HDTV + Digital TV + Satellite + Telephony + Computer + Calibration =

The WOWVision! Interactive Glossary:

 Where even learning is in High Definition!!!

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3:2 Pull down - Is a method for transferring 24-frame/second film images to 60-field/second video.  Film frames are transferred to three video fields followed by two video fields for the next frame.  

4 X 3 Format  - This is the aspect ratio for a traditional analog TV format, which is more of a square screen shape.

480i - Is the resolution of standard definition television.  This can either be a 16:9 format or 4:3 format.

480p - Is a lower resolution HDTV format or the output from a progressive DVD player.  This can either be a 16:9 or 4:3 format.  

5.1 Audio Format - This is a digital audio recording and playback system for home theater. It includes five channels (left, right, center, rear/surround left and right) plus a subwoofer channel. The major 5.1 channel standards are Dolby AC-3 and Philips Musicam.

720p Resolution- Is a progressive HDTV format.  This is a 16:9 aspect ratio (rectangular) format.

8-VSB - Eight discrete amplitude level, "vestigial side-band" broadcast transmission technology. VSB is an analog modulation technique used to reduce the amount of spectrum needed to transmit information through cable TV, or over-the-air broadcasts used in the NTSC (analog) standard. 8-VSB is the U.S. ATSC digital television transmission standard. 8-VSB and COFDM are two possible methods of delivering DTV broadcasts to the home.  8-VSB is a single carrier modulation system and COFDM is a multi-carrier system. Multiple carriers allow information to be divided among the carriers which, under certain circumstances, makes the system more resistant to multi-path (ghosting) reception conditions.

1080i  Resolution- Is an interlaced HDTV format.  This is a 16:9 aspect ratio (rectangular) format.

1080p Resolution - Is the most recently available HDTV using progressive scan format. Currently 1080p Blu-Ray and HD-DVD provide the only source of 1080p.

1080i vs. 720p - Bottom line: For average viewers it is hard to tell the difference. HDTV programming is typically broadcast in one of two resolutions: 1080i or 720p. Most networks have opted for the 1080i format, boasting that it provides the highest possible resolution, while ABC, Fox, ESPN/ESPN2, and the National Geographic Channel went for the smoother pictures of 720p. What's the real difference between the two? While 1080i technically offers the most lines of resolution, it's delivered in the old-style interlaced format, meaning that your TV set draws each frame in two passes: once for the even horizontal lines and a second time for the odd lines. The 720p (progressive) format has fewer lines of information than 1080i but draws each frame in a single pass, delivering pictures that may look slightly smoother than an interlaced image, especially when there's a lot of movement on the screen.

16 X 9 aspect ratio or format- This is the aspect ratio for a "Widescreen" TV format, which more closely resembles a movie screen than a traditional TV.

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A/D - Is an analog signal to digital signal converter.  This is used to transform a signal which is based on a continuous voltage and/or frequency to ones and zeros.

ADSL- Asymmetrical Digital Subscriber Line. ADSL is type of DSL that provides T1 rates or higher in the downstream (towards the customer) direction and 64 KBPS or higher in the upstream direction.

Advanced Television Systems Committee - A.k.a. ATSC - Is the name given to the 8-VSB broadcast standard for HDTV in the USA.  Also, the committee responsible for digital television standards and development, as well as all 18 formats of DTV. The new standard.

Advanced Television Enhancement Forum (ATVEF)- A commercial technology organization or "cross-industry alliance" formed by many different companies from the broadcast and cable networks, television transports, consumer electronics, and PC industries. The goal is to develop HTML-based protocols to promote the standardization of enhanced TV. Tools and other supportive technologies that will be "ATVEF-compliant" will enable the creation and distribution of enhancements through the analog and digital signal. The URL for the organization is: ATVEF. ATVEF (pronounced "atvehf,") representatives developed a technology specification that enables broadcasters to send data (based on Internet standards) through the "Vertical Blanking Interval." If the viewer's set-top box has the proper software to receive and interpret ATVEF data, whatever was designed and sent will show up on the TV screen. That data might appear as raw data or complex interactive interfaces.

Additional Outlet - An additional outlet is an extra satellite or cable outlet that can be plugged into the satellite or cable box to provide an additional feed of the satellite signal. This new feed can then be used to take the satellite signal in an extra and different room, allowing residents to watch different channels on separate televisions at the same time. The additional outlet usually costs a set installment fee and also a small amount extra per month, as you will be using two satellite signals.

Aliasing - Is when a wider spaced line pattern is created from a finer line pattern.  This is caused by improper filtering and/or insufficient resolution of the display relative to the source.  

Algorithm - A formula or set of steps used to simplify, modify, or predict data. Complex algorithms are used to selectively reduce (compress) the high digital audio and video data rates. Algorithms are formulated to selectively reduce the data rate without affecting picture quality.

Amplifier - Boosts the strength of an electronic signal. Used to compensate for loss of signal due to the length of cables and number of in-line connections.

AM (Amplitude Modulation)- A method of impressing a signal on a radio carrier wave by varying its amplitude instead of modulating the frequency (FM Radio). See Frequency Modulation (FM)

Analog_signal - Analog data is expressed in the form of continuously variable waves (e.g. amplitude or frequency of sound waves or electromagnetic waves). Susceptible to noise and are not easily compressible. Conventional analog television uses a system of varying wavelengths to represent picture elements. By comparison, digital television (DTV) handles data much the way a computer does. For example, each element in a frame (a complete video picture) is converted to a binary word composed of 1s and 0s for transmission. You can convert an ANALOG signal to a digital signal by using an analog to digital converter (A to D).

Analog TV - "Standard" television broadcasts analog TV. Analog signals vary continuously, representing fluctuations in color and brightness. Ghosting, interference and intermittent reception, are Hallmarks of analog signal.

Antenna or Aerial a.k.a. OTA is an arrangement of aerial electrical conductors designed to transmit or receive radio waves. Antenna in the context of DBS, refers to the "dish-like" signal collector typically seen on homes. Help, below.

Archive - Off-line storage of video/audio onto back-up tapes, floppy disks, optical disks, etc.

ARPANET- Advanced Research Projects Agency Network. DARPA was founded in 1957 in response to a successful launch of a Russian satellite. ARPANET was a project intended to maintain communications within the country via important government computers in the eventual threat of nuclear war.

ASCII - American Standard Code for Information Interchange. A standard code for transmitting data, consisting of 128 letters, numerals, symbols, and special codes, each of which is represented by a unique binary number. An ASCII word typically is 8 bits of binary data.

Artifacts - Are false information that can be present in an image.  They can appear as spots, patterns, lines, jagged edges or any other localized imperfection. These can be caused by signal processing, electrical noise or optical imperfections. Undesirable elements or defects in a video picture. Most common in digital are macro-blocks, which resemble pixilation of the video image, and pops and clicks in audio. 

Aspect Ratio-The width-to-height ratio of the picture frame. TV broadcasts at a 4:3 (1.33:1) aspect ratio; digital TV will be broadcast with a 16:9 (1.78:1) ratio; and most feature films are shot in at least a 1.85:1 ratio.

Asynchronous - Lacking synchronization. In video, a signal is asynchronous when its timing differs from that of the system reference signal.

ATM - Asynchronous transfer mode. A high speed data transmission and switching technique that uses fixed size cells to transmit voice, data, video which greatly increases the capacity of transmission paths, both wired and wireless.

Attenuator - A device used to reduce the level of the signal strength in a system without introducing appreciable distortion. This can be a resistor network or a control on a piece of equipment.

Audio/Video Jacks - Audio/Video jacks are electrical connectors on the back of your television set that allow you to input audio and video from another device (such as video game consoles, digital video cameras, DVD players, etc) to be displayed on the TV. These jacks are called "input jacks" as they receive video and audio as input. Your TV may also have output audio jacks that allow you to redirect your TV audio to a sound system (Labeled "Audio Out").

Azimuth - Azimuth is the term that is used to describe the rotation of a satellite antenna around a vertical axis, measured in degrees on a compass. The azimuth is the side-to-side angle of the antenna and is used to position the satellite dish in the correct direction, to receive the satellite signals. A dish-pointing calculator is used to find the required azimuth angle and this angle is given in relation to true north, which is zero degrees.

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Backbone - A fat pipe within a network. The term is relative to the size of network it is serving.

Backchannel - Term commonly used to describe the action of sending data back to a host server over a phone wire or cable pipe. A means of communication from users to content providers. Today, a common type of back channel is an Internet connection using a modem.

