Published by: Larry Bloomfield & Jim Mendrala
The following are our current e-mail addresses:
E-mail = firstname.lastname@example.org
We have copied the original Tech-Notes below as it
was sent out. Some of the information may be out of date.
by: Larry Bloomfield & Jim Mendrala
778-3412 or (661) 294-1049
= email@example.com or J_Mendrala@compuserve.com
Note - 038
does what it can, but genius does what it must!
Our Mission: Sharing experiences, knowledge,
observations, concerns, opinions or anything else relating to Electronic
Cinema, DTV, etc., with fellow engineers and readers. We do hope
that everyone will participate with comments, experiences, questions
and/or answers. The other stuff that used to be up here is
now at the end of this newsletter. We're growing. We
now have over 465 subscribers.
This is YOUR forum!
issues are available at: WWW.SCRI.COM
DTV STL, Fixed Link Systems
By: David O.
Thomas, VP of Sales & Marketing Nucomm, Inc.
With the November 1, 1998 HDTV official launch
date in the USA come and gone, much has been learned about Microwave
HDTV STL systems and their performance. Two years ago we were
all wondering how we were going to transmit our HDTV and NTSC signal
out to the transmitter sight. At the time of writing this
article many HDTV STL systems are in place and working.
When planning your HDTV STL, there are several
key areas you must concern yourself with. First we will look
at data rate through put capacity and second Modulation formats.
It is important to understand the relationship and tradeoffs between
the modulation formats used and the data rate through put capacity
the modulator can provide versus the performance of the link or
Fade Margin. For example, the modulation format QPSK offers
an excellent robust signal (better than analog). However,
its data through put capacity is limited compared to other digital
Modulators. While on the other hand, 16QAM offers high data
rate through put but the link performance is worse than that of
an analog link.
This is only a few paragraphs of the full 17-page
article that concerns itself with all digital microwave HDTV STL
systems. There are systems that can carry both an analog and
digital video signals on a microwave channel but this system will
be discussed in a future article.
There are typically two types of “all digital”
HDTV STL systems. One system transmits just the 19.39 Mbts
ATSC signal or while the other carries both the ATSC and MPEGII
NTSC encoded signal. In the second case, an encoder is required
to digitize the analog signal and than combine or multiplex it with
the ATSC signal. In either case, different data rates will
be used thus giving you the option to decide on which modulator
format will give you the data through put and link performance or
Fade Margin required.
In cases were a second microwave channel is not
available, the ATSC and MPEGII encoded NTSC signal are combined
on to one microwave channel. Therefore, the link will operate
at a higher data rate. It is typical to run the MPEGII encoder
at 15 to 20 Mbts and achieve excellent video quality. Combine
this data rate with the 19.39 Mbts and the result is 34.39 Mbts.
In the full article, we talk about the different
HDTV STL System types that are available, how to determine data
through put capacity and how the modulator determines the link performance
and data rate through put capacity. These tools will allow
you to determine which system will work for you.
Having a second STL channel can certainly make
life easy for you but most folks will not be so lucky. The
“Dual Digital” and “Dual Stream PLUS” systems will allow you to
send both your NTSC and 19.39 ATSC signal down one microwave channel.
The modulator plays a vital roll in the STL link
by determining the data rate through put and system performance.
You will have to take a look at your situation and determine what
is more important, performance vs. data through put. Remember
QPSK will give you the best performance but limited data capacity
whereas 16QAM gives you high data through put but your system performance
Since we are traveling uncharted waters, it may
be wise to select a system that gives you the most flexibility as
possible such as DTV STL systems with open architecture platforms.
This will allow you to change rapidly to the ever-changing Television
market place. Flexibility can come in the form of many things.
For example, several modulation types per modulator or a Dual Stream
system that can change to a Dual digital system with little problem.
For the full
article on this subject matter and other interesting tidbits, visit
Nucomm's web site: www.Nucomm.com
(not the Wendy's guy) Thomas -- Nucomm, Inc.
Can Be Bought!
