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EAS in transition

In the post Sept. 11 world the Emergency Alert System (EAS), as well as all emergency related communication systems, have come under scrutiny and criticism.

The national emergency alert communications system was born during the Cold War as CONELRAD. It evolved to the Emergency Broadcast System (EBS) in 1963 and was upgraded to the EAS in 1997. FEMA, as part of the Department of Homeland Security, has jurisdiction over the EAS. The FCC defines technical standards, operational rules and enforces broadcaster compliance with EAS requirements.

How the current system works

The technical structure of the EAS consists of three parts: transmission pathways, a mandatory message protocol and equipment requirements. It is compatible with both analog and digital transmission systems.

The EAS transmission pathways consist of a network of radio relay stations, the “EAS Web”. Thirty-four radio stations are designated as national Primary Entry Points (PEP). PEP facilities are radiation hardened and intended to continue operating in the event of a nuclear blast. They have a National Primary (NP) designation and are monitored by Local Primary 1 stations.

At the request of the president, FEMA distributes Presidential Level messages to the PEP stations. At the state level, a governor may initiate an emergency message. Similarly, a request for activation on the local level is directed to the local primary station.

The problem

Studies of the EAS system have found that the relay system does not function in a reliable manner. With daisy chain transmission paths, a failure at one station will cause a failure in the relay chain.

Operator error can produce erroneous alerts. A radiological warning and an Emergency Alert Notification (EAN) — reserved for presidential communications at a time of extreme national emergency — were erroneously activated. Low-quality technical implementations that result in unintelligible communications from limited bandwidth audio systems render the alert useless. Failure to identify an alert or dead air during insertion will encourage channel changes and the message will be missed.

Other concerns and criticisms:

  • Funding for EAS from government sources has been repeatedly reduced.
  • Security and access. Only a national alert requires authentication.
  • Participation is not mandatory on the state and local level.
  • Not all types of alert messages are required to be relayed.
  • The EAS could be the target of an attack.
  • EAS regulations do not apply to DTV.

To address these issues, the FCC issued a NPRM Aug. 4, 2004, concerning EAS improvements and implementation in evolving digital technologies. The SBE has filed comments in response to the FCC’s EAS NPRM specifically addressing each issue.

A system of systems

The ultimate goal is to establish an All-Hazard warning system. Hazards include weather, technological accidents, AMBER Alerts and terrorist attacks. The EAS is now used for natural and AMBER Alerts.

The National Weather Service (NWS) may initiate messages at either the state or local entry point. Child abduction AMBER Alert and other public safety messages maybe initiated by other government officials who are designated in FCC-approved state and local EAS plans. Many state highway systems have AMBER Alert signs along the roadway.

The FCC requires that event codes for NWS and AMBER Alerts must be enabled in equipment manufactured after August 1, 2003. Any replacement of EAS equipment at a facility after February 1, 2004, must accept the new codes.


The creation of interoperability standards ensures that emergency warning systems can communicate with each other. This will allow first responders, emergency and event managers, public health agency officials and executive management in the public and private sectors to share critical information during an emergency or major event. Messages can be communicated in a timely manner and in way that is understood by all.

The DHS has signed a Memorandum of Agreement (MOA) with the Emergency Interoperability Consortium (EIC), to promote the development of data sharing standards using of XML for emergency response.

Common Alerting Protocol (CAP) is an open standard for the exchange of emergency alerts and public warning over data networks, computer-controlled public warning systems and emergency management software applications. CAP allows a consistent warning message to be disseminated simultaneously over many different warning systems, thus increasing warning effectiveness while simplifying the alerting task. Using CAP, emergency responders can:

  • Ensure alert messages reach the right audience at the right time.
  • Reduce the workload and costs associated with using multiple warning systems.
  • Enhance technical reliability.
  • Ensure consistency in the information transmitted over multiple delivery systems.
  • Reduce costs and operational complexities by eliminating the need for multiple. custom interfaces to warning sources and dissemination systems.

In August 2003, the EIC released a draft of the CAP by the OASIS Emergency Management Technical Committee. In April 2004, CAP version 1.0 was adopted as a full OASIS standard.

The multiplatform future

The Partnership for Public Warning ( is a not-for-profit, public-private partnership with the goal of improving the nation’s alert and warning capabilities. Its members include the SBE, DHS, the FCC and other public safety oriented groups.

Recommendations for upgrading the EAS system include the following features and requirements:

  • Mandatory compliance for all EAS, NWS, All-Hazard and AMBER Alerts on state and local levels. All alerts must be relayed.
  • Common Alert Protocol (CAP): one standard message protocol.
  • Redundant delivery platforms such as TV, cable, satellite, AM/FM/digital radio, the Internet, cell phones and PDAs.
  • TVs and other devices that turn on or change channels for a relevant EAS.

The tsunami that hit South Asia in December 2004 painfully pointed out that even with existent sophisticated communication networks, a timely warning was not issued. Something as trivial knowing whom to call could possibly have saved many lives. The United Nations is attempting to establish a global system to predict disasters. The International Early Warning Program (IEWP) is an effort to establish a global emergency alert system.

Congressional legislative efforts have included The Emergency Warning Act of 2003, S. 118, H.R. 2573, H.R. 10, H.R. 5238 and H.R. 2250. These bills implement the 9-11 Commission recommendations and require a study of the feasibility of implementing an emergency telephonic alert notifications system and creation of a READICALL emergency alert system. A pilot study using network technology now being used for AMBER Alerts to improve public warning systems is also proposed.

Transition to digital technologies and an All-Hazard system is the future. NOAA Weather Radio (NWR) utilizing digital EAS technology is now incorporated into the NOAA Weather Radio All-Hazards Network. EAS equipment used by the media can receive and decode NWR messages automatically. Special weather radios are tuned directly to NWR channels and can be programmed to receive only specific types of messages and for specific locations, using Special Area Message Encoding (SAME).


NPRM Review of the Emergency Alert System, EB Docket No. 04-296, August 4, 2004,

Comments of the Rehabilitation Engineering Research Center on Telecommunications Access Submitted to the Federal Communications Commission on October 29, 2004 In the Matter of Review of the Emergency Alert System, WC Docket No. 04-296,

Emergency Communications: The Emergency Alert System (EAS) and All Hazard Warnings, CRS Report for Congress, Moore, 2004

An Advanced EAS Relay Network Using Common Alerting Protocol (CAP), Botterell, 2003,

Developing a Unified All-Hazards Public Warning System

EAS organizations and information


911 Broadcast Library

National Weather Service

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