Bandwidth - Bandwidth is the word that is used to define the rate at which information travels through a network connection. The information is data that is in a range of frequencies and is expressed in Kilobits per second. The bandwidth determines the rate at which information can be sent through a channel. The greater the bandwidth, the greater the amount of information that can be sent in a given amount of time. A common standard to describe the bandwidth is a full page of English text. This text is about 16,000 bits and a 56Kbs modem can easily move 16,000 bits in less than one second.  1. (broadcast) The range of frequencies available for signaling. The difference expressed in cycles per second (Hertz) between the highest an lowest frequency of a band - James Martin 1971. 2. (data wire) Analog telephone lines measure capacity in Hertz (the difference in the highest and lowest frequency in the channel). Digital channels measure capacity in bits per second. A T3 connection is approximately thirty times as fast as a T1 connection, which is 50 times as fast as a 28.8 modem, which is twice as fast as a 14.4 modem.

                     Broadcast: 6 MHz analog
                           Cable: 450 MHz analog signal
               Cable Modems: up to 27 mps downstream - shared
                Internet data: 14.4k - 26 MBPS with VDSL
                             VBI: 4 Mbps
                 Digital Signal: 19.2 Mbps

Baseband - Baseband is the name given to a transmission method in which the entire bandwidth (the rate at which information travels through a network connection) is used to transmit just one signal. Baseband is a cheaper method than broadband and is typically used for shorter distances of transmission. The digital signals that are carried via baseboard are un-modulated meaning that the signal is not adjusted before hand. Baseboard is commonly used in LAN networks (Local Area Networks) that are most commonly used in offices.

Beam - The word beam describes a signal that is transmitted over a narrow path. Satellites use a beam to transmit information from the satellite orbiting the Earth to the Antenna that catches the information. The antenna catches the beam as a data stream and routes this through the satellite cables into your TV. The satellite beams form a footprint over certain areas, showing the coverage and signal strength over various regions. The stronger the beam, the more area it can cover and the better the signal reception.

Bit - The smallest increment of digital information. A bit may be either a one or a zero. For the purposes of digital television signals, bits are counted in groups of a million each (Megabits, or Mb). Digital television signals use a data rate of 19.4 Megabits per second (Mb/s).

Bit-Rate - Measured as "bits per second," and used to express the rate at which data is transmitted or processed. The higher the bit-rate, the more data that is processed and, typically, the higher the picture resolution. Digital video formats typically have bitrates measured in megabits-per-second (Mbps). (One megabit equals one million bits.) The maximum bit-rate for DVD playback is 10 Mbps; for HDTV it's 19.4 Mbps. (From Dish Network Glossary)

Bit error rate - Average fraction of wrongly transmitted bits in a communication link.

Bird - A bird is merely a slang term to describe a satellite in orbit. In the case of satellite TV, those birds beam an uninterrupted signal down to earth that contains millions of bytes of condensed programming. The term hot bird is most often used in the context of European satellites offering Europeans satellite programming.

Blackouts - A blackout is a period where the signal communication between the satellite and the antenna is lost and no signal is able to appear on the TV screen. A blackout can occur due to any number of reasons including solar storms and sunspots, which release cosmic particles that interfere with satellite communication. Blackouts are not that common with satellites and generally they do not last for a prolonged period.

BLOOMBERG TV - Brought to market by Michael R. Bloomberg in 1994. Bloomberg TV terminals were distributed to financial institutions and were first to incorporate television with one-way data streams (sent over the "Vertical Blanking Interval"). These data streams were constantly updated. Bloomberg television focuses primarily on financial news and analysis. Bloomberg TV is making plans to transform their services into an interactive television network.

Blu-Ray - Is a new HDTV recorded video format with improved audio. See HD-DVD.  

BNC Connector - Is an abbreviation for Bayonet Neill Concelman connector.  This connector has a pin in the center that is connected to the wire in the cable and a metal tube connected to the cable shield. An outer ring on the male connector locks it to any female connector.  These are typically found in higher quality products where a true 75 ohm connection is desired.  This is the best analog connector type to use with video.  

Brightness or black level, brightness actually adjusts how dark the black sections of the picture appear. An adjustment in the user menu for setting the intensity of black.  When brightness is set correctly the lowest level signal above black should be barely visible.

Broadcast - A transmitted frequency signal for radio, television or similar communications.

Visual St. Louis - See broadcast locations on the map...

BROADBAND - A network capable of delivering high bandwidth. Broadband networks are used by Internet and cable television providers. For cable, they range from 550 MHz to 1GHz. A single TV regularly broadcast channel requires 6MHz, for example. In the Internet domain, bandwidth is measured in bits-per-second (BPS). See DSL.

Burn-In - Is an artifact that is caused by having an image on a screen too long.  Plasma and CRT have the biggest problem with this and the damage was thought to be permanent on these devices. No longer believed to be permanent, burn-in can be "erased" by playing fast moving, bright, content repeatedly until the image retained fades.  Other technologies can suffer a similar problem with image retention.

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CEEFAX - The branded "teletext" service from the BBC still in use today across analog systems in the UK.

CCI - Acronym for "Customer Called In"

CIE - The International Commission on Illumination (Commission Internationale de l'E'clairage), this is an international organization concerned with color and color measurement.  The CIE established an international standard for primary colors in 1931.  This standard allows all colors to be defined as a combination of three primary colors (red, green, blue).  

COFDM (CODED ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING) - a modulation scheme for digital television broadcasting which competes with 8VSB.

CRT (Cathode-Ray Tube) - A CRT ("picture tube") is a specialized vacuum tube in which images are created when an electron beam scans back and forth across the back side of a phosphor-coated screen. The regular "direct-view" TVs most people grew up watching have a single large picture tube, while CRT-based rear-projection and front-projection TVs use three CRTs: one each for the red, green, and blue primary colors. Each time the beam makes a pass across the screen, it lights up a horizontal line of phosphor dots on the inside of the glass tube. Images are created by rapidly drawing hundreds of these lines from the top to the bottom of the screen.

CS - Acronym for "Check Switch"

CSR - Acronym for "Customer Service Representative"

C-Band - While most smaller satellite TV providers have begun offering high-speed Internet to their customers, C-Band is the first to offer the service to owners of the old model larger dishes. The principal is still the same. The Internet signal is beamed down and users can surf the web and download like any other high-speed connection. Users cannot upload however, as that would require a transmitter powerful enough to reach space.

Cable CARD - Digital cable customers may obtain this security card in order to view high-definition scrambled programming and premium services without a set-top box.

CABLE MODEM- A device that permits one-way or two-way high speed data communication over a cable television system for purposes such as Internet access at speeds of around 1.5 MBPS. Download rate is 27 Mbps.

CABLE PLANT - Term which refers to the central equipment and broadcasting headquarters of a cable operator. All initial broadcasts from the content providers are sent to the cable plant, aggregated, re-encoded, and broadcast to its set-top box network.

Cable Television - The system network for the distribution of the television signal and now digital data by cable (co-axial, twisted pair or fiber optic).

Cache - Storage of digital data (video, audio, text, etc.).

CABLE TELEVISION LABORATORIES (CABLE LABS) - A non-profit research and development organization for cable operators in North and South America. Cable Labs organizes member meetings and develops standards for all manner of cable equipment and software.

Castle Rock Broadcast Center - The Castle Rock broadcast center is where Direct TV has colluded all of their uplink satellites to receive the transmission from their six satellites orbiting the earth. Once collected, the signal is then beamed to Direct TV dishes.

CEA - Consumer Electronics Association

CEA Connections Guide an easy to use, interactive guide to assist you in connecting all of you A/V equipment.

CE Training - http://www.cyberscholar.com/ceknowhow/index.cfm

Chromatic Aberration - Is a distortion of the picture that is caused by the light not being focused properly.  This is caused by the lens system spreading the light like a rainbow.  This is only found in displays the use lenses to project the image.  Calibration cannot influence this, but display selection can.  Typically more expensive display devices use higher quality lenses to reduce this effect.

Chroma Delay - Is a video artifact that appears as the color information shifted to the left or right of the black and white.  This is caused by timing errors in the signals.

Chroma Keying -the process of overlaying one video signal over another, the areas of overlay being defined by a specific range of color, or chrominance, on the foreground signal.

Chrominance - The color component of a video signal that includes information about hue (shade) and saturation (intensity).

Clarke Belt -(Clarke Belt - NASA's satellite tracker!) Named after Arthur C. Clarke, this is the ring of communications satellites that circle the earth. The Clark Belt is located  23,000 miles from the earth's surface, directly above the equator.

Cliff Effect - When approaching the fringes of reception, analog TV pictures begin to degrade by becoming "snowy." By contrast, when in a weak digital signal area, a relatively small change in received power may cause the DTV picture to abruptly change from "perfect' to nothing; hence the name, "cliff effect." The cliff effect is usually seen in conjunction with pixelation on the screen.

Clinometer - A device that combines a compass with an elevation meter that allows for "sighting" or determining with good accuracy, the position of a satellite in the sky.

Clone - An exact digital copy, indistinguishable from the original.

