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Japanese Emergency Alert System, How Does It Works?

Posted on the 13 March 2011 by Onthatpage

Japanese Emergency Alert System, How does it works?Hellow Fellow readers! With the recent japanese disaster, there are tons of videos and pictures about how the nippon country is confronting this horrible crisis. But some maybe ask themselves, how all this Live information and videos when the events were happening were record? the japanese aren’t afraid of their lives and stop to get a movie about the earthquake or tsunami? Well this is part of the answer and a well design system to save the people’s life with the in time warning information about an imminent disaster.

This information came to us from [], they have this original post in spanish, i have translated it and add some stuff about the amazing japanese broadcast emergency system.

If there is a country that can be proud of having with one of the most advanced emergency warning system in the world is Japan, developed from their traumatic experience lived on the horrible Kobe earthquake in 1995 (where 6434 people died).

In 2000, the Japanese government mandated that all broadcasters convert to digital terrestrial broadcast systems and that there will be no more analog broadcast by 2011. As emergency broadcast technology existed in analog broadcast systems in the past, emergency alert systems (EAS) are being implemented into the digital systems of today. Many technology companies have also joined the effort to refine the emergency broadcasting technology, such as Panasonic, Fujitsu, and KDDI.

In the beginning, the system started with the installation of a sensor network with more than 4000 seismic sensors all around the country, with the capacity to send information in real-time to the Japan Meteorological Agency. This Agency is in charged of possessing the data of the sensors and evaluate the necessity or not to send an alert to the population.

Japanese Emergency Alert System, How does it works?

Image of how the emergency alarm system works

Thanks to the advanced technology developed specially for this sensor network, depending on the distance where the sensors that feel the earth movement of some magnitude are located, the warning can be sent some seconds before an important earthquake.

From this moment the Japan Broadcasting Corporation (NHK), who is in charged to alert the population, take advantage of one of the characteristics incorporated to the digital television standard ISDB-T developed precisely in Japan. (In Latin-America will be used the ISDB-Tb standard, similar to the japanese norm but adapted by Brasil)

In very simple terms, the ISDB-T standard broadcast the digital signals divided in 13 segments, where 12 of them are used for the high-definition television, and the remaining segment (called as “1-Seg”) allows the transmission of digital signals and alert messages to mobile devices (as cell phones, tv sets, laptops, etc.)

This way when the Japan Meteorological Agency receives an important warning from his seismic sensor network, it sends the information to the NHK network, who are in charge to send the alert signal to the population using the “1-Seg” channel and even with the ability to turn on those devices that are turned off .

Japanese Emergency Alert System, How does it works?

This is the architecture of the Emergency Broadcast System


The residents of a determined place gets the information about the magnitude of the earthquake, the time of arrival of the waves, evacuation maps and all the necessary information to make the reaction of the population the best way possible.

Besides all that was described above, the NHK counts with some helicopters to broadcast live from may places through the country and  more than 400 robotic cameras and broadcast equipments that has allow us to see the live transmission of what has happened live on the last earthquake and tsunami on japan.

On the next video you can see how the emergency broadcast works LIVE, this video was recorded during the earthquake on March 11. Notice how the warning was issue and the guy was watching his computer, and suddenly the earthquake started, this gives the population some time to scape from a hazardous zone and be safe.



Amazing don’t you think? was only like 30 seconds of warning but  in an emergency maybe is the time that will keep you alive, this time is enough to allow people to switch off their gas lines and get beneath a door frame or a table and it was very accurate, when the girl voice counting backward in japanese reach to zero, like 3 seconds before is when the earthquake really started.

Let’s hope the Japanese people overcome this crisis in a no longer future, and all the people over the world can help this country. This technology can demonstrate that it can help to save lots of humans lives, but the mother nature always have the last word. They need us…. please contact the Japanese embassy on your country to see how you can help.

For more information about the emergency broadcast system visit:

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