January 2017
« Nov    



Three generations of emergency communications

Even before CONELRAD was introduced in 1951, radio broadcasting was a critical part of the emergency communications infrastructure.  The government recognized early on the ability of radio to transmit data and information quickly, over large areas to the general public.  It works when all other systems fail, as demonstrated repeatedly over the years, the last of which occurred during Hurricane Sandy last October.  Massive destruction from flooding in lower Manhattan and shore side Brooklyn rendered the electrical grid, telephone network, the cellular network and the internet out of order.  Fortunately, enough radio stations stayed on the air and people used battery powered AM and FM receivers to obtain information.

CONELRAD poster, circa 1950's

CONELRAD poster, circa 1950’s

CONELRAD served two purposes; first, radio stations either re-tuned their transmitters to 640 or 1240 KHz or switched off the air. Then, each station that was still on the air would transmit for ten minutes, after which, they turned off and the next station in the chain would turn on and transmit for ten minutes. This was designed to confuse the Soviet bombers flying over the north pole on their way to incinerate us. Secondly, the CONELRAD stations were to distribute emergency information during and after said attack.

CONELRAD receiver

CONELRAD receiver

Recently, I found this CONELRAD receiver in a bomb shelter at a radio station. It dates to pre 1963, which is when CONELRAD was replaced by EBS.

EBS encoder/decoder

EBS encoder/decoder

EBS or the Emergency Broadcast System was a refinement of CONELRAD in several areas.  EBS used a two tone attention signal to unmute receivers and alert the public that something important may be happening.  Initially designed as a national system to warn of an impending attack, in later years it was also used by state and local governments to warn of other emergencies like weather, etc.

The current system is EAS or Emergency Alert System.

CAP compliant EAS

CAP compliant EAS

The Emergency Alert System was an advancement of the EBS in several areas.  Using SAME protocol in the message headers allowed stations to automate alert message relays.  This was driven by the desire for unattended operation.  The use of SAME also allowed many different types of messages to be filtered by alert type and area.  Each EAS unit also had an internal voice recorder.  All of this was upgraded in 2011 with the introduction of CAP, which would take email messages and generate computer voice alerts to be sent out over the broadcast stations.

Three generations of emergency communications equipment found at one facility.

The main problem with EAS CAP is it violates the engineering principle of KISS (Keep It Simple, Stupid).  It is an overly complicated system that relies on the internet, e-mail servers, the public telephone system and other infrastructure that may not survive natural or man made disasters, enemy attack or other disruptions.  Even something as simple as a national test proved to be problematic in 2011.

For a real emergency information network, the idea of WGU-20 has some merit.  Two or more well positioned medium to high powered LF stations could serve as a PEP distribution network and reliably cover the entire country.  With such a system, every broadcast station, cable head end and NOAA radio transmitter could monitor the LF stations directly, thus replacing most of the over the air daisy chain and or FEMA leased lines.  The advantages of LF is that it is fairly immune to HEMP, it goes a long way reliably, can have multiple redundant transmitter sites located within secure areas like military bases and uses time proven technology.  That would be a real, cold war solution.  But no, let us instead rely on a hodge podge of ISPs, TELCO leased lines, 3/4G wireless networks, SMS, satellite links, e-mail servers and the like, because: Hey!  It’s the digital age, we don’t need none of that stinking broadcasting crap.

Less than one month until the Coordinated National EAS test

November 9, 2011 at 2pm EST, FEMA will be testing EAS with it’s first ever national level test.  To promote that event, they have released a twenty eight page “tool kit,” (near the bottom of the page) designed to help everyone get through the test.  It should be interesting.  According to FEMA:

The nationwide EAS Test is not a pass or fail measure, nor will it specifically test Common Alerting Protocol (CAP) compliant equipment (although CAP compliant equipment should pass the Emergency Action Notification [EAN] live-code in the same manner as legacy EAS equipment).

They will release a Emergency Action Notification (EAN) to all the Primary Entry Point (PEP) stations, which should then flow down stream through all the radio, television, cable systems, and direct broadcast satellite systems.  The test should last about two minutes and will conclude with a standard EOM.

I doubt very much it will sound like this:

That is WHEN, Syracuse, NY singing EBS test.  A bit of originality there. WHEN played this for their weekly EBS test for the better part of the 70’s.  Naturally, the FCC found out about it and told them to stop.  Shame, really, it is kind of catchy.

If you have some spare time, download the tool kit and study up for the test.

WOWO EBS activation

An oldie, but a goodie, February 20, 1971, WOWO gets a EAN via AP teletype and follows procedure:

Back in the days of EBS, there were weekly closed circuit tests via AP and UPI teletype. In the event of a real Emergency Action Notification (EAN) there was a red envelope that contained a set of code words for each month. The test code words were on the outside of the envelope. If a EAN was received, the envelope would be torn open and the actual code words would be matched against the code words in the message. If it were authenticated, then the station would do just what WOWO did right then, send the two tone EBS alert for 25 seconds  and break into programming.

It is amazing that this did not happen more often, especially on a Saturday morning with some a sleepy Airman in Colorado pulling the wrong message tape off the rack at the message center responsible for the whole system.

It has happened more recently when an EAS message was sent to evacuate the entire state of Connecticut.  A EAN was sent in Chicago warning of a national attack when state officials were testing their new system.  I am sure that others have been sent as well.

I suppose the emergency notification has always left something to be desired.


A pessimist sees the glass as half empty. An optimist sees the glass as half full. The engineer sees the glass as twice the size it needs to be.

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution

Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin

The individual has always had to struggle to keep from being overwhelmed by the tribe. To be your own man is hard business. If you try it, you will be lonely often, and sometimes frightened. But no price is too high to pay for the privilege of owning yourself.
~Rudyard Kipling

Everyone has the right to freedom of opinion and expression; this right includes the freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers
~Universal Declaration Of Human Rights, Article 19

...radio was discovered, and not invented, and that these frequencies and principles were always in existence long before man was aware of them. Therefore, no one owns them. They are there as free as sunlight, which is a higher frequency form of the same energy.
~Alan Weiner

Free counters!