Closed Captioning - Text stream included in broadcast signal that provides narrative description of dialogue, action, sounds, and other elements of the picture. Most often used by the hearing impaired and in environments where audio is undesirable (such as in restaurants).

Coaxial cable - "Co-axial" cable is the general term referring to two "Co" cables running along the same axis "axial". In satellite technology, this is most commonly referring to the stiff cable with a center wire (usually copper) surrounded by a nonconductive substance known as the "dielectric", then surrounded by a braided cable, that acts as shielding and also as the negative, or ground return path of a ground loop. Commonly used coaxial cables are RG6 (the current standard) and the older RG59, commonly found in older home cable installations.

Codec - "Coder-decoder." A device that converts analog video and audio signals into a digital format for transmission. Also converts received digital signals back into analog format.

COFDM - "Coded orthogonal frequency division multiplexing." COFDM can transmit many streams of data simultaneously, each one occupying only a small portion of the total available bandwidth. The DTV standard used in Europe.See also 8-VSB.

Color - Also called saturation, this control adjusts how intense the colors look. An adjustment in the user menu for setting the intensity of colors.  When color is set correctly the intensity of  blue is the same as its intensity in white.  

Color Analyzer - Is a device that can measure the color of light.  

Color Bars - Are a standard test pattern with white, yellow, cyan, green, magenta, red and blue bars that are used to make the color calibration on a display device.  

Color Calibration - The matching of colors to a base color, or from one device to another. Color calibration is widely used in print publishing in order to display on screen an accurate representation of the colors that will be printed on paper. Monitors use red, green and blue (RGB) to display the color gamut, while printers use cyan, magenta, yellow and black (CMYK) inks

Color Decoder - How color is translated from an input signal into what is displayed on your screen.  Default factory settings for this frequently result in skin tones that are too red (red push).  This is one of the key areas calibration is intended to improve.

Color Temperature - Is a user menu setting that refers to the color of gray.  6500K is the target color temperature, but most displays do not come properly calibrated to match it.  Settings can also be referred to as cool, warm or neutral.  Neutral or warm are most likely to look best on your TV, or be closest to D65.

Comb filter - A comb filter's task is to remove residual chrominance (color) information from the luminance (brightness) signal. Comb filtering enhances fine detail, cleans up image outlines, and eliminates most extraneous colors. Comb filters are not required and not used with S-video or component video connections since those connections carry the chrominance and luminance information separately. There are 4 types of comb filters found in today's TVs:

• Glass - may also be referred to as an "analog" comb filter.
• 2-Line Digital - compares consecutive scanning lines within one field of video and makes adjustments to reduce cross-color interference.
• 3-Line Digital - compares 3 scanning lines within a field of video. By comparing more picture information, a 3-line filter further reduces color bleeding and dot crawl.
• 3D Digital - not only analyzes consecutive scanning lines within a field, but also analyzes the preceding and following fields. Results in improved color purity and a more stable video image, and nearly eliminates dot crawl and color bleeding. Also called 3D Y/C.

Component Video - Are three cables for transmitting an analog video signal.  This type of connection is capable of carrying the complete resolution of HDTV and NTSC.  SEE IT... 

Compression - The technique of reducing the amount of data needed to represent a video or audio signal (by reducing the size of digital data files). Compression makes it possible to transmit DTV signals containing high-quality pictures, high-quality sound and data using the same amount of bandwidth (spectrum) as the existing analog television service. Compression can be accomplished in two ways: by removing redundant information in the files (called "lossless" compression) or by removing non-critical data (called "lossy" compression). In the United States, the DTV signal is reduced to 19.4 million bits per second.

CONDITIONAL ACCESS TECHNOLOGY - Technology embedded on the set-top box and satellite receiver that enables the cable or satellite broadcaster to filter out content the subscriber has not paid for or provide them with movies or special programs they have purchased on a pay-per-use system.

Contrast or Picture or white level - contrast controls the intensity of the white parts of the image and determines the overall light output of the display.   When this is set correctly your display will not shift in color, gamma or geometry at high levels.  Too high of contrast levels can also cause burn-in to be a greater problem.  

Contrast Ratio (ANSI) - Is the ratio of light output from white sections and dark sections of a display with a checkerboard like pattern.  This is typically much lower than the on/off contrast ratio.  

Contrast Ratio (On/Off) - Is the ratio of light output when the screen is white versus when it is black.  These measurements are frequently exaggerated by manufacturers making published figures less useful.  

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 

D65 - Is the standard point (x=0.3127, y=0.329) in perceptual color space used to define the standard for gray for NTSC and HDTV video.  Your display will not accurately display the image if it does not closely match D65 when no color is present in the image.  This is due to the way an image is created by painting colors on top of the base gray image.  The D65 image in essence is the color of the canvas that your TV uses to display a picture.  The closer an image is to gray the more it will be in error if your display is not calibrated to D65.  A quality display calibration must include verification or calibration that a display adheres to the D65 standard.  

dB (Decibel) - A unit used to express the intensity of a sound wave, equal to 20 times the common logarithm of the ratio of the pressure produced by the sound wave to a reference pressure, usually .0002 microbar or 1 microbar.

D-ILA - Is an abbreviation for Direct-drive Image Light Amplifier which is JVC's proprietary LCoS technology.  

D-Theater - Is an encrypted prerecorded format that is found on D-VHS.  This format offers exceptional quality for prerecorded content.  

D-VHS - Is a digital version of VHS that is more like a digital tape backup using a VHS tape form factor.

DBS - Direct Broadcast Satellite  - Satellites powerful enough (approximately 120 watts on the Ku-band) to transmit a signal directly to a medium or small receiving dish (antenna) at 18" and 3 feet in diameter. DBS does not require reception and distribution by an intermediate broadcasting facility and transmits directly to the end user.  A DBS, or Direct Broadcasting Satellite, is a satellite with high transmission powers, especially designed to transmit radio and TV programs. Because of its high power (up to ten times the power of a FSS satellite), its signals can be received with smaller dish antennae of 25-40 cm in central receiving areas.

DDS - "Digital Data Service."

DLP - a.k.a. digital light processing which is Texas Instrument's proprietary technology. This technology uses a large number of very small mirrors that represent pixels. These mirrors move rapidly on and off to change to intensity of each pixel. The color of each pixel can be based on an individual DLP for each color primary or a single DLP device that uses a color wheel to change the color. It's not magic, but it IS all done with mirrors!

DNG - "Digital news gathering." Electronic news gathering (ENG) using digital equipment.

DTH - DTH stands for Direct To Home satellite service. This is simply what Canadians call DBS. In Canada, they have a similar situation as Americans with two large companies competing for the satellite TV market.

DVB - DVB is an acronym for "Digital Video Broadcasting". It is an industry consortium of over 300 companies working together to promote a worldwide standard for the progression from analog to digital broadcasting. The DVB Consortium has a website at http://www.dvb.org  that has information on background information and Membership.

DVD - Is an abbreviation for Digital Video/Versatile Disc and was launched by The Digital Entertainment Group.  

DVI - Is a single cable that is used to carry digital video data.  DVI can have picture degradation from poor connections or cables because it does not include error correction or detection. The signals are encrypted with High-bandwidth Digital Content Protection (HDCP) to prevent recording 

DVR - Is an abbreviation for digital video recorder.  This is the same thing as a PVR.  

Datacasting - While broadcasting in HDTV or multicasting in SDTV, digital technology allows broadcasters to use leftover bandwidth to transmit additional program material or non-program related resources, such as video, audio, text, graphics, maps and services, to specially equipped computers, cache boxes, set-top boxes, or DTV receivers. This is called datacasting. DTV's broader bandwidth channel allows information to be downloaded at a transmission rate currently 600 times that of a personal computer modem.

DECODER - Term sometimes used for set-top box.

De-interlace - Is an educated guess that is made to video interlaced signals to reconstruct the missing information. For TVs, de-interlacing is often referred to as "line-doubling" or "upconversion." 

Delta C  - Are relative errors in color measurements.  

Delta E  - Are relative errors in color measurements.  

Desktop Video - Video editing and production using standard desktop computing platforms running with add-on video hardware and software.

Diagnostics - Tests to check the correct operation of hardware and software.

Dielectric - A dielectric material is a substance that is a poor conductor of electricity, but an efficient supporter of electrostatic fields. If the flow of current between opposite electric charge poles is kept to a minimum while the electrostatic lines of flux are not impeded or interrupted, an electrostatic field can store energy. This property is useful in capacitors, especially at radio frequencies. Dielectric materials are also used in the construction of radio-frequency transmission lines.

Digital - Circuitry in which data-carrying signals are restricted to either of two voltage levels, corresponding to logic 1 or 0.

Digital-to-analog converter (DAC or D-to-A)  The digital-to-analog converter  is a device for converting a digital code to an analog signal. These devices are found in all digital TVs and receivers to process the incoming digital signal from the antenna. 

