Bob Miller
On Nov 27, 2007 1:03 PM, John Willkie <johnwillkie@xxxxxxxxxxxxx
<mailto:johnwillkie@xxxxxxxxxxxxx>> wrote:
You mean that's what the 11 proposals for h/h being sorted out by
ATSC TSG/S4 is all about? I do believe you are talking about
legacy proposals, not the trade offs of today.
I'll leave aside your predictions about DTMB being operational by
Christmas. At best, you're talking about one transmitter.
John Willkie
------------------------------------------------------------------------
*De:* opendtv-bounce@xxxxxxxxxxxxx
<mailto:opendtv-bounce@xxxxxxxxxxxxx>
[mailto:opendtv-bounce@xxxxxxxxxxxxx
<mailto:opendtv-bounce@xxxxxxxxxxxxx>] * En nombre de *Bob Miller
*Enviado el:* Tuesday, November 27, 2007 9:54 AM
*Para:* opendtv@xxxxxxxxxxxxx <mailto:opendtv@xxxxxxxxxxxxx>
*Asunto:* [opendtv] Re: New Thread: What becomes of Legacy Analog
Equipment
And when you are talking alternative modulations today it is a
moving target. The trade off today is not between DVB-T and ATSC
but between DVB-T2 coupled with MPEG4 or DTMB and MPEG4 and ATSC
crippled with A-VSB and MPEG2.
No contest.
Any realistic comparison in any real world test between these
standards would doom any concoction of 8-VSB saddled as it is with
legacy receivers.
Just allowing the US broadcast system to use MPEG4 would increase
the value of the US OTA spectrum below channel 51 so much that it
probably would pass the tipping point that would make it a valid
competitor to cable and satellite used right even using 8-VSB.
But of course you can't go there because logic says if you
sacrifice legacy receivers that opens the pandora's box of all
modulations being considered. After all if you are going to dump
all current receivers why not upgrade everything to the best it
can be.
DTMB should be operational in the US by Christmas. The testing is
to compare DVB-T to DTMB. You want to test 8-VSB or A-VSB against
them in the open air and the bright light of day? It could happen.
I am calling all 8-VSB types chicken. They were before, they are
today and they will be tomorrow. I give them one thing, they are
smart enough to stay chicken.
Bob Miller
On Nov 27, 2007 11:55 AM, John Shutt <shuttj@xxxxxxxxx
<mailto:shuttj@xxxxxxxxx>> wrote:
Bert,
Combine 1999 guard interval performance of DVB-T, add in 2007 blind
equalizers, and what do you get? Still something far superior to
ATSC.
ATSC still cannot do mobile at all, and the A-VSB and E-VSB
schemes proposed
come with a much higher bitrate hit than DVB-T HM.
DVB-T still has a full continuum of bitrate vs. robustness that is
settable
by each individual broadcaster to meet their perceived needs.
ATSC does
not.
I told you 5 years ago and I will repeat it today: Even if every ATSC
reception issue was solved, I would still prefer DVB-T because of
it's built
in flexibility it affords the broadcaster.
John
----- Original Message -----
From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx
<mailto:albert.e.manfredi@xxxxxxxxxx>>
> The facts are, one by one all the oft-repeated objections to
8-VSB have
> dropped by the wayside, as was predictable from fairly early on. The
> dreaded cliff effect remains, of course, which affects all modulation
> schemes. It would be great to do another comparison test now, but
since
> no one would benefit from it, it won't happen. Alas.
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