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Comment by nwh | Hacker News Reader

Strangely enough, iPhones do have an ability to receive geographic-targeted alerts like this. I've seen them used for severe weather warnings.

They look like this — http://i.imgur.com/gWrDXFD.jpg

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Most current (~2012) cellphones do in the US, see http://en.wikipedia.org/wiki/Commercial_Mobile_Alert_System

(I'm unclear on how these are delivered within the network, seems to be SMS but I can't source that)

I was in Hawaii 2 weeks ago, and they were broadcasting these types of alerts to my girlfriend's phone (Android 4), to warn about a risk of flash floods. Android was even using text-to-speech to read the alert out loud, and automatically, which woke us up during the night!

Think how exactly the alerts happen is up to the OEM, beyond 'loud noise'. The iPhone uses something similar to the EBS tone in 1s bursts (it was 1AM when mine fired, so I can't say with certainty if it was the same tone or not). I've heard similar from other Android users, but I've shut off the alerts on all my phones since.

It's SMS-CB with some magic numbers to activate the Text To Speech and alarms https://android.googlesource.com/platform/frameworks/opt/tel...

I received an Amber Alert for a girl from Philadelphia a few months ago on this system (or a similar one). It was surreal being in a restaurant and hearing over a dozen phones go off almost simultaneously.

I did not get an amber alert, and I am in Boston. Maybe due to the cell signal jamming to stop any additional detonations. I had to call family from Google Voice on my laptop to get in touch. Pretty crazy

Just to clarify, Amber Alerts are a specific type of these emergency alerts and are used for missing children.

I haven't heard about whether emergency SMS were sent out for the Boston bombings.

I received one in Pittsburgh for that alert for Philadelphia.

I think they got all of PA, MD, NJ and the DC area as it was close to 3 hours after the incident that they sent it out.

All phones have the ability to get broadcast SMS messages based on the cell tower they're connected to.

http://en.wikipedia.org/wiki/Cell_Broadcast

I started getting them sometime within the last year. Weather warnings and amber alerts. I always assumed that I started getting these as a result of some change in the Android software, but maybe it was a change in policy somewhere?

Google Now also has emergency alerts

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