Digital Betacam - A development of the original analog Betacam that records digitally on a Betacam-style cassette.

Digital Disk Recorder (DDR) - A video recording device that uses a hard disk drive or optical disk drive mechanism. Disk recorders offer nearly instantaneous access to recorded material.

Digital Audio Broadcasting - In the past, sound was transmitted via the analog formats of AM (amplitude modulation) and FM (frequency modulation). Today, pure, crisp, uninterrupted sound is delivered to satellite systems using DAB. The sound is transformed into binary code, which is then sent to a receiver and translated back to its original form.

Digital Cable Ready (DCR) - A "plug-and-play" DTV for digital cable customers that plugs directly into the cable jack and does not require a separate set-top box.

Digital Compression - Digital compression uses the same principals as Digital Audio Broadcasting. The video signal is compressed into MPEG format, where it takes up less space. It is then beamed to a dish where it is the receivers job to decode it. This is same technology used for DVD. The compression allows for a smaller dish size and is the reason that DBS is replacing the larger satellite dishes.

DIGITAL SIGNAL TELEVISION (DTV)- A new broadcast approved by the Federal Communications Commission, which will ultimately replace the analog NTSC (United Sates) television signal we receive today (June 12th, 2009). DTV allows for high-resolution and wide screen presentation and will require new television receivers as well as new broadcast facilities. Because of the scope of this conversion, the changeover from analog to digital TV will be gradual and take place from 1998 - 2009.

DTV Broadcast Stations - Find out who is broadcasting in your city...

DIGITAL SUBSCRIBER LINE (DSL)- Modem telecommunications technology that enables broadband, digital data to be transmitted over ordinary telephone line. DSL comes in many flavors, known collectively as xDSL, see ADSL, HDSL, SDSL, VDSL.

Digital TV (DTV) Transition - The conversion of all television broadcasting signals from analog to digital. Currently taking place with the conversion to be completed by February 17th, 2009.

www.dtv.gov - Who's behind it all.

DIGITAL VIDEO BROADCASTING - MULTIMEDIA HOME PLATFORM (DVB-MHP) - DVB-MHP is a standards based software layer developed by members of the DVB that allow ITV producers to develop applications that will run on all DVB-compliant set-top boxes.

DIGITAL VIDEO RECORDER (DVR) - A high capacity hard drive that is embedded in a set-top box, which records video programming from a television set. These DVRs are operated by personal video recording software, which enables the viewer to pause, fast forward, and manage all sorts of other functions and special applications. TiVo, ReplayTV, and UltimateTV are commercial examples of a DVR.

DIGITAL VIDEO SERVER - A robust, dedicated computer at a central location that receives command requests from the television viewer through a video-on-demand application. Once it receives this request, it then instantly broadcasts specific digital video streams to that viewer. nCUBE, SeaChange, and Concurrent are examples of companies that provide this kind of equipment and software services.

Diplexer - A diplexer (sometimes called a combiner) is a device that combines the radio frequency output of two or more radio transmitters into a single output. Small diplexers are also used in the home, allowing direct broadcast satellite TV signals from the dish to the receiver to piggyback on one regular coaxial cable, along with lower-frequency signals from an outdoor terrestrial TV antenna for local channels. This is extremely useful in homes which are already pre-wired, as it eliminates the need for the difficult installation of unsightly extra cables. However, the cables must be the higher-quality RG6, as the less-expensive RG59 will not pass the high intermediate frequency (usually 950 to 1450MHz) which the LNB outputs from the feed horn.

Dish 300 - The name given to an 18" satellite antenna designed to receive only one satellite.

Dish 500, 1000+, 1000, 1000.2 - Common Dish Network satellite antennas.

Direct View - Is a type of display that does not use a lens system to create an image.  CRT, LCD and plasma displays are common types of these.  

Display Device - Is anything that can be used to view a video or film.  This would include an ordinary CRT television to a front projector.  

Distribution Quality - The level of quality of a program feed from a network to its stations.

Dolby Digital/AC-3 Compatible - Dolby Digital has become the standard audio for most DBS systems. Essentially Dolby digital means the audio of your programming is encoded for maximum clarity. But its real advantage is its 5.1 channels. Think of it this way: when you are watching television, sound only emits from one speaker. With Dolby digital, you can have up to five simultaneous audio tracks. These five separate tracks can give the effect that there are five distinct audio events happening at the same time.

Dolby Pro Logic - When a provider wants the sound accompanying an image to be surround, it has to be recorded and coded with five distinct channels. What Dolby Pro Logic does is takes audio that was not recorded with the intention of surround sound and extrapolates what it would sound like if it had been. This is in effect a mimic of surround sound that, while not the real thing, still sounds remarkable.

Downlink - Simply enough, the downlink is the signal that is sent from the satellite orbiting the earth to the satellite dish. In the case of DBS, the downlink is actually received at a broadcasting center and then redirected to your personal satellite. Currently the downlink can also contain a wireless Internet signal.

Downconversion - A term used to describe the format conversion from a higher resolution input signal number to a lower display number, such as 1080i input to 480i display. Some HDTV conversion box tuners are able to downconvert digital HDTV signals for display on a regular analog TV.

DRAM - "Dynamic Random Access Memory" (RAM). High density, cost-effective memory chips.

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EIA - "Electronics Industries Association."

Edge enhancement or scan-velocity modulation- a.k.a. VSM or SVM , set this TV user control to Off for the best quality high definition viewing, if possible.

Electronic Programming Guide (EPG) - An application that provides an on-screen listing of all programming and content that an interactive television service or digital television viewer has available to them.

Elevation - A close cousin of the Azimuth, elevation refers to the height and angle (vertical axis) the satellite dish points while searching for a signal. Satellite calculators will let you know what the correct elevation is. The elevation of your dish must be properly fixed in order to get the best signal possible.

Encryption- The process of coding data so that a specific code or key is required to restore the original data, used to make transmissions secure from unauthorized reception.

Enhanced Definition Television (EDTV) - EDTV refers to a complete product/system that receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats, has active vertical scanning lines of 480 progressive (480p) or higher and receives, reproduces, and/or outputs Dolby Digital audio.

EDTV Monitor - EDTV monitor refers to a monitor or display that has active vertical scanning lines of 480 progressive (480p) or higher.

EDTV Tuner - EDTV tuner refers to a RF receiver that receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats. It outputs the ATSC table 3 720p and 1080 i/p and 480p formats with minimum active vertical scanning lines of 480. Alternatively, the output can be a digital bit stream output capable of transporting 480p, except the ATSC table 3 480i format can be output at 480i. It also receives and reproduces, and/or outputs Dolby Digital audio.

EXTENSIBLE MARKUP LANGUAGE (XML) - A language which acts as a "meta-language," XML allows programmers to use it to create their own markup languages for specific uses. XML is written in SMGL or Standard Generalized Markup Language.

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FEC-Forward Error Correction - error correcting logarithms and schemes used to correct errors in digital data streams. Cable TV uses these:

      Reed-Solomon (R-S) Coding − Provides block encoding and decoding to correct up to three symbols within an R-S block.

      Interleaving − Evenly disperses the symbols, protecting against a burst of symbol errors from being sent to the R-S decoder.

      Randomization − Randomizes the data on the channel to allow effective QAM demodulator synchronization.

      Trellis Coding − Provides convolutional encoding and with the possibility of using soft decision trellis decoding of random channel errors.

FSS - Fixed Satellite Service – A satellite service in which the ground station is at a fixed location. Fixed Service Satellites (FSS) are satellites designed to transport telephone calls, data transmission and TV signals for broadcasting and cable organizations. Because these satellites have a relatively low power output of 10-20 watts per transmitted channel, it means that a large dish antenna is required for good reception. (Less power means a weaker signal which is harder to pick up, therefore requiring a larger antenna.) However, the advantage of low power satellites is that more programs can be broadcast.

Failure Point (FP) - In digital receiver reception (DVB-T), the failure point is defined as the lowest rate it is practical to observe requiring an observation interval of about 1.5 minutes, or an average of two correctable packets per ten seconds. ATSC definition of failure is a Bit Error Ratio of 3 x 10^-4 at the final modern output. ATSC uses a reference point just above the failure point called the 'Threshold Of Visibility (TOV)' on decoded pictures. ATSC defines TOV as a Bit Error Ratio of 3 x 10^-6 at the final modern output.

Feed Horn - The feed horn in a satellite receiver system consists of scaler rings and a resonant cavity where the signals coming down from a satellite are consolidated for amplification by the Low Noise Amplifier (LNA). See LNB

Fiber optics - Thin glass filaments within a jacket or bundle that optically transmit images or signals in the form of light over distances, with extremely low high-bandwidth quality losses.

Firewire - Is another name for IEEE-1394.

