[sbe-eas] FCC says: CAP-in, SAME-out

[Sean Donelan]

On Sat, 28 Jan 2012, James Gorman wrote:

> If EAN is sent over the internet I don't see any provision for EOM 

> in CAP 1.2.


CAP audio streams don't include any of the EAS data tones (header, 
attention signal, and EOM).  All the EAS data tones are locally generated 
by the CAP-EAS device.  Each streaming audio protocol has either an end 
of stream flag, closes the connection or times-out.  Same way your web 
browser "knows" the end of a web page or YouTube video.  After the end of 
the audio stream is received, the CAP-EAS box adds the EOM data tones 
when forwarding the message using the EAS protocol.

News directors could instead decide to use the audio and CAP information 
without the EAS protocol, as part of a breaking news story.  Many stations 
already do that with weather warnings from the NOAA weather wire.

That's the general case.  There are a lot of details and interoperability 
issues that can happen.  I don't know how specifically an EAN would be 
handled with CAP.  CAP has lots of options, and a URI could be almost 
anything.