By: Larry Bloomfield
The impact of this could have very deep reaching
consiquences in all the American Broadcast industries and should
not be dismissed lightly. According to a miryad of press releases
back on August 16th, a Dutch publisher, VNU has reached an agreement
to buy the well know media research company, Nielsen for a tidy
$2.5 billion -- that's billion with a "B". Including Nielsen's
net debts, the deal is said to be worth $2.7 billion. The offer
commenced on August 20 and expected it to close in the autumn after
normal US regulatory scrutiny and approvals.
If you are one of the two or three people in
the business who don't know who they are, Nielsen is the company
that measures television audiences and internet use. Remember,
it is how many eyes and ears a station can deliver to an advertiser
that determines what can be charged for a network or local spot.
Nielsen plays a very critical roll in this processes. Nielsen
also plays a major roll in determining the DMAs which the FCC uses
in determining duopoly rules etc.
It is important to note that the FCC has very
stringent rules on foreign ownership of broadcast stations and now
a foreigh organization will be running the organization that spells
out who is watching what and when, which determines the financial
wellbeing of the American broadcast industry. Interesting
dicomoty, to say the lease.
Nielsen has 3,300 employees and grossed $408
million in 1998 with earnings before interest, tax, depreciation
and amortization of $126 million. A. C. Nielsen offers services
in over 90 countries and reports its 1995 revenues as $1.4 billion.
They say they are a global leader in delivering market research,
information and analysis to the consumer products and service industries.
On the other hand, Nielsen Media Research has been part of the Cognizant
Corporation. According to their web page, they say their primary
concern is media measurement across the United States and Canada.
You may find
more information at http://www.nielsen.com
By: Larry Bloomfield
Names like Gates, GE, RCA and others have come
and gone in the broadcast arena, but Harris is one that's still
with us. In fact they're a relative new comer. According to
information recently received, "It's year 15 for the Harris
radio and TV Open House to be held at our new 165,000 square foot
"Center of Excellence for Digital Technology" in Greater
Cincinnati, Oct 1."
The bash sounds like something that, if you were
in the area, would be worth visiting. There is no charge for
admission and the event will feature tours of their new engineering
and integration facility. Attendees will have the opportunity
to meet factory people and see demos from Pluto, Sony, SAS, Telos,
Comrex, Vinten, 360 Systems and 40 more radio and TV suppliers.
For additional information and registration, call 800-622-0022.
The contact name supplied from Harris is that of Dave Burns, Harris
about time and STBs
By: Larry Bloomfield
The cable industry has been dragging its feet
in getting what is necessary for an OpenCable or interoperable set
top box (STB) ready in time to meet their FCC designated deadline.
CableLabs is an exception to this statement. Most manufacturers
have been pushing for priority technology that would have everyone
else come to them for the rights to use the infrastructure.
Shades of DOS and Microsoft. CableLabs has managed a project
that seeks to facilitate the development of advanced digital devices
from multiple suppliers that will communicate, or inter-operate,
with one another. The project is working to achieve a retail available
set-top box or integrated television set that employs a point-of-deployment
(POD) module by the July 1, 2000, deadline established by the FCC.
Additional interoperability events are scheduled to help meet FCC
for these future interoperability events, CableLabs issued a request
for information (RFI) that seeks to identify companies interested
in providing set-top boxes, integrated television sets, or computer
cards as part of OpenCableÔ
interoperability waves starting in September. The RFI is available
on the CableLabs website (www.cablelabs.com). Although
the date for this is now past due, if you really think you have
something worthwhile, it might be in your best interest to contact
Paul Zimmerman, systems integration manager for CableLabs as soon
as possible. If you've got something that would save the world
from famine, world war and bring copious amounts of "yenom,"
that's money spelled backwards, I'm sure they'll bend over backwards
to accommodate your widget.
Cable Television Laboratories Inc., better known
as CableLabs of Louisville, Colorado have been working with a number
of manufacturers in an area that focuses on removable security cards
that allow for retail availability of cable digital set-top boxes.