Fixed Data Rate Compression - Techniques designed to produce a data stream with a constant data rate.

Fixed Dish System - A fixed dish system is another term for a DBS system, although it could mean larger satellite systems used by the government or military. A fixed dish system means that the actual dish only ever faces one direction and it uplinks with a geosynchronous satellite in orbit. This is in contrast to the large satellite dishes you see on top of sports bars and in rural backyards.

FLASH DOWNLOADING - The ability to automatically send software upgrades to a set-top box network.

Flat Screen Display - New TV screen technology will reduce the depth of TV sets to that of a framed picture. The TV screens on today's larger sets use bulky cathode ray tubes (CRTs), which are made of a glass envelope and use a controlled beam of electrons striking light-emitting material to display the picture.

Footprint - When a satellite in orbit beams its signal back to earth, it can only reach a portion of the earth’s surface. This portion is called a footprint. Therefore, to receive a satellite signal, you must be inside the footprint. However, companies like Direct TV have managed to cover a massive portion of the globe by launching six individual satellites. Because of the altitude of the satellite and its geosynchronous orbit, this is a lot of ground.

Format - The general layout of data in a presentation. In DTV, related to aspect ratio.

Format Conversion - Process of both encoding/decoding and re-sampling digital rates to change digital data from one format to another.

Forums - Satellite and HDTV

  High Def Forum -  Interact with others for troubleshooting, information, and fun!

  Satellite Guys - Another forum for HD, satellites, and fun!

FM (Frequency Modulation) - Method of impressing a signal on a radio carrier wave by varying its frequency rather than the amplitude. (AM Radio) See Amplitude Modulation.

Frame - A complete, individual picture in a movie film. In a video signal, a frame contains all of the picture's scanning lines. The frame rate of a progressive-scan format is twice that of an interlaced-scan format.

Frames Per Second -fps The number of still frames (pictures) that give the allusion of motion, which appear in a single second of time.

Frame rate - The rate at which frames are displayed. The frame rate for movies is 24 frames per second (24 fps). In regular NTSC video, the frame rate is 30 fps. The frame rate of a progressive-scan format is twice that of an interlaced-scan format. Example: the frame rate for 480i DVD is 30 fps (or 60 interlaced fields per second); for progressive-scan DVD at 480p, it's 60 fps.

Fragmentation - Scattering of data over a hard disk caused by successive recording and deletion operations. Generally this will eventually result in slow data recall - a situation not suitable for video recording or replay.

Freeze frame - Display of a single (frozen) frame of video.

Frequency - A term to describe the operation band of radio, TV, radar, and other broadcast transmissions.

Front Projector - Is a display type that uses a lens to project on a screen.  This is the type of display device that professional theaters use.  Home theaters are based on CRT, DLP, LCD and LCoS implementations instead of the film that most theaters use.  

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Gallery Player - Turn your HDTV into a work of art or MUSEUM!

Gamma -  Is a measurement of the how the image brightness changes with the input signal level.  

Gain - In electronics, gain is a measure of the ability of a circuit to increase the amplitude or power of a signal. In TV, it measures the light-reflecting ability of a projection screen. The higher the number, the greater the amount of light reflected back to the viewer(s)

Generation Loss - Video degradation caused by successive recordings (dubs of other dubs) from the master source. This is overcome by digital recording.

Geometry - Is how square the image is.  Some display types liked plasma and LCD panels do not have problems with this.  Direct view, CRT, and rear projection sets, frequently have problems that can be improved with calibration.  

Geostationary - a.k.a. Geosynchronous, geostationary is used to describe satellites orbiting the earth at the same speed as the earth rotates. Essentially, it orbits in unison with the earth. This allows fixed dish satellites to receive a satellite transmission without rotating the azimuth and elevation. This means fewer moving parts on the dish and fewer repairs. It also allows the dishes to be smaller.

Ghosting - an image on the screen which doesn't belong there, appearing superimposed on the desired image. In a more specific sense, a ghost is a replica of the desired image appearing fainter and offset in position with respect to the primary image. This occurs commonly in analog TV broadcasts due to multi-path signals.

Grand Alliance - U.S. consortium, formed in 1993, to produce "the best of the best" DTV transmission system from among the initially proposed separate systems. Participants were: AT&T, General Instrument Corp., MIT, Philips Consumer Electronics, David Sarnoff Research Center, Thomson Consumer Electronics, and Zenith Electronics Corp. The group eventually proposed the current ATSC digital standard.

Grayscale or Greyscale or Gray Scale - Is the color of gray over different intensity levels.  Calibration of this requires an accurate color measurement tool.  These include optical comparators, spectra radiometers and color analyzers.

Ground - A ground is a direct electrical connection to the earth, a connection to a particular point in an electrical circuit, or an indirect connection. It is the reference point in an electrical circuit from which other voltages are measured

Ground loop - A ground loop is an induced "loop-antenna" that receives interference currents, creating noise. It forms when improper grounding practices cause duplicate ground paths, creating the "loop antenna". Resulting instability of the ground reference in the system causes the signal to ride on the noise. The noise becomes part of the signal. 

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HD-DVD  hddvd - WAS the next generation high definition DVD player competing with Blu-ray for the DVD HD market. Blu-ray survived the DVD technology war. See Blu-ray.

HDCP  (High-Bandwidth Digital Content Protection) - Is an encryption technique used to protect video content.  This feature is required to ensure future compatibility with HDTV sources (cable, satellite, HD-DVD, Blu-Ray).

HDMI  HDMI (High-Definition Multimedia Interface)—The successor to DVI, HDMI is an interface that supports uncompressed, all-digital audio and video. The HDMI connector can have problems due to cable stress on the connector. Avoid Monster™ Cables. http://www.hdmi.org/learningcenter/videos_overview.aspx    http://www.hdmi.org/learningcenter/installer_training.aspx  

HTPC - Is an abbreviation for home theater personal computer.  These computers are used in conjunction with a display to project film/video images as well as allowing the display to act as a large monitor. 

HEADEND - The electronic control center of a cable television system- generally located at the antenna site of CATV system. The headend takes incoming signals and amplifies, converts, processes, and combines them into a common coaxial or optical cable for transmission to cable subscribers.

HIGH BIT RATE DIGITAL SUBSCRIBER LINE (HDSL) - HDSL is a type of DSL that Transmits 2 Mbps bi-directional signals over one or two twisted copper pairs. HDSL is used in applications such as corporate Internetworking, video conferencing, and remote data center access.

High-Definition Television: (HDTV) - HDTV refers to a complete product/system that receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats, has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i) or higher. Is capable of displaying a 16:9 image and receives, reproduces, and/or outputs Dolby Digital audio.

HDTV Monitor - HDTV monitor refers to a monitor or display that has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i) or higher and is capable of displaying a 16:9 image. Manufacturers are required to disclose the number of vertical scanning lines in the 16:9 viewable area, which must be 540p, 810i or higher to meet the definition of HDTV.

HDTV-ready - Term used to describe TVs that can display digital high-definition TV formats when connected to a separate HDTV tuner. These TVs generally have built-in tuners for receiving regular NTSC broadcasts, but not digital. An HDTV-ready TV may also be referred to as an "HDTV monitor."

HDTV Tuner - HDTV tuner refers to a RF receiver with the following minimum performance attributes:

• Integrated Tuner - An HDTV that has the tuner built into the set. It does not need a separate set-top box.
• Receiver - Receives ATSC terrestrial digital transmissions and decodes all ATSC table 3 video formats.
• Outputs - Outputs the ATSC Table 3 720p and 1080i/p formats in the form of HD with minimum active vertical scanning lines of 720p, 1080i or higher. Additionally, it may output HD formats converted to other formats. The lower resolution ATSC Table 3 formats can be output at lower resolution levels. Alternatively, the output can be a digital bit stream with the full resolution of the broadcast signal.
• Audio - Receives and reproduces, and/or outputs Dolby Digital audio.

Host - Any computer on a network that offers services or connectivity to other computers on the network. A host has an IP address associated with it.

House wrap - A term used in installation referring to cabling that is routed around the outside of a home. Usually, this happens when the interior route is inaccessible due to a finished basement or with slab houses. A proper pre-wire at the time of construction will, ideally remove the need for a house wrap. 

HYBRID FIBER-COAXIAL (HFC) - A local cable TV or telephone distribution network. An HFC consists of fiber optic trunks ending at neighborhood nodes, with coaxial cable feeders and drop lines downstream of the nodes.

Hypertext - hyperlinking technology enabling users of computers and the Internet to link from one page to another by simply clicking from word to word.

Hypervideo - Hypervideos are digital video clips embedded with hotspots and markings, links to the Web or to other movies and media formats, and/or other triggers leading the viewer in different directions.

