What is DTV
Technology?
A Brief Introduction
What is DTV?
The standard for
broadcasting picture and sound using digital signals, DTV allows for
dramatic improvements in both picture and sound quality versus conventional
NTSC analog programming. DTV programming can be delivered in two basic
formats: standard analog definition (SDTV) or high definition (HDTV).
|
DTV Format
Comparison |
|
Transmission Type |
Analog |
Digital |
Digital |
Digital |
Digital |
|
|
NTSC |
Standard Definition |
Standard Definition |
High Definition |
High Definition |
|
Maximum Resolution |
480i |
480i |
480p |
720p |
1080i |
|
Aspect Ratio |
4:3 |
4:3 |
4:3 or 16:9 |
16:9 |
16:9 |
|
Channel Capacity |
1 |
5-6 |
5-6 |
1-2 |
1 |
|
Description |
Standard TV as we
know it today |
Good Picture and
Sound —DVD or DBS Quality |
Better, depending on
source; can be outstanding |
Best Possible |
Best Possible |
The highest form of digital television,
delivering up to 1,080 scan lines, HDTV produces images that go beyond
anything you've ever seen in a home environment. SDTV, or Standard
Definition Television, is also a dramatic improvement over today's TV, with
the added benefit of allowing stations to broadcast multiple programs within
the same bandwidth as an HDTV signal.
|
DTV Format Detail
|
|
ScanLines |
Scan Rate |
Pixelization |
Frame Rate |
Aspect Ratio |
Formats |
|
SDTV |
525 total
480 active |
15.75 kHz (60i) |
480 x 640 |
24p, 30p, 60p or 60i
fps |
4:3 |
4 |
525 total
480 active |
31.5 kHz (60p) |
480 x 704 |
24p, 30p, 60p or 60i
fps |
4:3 or 16:9 |
8(4x2) |
|
HDTV |
750 total
720 active |
45 kHz
(60p) |
720 x 1080 |
24p, 30p, 60p |
16:9 |
3 |
1125 total
1080 active |
33.75 kHz
(60i) |
1080 x 1920 |
24p, 30p, 60i |
16:9 |
3 |
Adopted DTV formats
also include both interlaced and progressive broadcast and display methods.
Interlaced Scanning: The frame/picture is made up of two
fields
—consisting of 525 lines (480 viewable) or 1125 lines (1080 viewable) |
 |
 |
 |
| All
odd numbered lines are scanned on the screen in 1/60th of a second |
All
even numbered lines are scanned on the screen in 1/60th of a second |
This
presents an entire picture in 1/30th of a second |
Progressive Scanning : The frame/picture is made up of one field
—consisting of 525 lines (480 viewable) or 765 lines (720 viewable) |
 |
|
| All
horizontal lines are scanned in succession in a single pass |
This
presents an entire picture in 1/60th of a second (twice as fast as
interlaced) |
Where is DTV
programming?
Right now, a little over 50% of American homes have access to digital
television through the four major networks. By 2002, 100% of all commercial
stations will offer digital programming. And according to FCC mandate, all
U.S. television stations must begin digital broadcasting by 2003, and be
exclusively digital by 2006. It's time you went digital. It's in your
future.
|
DTV Broadcast Timeline |
| 1999 |
2000 |
2001 |
2002 |
|
Top 4 Networks and
Top 10 Markets by May 1 (30% households) |
|
|
All Commercial
Stations by May 1 (100% households) |
|
Top 4 Networks and
Top 30 Markets by November 1 (53% households) |
|
|
|
| 2003 |
2004 |
2005 |
2006 |
|
All PBS by May 1 |
75% Simulcast by
April 3 |
100% Simulcast by
April 3 |
All Stations 100%
Digital |
|
50% Content
Simulcast |
|
|
Return Analog
Spectrum |
The content shown
above was provided by
Panasonic.
