[BC] Changes in the Channels

[Hershberger, Dave]

> In a message dated 01/10/2006 01:08:01 PM Eastern Standard Time, 
> DHershberger at axcera.com writes:
> 
> > It is 19392658.459751111508300006702563 Hz (about 19.39 
> megabits) (564/313
> >  times 1.539 GHz/143).
> 
> Thank you, Commander Data. ;>
> (Or Mr. Spock, if you prefer.)
> 
> I knew it was a pretty fat pipe... so there's obviously 
> *plenty* of room for 
> very high quality digital video. I can only presume that the 
> big retailers are 
> using some kind of highly-compressed (Dish?) delivery system, then.
> 
> Willie...
>

Oh yes. I think it was at NAB 2003 or 2004 that there was a paper given on
how cable TV systems were going to handle ATSC signals. There are several
different forms of QAM modulation on cable systems. One system (the one the
presenter was talking about) has a payload capacity of about 38-39 megabits.
It would be a very good match for handling TWO ATSC signals.

Boy was I naive. The "cable guy" said that they would squeeze not two, but
THREE ATSC signals into the 38-39 megabit QAM channel on cable systems.

This will (does) cause a significant quality degradation. The "cable guy" at
NAB had to endure some (well-deserved) hostile remarks from the broadcasters
in the session.

Dave Hershberger 
Principal Engineer 
AXCERA
Tel: 530-272-HDTV (4388)
Fax: 530-272-4505 
dhershberger at axcera.com <mailto:dhershberger at axcera.com> 
AXCERA. Axcessing the new era of digital communications. www.axcera.com 
960 McCourtney Road, Suite C, Grass Valley, CA 95949-7423