The roll call included names like: General Instrument, Mindport,
NDS, Nagra, Philips Electronics, SCM Microsystems, and Scientific-Atlanta.
Approximately 40 representatives from these companies were at CableLabs
during the week of testing. CableLabs expects to attract additional
supplying companies to future interoperability events. Many
of the firms that demonstrated this functionality also partnered
with suppliers of headend equipment and set-top boxes, including
Divicom, Samsung, and Panasonic.
Incase you don't know, CableLabs is a research
and development consortium of cable television system operators
representing the continents of North America and South America.
CableLabs plans and funds research and development projects that
will help cable companies take advantage of future opportunities
and meet future challenges in the cable television industry.
It also transfers relevant technologies to member companies and
to the industry. In addition, CableLabs acts as a clearinghouse
to provide information on current and prospective technological
developments that are of interest to the cable industry.
CableLabs maintains web sites at www.cablelabs.com; www.cablemodem.com; www.cablenet.org;
www.opencable.com; and www.packetcable.com.
Subj: What will it take?
By: Jim Mendrala
and Larry Bloomfield
I'm not sure if the vendors don't understand
the exigencies of electronic cinema or they are too willing to compromise.
One thing for sure, they've got to stop listening to the scuttlebutt.
Permit me to explain. There is as much difference between
electronic cinema and high definition television as there is between
analog-NTSC television and digital high definition television and
perhaps even more. The standards and specifications that applied
to analog television just didn't work for digital and high definition
television. A whole new set of standards had to be developed
to accommodate the newer HDTV technology.
By the same token, there is no way that electronic
cinema can achieve the level of quality required using the standards
and specifications that apply to digital high definition television.
Pundits in the emerging electronic cinema industry must establish
criteria, specifications and standards applicable to the new needs
of this very different media. The three primary concerns are
in the areas of screen brightness, colorimetry and required resolution.
Don't think for one minute that these are the only concerns.
We will address each of these three issues and others in future
There are many similarities, but there is also
much dissimilarity. The larger high definition television
displays are normally in the 70-100 inch range, diagonally.
In contrast, movie theaters typically have 20 feet and more in height
by whatever aspect ratio. Keep in mind that this is nearly the height
of a two-story building. Even the slightest anomaly in the
HDTV presentation, that would probably go unnoticed in the wonderful
world of television world, would be highly objectionable on the
larger screens in an electronic cinema theater.
The creative forces and genius behind the entertainment
industry will nearly always shoot a presentation much differently
for presentation on a television screen than they will if the target
presentation media is the motion picture screen. The quest
for improved quality has seen the movie industry evolve from small
frame formats to 70-mm. The number of photosensitive particles
on a piece of film is limited. In poorer types of film it
appears as grain. There is also a physical limit to how far
the chemistry of film will permit the variety and gradation of colors.
An all-electronic system does not have these same photochemical
limits. The eye plays tricks on us and both television and
film take advantage of these physical peculiarities.
Since the most common type of film used today
is 35-mm, that will be my reference point, but electronic cinema
engineers never loose sight of the fact that some material is done
in 70 mm and it's quality must be accommodated in the standards
as they are evolved. There are a finite number of pixels that
will resolve 35-mm film where by the media doing the resolving becomes
transparent. High definition television rounds out at about
2 million pixels per frame. Electronic cinema will begin with
approximately 8 million pixels per frame.
It is blatantly obvious that electronic cinema
should and will take advantage of the ever evolving world of digital
where ever possible. With that in mind, most people who are
familiar with digital video are aware that it is a memory and bandwidth
hog and that's being kind. Compression is an absolute must,
but the current techniques and technology are not satisfactory and
do not lend themselves to the quality required in electronic cinema.
Work is on going at such places as Sarnoff Research and other laboratories
in an effort to develop a compression system that will accommodate
the larger number of pixels per frame without introducing unwanted
artifacts and anomalies. Compromise is not an option.
It seems that the current thinking at the several
projection companies we have been dealing with is very myopic in
nature. At the risk of raising a pun, they do not see the
big picture of electronic cinema as a market in the near future.
