[opendtv] Re: News: Reps. Barton, Stearns Offer Alternative DTV Bill

  • From: Craig Birkmaier <craig@xxxxxxxxx>
  • To: opendtv@xxxxxxxxxxxxx
  • Date: Fri, 6 Feb 2009 11:02:23 -0500

At 11:20 AM -0500 2/5/09, Manfredi, Albert E wrote:

Craig Birkmaier wrote:


 If HD is included in the mix the number of SD channels (or
 their quality) is significantly reduced. You are well aware
 of this based on all of your posts regarding the issues that
 the UK is facing relative to adding HD to the Freeview mix.


Again, with HD in the mix, I now get 29 channels (30 reported after the
last channel scan, but we must have lost one multicast along the way --
oh yeah, it's Mark Aitken's fault, on CW54). Granted, not all stations
transmit an HD stream. The PAX station and the fun independent station
only transmit SD streams (respectively 4 and 5 streams). *However*, to
balance that out, most of the main network stations either transmit just
one stream, or maybe two. Only PBS and these other two I just mentioned
are using their spectrum efficiently. So there's plenty of growth
possible.
But you situation is IRRELEVANT. You are getting that may channels because you are pulling bits from two markets. Furthermore, a very high percentage of those bits are duplicated.
Please stop trying to use your example to prove something that is not relevant to the discussion. 



Besides which, 8T-VSB is relatively high in spectrum efficiency. Given
that stations in the US are separated into markets, and that many
markets are adjacent with no discontinuity in coverage possible between
them, there is not a whole lot better you can do. Even DVB-T2 would not
provide higher spectral efficiency, at least not while staying *within
the FCC planning factors* that apply here. When DVB-T2 is tuned to
higher spectral efficiency than 8T-VSB, it also requires higher power
density. I showed you this already. And it still has a higher peak to
average ratio, that also conspires against it in some ways. There is
simply no free lunch.
Yes, 8-VSB is relatively efficient in its use of the 6 MHz channel. But this is NOT why the current broadcast system is VERY inefficient in terms of actual spectral efficiency. It is inefficient because almost half of the spectrum cannot be used to protect the other half from market-into-market interference; this is especially true in congested population areas like the one in which you live. The very fact that you can receive signals from two markets illustrate this problem perfectly.
I agree there is no free lunch. But there ARE better ways to achieve high spectral efficiency - the most important one is to control spurious emissions. You cannot win this argument Bert, because the reality is that we CAN use the same spectrum to deliver twice as much data simply by building proper transmission networks that DO NOT interfere with adjacent markets. 



First off, there's nothing in the UK system that differs substantially
from the one here. I'm speaking in terms of RF spectrum usage. They also
have to achieve continuous coverage (with multiple translators), or they
rely of Freesat. Even with national service. They rely on lower power,
but many more towers. Essentially the same scheme, scaled down. Ditto
with Italy and France.
You are correct. The topology of the transmission networks in the UK and most of the rest of Europe ARE substantially different than the high powered big sticks we use here. 


At the very most, I get THREE programs that are duplicated, and mostly
in prime time. Because those 29 channels I'm talking about come with my
current antenna setup, which does not receive all of the Baltimore
stations. So no, there is not much duplication at all now. Below, is a
list of the programs, so you can see (a) how many stations do not
multicast, or not enough, and (b) just what the Baltimore content really
is.


You cannot even count.
Two ABC, Two CBS, Two Fox, Two PBS, Two CW, and countless duplications among all of the sub-channels for which you do not list the content delivered. Remember, the vast majority of the broadcast day is filed with off network and other syndicated programming. There is only so much of this stuff to go around and it is HIGHLY duplicated between the Washington and Baltimore markets, but not necessary offered in the same time slots.
Sorry Bert, but you are missing the forest for the trees. You may get a lot of channels, but you do not ANY of the channels that make up about 60% of what US TV viewers watch. 



Also, remember that broadcasters can transmit whatever they want on
their multicast channels. For example, EVEN during prime time, the Fox
affiliate in Baltimore transmits a multicast channel that our local Fox
station does not provide. And the ABC affiliate here similarly transmits
multicasts not available in Baltimore.
This stuff is either drawn from the same pool of syndicated programming available to both markets, or it is locally produced by the stations. How much of the stuff on the sub-channels do you watch? 

60%?



The content is in fact varied, and it could be far more so, if
broadcasters made it happen.
BIG IF. But still irrelevant since it is based on pooling the channels in TWO markets. 

Regards
Craig


----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org 
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word 
unsubscribe in the subject line.

Other related posts:

  1. Home
  2. opendtv
  3. Archive
  4. 02-2009