[opendtv] Re: 8VSB Still Not Working (everywhere)
- From: "John Willkie" <JohnWillkie@xxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Mon, 10 Jan 2005 10:41:13 -0800
Stephen;
Sorry to hear about your reception problems, but I think you're missing a
thing or two on the data side.
There are certainly problems with receiving video while moving; not
suprising, since the system was never intended for such use.
However, with just a few assumptions, the same does not necessarily apply to
data transmission. The assumption is just one: that the data is repeated
several times while the firetruck is stationary or in transit.
This is the case with MOST data; PSIP gets through, because all the tables
are repeated and have their own inner consistency to check against. This
repetition would be required even if 99% of the data got through the first
time, but I'm sure there is a lower limit where even it would not be useful.
I'm not so sure of the application, since existing communications nets seem
to work very well, even without the work-arounds. In my experience,
firefighters know where they are going when the door rolls up on the
firehouse; the existing nets can update the firefighters on the way. As you
correctly point out, what firefighters do when they get to the scene is
"rush in" not look at their PDAs.
John Willkie
----- Original Message -----
From: "Stephen W. Long" <longsw@xxxxxxxxxxxxxx>
To: <opendtv@xxxxxxxxxxxxx>
Sent: Wednesday, January 05, 2005 9:44 PM
Subject: [opendtv] 8VSB Still Not Working
> A month or so ago I received an interesting briefing from a company that
> wanted to use ATSC / 8VSB to deliver data to fire departments and other
> first responders. They had no clue about who they were briefing (my
> history, etc.), other than my current title. Their business plan was for
> the fire engine to get all the way to the site of the fire where they
would
> stop then they would be able to receive data about where the fire was. I
> gently pointed out to them that once the fire department got to the fire,
> they kind of knew where the fire was and would not wait around the fire
> engine for data to arrive - firemen tend to run into the fire first thing
> when they get there. The point to the story is, as thick as these folks
> were, even they knew they could not receive 8VSB data while the truck was
> moving (they must have tested their system prior to deployment - what a
> concept).
>
> To quote a lawyer from my swimming with sharks experience a few years
back,
> ATSC is great, it works 75% of the time for fixed locations. To which my
> boss's boss responded, we tend to like communications channels to work
> somewhere in the high 90s.
>
> I am now also enjoying HDTV via my DirecTV HDTV receiver, which also has
an
> integral OTA ATSC decoder. Lots of signal strength for my Fox channel
> (signal bars full strength), but I can not watch it at all - the picture
> breaks up so often that it makes any sports program (Redskins football,
> etc.) too painful to watch (pain on multiple levels), so I have to watch
> Fox via SDTV satellite, no OTA HDTV for me. I know why the reception is
so
> bad - a one story hill behind my house causes a large standing reflection,
> which we noted long ago when my house was one of the ATSC DC test sites.
> 8VSB does not work for me, never has, never will. I also can not receive
> the local digital UPN station. The signal strength swings from 0 to 80+
> every couple of seconds, which never gives the decoder a chance to lock up
> and display a signal. So back to DirecTV for UPN at my house, no HDTV
Star
> Trek Enterprise for me.
>
> The COFDM proponents lost the political fight several years back, but they
> were still right - 8VSB was a poor choice for our nation. Isn't it a
> wonderful irony that 8VSB was added to the ATSC specification as a bone to
> the last US TV manufacturer, which was subsequently sold to a foreign
> company who now owns the patents on 8VSB. Simply lovely.
>
> It was cool to read Voom is going to add hundreds of channels of satellite
> based HDTV. It is cool to get local traffic and weather on my XM
satellite
> radio now, and they even have emergency channel provisions now in case
> things go stupid. Maybe the most cynical people I heard during the
> 8VSB/COFDM wars were right all along - the choice of 8VSB was a method to
> kill over the air TV so everyone would move to cable and satellite then
the
> OTA spectrum would be sold off once and for all. If all of the HDTV is
> over satellite, and now the last uses for local service (local traffic,
> weather, and emergency broadcasts) are replaced by satellite service, why
> would we need local OTA digital service anymore? Inquiring minds want to
> know.
>
> To my old friends on this list, hello, I've been away for awhile, busy
> fighting a couple of wars recently. But my duties are changing soon, and
I
> am thinking about getting back into the digital Motion Imagery game.
Watch
> this space.
>
>
> At 12:50 PM 1/5/2005 -0500, you wrote:
> >At 12:42 PM -0500 1/5/05, Manfredi, Albert E wrote:
> >> > But NONE will be able to receive ATSC on
> >>> portable or mobile receivers).
> >>
> >>Are you willing to put money on that?
> >>
> >
> >Yes.
> >
> >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.
> >
> >
>
>
> ----------------------------------------------------------------------
> 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.
>
----------------------------------------------------------------------
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:
- » [opendtv] Re: 8VSB Still Not Working (everywhere)
