from http://www.rbr.com/radio/engineering/tech-topics/cap-eas-messages-now-transmittable-via-hd-radio.html

CAP-EAS messages now transmittable via HD Radio

11 April, 2011 04:14:00

Yes, Virginia, there are cell phones with FM receivers using RBDS for text alerting, and soon there will be HD Radios doing the same. Global Security Systems (GSS), the systems integrator and service provider of GSSNet-satellite CAP-based EAS data delivery- and ALERT FM- FM radio based Emergency Alert System; Sage Alerting Systems, provider of broadcast alerting equipment; and iBiquity Digital announced at NAB that HD Radio-enabled broadcasting is now capable of Common Alert Protocol (CAP)- Emergency Alert System (EAS) audio and text messages.

This new technology verifies that HD Radio Technology is compatible with the Integrated Public Alert and Warning System (IPAWS)-Open and other emergency notification systems, including ALERT FM and over AM transmissions. A live demo of the text delivery was also performed.

This potentially lifesaving information is available over HD Radio broadcasts because of the use of the Sage Digital ENDEC, which is the same technology used to send EAS messages over FM radio. CAP-EAS messages are received on the ENDEC via the GSSNet satellite data delivery system, or the Internet. The messages are then processed, converted, and pushed out over HD Radio Broadcast systems, where they are heard on enabled HD Radio receivers.

On 4/6 WTGE-FM (100.7), a Guaranty Broadcasting station in Baton Rouge became the first HD FM radio station in the country to broadcast Satellite-delivered CAP-EAS messages over HD radio. Test CAP EAS messages with text were sent across an HD Radio broadcast channel successfully.

So, to sum it up, EAS messages are now capable of being broadcast audibly through Analog FM and with audio and text over HD Radio via the Sage ENDEC; as well as textually through ALERT FM’s use of the Radio Broadcast Data System (RBDS).

RBR-TVBR observation: We will note that if your HD Radio is not enabled with the ability to receive EAS text over the HD Radio signal, the receiver is still RBDS-equipped for analog-only stations sending out the texts.