Hue - Is the intensity of blue in magenta and cyan.  When set correctly the intensity of blue in cyan and in magenta is identical.  

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IEEE-1394 a.k.a. Firewire- Is a single thin cable that is used to transmit video and audio digitally.  IEEE-1394 is a bidirectional communication that allows remote control of connected devices.  This type of connection frequently works the best, but many display devices do not have it and some devices may not be supported by those that do  

I/O - "Input/output." Typically refers to sending data to and from devices.

IRD (Integrated Receiver Decoder) - This is simply a fancy term for a standard Satellite TV Receiver, used primarily by DirecTV. When the information is beamed from the satellite, it is collected by your satellite dish and sent to the receiver. The information is then decoded and decompressed, allowing you to view your programming.

IVR - Dish Network acronym for  "Interactive Voice Recognition"

Image Artifacts - Are defects in the image that can be caused by the display type or image processing. Artifacts may be generated by settings in an HDTV.  

Image Retention - Is similar to burn-in and is caused by displaying the same image on a screen too long.  LCoS and LCD can suffer from this, but it does not tend to be permanent.  

Impulse Pay Per View - In the past, pay per view movies were ordered over the phone. Now, a connection is established between the receiver and your phone line that allows you to simply make a selection on the menu screen and your movie will begin. This has saved the satellite providers a lot of money and it is more convenient for the customer.

Interactive TV - Most satellite TV receivers are now outfitted with a telephone jack that plugs into your existing phone line. This connection allows you limited access to the Internet; this is interactive TV. With interactive TV you can shop online, access your banking information and send and receive emails.

Interface - A set of textual or graphical symbols that allow a computer user to communicate to underlying software. Computer Interfaces work in many ways. Some are text-based and communicate only in letters, numbers, and other keyboard symbols. Others are graphical and require the use of a mouse. Still others are touchscreen.

Interlaced Display OR Interlace Scan - A way to scan vertical lines onto a TV picture by scanning all the odd lines first, then filling in the even lines; a display that refreshes half of the screen at a time. 

INTERNET PROTOCOL (IP) - A protocol telling the network how packets are addressed and routed.

INTERNET SERVICE PROVIDER (ISP) - Telecommunications companies that sell Internet access. Users either dial-up to an ISP server or have a broadband connection such as DSL. Once connected, they can branch out onto the Web.

Inverse Telecine - Is a process that can be applied to a video source that can recreate the individual film frames if the source used what is referred to as telecine or 3-2 pull down process to create the interlaced image.  The inverse telecine can be perfect, but problems with DVD authoring and inherent problems with the color compression process can cause image artifacts.  

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Java - A general purpose programming language developed by Sun Microsystems and best known for its widespread use on the World Wide Web. Computer programs written in Java can run on any platform type (including set-top boxes), as long as they contain a Java Virtual Machine.

JAVA TV - Sun invented this application programming interface (API) called Java TV, which enables the development of more complex functionality and interfaces to launch from the set-top box if this Java layer is embedded in the device.

JPEG - "Joint Picture Experts Group"

Judder - Is an image artifact that appears as unsmooth pans.  This is caused by the inverse telecine process normally operating at 60 Hz in the USA.  To fit 24 frames/second into a 60 frame/second system requires alternating the frame sequence 3,2,3,2....  Processing at a multiple of 24 (i.e. 72 Hz) allows each frame to be on the screen for the same amount of time.  

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Keystone correction - "Keystoning" is a form of video image distortion that occurs with front projectors if the centerline of the projector's lens is not perpendicular to the screen. Keystoning results in an image which is shaped like a trapezoid rather than a rectangle - the top of the picture is wider than the bottom, or the left side is taller than the right, or vice versa. Most front projectors include "keystone correction" to correct this distortion. Some models have vertical keystone correction, while others include both vertical and horizontal correction. Although keystone correction allows greater mounting flexibility, it is a form of processing which usually has a slight softening and dimming effect on the picture.

KU-Band - Ku-Band satellite signal is the designation given to the satellite signal for smaller fixed dish systems and DBS systems. The larger, older model satellites use C-Band technology. Ku band allows for more information to be beamed to one footprint because of its compression technology and MPEG video format. Direct TV and Dish Network use the Ku-band dish signal.

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LCD (Liquid Crystal Display) - Liquid Crystal Display technology is one of the methods used to create flat-panel TVs. Light isn't created by the liquid crystals; a light source (bulb) behind the panel shines light through the display. The display consists of two polarizing transparent panels and a liquid crystal solution sandwiched in between. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal acts like a shutter, either allowing light to pass through or blocking the light. The pattern of transparent and dark crystals forms the image. LCD technology is used in flat-panel, rear-projection, and front-projection TVs.

LCoS (Liquid Crystal on Silicon) - A projection TV display technology that sandwiches a layer of liquid crystal between a cover glass and a highly reflective, mirror-like surface patterned with pixels that sit on top of a silicon chip. These layers form a micro-display that can be used in rear-projection and front-projection TVs. Manufacturers use different names for their LCoS-based technologies. JVC uses D-ILA™ or HD-ILA™, while Sony uses SXRD™.

LNA (Low Noise Amplifier) - See LNB.

LNB (Low Noise Block down-converter) - The LNB is the component located at the end of the arm projecting from the satellite dish. It converts the Ku-band signal beamed from the satellite to a 3.7 - 4.2GHz signal, then filters out low-end frequencies and amplifies the high-frequency signal before sending it to the LNB's coaxial output(s). Satellite service providers  have satellites in multiple orbital positions and a separate LNB is needed to access each satellite position. Essentially it ‘tunes’ or selects the feed from the satellite.

Legacy System - A computer system or application program which continues to be used because it is too costly to redesign or replace. This continues despite the older systems poor compatibility or competitiveness with newer equipment. Dish Network describes this older equipment (receivers and LNB's) as "legacy" systems. Newer Dish Pro Plus equipment provides backward compatibility for use with legacy equipment.

Letterboxed video - On a TV screen with standard aspect ratio (4:3), letterboxed videos appear with horizontal black bars above and below the image. This is a method for displaying the entire picture, as seen in a movie theater.

Live-Streaming - Feeding (streaming) video/audio or other data to end-users at a specific time (that is, live). Today the term is most often used for on-line services.

Locks & Limits (Parental Controls) - Because all of the programming for satellite TV goes through broadcasting centers, it can all be given a designation based on content. This designation can specify whether the content is suitable for children. Parental controls allow you to block these channels and restrict their access to people with a certain permission code.

Luminance - Component of video data that includes technical "information" about its brightness.

Lumen - The unit of measure for light output of a projector.

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Mb or MEGABIT - 10^6 bits of information (usually used to express a data transfer rate; as in, 1 megabit/second = 1Mbps).

MHz- Megahertz - A frequency equal to one million Hertz, or cycles per second.

Macro Blocking - Is an image artifact that is caused by a combination of MPEG compression, image enhancement and the display performance.  It appears to be a sea of small blocks that dance in an image with similar image intensity or color.  Plasma displays and a DVD player with Faroudja processing is one of the most common combinations that can have this problem.  

Microwaves - Microwaves are a type of radio waveform that is relatively short compared to radio waves. Microwave transmissions are used in satellite communications, RADAR, and cell phones. See  http://science.hq.nasa.gov/kids/imagers/ems/micro.html

Modem - MOdulator-DEModulator, a device that takes digital computer signal, converts it to analog, and sends it across the phone line. Another modem on the reverse does the exact opposite action. Most members connect to ISP services, and ultimately to the Internet, with a modem, though that is quickly changing to high speed cable and xDSL. There are both internal and external (to the computer) modems. Modems transfer data at different speeds or rates, called baud. The current standard is 56kb.

Modulator - A device which modulates a carrier wave; found as components in broadcasting transmitters and satellite transponders. Modulators are also used by CATV companies to place a baseband video television signal onto a desired VHF or UHF channel. Home VCRs have built-in modulators allowing recorded video played back using a television receiver turned to VHF channel 3 or 4.

Motion Adaptive - Is a type of de-interlacing that guesses based on the motion as to what is missing.  

Moving Pictures Experts Group  MPEG- 1. The group which is in charge of the development of standards for coded representation of digital audio and video.  Several of the digital compression techniques in common use were developed by this group. 2. This is the Digital video format that has changed the way video is watched, not only on computers, but also on DVD’s and satellite systems. MPEG’s are compressed digital video files that take up far less space than previous video files. This technology allows satellites to beam a larger signal to a smaller dish. MPEG also contains compressed digital audio information that is converted into digital sound tracks.

MPEG I/II Compression - Originally created in 1988, MPEG I was the first file format to deliver high quality information in a smaller compressed file. It was used in Video CD’s and MP3’s. Currently, MPEG II is the standard for digital televisions and DVD’s. In development are MPEG formats as high as MPEG 21, which will be used for complex multimedia especially designed to stream over the Internet. It stands to reason that the compression technology will continue to improve making for faster high quality data transfer. This means more channels on your satellite TV. Currently, HD satellite receivers are MPEG 4.

