Since private TV channels and digital signage networks disseminate information quickly, it is feasible to use them for emergency messaging when a threat is posed. However, unlike Emergency Alert System messages transmitted by radio and TV stations or the wailing neighborhood siren in the distance, the delivery of emergency messaging via private TV channels and digital signage networks can target specific warnings and instructions to a defined group of people, who may be facing a unique emergency, such as a fire in their office building.



Let's focus on several points you need to know if you want to prepare your digital signage network or private TV channel to deliver Emergency Alert System messaging from the National Weather Service or governmental authorities, including those at the local, state and federal level.

EAS warnings

The Emergency Alert System stems from the desire of the president of the United States to communicate with the public in times of national emergencies. In the early 1960s, the chief executive began allowing local and state authorities to use the system to transmit localized warnings.

The system has been designed to deliver messages quickly and automatically in the event of an emergency. Among its most conspicuous features to the public may be the automatic interruption of broadcast programming that replaces program audio with an aural alert and superimposes a text crawl with warning information at the bottom of the TV screen.

EAS works automatically largely because of the efforts of the Federal Communications Commission to standardize the system and the cooperation of the nation's broadcasters to participate in the program.

To add EAS capability a private TV or digital signage network requires:

* a special weather radio receiver tuned to receive emergency warnings, such as tornado warnings issued by the National Weather Service for a given geographic area; or

* an EAS ENDEC or encoder/decoder that can transmit and receive digitally coded emergency messages;

* a communication interface between the ENDEC and the media server used to drive the private TV or digital signage network;

* media server software that automatically recognizes incoming EAS information, generates the appropriate text crawl, and interrupts the ongoing playlist or adds the emergency crawl.

Using a weather radio would only provide partial EAS capacity requiring constant monitoring by someone who's responsible for the digital signage network and direct physical intervention with the system. Using an ENDEC provides for full EAS coverage -specifically weather and emergency messages for local, state and national authorities.

The ENDEC receives transmitted EAS data that includes information about who transmitted the alert, for instance civil authorities or the National Weather Service, the type of emergency, such as flash flooding, tornado or Amber Alert, the geographic area of the emergency, how long the emergency message is valid and the when it was issued.

Onward and upward

The FCC has been active in promulgating rules to update the EAS system to take advantage of the latest digital technologies and new means to reach the American public. In May, the commission moved to add support for a new technology known as CAP -or Common Alerting Protocol- to the EAS delivery system. CAP will usher in support of a variety of transmission formats including text, audio and video via broadcast, cable, satellite and other networks.

Most notably it promotes next generation EAS, which among other things may lead to automatic generation of aural warnings based on text crawls to assist those with hearing impairments as well as generation of warnings for non-English speakers.

While these moves by the FCC will take time to play out, it's encouraging to note that the nation's EAS system continues to develop. In the meantime, there's a clear path for those with private TV and digital signage networks to traverse to support today's EAS messaging.