AC-3
Dolby’s third generation Audio Coding algorithm, also known as "Dolby Digital®." It’s the multi-channel sound system specified as the standard for Digital HDTV. AC-3 delivers CD-quality digital audio and provides five full-bandwidth channels for front left, front right, center, surround left and surround right speakers, plus an LFE (low frequency effect) subwoofer, for a total of 5.1 channels.
A/D
Analog to digital conversion (or converter).
Addressable Resolution
The highest resolution signal that a display device (TV or monitor) can accept.
Caution: Consumers should be aware however, that although a particular device (Digital-HDTV) is able to receive the resolution, it may not be capable of displaying it.
Analog TV
Analog TV is the NTSC Standard for traditional television broadcasts. Analog signals vary continuously, representing fluctuations in color and brightness.
Artifacts
Unwanted visible effects in the picture created by disturbances in the transmission or image processing, such as 'edge crawl' or 'hanging dots' in analog pictures, or 'pixelization' in digital pictures.
Aspect Ratio
Refers to the width of a picture relative to its height. If an NTSC picture is 4 feet wide, it will be 3 feet high; thus it has a 4:3 aspect ratio. HDTV has a 16:9 aspect ratio.
ATV
"Advanced Television" is an older term used to describe the development and advance applications of digital television, now simply referred to as DTV.
Bandwidth
The range of frequencies used to transmit information such as picture and sound. For TV broadcasters, the FCC has allocated 6Mhz for each channel. For DTV, the maximum bit rate possible within the bandwidth is 19.4 Mbps, which is one HDTV channel. SDTV has a lower bit rate, therefore the bandwidth can accommodate more than one channel.
Channel
A 6 Mhz (bandwidth) section of broadcasting spectrum allocated for one analog NTSC transmission
Component Video Connection
Output of a video device (such as a DTV set-top box), or the input of a DTV receiver or monitor consisting of 3 primary color signals: red, green, and blue that together convey all necessary picture information. With current consumer video products, the 3 component signals have been translated into luminance (Y) and two color difference signals (PP, PR), each on a separate wire.
Compression
Electronically reduces the number of bits needed to store or transmit data within a specified time or space. Several types of compression methods are used buy the industry, but the method adopted for DTV is called "MPEG2." Ten or more full-range channels of programming and data can be compressed into the same space required by a single analog channel.
D/A
The conversion of digital to analog signals, also referred to as DAC (D/A converter). For conventional television technology to display digitally transmitted TV data, the data must be decoded first and then converted back to an analog signal.
DBS
Abbreviation of "Digital Broadcast Satellite" - refers to digital TV transmissions via satellite.
DTS
Digital Theater Systems sound. Discrete 5.1 channel surround system similar but not the same as Dolby Digital®. Dolby Digital is the DTV standard, but DTS competes with it on DVD and in the movie theaters.
Frequency
The number of times per second that a signal fluctuates. The international unit for frequency is the hertz (Hz). One thousand hertz equals 1 KHz (kilohertz). One million hertz equals 1 MHz (megahertz). One billion hertz equals 1 GHz (gigahertz). Television is broadcast in frequencies ranging from 54 MHz to 216 MHz (VHF) and 470 MHz to 806 MHz (UHF).
