[opendtv] Re: New Thread: What becomes of Legacy Analog Equipment

  • From: "John Willkie" <johnwillkie@xxxxxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Tue, 27 Nov 2007 10:03:53 -0800

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] En
nombre de Bob Miller
Enviado el: Tuesday, November 27, 2007 9:54 AM
Para: 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> 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>

> 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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