[opendtv] Re: Hearings :Cost of Converter Boxes
- From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
- To: "OpenDTV (E-mail)" <opendtv@xxxxxxxxxxxxx>
- Date: Mon, 21 Feb 2005 14:42:24 -0500
Craig Birkmaier wrote:
> > This sort of comment needs to be placed in context. And
> > the best way to do that is to ask, "As opposed to what?"
>
> As opposed to an open platform where only the bare
> minimum enabling standards are specified.
>
> As we told the FCC back before 1995, they only needed to
> do two things.
>
> Choose a modulation standard and a transport stream
> standard. Everything else can be driven by the
> marketplace.
>
> The analogy to this is Ethernet and TCP/IP.
Except that it isn't an apt analogy, and what you told
the FCC was incomplete. TCP/IP by itself does nothing.
TV distribution is comparable to distribution of any
content over TCP/IP or UDP/IP. In order for everyone to
understand the content, they have to know what it looks
like. Which means, how to identify it and how to decode
it, when it's layered over TCP or UDP.
The most basic example of this might be transferring
simple text over TCP/IP. At very least, all players
need to know to expect, e.g., ASCII, and all the
various control codes that go with it. Just saying
TCP/IP is simply inadequate. A TV system based on this
notion would never fly.
So again, context is everything. The marketplace alone
does not create standards. It takes effort from
organizations such as ANSI, or the IETF, *or* the ATSC.
Or, of course, proprietary standards can be adopted,
created by private industry.
> Hmmmmm....A digital standard that has lasted more
> than 30 year...
>
> Not bad!
>
> Better yet, its replacement is not a sea change in
> technology, but rather an evolutionary extension.
Darn right it ain't bad. And it shows how this DTV
thing will evolve over time. You DO NOT reinvent the
wheel every time some trendy new buzzword makes it to
the trade press. The standard is evolved, warts and
all.
> ATSC is a wonderful example of a standard that has
> been driven by techno-political gerrymandering, NOT
> the marketplace.
>
> The lack of enthusiasm in the marketplace is
> entirely predictable.
Again, context. ATSC, and DVB-T, are slow at
establishing themselves for the same reason IPv6 is
slow. There is an existing standard that works very
well, and which provides nice revenues for the
businesses involved in it. But the fundamental reason
to install these DTT systems is to more efficiently
allocate RF spectrum. So it is right and proper for
the spectrum manager to make the shift happen.
> Layered standards are an excellent way to deal with
> continuous evolution. DTV standards can be designed
> with the same layered concepts.
Welcome to ATSC. Welcome to DVB-T/C/S. Welcome to
DOCSIS. That's the whole point I've been trying to
make, over many years now. These are all layered.
MPEG-2 TS is the exact functional equivalent of
Ethernet, and upper layer protocols have to be very
precisely defined, as they are carried over MPEG-2
TS.
> The DBS systems control the technical evolution of
> their platforms. DirecTV went on the air before the
> MPEG-2 standard was finalized. They deployed
> hardware with enough flexibilty to implement MPEG-2
> after the fact, but they got on the air with a subset
> of MPEG-2 functionality. Now they are beginning to
> migrate some of their services to H.264.
What you are missing is that these are proprietary
solutions. Comparable not to IP, but to DECnet or
AppleTalk. ATSC cannot be, because that's not the way
DTT works. In FOTA DTT, you have *multiple*
organizations that must coexist over the same medium,
and must be interoperable.
> But the ATSC standard is for all intents and
> purposes frozen in time.
Not true. The standard can and has evolved, and will
no doubt continue to do so. The addition of H.264 is
an abvious example, as are the additional FEC options
in E-VSB.
> This is only one of the issues. The major issue is
> that when you put a megawatt transmitter atop a
> 2000 foot stick, you cannot re-use that channel
> anywhere within hundreds of miles.
This is only a function of coverage area you want.
How high and how powerful is *not* dictated by DVB-T
or ATSC. France does it their way, Germany is more
like here. This is merely an implementation issue.
I'm fairly positive that the Mantes market is not
considered different from the Paris market, and that
the channels available in the Mantes multiplexes are
identical to those in Paris. So in fact, it would be
possible to go with more power at transmitters such
as the Eiffel Tower ones (over 1000' antenna
heights), barring any issue with safety of tourists
and diners in the restaurant.
So in fact, for spectrum resuse, one could make the
case that synchronized SFNs with higher power
transmitters is the ultimate solution.
Gotta run now.
Bert
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