DASDEC Advanced Extended Communication Software Options -
TDX : Transforming EAS With Details and IP Compatibility

TDX -
	Does not violate the EAS ruling
	Does not change the EAS protocol
	Does not render the installed base obsolete
	Can be incrementally added

TDX, or Textual Data eXchange, is a new OPEN method to improve the protocol of EAS with established technology. The TDX method simply uses presently defined EAS header tones to create an audio data packet, and places that packet at the front end of the audio envelope in the EAS message.

The data packet can contain additional event-specific text or it can contain one or more URLs. If the packet contains text it makes that text available at the decode site for use or forwarding, completely independent of the Web. If the packet contains a URL, the decode site can access that URL, making all the information used in the EAS release automatically available. This information could contain pictures (as in AMBER or evacuation alerts), additional text, and any additional audio with source-related accuracy.

The duration of the data packet containing a URL is approximately 1.5 seconds. It sounds like an additional header burst so it does not objectionably add to the EAS interruption. The TDX method can be fully tested during weekly (RWT) or monthly (RMT) tests. With the RWT, it sounds like four header bursts. With RMT, it sounds like an additional “quack” after the two tone.

The TDX method leverages unused bandwidth in the EAS protocol. Very simply, with this method, EAS becomes IP compatible by placing IP-compatible data inside the EAS message. Making TDX IP compatible makes it CAP compatible and brings it into line with the "CAP compatible" definition being further defined by FEMA.

TDX was defined and tested by Digital Alert Systems, LLC, and is offered as an OPEN and published method to invite constructive comment or criticism, make changes as may be required, develop a competitive economic base, and encourage a broader implementation to improve EAS. DAS has removed any proprietary restriction on this method and will work with anyone considering the implementation of TDX to insure an understanding of the protocol and the method.