Philips Projection Television - Manual (Page 8)

D
IGITAL
TV R
OLLOUT
- T
IME
/T
ERMS
/T
ECHNOLOGY
(
AS OF FALL
/1998)
T he switch to digital pro-
gramming won’t happen
overnight, but broadcasters are
beginning the task of convert-
ing equipment and production
capabilities to meet the FCC’s
rules for signal format and
launch of digital TV.
The first step for the networks
will be to supply their affiliates
with one satellite program feed
for continuing NTSC service (at
least thru the year 2006), and
another feed for a single chan-
nel of HDTV (or SDTV format
channels). ABC, CBS, NBC,
and PBS networks are all
attempting to broadcast some
HDTV programming beginning
in the fall of 1998 (see the digi-
tal InfOrmation section to the
right for specific plans and
details), but much in the way of
new digital broadcast tower con-
struction, site zoning and other
conversion issues will need to be
resolved in order for the broad-
casts to begin in earnest.
In the beginning local stations
can offer different program-
ming on their allotted digital
channel space, but as time pass-
es the percentage of NTSC pro-
grams that must be converted to
digital “simulcast” broadcasts
will increase (in order to meet
specified conversion schedule
requirements.)
The Cable TV industry’s stan-
dard for the use and carrying of
digital broadcasts, which has a
different frequency modulation
than cable signals, is unresolved
(as of the date of this publica-
tion.) Although some cable
operators promise that digital
set-top boxes or decoders will be
available to pass HDTV signals
to digital TV sets, no official
“must carry” design for the
interfacing of cable TV pro-
gramming and digital TV tech-
nologies has been agreed upon.
Even without firm program
launch dates or established
guidelines, digital cable decoder
equipment and program offer-
ing plans (by such cable pro-
gram providers as HBO, Turner
Broadcasting and the Discovery
Channel) are all underway for
the interconnection of cable TV
and the arrival of HDTV. It may
not have immediate solutions at
the outset, but market and
industry demands should speed
cable operators to provide for
the HDTV signal to make it into
the cable supplied home.
Direct-broadcast satellite system
(DSS) providers (such as Direc
Tv, Unity Motion, Dish
Network, etc.) have also
announced plans to deliver
HDTV to its customer base in
the spring of 1999. DSS sub-
scribers will likely need upgrad-
ed dish and satellite receiver
designed equipment to complete
their digital reception package,
but a number of providers are
working on both off-the-air sig-
nal and direct satellite feed solu-
tions.
P ROGRAM A VAILABILITY
DTV T IMETABLE
While they may dif-
fer on the choice
of digital formats
(1080i, 720p, 480i,
etc.) the netw orks
broadcast plans
center mainly on
select primetime *
program viewing.
Because of the
production tech-
niques and equip-
ment upgrades
necessary for digi-
tal broadcasts the
telecasting of
sports or other
live events will not
become available
until audience view -
ership can justify
costs.
Some initial net-
w ork plans for digi-
tal broadcasts:
ABC- Wonderful
W orld of Disney (in
720p format); to
phase in other
HDTV broadcasts
later.
CBS- proposed to
send five hours of
1080i programming
per week
NBC- to begin
shooting The
Tonight Show with
Jay Leno in HDTV
beginning in 1999;
also plans to show
other primetime
show s in HDTV
Fox to distribute
some portion of its
schedule in 720p
HDTV.
*Outside of the
primetime slot for
netw ork digital
show s local sta-
tions can provide
different program-
ming on their digital
broadcast channel.
They are free to
convert current
NTSC programming
into digital SDTV or
even upgrade their
signal to true HDTV.
ABC, NBC and Fox
are advising affili-
ates to use 480p
for the majority of
its broadcast day,
while CBS recom-
mends its stations
use the 480i for-
mat.
digital 1
nf
0
rmation T OP T EN M ARKETS (30% OF US H OUSEHOLDS )
T OP 30 M ARKETS (50% OF US H OUSEHOLDS
• Baltimore
• Charlotte
• Cincinnati
• Cleveland
• Denver
• Hartford/New Haven
• Houston
• Indianapolis
• Miami
• Minneapolis/St. Paul
• Orlando
• Phoenix
• Pittsburgh
• Portland
• Raleigh/Durham
• Sacramento
• San Diego
• Seattle/Tacoma
• St. Louis
• Tampa/St. Petersburg
• By November 1999
• By November 1998
(Voluntary)
• By May 1999
(Mandatory)
• Atlanta
• Boston
• Chicago
• Dallas
• Detroit
• Los Angeles
• New York
• Philadelphia
• San Francisco
• Washington, D.C.
• High Definition Television (HDTV) is approxi-
mately twice the vertical and horizontal resolu-
tion of today’s NTSC TV. Because of the extra
width (16:9) format of HDTV the picture con-
tains about five times as much information (or
pixels) as conventional TV.
