WFCR Delays Met Opera (perche?)
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?
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.
More information about the Boston-Radio-Interest