Maryland Bar Bulletin
Publications : Bar Bulletin

Editor: W. Patrick Tandy

February, 2004

Technology Talk

HDTV

By John Anderson

For a few years now I’ve been hearing about certain TV channels being broadcast in High Definition Television (HDTV). Sure it sounds good, but how much better can it be?

Well, it is much better by far.

Why is It Better?

HDTV signals are digital signals which offer crystal-clear, noise-free pictures and CD-quality sound that has a much crisper image than regular analog TV. Your conventional analog TV uses a cathode ray tube to deliver images to you through a screen resolution of about 512x400 pixels. HDTV uses a digital display, like your computer monitor, with a screen resolution that is at least 1,280x720 pixels. A higher screen resolution means a crisper, clearer picture, free of ghosts, interference and picture noise.

A current analog TV picture is made up of 480 horizontal lines. An HDTV picture can have up to 1,080 lines, allowing for stunning picture detail.

What is HDTV?

The Federal Communications Commission has defined 18 different transmission formats in the “Digital Television Standard.” DTV is the umbrella term for all 18 new formats. Six of these formats are considered “High Definition” because of their improved resolution quality. All of these formats require television units with special decoders to receive the HDTV signals. Yes, to view the enhanced images you will need a new TV.

In addition to dramatically improving picture quality, HDTV also offers a wider format. This makes an HDTV image more like a movie-screen image. The width-to-height ratio – called the aspect ratio – of HDTV is 16:9. Analog TV has an aspect ratio of only 4:3.

The difference in aspect ratio is most noticeable when watching theatrical movies on TV. For analog TV, the movie must be cut down in a process called “pan and scan,” in which a part of every scene is deleted to fit the lower aspect ratio. The only way to see the entire movie scene on an analog TV is to “letterbox” the movie. In letterboxing, the full movie is shown in the middle of the screen with black bars at the top and bottom. HDTV eliminates letterboxing and allows you to see the complete movie on the whole TV screen.

Complimenting the lifelike pictures are 5.1 channels of CD-quality digital audio. Current stereo TV sets offer only two channels of audio. HDTV delivers true surround sound: front speakers on the right, center and left, along with two back speakers and a subwoofer.

Where Can I Buy An HDTV Set? How Much Do They Cost?

If your TV has progressive-scan inputs for connection to a computer display card or DVD player, you’ll be able to see some HDTV signals by adding a set-top box receiver (STB) which will generally yield some but not all of the advanced resolution of HTDV. These receivers cost in the range of $400 to $1,000. Otherwise, you can buy new HDTV sets at most electronics stores. The early receivers were expensive. When HDTV sets came on the market, they cost as much as $8,000. In a short amount of time, however, prices have dropped to around $2,000, and they may drop to as low as $1,500 within a year.

As with most new consumer electronics technologies, DTV sets have become less expensive since their introduction. It is expected that prices will continue to decrease over time. Prices vary depending on screen size, display technology, and other features.

The End of Analog

Digital TV is a more flexible and efficient technology than the current system, which has been in place for the last 50 years. In the same bandwidth in which a broadcaster provides one analog programming channel, a broadcaster may provide a super sharp “high definition” program or multiple “standard definition” DTV programs simultaneously. Providing several program streams on one broadcast channel is called “multicasting.” A broadcaster can also use DTV to provide interactivity and data services that were not possible with analog technology.

Congress has determined that the current broadcast television service must eventually completely convert to digital. DTV technology is more efficient than analog technology and will allow the same number of stations to broadcast more program material using fewer broadcast airwaves. DTV offers a more efficient use of the spectrum and will make increased options in services available to consumers.

Converting to DTV will also free up parts of the scarce and valuable broadcast airwaves, allowing those portions of the airwaves to be used for advanced wireless and public safety services (police, fire departments, rescue squads, etc.).

As of May 1999, the FCC requires the top TV networks to broadcast a digital signal in the 10 biggest markets, which represent 30 percent of TV households in the U.S. The networks plan to expand digital coverage and phase out analog TV broadcasts entirely by the end of 2006. At that point, broadcasting on the analog channels will end and that spectrum will be put to other uses. Until the transition to DTV is completed, television stations are required to broadcast on both their digital and analog channels.

HDTV or Old TV?
That is the Question...

Your current television will work as it does now until analog broadcasting stops. A converter box can be used to receive Digital TV (DTV) signals and change them into the format of your current television. However, even with a converter your current analog television is not capable of displaying the full picture quality of HDTV. To enjoy the full picture quality, you will need to purchase an HDTV set.

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Publications : Bar Bulletin: February, 2004

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