{"id":6428,"date":"2013-03-13T08:00:39","date_gmt":"2013-03-13T12:00:39","guid":{"rendered":"http:\/\/www.engineeringradio.us\/blog\/?p=6428"},"modified":"2023-04-08T20:00:53","modified_gmt":"2023-04-09T00:00:53","slug":"three-generations-of-emergency-communications","status":"publish","type":"post","link":"https:\/\/www.engineeringradio.us\/blog\/2013\/03\/three-generations-of-emergency-communications\/","title":{"rendered":"Three generations of emergency communications"},"content":{"rendered":"\n

Even before CONELRAD<\/a> was introduced in 1951, radio broadcasting was a critical part of the emergency communications infrastructure.\u00a0 The government recognized early on the ability of radio to transmit data and information quickly, over large areas to the general public.\u00a0 It works when all other systems fail, as demonstrated repeatedly over the years, the last of which occurred during Hurricane Sandy last October.\u00a0 Massive destruction from flooding in lower Manhattan and shoreside Brooklyn rendered the electrical grid, telephone network, cellular network, and the internet out of order.\u00a0 Fortunately, enough radio stations stayed on the air and people used battery-powered AM and FM receivers to obtain information.<\/p>\n\n\n\n

\"CONELRAD<\/a>
CONELRAD poster, circa 1950’s<\/figcaption><\/figure>\n\n\n\n

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 the said attack.<\/p>\n\n\n\n

\"CONELRAD<\/a>
CONELRAD receiver<\/figcaption><\/figure>\n\n\n\n

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.<\/p>\n\n\n\n

\"EBS<\/a>
EBS encoder\/decoder<\/figcaption><\/figure>\n\n\n\n

EBS or the Emergency Broadcast System<\/a> was a refinement of CONELRAD in several areas.\u00a0 EBS used a two-tone attention signal to unmute receivers and alert the public that something important may be happening.\u00a0 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.<\/p>\n\n\n\n

The current system is EAS or Emergency Alert System.<\/p>\n\n\n\n

\"CAP<\/a>
CAP compliant EAS<\/figcaption><\/figure>\n\n\n\n

The Emergency Alert System<\/a> was an advancement of the EBS in several areas.\u00a0 Using SAME<\/a> protocol in the message headers allowed stations to automate alert message relays.\u00a0 This was driven by the desire for unattended operation.\u00a0 The use of SAME also allowed many different types of messages to be filtered by alert type and area.\u00a0 Each EAS unit also had an internal voice recorder.\u00a0 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 broadcast stations.<\/p>\n\n\n\n

Three generations of emergency communications equipment found at one facility.<\/p>\n\n\n\n

The main problem with EAS CAP<\/a> is it violates the engineering principle of KISS<\/a> (Keep It Simple, Stupid).\u00a0 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 attacks, or other disruptions.\u00a0 Even something as simple as a national test proved to be problematic in 2011.<\/p>\n\n\n\n

For a real emergency information network, the idea of WGU-20<\/a> has some merit.\u00a0 Two or more well-positioned medium to high-powered LF stations could serve as a PEP distribution network and reliably cover the entire country.\u00a0 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.\u00a0 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.\u00a0 That would be a real, cold war solution.\u00a0 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!\u00a0 It’s the digital age, we don’t need none of that stinking broadcasting crap.<\/p>\n","protected":false},"excerpt":{"rendered":"

Even before CONELRAD was introduced in 1951, radio broadcasting was a critical part of the emergency communications infrastructure.\u00a0 The government recognized early on the ability of radio to transmit data and information quickly, over large areas to the general public.\u00a0 It works when all other systems fail, as demonstrated repeatedly over the years, the last … Continue reading Three generations of emergency communications<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[41,154,300],"class_list":["post-6428","post","type-post","status-publish","format-standard","hentry","category-fcc","tag-eas","tag-ebs","tag-fcc"],"_links":{"self":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/6428","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/comments?post=6428"}],"version-history":[{"count":16,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/6428\/revisions"}],"predecessor-version":[{"id":11443,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/posts\/6428\/revisions\/11443"}],"wp:attachment":[{"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/media?parent=6428"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/categories?post=6428"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.engineeringradio.us\/blog\/wp-json\/wp\/v2\/tags?post=6428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}