DTV Now Resources
Glossary of DTV Terms
Analog
The TV broadcast technology all of us have grown up with. Analog signals vary continuously, creating fluctuations in color and brightness.
Aspect Ratio
The ratio of screen width to screen height. For HDTV (high-definition TV), the aspect ratio is 16:9 (16 units wide by 9 units high), much like a movie screen. Older television screens are 4:3, or nearly square.
Bandwidth
The range of frequencies over which a TV station is allocated to function. In transmission, the U.S. analog and digital television channel bandwidth is 6 MHz. OPB can use its bandwidth for one analog signal or up to four digital signals and/or data transmission.
Channel
The television broadcast frequency. The Federal Communications Commission assigns over-the-air television channels in the VHF (very high frequency) and UHF (ultra high frequency) band.
Compression
Compression refers to the reduction of the size of digital data files by removing redundant and/or non-critical information. Digital TV in the U.S. would not be possible without compression.
Digital TV (DTV)
Digital TV is the umbrella term encompassing high-definition television and several other applications, including standard-definition television, datacasting, multicasting and interactivity.
Digital Tuner
A digital tuner serves as the decoder required to receive and display digital broadcasts. It can be included inside TV sets or via a set-top box.
Dolby Digital
This is a digital surround sound technology used in movie theaters and upscale home theater systems that enhances audio. Home theater components with this technology work in conjunction with a "5.1-speaker" system (five speakers plus a low-frequency subwoofer) to produce true-to-life audio that draws the listener into the onscreen action.
Federal Communications Commission (FCC)
U.S. Government agency charged with regulating radio, television, wire, cable and satellite communications.
HDTV: "High-Definition Television"
This is the most superior video picture available in DTV. In the U.S., the 1080i and 720p formats in a 16:9 aspect ratio are the two acceptable HDTV formats. HDTV is a component of DTV.
Multicasting
Option made possible by digital technology to allow each digital broadcast station to split its bitstream into 2, 3, 4 or more individual channels of programming.
Pixel
A pixel is the smallest picture element in a TV image. The more pixels in an image, the greater the resolution.
Resolution
The amount of lines and dots (pixels) that make up a TV image. Typically, the higher the number of lines or pixels, the sharper and more detailed the picture will be.
SDTV: "Standard Definition Television"
Digital formats which do not achieve the video quality of HDTV. SDTV is at least equal, or superior to, current television pictures. It offers the ability to transmit at least four standard-quality programs simultaneously using the digital channel.
Set-Top Converter Box
This unit sits on top of the viewer's analog TV, receives the digital TV signal, converts it to an analog signal, and then sends that signal on to the analog TV.
Simulcast
The broadcast of the same program simultaneously over two or more different systems or channels.
Widescreen
Widescreen generally refers to an aspect ratio of 16:9, which is the optimum viewing ratio for DTV and HDTV broadcasts. Traditional TV sets have an aspect ratio of 4:3.
- Plan to Rescan:
- If you use a TV with an antenna, be sure to rescan your digital TV or converter box after the digital switch so you receive all the channels available. Find out how to scan
- Getting Started & Troubleshooting
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- How to Switch
- E-mail your question about DTV
- Need more help? Call the Digital Help Center at 800.241.8123.
OPB's Digital TV Fact Sheet 
