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Comment by walrus01 | Hacker News Reader

While on the topic of causing a "boy who cried wolf" problem with emergency tones. All of the Amber alerts on cellular networks in Ontario are currently being sent as "presidential alert" priority level.

On many phones' OSes you can disable audible amber alerts but not presidential alerts. Some people in network engineering at the mobile network operators in Canada screwed up big time.

https://www.cbc.ca/news/opinion/amber-alerts-1.5137889

https://globalnews.ca/news/5683167/amber-alert-system/

Presidential alerts are only supposed to be used for absolute max priority events, such as literally a nuclear missile attack, a fire storm that's about to engulf a town, tsunami that will affect hundreds of thousands of people, etc.

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>Some people in network engineering at the mobile network operators in Canada screwed up big time.

if that was just the network engineers screwing up, they would have fixed it. Broadcasting amber alerts as "presidential" level is an intentional choice at the policy level.

One supposes that this was inevitable, but it seems that the "Amber alert" itself has a bit of a cry-wolf problem. We might imagine a depraved kidnapper every time, but most alerts turn out to be estranged divorced dads who don't take the family court's "no" as final.

Canada doesn’t even have a President!

I believe in the US “Presidential alerts“ actually require approval from POTUS. What’s the intended protocol in Canada?

The entire process was badly bungled. The FCC designed a nicely tiered alert system for mobile phones. The CRTC then adopted the same system but tossed out all but the "Presidential" level. Then they delegated responsibility for what to alert about to local authorities.

The end result is cops in Burlington sending end of the world alerts that can't be silenced to people 1500 km and 15 hours away in Thunder Bay about events that took place 2 hours ago. It's complete lunacy.

The tone is so disruptive and loud people are calling 911 to complain. It's so jarring I'm shocked it hasn't resulted in fatal car collisions.

I've been in the states during amber alerts and even natural disaster warnings and the process is simple and effective. The alerts come in and you action them if warranted. Ours are literally the end of the world tone no matter what.

How those alerts work technically? They are SMS with special header or entirely separate message type?

(eg. in Poland alerts are sent as plain old SMS)

No, they are not done like SMS. Think of SMS like a normal IP packet, it has a source and destination. Belaboring the analogy, the WEA messages are more multicast packets.

WEA messages are encapsulated in Cellular Broadcast data (CB Data) payloads which are then encapsulated in System Information Blocks (SIB12 specifically). The way they are “routed” to your phone is by being near a tower in the coverage area of the alert. Even if you weren’t in range of the tower when the alert initially went off, you’ll still receive the message as soon as you are within range of the tower(s) broadcasting it (assuming the alert hasn’t been cleared). Each payload has the equivalent of a payload ID which is supposed to prevent duplicate notification on your device of the same alert (but for different reasons, isn’t always done right).

It's cell broadcast which is related to SMS but slightly different.

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

I believe there's a functionally equivalent system that comes from a group of people at DND who report directly to the PM's office and the privy council.

Possibly military/NORAD related, maybe at CFB North Bay, if they ever need to send an alert that is basically "ICBMs inbound, bend over and kiss your ass goodbye".

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