EWBS Emergency Warning Broadcast System
The Emergency Warning Broadcast System (EWBS) incorporates new technology into early warning systems alongside traditional methods of communication.
EWBS is a remote activation system for Radio & TV that transmits alert/warning information to viewers and listeners about a relevant disaster. EWBS is a feature of the Integrated Services Digital Broadcast-Terrestrial (ISDB-T) system, which is initially created by Japan.
The ISDB-T standard has been adopted by more than 15 countries in recent years. Japan, Brazil, Argentina, Peru, Philippines, Maldives, Uruguay, Chile, Venezuela, Ecuador, Costa Rica, Paraguay, Bolivia, Nicaragua, Guatemala, Belize, Botswana, Sri Lanka, El Salvador ISDB-T Digital TV Receiver and Digital Terrestrial Television (DTT).
The EWBS signal (Emergency Warning Broadcast System) is a system for warning and information that is implemented in analog and digital broadcasting. In an emergency, devices compatible with this system automatically turn on and emit an audible warning. Then they show information in different formats, depending on the device.
On September 1, 1985, NHK public broadcaster in Japan launched the EWBS system. The first real use was in 1987, to warn of the tsunami. Since then it warned of natural disasters more than 15 times. With this system the population has more time to take protective measures, avoiding the death of thousands. In 2000 the digital version of EWBS for digital satellite television (ISDB-S) was implemented and in 2003 for digital terrestrial television (ISDB-T).
In an emergency, devices compatible with this system automatically turn on and emit an audible warning
EWBS Warning System operation
The EWBS is enabled in the following cases:
- Earthquake warning/forecast (over level 3).
- Tsunami warning/forecast.
- Warnings and forecasts of other natural disasters such as typhoons, floods, eruptions …
- National emergency message from the government.
In digital broadcasting, the EWBS signal is multiplexed into the transport stream of the ISDB-T/ S digital signal. The warning signal and emergency information descriptor (area code, time, etc) is in the Program Map Table.