HDTV also includes 5.1 channels of Dolby
Digital surround sound to be broadcast through
two front speakers; one center speaker; two rear
back speakers; and a separate bass channel or
subwoofer signal.
• HDTV refers to the product/system with the fol-
lowing minimum performance specs:
- Resolution: vertical display resolution of
720P, 1080I, or higher
- Aspect Ratio: capable of displaying 16:9 for-
mat images at the minimum resolution levels
- Audio: receives, reproduces, and/or outputs
Dolby digital audio
- Receiver: receives all ATSC (Table 3) formats
• Standard Definition Television (SDTV) offers
about the same picture resolution as today’s
NTSC TV, but the picture quality is improved
because of the lack of snow and ghosts that
accompany normal NTSC over-the-air broad-
casting.
Multiple channels are possible with SDTV since
the 6-MHz signal space allotted for digital
broadcasts can be used for other types of less
data filled format programming.
• Standard Definition Television (SDTV) refers to
the product/system with the following perfor-
mance attributes:
- Resolution: display resolution lower than that
of HDTV
- Aspect Ratio: none specified
- Audio: produces useable audio
- Receiver: receives all ATSC (Table 3) formats
and produces a useable picture
all other commercial stations must construct digital facilities by May 2002
(non-commercial stations, such as PBS affiliates, by May 2003)
Digital Television
Format/Name
Screen/Image
Aspect Ratio
(width to height)
Horizontal
Resolution
(pixels across screen
width)
Vertical
Resolution
(Viewable Scan
Lines)
High Definition TV
HDTV 1080P/1080I
High Definition TV
HDTV 720P/720I
Total Pixels
(transmitted per
video frame*)
Standard Definition
TV (SDTV)525P/525I
1920 16:9 2,073,600
16:9
4:3 - 16:9
Standard Definition
TV (SDTV)
ADVANCED TELEVISION SYSTEM COMMITTEE FORMATS
PROGRESSIVE (P) AND INTERLACE (I) SCAN
• Progressive and Interlace refer
to the method in which the video
from a picture telecast is scanned
or displayed on the TV screen.
- Interlace scans or paints half
the vertical lines for the picture
on the screen every 1/60 of a
second. Then the rest of the pic-
ture is filled in between the lines
of the first half on a followup
scan. The speed of this process
is so fast that it appears to the
eye as being one complete pic-
ture. Due to the amount of infor-
mation contained in a 1080-line
HD picture, interlace is needed
to fit the format into the allotted
6MHz channel space.
- Progressive scans or paints the
entire video picture one line
after another. Used with today’s
computer monitors this progres-
sive process can eliminate some
of the picture artifacts found
with interlace scan, but does
require a larger bandwidth in
order to deliver programs at the
same frame rate.
4:3
1280
704
640
1080
720
480
480
921,600
337,920
307,200
8
FREQUENTLY ASKED DTV QUESTIONS
Q: What are the goals of DTV?
A: In the United States the commit-
ment for free and local digital
broadcasts is a main standard for the
new ATSC system. The reception
and interaction of local terrestrial
broadcasting for DTV programming
is to remain the same regardless of
the region or area of the country in
which you reside.
Q: How long will the transition to
DTV take?
A: The move to digital program-
ming will shift from initial select
program offerings; to increased
simulcast availability; to the ulti-
mate return of analog NTSC broad-
cast channels to the federal govern-
ment in 2006. The NTSC and ATSC
systems will coexist for years to
come (with possible date extensions
provided for the return of NTSC
system channels if needed.)
Products such as the 64PP9901
DPTV are uniquely positioned with operation capability matched for
both the NTSC and ATSC systems.
Q: What’s in the future for DTV?
A: Because of the computer, multi-
media, and broadcast services
involved in setting ATSC and signal
compression standards, DTV picture
formats can be universally adopted
not only for TV broadcasts but also
for computer and other interrelated
web and network service purposes.
Digital Television (DTV) is the umbrella term used to describe the new digital television system adopt-
ed by the FCC. DTV is an open standard with few specific format rules for the implementation of
HDTV/SDTV/and a host of potential data broadcast applications. Although there are certain guidelines
for frequency/bit rates/transmission power/etc. the FCC has taken the position that the marketplace
should decide or dictate what formats will best serve the public.
The interlace scan process was first used with
NTSC broadcasts to conserve video bandwidth
space. With certain scenes or video material
the interlace process can cause image blurring
or other visual screen artifacts.
INTERLACE FIELDS
(Separate scans sent every 1/60 of a second)
*60 frames per second
(fps) for live video; 24
and 30 fps for material
produced in film.
FOR BROADCAST