WFCR Delays Met Opera (perche?)

Scott Fybush
Mon Dec 13 08:18:26 EST 2004

At 07:49 AM 12/13/2004 -0500, Dan Strassberg wrote:
>But what is the duration of the IBOC delay. I don't think it is 7 seconds.
>Four seconds, maybe? And is it the same for the AM- and FM-band versions of
>HDRadio? Now what if CCU runs one of its national call-in contests and the
>stations that are not running HDRadio don't insert a dealy equal to the IBOC
>delay. Will there be lawsuits from listeners whose chances of getting
>through were diminished to the vanishing point by the fact that some
>listeners could hear the program several seconds earlier?

Interesting question.

The "standard" IBOC delay right now is actually closer to 8 seconds, but 
one of the things Ibiquity is working on as it continues to improve the 
codec is a low-delay setting that would make it easier for stations to 
carry live sports play-by-play and such.

Less than half the delay currently in use is actually needed for encoding 
and decoding the digital signal. It's as long as it is to provide better 
time diversity to the signal, the idea being that any transient reception 
problems (a lightning strike, driving under a power line, meteor scatter 
<g>, what have you) won't last for 8 seconds, so the radio can fall back to 
analog mode in time to recover usable audio for whatever period the digital 
signal was lost.

In practice, it's my understanding that the analog fallback mode hasn't 
really worked that well and that Ibiquity's putting less emphasis on it in 
newer implementations of the codec.


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