We are developing a need. If the current projector companies
can't fill that need, trust me, someone will step up to bat and
do the job.
In future issues
of the Tech Notes, we will also address the totally electronic cinema
system that includes everything; cameras, post-production, storage,
distribution and display.
We haven't even acquired the microphone, much
less put it out for the "fat lady." Stay tuned for
more as we share with you the evolution of this embryonic and vital
From: Nicholas Bodley >>>
About your story: Performance Comparison of ATSC 8-VSB
and DVB-T COFDM Transmission
Systems for Digital Television Terrestrial Broadcasting
By: Dr. Yiyan Wu - Communications Research Centre
I'm sure I'm not the only one who thought this item (below) left
off rather suddenly; no URL for a follow-up, either. Nevertheless,
it's good to see a list of good things about 8VSB, and also, enjoyed
the rest of the newsletter.
Regards, Nicholas Bodley
Subj: An answer to above.
By: Larry Bloomfield
Nicolas, we agree. There was no URL in
the material that we received that would have lead anyone back to
Dr. Yiyan Wu. This is why his snail mail address was included,
which we normally don 't include.
Although I would like to see a mobile friendly
modulation system in place, it wasn't dummies or idiots that decide
upon 8VSB, these are well educated and well grounded engineers who,
I believe thought they were doing the right thing. Perhaps
if the developers of digital television had a little more time to
ensure they had made the correct decisions instead of being pressured
by a bunch of money grubbing politicians who were blinded by all
the money they could raise from the auction of spectrum, thing might
be different. Well they're not and we've got to either fix
it or replace it before more good money changes hands. What
we've got as a digital television system doesn't work in a practical
day-to-day sense as the average television viewer is accustomed
to. Then I'm probably preaching to the choir.
You know there's a lot to be said for the caliber
of receivers available. In a word, they stink. I could
fill pages justifying that comment. It is, however, anticipated
that 2nd, 3rd, etc generation 8VSB receivers
will perform much better. NAB has made this point and so do
many that are familiar with today's receiver design. The question
is, can the implementation of digital television afford the delays
while the receiver manufacturers catch up? Here's another
instance where a politically rather than a technically motivated
FCC truly blew it. Why couldn't these very well educated engineers,
when they were setting transmission standards also set receiver
standards as well? But then with their current philosophy
of how to do business, what could we expect? And BTW: The
only significant step in tuner design improvement in the past several
years has come from Microtune. LB
Subj: A couple of questions
By: Larry Bloomfield
Both of my questions can and should be answered
by one or more of our readers. Although totally unrelated,
I believe they have substance and I'm sure that more than one of
you has given at least passing thought to the subject matter.
I have seen the first issue addressed in other Internet forums I
subscribe to. The second area addresses some residual professional
pride from the days with one of my former employers.
The first is in the area of the digital domain.
Hardly a week goes by when we hear of some virus or another affecting
the Internet or some program that has been infected. Hard
drives are allegedly erased. Programs destroyed and computers
(I would assume the CPU) rendered useless. With the migration
to digital, what is to prevent some twisted mind basement savant
from coming up with a virus that would do something similar to set
top boxes (STB) or other areas of the digital television plant?
If this is true, what measures is the industry taking to prevent
such a thing from happening? I don't have the answers and
would entertain publishing any reasonable addresses from our readers
to these questions.
Several years ago, I had the distinction of being
an employee of CBS at there locally owned and operated station in
Los Angeles, the then KNXT now KCBS-TV. I pulled more than
one shift in Central Control (CC), Master Control elsewhere.
As CC supervisor, we were responsible for the technical quality
of all program material that left our studios on its way to the
mass of viewers. To the number, each and every one of us was
proud of the quality CBS put into their product.
Until several months ago, that quality was passed
on via the direct broadcast satellite services. Although the
material was, and is, NTSC, it was then, as it is now, delivered
to the viewer's IRD, digitally. The quality was literally
the same as that delivered to any of the several hundred affiliate
stations in the CBS network. The West Coast CBS programming
was from KPIX in San Francisco.
