[opendtv] Re: Doug Lung series on OFDM

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: "opendtv@xxxxxxxxxxxxx" <opendtv@xxxxxxxxxxxxx>
  • Date: Thu, 15 Nov 2012 15:32:28 -0600

Craig Birkmaier wrote:

> Yes this is doable in an ideal world. But the station may not have
> the bits necessary to execute this strategy, especially in markets
> like yours, where almost every station is already multicasting.

I've gotten used to watching ads in lower resolution than the main program, 
because that's how a lot of the Internet TV shows work now. The ad breaks, for 
whatever reason, are much grainier than the show. And that's how this scheme 
would show up.

It seems to me that Internet TV is more similar to OTA and to DBS, than it is 
to any walled garden, non-standard, proprietary, 
politically-limited-by-county-boundaries, cable system. The OTT sites cover (I 
think) a much larger area than local cable. And this is the future, as far as 
I'm concerned.

The future is, you tailor the ads and other content through clever routing of 
packets, not through the physical separation caused by a cable plant. You need 
to stop thinking in terms of old infrastructures and old techniques. Even cable 
systems are moving more and more to IP.

> Who is doing this [interactive ads to determine your preferences]? Not cable.

Who is doing this is the OTT sites, including Hulu, but also some ads on 
cbs.com and other network sites, for example. Some of the Lowes ads ask for use 
participation, for instance. And not infrequently, when these OTT sites try to 
get too fancy, they mess up royally. To where the ad freezes up, for instance. 
(I found out that pressing the F5 key can unfreeze some of these unnecessary 
glitches, caused by overzealous and technically less than competent bean 

> It might even be time for another Open DTV forum...

Or, same forum, but new discussion about topics that matter today, rather than 
topics that mattered 15-20 years ago. The 8-VSB vs COFDM debate is old, and 
quite frankly, even if DVB-T2 would be a good choice for a new one-way 
broadcast scheme, if I were the FCC commish, such a change would make me 
rethink and requestion everything about spectrum for broadcasting.

> You can also checkerboard your channels so that each zone is independent.

Arm-waving again? You can indeed, but then it wouldn't be a SFN. A cellular 
system is totally different from small sticks used in SFNs. If you set up a SFN 
for the main program material, then you can't use the same SFN frequency for 
cellular ads. You'd have to tell the receivers to retune their receivers for 
the cellular ads, where in these new and separate freqs, the small sticks each 
create a different cell. *WHICH MEANS*,

Since you have to dedicate those separate frequencies anyway, you can also set 
up a true cellular broadcast infrastructure, as I described more than once 
before, in which case you don't need LTE or DVB-T2. 8-VSB can do it this just 
as well. For mobility, this scheme wouldn't work very well anyway, switching 
the mobile user from one ad to another in mid stride. Instead, the idea of 
using the ad based on your preferences, and the IP mcast address, would work 
much better.

We've been over this more than once. Let's not arm-wave about this stuff.

> You need to stop thinking in terms of individual channels (streams) and
> start thinking in terms of how websites are created from multiple servers.

This is a complete non-sequitur, and a different subject, and also not one that 
requires any different modulation scheme.


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