coverage is unavailable. We have written about this on our article: https://www.scienceabc.com/innovation/how-can-mobile-phones-make-emergency-calls-when-theres-no-network-coverage.html

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