You see in addition to using Japan’s huge network of early warning sirens, the government decided to employ an almost never seen and relatively new technology.
In a matter of seconds Japan is able to send an Emergency Alert notification to just about every smartphone in the country.
It’s all tied into the country’s J-Alert emergency broadcast system. Created in 2007, the system uses a single satellite orbiting the Earth to then broadcast universal warning messages to TV, Radio and now smartphones as well.
The government can also target specific geographical regions.
Meanwhile J-Alert can hijack television channels in much the same way that our own emergency broadcast system can.
Thanks to its unified system, J-Alert can send follow up notifications keeping residents informed of what’s happening or giving them new instructions.
Once it was clear that the missile was heading past Japan and safely into the ocean a notification was sent reassuring residents.
The system is currently undergoing a massive upgrade. By 2019 Japan wants all local municipalities using the new receivers which can receive and process a alert in just a few seconds, compared to the 20 seconds it currently takes.
That may not sound like much but in the case of a military attack or major natural disaster seconds can mean everything.
Japan isn’t the only country to use an advanced warning system like J-Alert.
The UK actually has something very similar that uses a combination of SMS text messages or cell broadcast messages that would appear on smartphones as notifications similar to those sent by J-Alert.