Emergency population warning systems

method of sending messages to multiple mobile telephone users in a defined area at the same time

audible signal for emergency population warning

U.S. radio/TV system for public alerts of threats to public safety since 1997

thumb|upright=1.3|Diagram of the J-Alert system

warning issued by authorities to the public en masse

communication system used for emergency coordination, often made up of both input devices, sensors, and communication devices, typically capable of both initiating and receiving information among multiple parties

CONELRAD (Control of Electromagnetic Radiation) was a method of emergency broadcasting to the public of the United States in the event of enemy attack during the Cold War. It was intended to allow continuous broadcast of civil defense information to the public using radio stations, while rapidly switching the transmitter stations to make the broadcasts unsuitable for Soviet bombers that might attempt to home in on the signals (as was done during World War II, when German radio stations, based in or near cities, were used as beacons by bomber pilots).

defunct emergency warning system used in the United States by television and radio stations between 1963 and 1997

U.S. company specializing in emergency lighting, sirens, industrial equipment, and public safety equipment

National obligatory radio and television broadcast in some Latin American countries