Emergency Alert System, Part 1

In this first post, I will attempt to explain the Emergency Alert System's history. I'll delve into some of the nuts and bolts in a later post.

This morning up in Alaska they conducted the first live-code test using the Emergency Action Notification (EAN) code. It was a success! What does that mean?

First... The Emergency Alert System's mission is spelled out in Title 47 of the Code of Federal Regulations section 11.1:

“…The EAS provides the President with the capability to provide immediate communications and information to the general public at the National, State and Local Area levels during periods of national emergency.”

A little history…

In the 1950's, President Truman created a system called CONELRAD (CONtrol of ELectronic RADiation). CONELRAD was based off a system from Hawaii that was created after the Pearl Harbor attack. The CONELRAD system had all radio stations go off the air, and certain stations had to switch to either 640 kHz or 1240 kHz. If you look at an old radio you'll see the little triangles under 640 and 1240. Remember, this is before FM was popular. This was a pain in the neck for broadcast stations because they had to perform minor surgery on their transmitters in order to achieve the frequency switch. Not only that but they would broadcast for 5 minutes, then switch off while another station switched on. The whole purpose was to confuse enemy bombers and prevent them from using radio direction finding to home in on the major cities.

Let's fast forward to 1963. FM radio is starting to become popular and the threat to the nation wasn't from enemy bombers so much as ICBMs. Guidance packages on ICBMs were more advanced than the radio direction finding capabilities of the bombers. So 1963 President Kennedy's administration created the Emergency Broadcast System (EBS). EBS still had the requirement of turning on and off the transmitter before transmitting a tone. For example, the primary Common Programming Control Station  (CPCS-1) would get the alert via teletype from AP or UPI and would authenticate the message against a list of words. Andrew Dart made a great webpage with some scans of documents from the EBS days. After the message was authenticated, the transmitter would be turned off for five seconds, then turned on for five seconds, then turned off for five seconds, then turned on for five seconds and then finally a tone would be broadcast for 60 seconds. Well that was quite labor intensive and hard on the transmitters (transmitters don't like to be turned on and off rapidly like that). Let's also take into consideration that this was a manual system, meaning that a live human being had to be at the control point paying attention at all times.

The process for EBS tests became a little more streamlined. No longer did the transmitter have to be cycled. The whole test was shortened. But it was still a manual system that required a live human being to be at the control point.

Deregulation was coming to the broadcast industry, and with that came automated stations. While it's lothesome that the radio station be just a jukebox now, it was significantly cheaper for owners to run the stations. Good or bad, didn't matter. Radio was beginning to change and the emergency warning aspects needed to change with it.

Enter the Emergency Alert System (EAS). 1996 brought us the new automatic EAS. It still fulfilled the same original mission, but it also became more of an "all hazards" alerting system. Included were tornado warnings, and blizzard warnings, and the like. The focus of the EAS was not end-of-the-world Presidential messages, but also local emergency messages.

But this new system also was automatic! Now stations can have the EAS encoder/decoder (endec) right before their transmitter and have alerts automatically take over the station and get broadcast. This way there doesn't have to be a human in the loop. The message comes from the originators (local government, state government, weather service, federal government) and goes out automatically to every radio, TV, and cable system in the area.

Stay tuned for part two about the Emergency Alert System.