Frequently Asked Questions -- What Is Digital TV?

ByABC News

— -- Television. The signals are a-changin'. The Federal Communication Commission has mandated that by 2006, every television network in the U.S. is expected to broadcast in the new digital television format. Here's what you need to know.

What is Digital Television?

Since its development more than 50 years ago, television broadcasts have traveled through the air using analog radio waves. Digital Television, or DTV, is a new broadcast method where the signals are encoded in the same 1s and 0s (or, binary code) used by computers, CD and DVD players.

What are the advantages of DTV?

Switching from an analog standard to a digital one offers many improvements for both consumers and the broadcast industry.

The most noticeable difference, at least for consumers, is a much improved image quality. Unlike analog signals, DTV signals are more resistant to the radio interference that result in static-filled or snowy videos or "ghost" images. Likewise, audio quality improves to crystal-clear stereo sound similar to that delivered from an audio CD.

Another advantage: DTV allows broadcasters to offer more than just audio and video. The amount of space, or bandwidth, given to each TV station allows for multiple "channels" of service. This "multicasting" means that a network could broadcast data — say a stock ticker, or e-mail — tied to the particular TV show.

Is ‘HDTV’ the same as ‘DTV?’

HDTV, or high-definition television, is a part of DTV since those signals are digital too.

The difference is that HDTV offers higher-resolution — in other words, even sharper images — than DTV. And because of its superior picture, much of the focus among broadcasters and consumer electronics makers has been on HDTV.

But even lower-resolution DTV offers a much improved visual experience over today's analog TV signals. The comparison, many say, is similar to watching a DVD as opposed to watching a videotape.

Is ‘Digital Cable’ or ‘Digital Satellite’ the same as DTV?

Yes and no.

Direct broadcast satellite, or DBS services, such as DirecTV and Dish Network, and some cable TV service providers deliver programming to their millions of subscribers using digital code. As such, they can offer many more channels of information and even advanced features, such as digital recording and "pausing" a pay-per-view movie.

Both cable TV and DBS industries have been working to carry the new FCC-mandated DTV signals.

Some service providers are offering HDTV channels, but more work needs to be done. In particular, local cable TV service providers have to beef up the physical cable network to carry the large amount of data that will result when all TV networks and stations "go digital." For DBS providers, that means launching even more satellites into space.

Is DTV or HDTV service in my area?

Chances are yes. Many local TV stations have been simultaneously broadcasting in both analog and digital standards over the last few years.

To see if your area is covered, check out the FCC's web site: http://www.fcc.gov/mb/video/files/dtvonair.html

Or, you can check out the list maintained by the National Association of Broadcasters: http://www.nab.org/newsroom/issues/digitaltv/dtvstations.asp

Do I need to buy a fancy new TV to watch DTV?

Surprise. The answer is no.

Although a brand new digital HDTV-compatible TV set would produce the best experience, consumers can view DTV on their current television — with a few additional pieces of equipment.

The most important piece is a so-called set-top decoder box. Shaped like a VCR, the box contains the electronics needed to "tune-in" the DTV signals, which can be pulled "off-the-air" using a plain old roof-mounted antenna. (In some cases, even old-fashioned "rabbit ears" will work if you live in an area where the DTV signals are particularly strong.)

To find out which antenna you'll need, check out this informational site managed by the Consumer Electronics Association: http://www.antennaweb.org

Subscribers of cable TV and DBS networks should check with their particular service to learn what, if any, other additional equipment may be need.

Where can I find out more about DTV and HDTV?

The Web is chock-full of information. Check out these sites:

FCC: http://ftp.fcc.gov/cgb/consumerfacts/digitaltv.html

Consumer Electronics Association: http://www.ce.org/hdtv

National Association of Broadcasters: http://www.nab.org/newsroom/issues/digitaltv/

The Advanced Television Systems Committee: http://www.atsc.org/faq/faq_general.html

The Audio-Video Science Forum: http://www.avsforum.com/hdtvfaq/HDTV-FAQ.htm

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