Improved Public Alerting for Emergencies and Disasters

EAS can be improved greatly if HD Radio and digital tv capabilities are exploited
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Public alerting technology has progressed significantly since the days of sirens and the Emergency Broadcast System. Now EAS can be revised by FEMA and other parties in a manner to address numerous problems and take advantage of new technologies.

The recent commentary in Radio World by Jerry LeBow ("You Need Not Fear the CAP," Aug. 12) is welcome in that it is helping to clear some of the fear, uncertainty and doubt about EAS.

The Federal Emergency Management Agency, via OASIS, released an improved IPAWS document that mentions an "Improved EAS." Certainly generating EAS messages from CAP or Emergency Data Exchange Language Distribution Element (DXL-DE) is a measure of improvement. However there have been many lessons learned from the analog system developed by Fred Baumgartner and the others in the Colorado Group of SBE engineers.

Now that DTV and HD Radio are here, if not universally adopted, there is the potential — for FEMA, the FCC, SBE, developers, standards organizations, manufacturers, emergency manufacturers and others — to address many limitations observed by SBE members and the emergency management community.

A good example is in a submission by Dale Gehman, which I've posted at www.globalcom123.com/eas. Another is the lack of selectivity in the present EAS system, e.g. to be able to select first responders, such as for an exercise.

There are many contributors to this dialog. Clay Freinwald and an SBE submission to which he contributed favor allocating a band in the released 700 MHz spectrum for CAP and EDXL-DE messages. I suppose RW readers would like to know more about this and perhaps enlighten the Washington administrators that the reality in Puerto Rico, Washington state or Alaska is not easily understood when looking at words on paper in an office in D.C.

One approach is to take a serious look at the core protocol and consider that by developing a standard, improved EAS functionality could be an optional feature in consumer digital radios and TVs. This is a basis of the EAS+ approach. There are other issues, summarized in a PowerPoint you can find at the URL cited above.

Total replacement

Gehman, a former broadcast owner and public warning consultant, has argued that the most desirable solution for the existing EAS-SAME nightmare would be a total replacement of EAS-SAME with EAS-CAP.

It is illogical to proceed with a forced EAS-SAME translation schema under which broadcasters will be obliged to purchase new equipment that will not resolve broadcaster public warning fallacies with EAS-SAME. Gehman feels strongly that we are marching toward a premature deployment of CAP that will be based on an EAS-SAME translation device harmful to public warnings. He believes that the federal/private CAP partnerships should instead focus on completion of a CAP Broadcast User Interface before a mandatory CAP implementation date occurs.

The development of such an interface would facilitate the broadcast of public warnings to the exact targeted warning area without the use of EAS-SAME and its inherently flawed fixed Event Codes and County FIPS Codes. The use of EAS-SAME inherently results in the broadcast of falsely IDed warnings to the public in areas that are not affected by the warning event.

A CAP Broadcast User Interface would compare the broadcast station's city-grade coverage polygon with the targeted warning polygon and activate the broadcast station only if the CAP warning is defined as the highest level "Certainty" and if the station's local coverage polygon provides service to the actual desired warning area.

However, as it appears there is simply not enough political capital to force FEMA and the FCC to abandon an illogical CAP-to-EAS-SAME hybrid schema, Gehman has stated that an EAS+ upgrade approach is at least the best alternative available. With a CAP Broadcast mode, EAS+ provides a path for the development of the EAS technology in the future, by enabling CAP, PDF, TXT and some other files to be broadcast to computers.

Lessons applied

There are going to be many other distribution channels for alerts, such as Twitter. However we should ask whether lessons learned from EAS would be applied to these new ideas.

Are the performance criteria of other technologies — penetration (24/7 of the population), response time (e.g., earthquakes), redundancy (e.g., a daisy mesh complementing the CAP WAN) and selectivity (to prevent over-alerting) — comparable? What about the value delivered for the price? I've offered a first approximation in the PowerPoint referenced above; it indicates where market research usefully could be applied.

However smart ideas are not sufficient to develop an appropriate new system. The quality of implementation is also important.

For example, soft errors in digital systems are one of the causes of crashes or errors you may have experienced. In entertainment, the consequences usually are not so serious; however EAS is a system in which significance is attached to each transistor. Errors can have serious consequences.

Digital alerting systems should include a specification for "radiation hardness." Perhaps we need not require "mil-spec" levels, but the radiation resistance of our alerting equipment is important information.

Questions that manufacturers of encoder/decoders and other alerting equipment could be asked include: Are the electrolytic capacitors rated at 105 Celsius or more? Does the EAS equipment have redundant power supplies? Can the fan(s) be changed without powering off the equipment? Can it be monitored remotely by means that integrate with the broadcast and a future (not well-defined) CAP QC environment? What backup for the hard drive is provided, e.g. USB flash?

A future EAS can have a number of capabilities beyond those discussed above, e.g.:

  1. EAS messages sufficiently detailed that they could be used to regenerate CAP messages in the event that the CAP WAN connectivity fails.
  2. Improved selectivity as a feature in consumer digital radio and TV, for some user selectivity and improvement with time. A standard and certification rather than a mandate are appropriate for implementing this.
  3. A QC and value reporting system, based on market research.
  4. The ability to send CAP and EDXL-DE messages to suitable destinations from digital broadcasts, a future possible improvement.


Analog radio stations (not HD Radio) would not need new EAS encoder/decoders, as a computer could provide the interface to the CAP network. For EAS+ compatibility this computer would also receive the audio and data from the digital receivers for the improved daisy chain/mesh and from Weather Radio. Such analog stations would be peripheral. Analog stations with RDS or RDBS can take the EAS+ data and broadcast that. Original design encoder/decoders could be used for QC monitoring receivers for such analog stations. (This would be QC in the www.asq.org sense.)

As can be seen, this is a complex subject. The solutions developed by myself and others may not be the most optimal, but a standards development process should address such items.

There are numerous important developments in emergency management; to bridge that arena and the broadcasting world is difficult. While to do so requires time and effort, I hope more discussion will follow.

The recent tragedy in Samoa has highlighted the desirability of a well-defined user interface. Broadcaster activations save lives, but the appropriate capabilities vary, so manual activation capabilities need to be configurable for the installation and jurisdiction. Also how to apply this in a CAP environment needs consideration.

Frank Bell, based in Clifton, N.J., is senior engineer for a digital media company and also has done engineering contract work for several New York state broadcasters. He has an interest in emergency alerting and has participated as an individual in EAS planning meetings held by various national organizations.

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