MPEG 4 - The most recent compression technology allowing for High Definition information transfer.

MTS (Multichannel Television Sound) - The method of broadcasting stereo sound over ordinary analog TV channels. MTS reception capability is built into virtually all stereo TVs and HiFi VCRs.

MULTI-CAMERA ANGLE OR INDIVIDUALIZED TELEVISION - This technology allows viewers to control camera angles during live events, select which commercials they want to watch, and generally control a selection of choices content producers provide as part of the broadcast. Ecommerce and interaction with those commercials is possible. In the backend, servers collect choice information and offer viewers further selections based on those choices.

Multicasting: A technique of using a single Digital Off-Air channel to deliver multiple sub-channels is called multicasting. DTV broadcasters can choose to use all of there bandwidth for one high-definition program or they might subdivide the channel, giving most of the bandwidth to one high definition program, and use the remaining bandwidth for one standard-definition program at a much lower picture quality. Alternatively, the broadcaster might deliver several standard-definition programs at the same time; all at a lower video quality.

Multipath - Is when a broadcast radio signal reaches the receiver multiple times because it is reflected off of objects and the reflected signal is delayed.  This creates ghosting (double images) in analog broadcasts, but it can confuse digital receivers because it does not know which one is the primary data stream.

MULTIPLE SYSTEM OPERATOR (MSO) - Term used often for cable operators that own a number of different networks and services.

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NASA's Satellite Tracker

National Television System Committee -NTSC - The National Television System Committee, or NTSC, established our North American 525-line analog broadcast TV standard about 60 years ago. Although it is referred to as a "525-line" standard, we're only able to see 480 lines on a TV display. The ATSC digital broadcast standard will eventually replace NTSC.

Noise - Extraneous signals in a system causing interference (hum, hiss, rumble) and sound distortion.

Noise Figure (NF)- The noise figure is the standard measurement for the performance of LNB’s. As the LNB ‘tunes’ your satellite TV signal, it strives to lower the noise figure. Noise figure is usually measured in dB. You should look for a noise figure anywhere between dB 0.7 and dB 0.4. Anything higher will not give you the quality that you would expect from a satellite system.

Nonlinear - A term used for editing and storage of audio, video and other data. Information (footage, for example) is retrievable and processed almost immediately without having to locate it in a traditional time-line format.
 

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ODU a.k.a. Outdoor Dish Unit - DirecTV terminology for the dish on the roof.

OTA a.k.a. Off-The-Air, terrestrial, Off-air, aerial, attic antenna, rabbit ears, broadcast. Used to describe broadcast television; and type of antenna (terrestrial).

Offset - Offset fed antennas are most commonly found on Ku Band DBS satellite dishes or ‘mini-dishes’. The benefit of the offset configuration is that it positions the feed horn away from the dish itself as to not get in the way of the satellite signal arriving from space. Offset dishes are often referred to as ‘asymmetrical’ and often have a parabolic satellite dish.

ON-DEMAND - The ability to request video, audio, or information to be sent to the screen immediately by clicking something on the screen referring to that choice.

One-Touch Recording - With only one single touch of one-touch button on the remote, a viewer can create multiple time recordings of future programs in the on-screen guide. The satellite also controls the VCR; its starting and stopping the recording at the proper times. See DVR

OPEN - A company affiliated with BSkyB's Sky Digital set-top box network in the UK, Open offers viewers a special dedicated channel inside which they can interactively shop, play games, get information about entertainment, travel, and more on the TV screen. Open was originally owned by several companies, but it is now primarily owned by Sky. To use Open, the viewer must click the Interactive button on the remote control, which brings up the Open home page offering various categorized selections. Video clips and audio often accompanies most screens alongside clickable data.

Organizations

  www.dtv.org - Who's behind it all.

Overscan - Is a measurement of what part of the picture that is being sent to the TV that is not being displayed.  Excessive overscan can cause you to miss seeing 5 to 10 percent of the picture. 

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PAL - Is an abbreviation for Phase Alternation by Line.  This is one of the common alternative video standards that is used in Australia and Europe.  

PQ - Is an abbreviation for picture quality typically found in use on the internet.

PVR - Is an abbreviation for personal video recorder.  These are a convenient way of time shifting your TV viewing.  They record the video to a hard disk like a computer.  Many cable systems offer this option and all satellite systems offer this option.  

Pay Per View - With satellite TV, you are able to interactively browse their selection of movies and, for an additional fee, you can have that movie sent to your home after a short phone call to order the movie. In the past pay-per-view was restricted to certain movies at certain times. Now there is impulse pay per view, which allows you to order movies from a far wider selection through the interactive display menu on your TV.

PAY-PER-USE - One pays a fee for every service, product, and download often on a tiered basis.

PAY TV - Television programming that requires payment upfront usually on a monthly basis as a subscription fee. Cable and satellite operators bundle content programming under packaged names like "Gold," "Silver," and so on.

PERSONAL COMPUTER (PC) - The device which enables anyone to compute, word process, or perform more complicated functions.

PERSONAL VIDEO RECORDING (PVR) - Software and data services combination that allow the viewer to interactively select programming choices from an electronic programming guide they want to watch or record on their digital video recorder. Data services are provided on a daily basis from the PVR provider.

PICTURE-IN-PICTURE - The ability to view a television broadcast in a small window on top of another broadcast or within a larger interactive interface.

Pixel - A PIXIL  is the smallest picture element in a TV image. The more pixels in an image, the greater the resolution.

Pixel response time - Response time refers to the amount of time it takes for a single pixel in a video display to switch from active to non-active; it is measured in milliseconds (ms). If a display's response time is too slow, faint motion trails may be visible following fast-moving onscreen objects. For smooth, accurate playback of high-quality video material, look for a response time of 16 ms or less.

Pixelated - (adj.) 1. Photography - Used to describe an image in which individual pixels are apparent to the naked eye. Typically, , the separate square pixels in bitmapped images such as GIFs do not appear individually. When the image is displayed too large or at a low resolution the image becomes pixilated (this is sometimes done purposely for special effect). 2. High Definition TV - Used to describe the blockiness or tiling of a television picture that happens due to low signal strength. This typically happens just before loss of digital signal. 

Plasma - A display technology enabling thin, lightweight TVs that can be hung on the wall. Plasma TV pixels are composed of gas-filled cells where an electric current is applied to create the TV image. 

Polarizer - Is a light filter used in an LCD projection system.  LCD blocks polarized light which the polarizer filters so that it will work.

DISH Network signals travel in a circular pattern from the satellite to the dish. This is referred to as "polarity." Two different types of circular polarity are used: right-hand circular (13 volts) and left-hand circular (18 volts).

DISH Network uses right-hand and left-hand circular polarity to enable our equipment to distinguish between two satellites broadcasting on the exact same frequencies. Polarity also helps to prevent the two signals from mixing or interfering with each other. This provides twice the programming capabilities from a single point in the sky.

In other words, circular polarity gives us the ability to provide more channels of digital quality.

        How does circular polarity on on satellites work? http://www.madsci.org

PORTAL - See "Walled Garden."

Posturization - Is an artifact found in some displays.  When a scene has changes in intensity that should appear smooth, but instead appear as obvious steps is Posturization.  

Primary Color - Is one of three colors used to display an image.  The primary colors of light are red, green and blue.  This combination of colors can create a very wide range of colors.

Progressive Display - This type of display refreshes the entire image at once.  This is typically once every 60 seconds for USA video.  This is the preferred display type for viewing film images and is generally considered superior to interlaced for all image types.

Progressive Scan - TV images are displayed using vertical lines. Progressive scan is a way to produce the vertical lines of a TV picture by scanning all the lines consecutively (progressively).

PROTOCOL - The "language" spoken between computers to help them exchange information. More technically, it's a formal description of message formats and rules that two computers must follow to communicate.

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QEF - Quasi Error Free The QEF point is the error rate where the reed solomon code reaches the limit of its correction ability for white noise degradation. Strictly, the QEF is defined as 1 uncorrectable transport packet per hour; or bit error ratio of 2E-4 after the Viterbi decoder for ATSC. Quasi Error Free (QEF)' condition - a BER of the order of 10^-11, at the final modem output, or around one visible picture artifact per hour. For cable TV the system FEC is optimized for quasi error free operation at a threshold output error event rate of one error event per 15 minutes.  

QAM tuner is a device present in some digital televisions and similar devices which enables direct reception of digital cable channels without the use of a set-top box. QAM stands for "quadrature amplitude modulation,"

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RCA Connector a.k.a. Composite video - Is a very common type of connection used for video and audio.  This type of connector does not have the best performance, but it can be very good. It is the cable with three color coded ends, yellow (video), red and white (Left and right audio).

