Overview

Digital Television (DTV) is a new type of broadcasting technology that will transform your television viewing experience. DTV enables broadcasters to offer television with movie-quality picture and sound. It also offers greater multicasting and interactive capabilities.

DTV is a more flexible and efficient technology than the current broadcast system, which is an “analog” system. For example, rather than being limited to providing one analog programming channel, a broadcaster will be able to provide a super sharp "high definition" (HDTV) program or multiple "standard definition" DTV programs simultaneously. Providing several program streams on one broadcast channel is called "multicasting." The number of programs a station can send on one digital channel depends on the level of picture detail, also known as "resolution," desired in each programming stream. DTV can provide interactive video and data services that are not possible with “analog” technology.

Converting to DTV will also free up parts of the scarce and valuable broadcast airwaves. Those portions of the airwaves can then be used for other important services, such as advanced wireless and public safety services (police, fire departments, rescue squads, etc.).

High-Definition Television

HDTV is a type of DTV service. HDTV provides high resolution programming in a widescreen format. A current analog TV picture provides resolution of up to 480 horizontal lines. An HDTV picture can have up to 1080 lines, allowing for stunning picture detail.

Widescreen format refers to an image's aspect ratio, which is a comparison of screen width to screen height. Analog television has an aspect ratio of 4 by 3, which means the screen is 4 units wide by 3 units high. The aspect ratio of HDTV is 16 by 9, the same as the wide scope of a movie theater screen. HDTV programs can include Dolby digital surround sound, the same digital sound system used in movie theaters and on DVDs.


Getting Digital Television

Receiving DTV signals over the air requires an antenna and a new DTV receiver that can decode the digital signals. In general, an antenna that provides quality reception of over-the-air analog TV signals will work for DTV reception. Cable and direct broadcast satellite (DBS) subscribers will need a new DTV receiver and other special equipment to receive DTV programming. A "Plug-and-Play" or "Digital Cable Ready" DTV or other device for digital cable customers plugs directly into the cable jack and does not require a separate set-top box. You must obtain a CableCARD from your cable company to receive high definition scrambled programming and premium one-way services.

A current television will work until analog broadcasting stops. Even after the transition to DTV is over, one will be able to use their current TV with a converter set-top box. A converter box can be used to receive DTV signals and change them into the format of a current television. Converters for over-the-air broadcasts are available at retail stores. Even with a converter, however, a current analog television will not display the full picture quality of DTV.

Most DTV sets have wider, more rectangular screens than current analog TVs. This widescreen format allows for wider images that are more like those you see in a movie theater. Like current TV sets, a range of sizes is available. As with most new consumer electronics technologies, DTV sets have become less expensive since their introduction. Prices are expected to continue to decrease over time and will vary depending on screen size, display technology, and other features.


Integrated DTV and DTV Monitors

An Integrated DTV set is a digital television with a built-in digital decoder or DTV receiver. If you have an Integrated DTV and live in an area served by a DTV broadcast station, you will not need any additional equipment, with the exception of an antenna (preferably an outdoor antenna) to receive over-the-air DTV broadcast programming. Integrated TVs can usually receive and display current analog signals also.

In contrast, a DTV monitor is not capable of receiving DTV programming without additional equipment; it is simply a display device similar to a computer monitor without the computer processor. A DTV set-top decoder must be connected between the antenna and the monitor to receive and display over-the-air DTV programming. Most monitors have a built in analog receiver and can display regular analog TV programming. They can also display standard resolution video from DVD players and VCRs.


What is digital?

Digital is an intelligence-carrying signal consisting of a stream of bits of zeros and ones for sound, video, computer data or other information.

Digital television involves signals transmitted and received in digital format. It is delivered and displayed using radio frequency waves that contain information that is digitally encoded for improved quality and efficiency.


based

1. http://www.fcc.gov/cgb/consumerfacts/digitaltv.html (public domain)