Some boy wonder, not satisfied with the status
quo, decided to change things and over night the quality went to
hell in a hand basket. Although the East Coast feed was switched
at the same time, I saw no appreciable loss in quality. I speak
only of the CBS West Coast DTH feed from KCBS-TV.
On any given night, viewers can experience any
manor of picture distortion and or interference: Everything from
radio frequency interference to fading. A person, who obviously
does not know that you don't screw around with the picture during
commercials, keeps punching on and off some form of logo in the
lower left-hand portion of the picture that resembles a distorted
postage cancellation mark. The insertion of this "bug"
is so poorly executed that it causes massive phase shift in the
As a former CBS employee, I still have some residual
pride in the work done at 6121 Sunset Blvd (Columbia Square - KCBS-TV).
I truly hate to see my former fellow workers required living with
this gross embarrassment and complete lack of professionalism.
I hope someone can address the issue and tell us why and when the
matter will be corrected.
Subj: More Extracts from HDTV Report
-- By When Expect to be Doing Local Productions From: Des Chaskelson,
Research Director, SCRI International >>>
It appears from our survey that stations are a bit leery of plunking
large sums of money down on an unknown and as yet unproven track
record where digital television is concerned. This seems be especially
true in the area of High Definition. It is a safe bet that as equipment
is replaced, it will be replaced with digital gear, but the question
of high definition does not seem to be the case until the year 2003
At most stations, news equipment and production equipment is not
normally shared. News equipment tends to get the greatest field
abuse and would therefore probably be replaced sooner. On the other
hand, the field production equipment used by the Creative Services
folks can fill the bill and be moved into the vacancies created
from time to time in local news/sport. With an eye to making the
newer production technology available to clients, this is where
the smart money says the newer, equipment with possible HD and SD
capability equipment, would start out in a station.
In addition to the new technology, different production techniques
must be employed with the wider screen 16X9 aspect ration than most
crews are accustomed to for the end product to look good. The numbers
from this year through to and including 2002 in all area of television
production appear to be in a holding pattern.
As the networks take the lead and the stations have the opportunity
to see the production techniques that work well and prove that the
new technology is not another folly, things will grow very slow
as the numbers indicate. This is especially true of High Definition
television. The numbers seem to show that standard definition is
more of a safe choice than anything else is.
Most stations have at least one studio where most everything comes
from. News occupies a wall or corner. With the new, computer created,
virtual sets, even more can be expected from the same studio area.
Since the studio doesn't get the abuse the field equipment gets,
the chances of it being replaced as often are less likely. Because
of this, Local Variety, Public Service, News production, Special
Events, Variety programming, Pre-recorded shows, etc. seem all to
be in a wait and see mode as well. Like in the early days of color,
when the public tunes in and wants the bells and whistles that go
with digital television, broadcasters will jump in with both feed
and wonder why there is a shortage of equipment. Again, anywhere
from a third to one half of the broadcasters responding to the survey
just don't know.
Tech Notes are published for broadcast professionals,
and others, who are interested in Electronic Cinema, DTV, etc.,
by Larry Bloomfield and Jim Mendrala. We can be reached by
either e-mail or land lines (408) 778-3412, (661) 294-1049 or fax
at (661) 294-0705. The Tech Notes are sent (BCC) directly
only to those who have asked to be on the mailing list, however
feel free to forward them, intact, to anyone who you think might
be interested. There is no charge for this Newsletter, no
one gets paid (sigh), there is no advertising and we do not indorse
any product or service(s). The ideas and opinions are those
of the individual authors. We still administer everything
manually. We don't use any "majordomo" automatic
servers. News items, comments, observations, opinions, etc., are
encouraged and always welcome. We publish when there is something
to share. Material may be edited for brevity, but usually
not. Tech Note articles may be reproduced in
any form provided they are unaltered and credit is given to both
Tech Notes and the originating authors, when named.
If they are to be used by a publication that normally compensates
their writers, please contact us first.