R/F Connectors - Shorthand for radio frequency connectors, Sometimes referred to as a "75-ohm coaxial" connection, RF connectors are the small, conductive screw-like mechanisms located on the end of coaxial cables. You use the RF connectors when you attach your satellite dish to the receiver.

Radio frequency (RF) – Region of spectrum or discipline of electrical design associated with high analog frequencies that require design considerations qualitatively different from traditional analog circuit design.

RF Video - Is how analog cable and analog OTA is distributed.  

RG59 - RG59 cables are "older" standard issue coaxial cables. These cables used to be run from your satellite dish system on the outside of your home to the satellite TV receiver above your television. R59 cables were typical in earlier satellite and cable installations.

RG6 - RG6 cables are currently the industry standard. They are a heavier gauge cable, capable of transmitting larger bandwidth information used in current technology.

RGB - Is a method used to encode a video data.  RGB and component are the most  common encoding systems used in consumer video.  All current consumer devices convert the incoming video to RGB for final display.  

Rainbows - Is an artifact that can be caused by the use of a color wheel.  Rainbows commonly appear as a momentary burst of color when it should not  be present.  This is easiest to see when an image is has very bright objects on a black background.

Rain Fade - This is the loss of signal from the satellite during a heavy rain. This happens more or less to all systems so if your signal fades, check the weather report. The loss of signal is usually only for a few minutes and usually only during heavy storms. Rain fade can occur even if it is not raining at your location. Large black thunderheads can block a signal if it gets between you and the satellite.

Rear-projection TV - As the name defines, rear-projection TV’s display a TV image by projecting images on the back of a screen. These TV’s are typically referred to as "big-screen" TVs.  Digital micro-display rear-projection technologies, including DLP, LCD, and LCoS, are most common now, and allow for more lightweight, space-saving designs.

Receiver - The receiver is the device that collects the satellite transmission signal from your home satellite dish and decodes and decompresses the information. A satellite dish is completely useless without a receiver. The receiver, which sits close to your television, also allows you to change channels, enjoy interactive features and browse the Internet. Newer receivers may have built in HDTV components and even personal video recorders (PVR’s).

Red Push - A color decoder that is set incorrectly to emphasize red in the picture.  

Reed-Solomon (R-S) Coding − Forward Error Correction that provides block encoding and decoding to correct digital coding errors.

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.  Digital Processing - The amount of data used to make up a picture, screen, or audio track. The more data in a picture, the richer the image and the higher the resolution. 

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S-Video Jack - The S-Video Jack is found on VHS VCRs, TVs, DBS receivers, DVD players as well as other types of audio/video equipment. S-Video inputs and outputs use a round, 4-pin jack to convey video signals. S-Video’s "S" means separate, as in having two separate paths transmit portions of a video signal so that they can be processed separately. The two portions of an analog video signal that get transmitted are color (chrominance) and brightness (luminance). Because of separate pathways, S-video is able to provide a much sharper picture than a composite video. A composite video input or output uses a single standard RCA-style jack to pass video signals. This type of connection can be superior to composite video, but it depends on the comb filter found in the source versus the display.  SEE IT...

SCART - Is an abbreviation for Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs.  This is a video connection found in Europe.

SDE or Screen Door Effect. This is not an artifact, but the result of sitting too close to a TV, that makes it look like you are looking through a screen door. This is caused by being able to see the surrounding "space" around the pixels of a TV screen.

SECAM - Is an abbreviation for Systeme Electronique Couleur Avec Memoire.  This is the French video standard.  

SMPTE - Is an abbreviation for The Society of Motion Picture and Television Engineers.  This organization sets many of the standards associated with film production.  

STB or Set Top Box.  This covers a broad range of products that convert a broadcast, cable or satellite signal to one that your display device can use.  

SXRD - Is an abbreviation for Silicon Crystal (X-tal) Reflective Display which is Sony's proprietary LCoS technology.

Sampling - Digital process by which analog information is measured, often millions of times per second, in order to convert analog to digital.

Satellite - Aerospace An object launched to orbit Earth or another celestial body. Astronomy A celestial body that orbits a planet; a moon. For Fun!

NASA's Satellite Tracker - For Fun and information

Satellite Home Viewer Act (SHVA) - was passed in 1988 and reenacted in 1994. It's purpose to protect the copyrighted area of local satellite network affiliates. SHVA states that satellite service providers can only allow clients with national networks to use their services when the signals from their local network affiliates are not available through the use of a rooftop antenna. Additionally, the SHVA act prevents clients who have not received network affiliated stations via cable within the past 90 days from hooking up their satellite systems. Satellite companies  have specific geographic areas that qualify for national network feeds. The SHVA act was further updated and passed on November 29, 1999. This SHVA legislation allows DirecTV and Dish Network to offer local network affiliated stations to their customers. However, if the local networks are not offered, customers must still meet the above criteria to receive the national networks.

Scalar - Is a device that is used to change the resolution of a source (DVD, HD Tuner...) to match that of a display.  These are usually inside of the display, but high quality ones can also be separate.

Selectivity - Ability of receiver to reject transmissions from frequencies other than the specific one to which it is tuned.

Service Mode or Service Menu - Is a hidden mode found in most video devices that is used by technicians to improve the picture quality.

Sharpness - Is a user menu adjustment that determines how edgy the picture looks.  Proper sharpness will result in a smooth transition from dark to white with no ringing.  This frequently requires service mode adjustment to remove edge enhancements. A TV user menu control, related to the calibration process.  

Super Signal! - Get the BEST satellite signal possible! Learn how...

Signal Generator - Is a device that is used to generate test images for display calibration.  These devices are useful in calibrating a display to industry standards.

Signal Quality - A measure of signal strength versus the limiting factors such as noise.

Signal-to-Noise Ratio - Ratio of desired signal to unwanted noise. A high signal-to-noise ratio is highly desired. Difference of 45 dB is required for clear reception.

Simulcast - The broadcasting of the same program on two different channels or frequencies. Until the DTV transition deadline, much of broadcast networks' DTV content must be simulcast with regular TV.

Skew is one of the three adjustments in satellite dish adjustment. This adjustment is angular and orients the dish to be in "line" with the satellites as they form an arc across the sky in the Clarke Belt.

Smart Card - The Smart Card identifies the satellite receiver to the general network. It is used to authorize descrambling of the satellite signal. Additionally, it authorizes purchases using the receiver.

Spatial Dithering - Is a method of rendering the appearance of a smooth image on a display with a device that is only binary.  DLP uses this method to draw an image on the screen.  

Spatial Resolution - Number of pixels horizontally and vertically in a digital image. Typical resolutions are 480, 720, and 1080.

Spectro-radiometer - A device that measures the color of light by dividing it into many wavelength segments.  This is the most accurate way to measure color.  

Spectrum - a.k.a. radio-wave spectrum a.k.a. "the invisible highway", spectrum is the collection of radio frequencies used by analog television broadcasters. Other users of spectrum include police and fire department radios, air traffic control, satellite transmissions, microwave ovens, cell phones and baby monitors. Intense overcrowding and competition for spectrum sparked a 10-year effort involving broadcasters, government agencies, scientists and engineers to reinvent television broadcast technology. This effort has brought us digital television, which will not only allow a more efficient use of available spectrum, but offers benefits that will revolutionize the way we watch and enjoy TV.

Splitter - A small device that splits a coaxial cable signal into two paths. A splitter lets you use one connection with two devices.

Spot Beam - A satellite antenna beam which provides service to only a part of the satellite's total coverage area. dishnetwork/TechPortal

Standard Definition Television (SDTV) - SDTV is the baseline display and resolution for both analog and digital.  Transmission of SDTV may be in either the traditional (4:3) or wide-screen (16:9) format.

Stream - To send data in such a way as to provide or simulate real-time delivery of media.

subwoofer—A speaker optimized for creating Low Frequency Emissions. Subwoofers usually feature a single, large speaker cone and are either passive (relying on the receiver for amplification) or active (using a built-in amplifier).

Sweetening - Electronically improving the quality of an audio or video signal, such as adding sound effects, audio ambience or laugh tracks.

Synchronous - A transmission procedure by which the bit and character stream are slaved to accurately synchronized clocks, both at the receiving and sending end.

SYNCHRONIZED TV (SYNCTV) - Often called "two screen TV", this term defines the simultaneous broadcast and use by the viewer of an Internet application directly related to a regular television broadcast of a show. For example, during the Oscar's in 2000, ABC prepared an application that enabled the home viewer, while watching the program, to play along and vote for their favorite star, movie, or director. Producers "pushed" application content and data updates to all logged in computers. Usage of the application was fairly dynamic with trivia questions, polls, voting, pictures of the reactions of the stars, special offers, chat, and more. SyncTV applications require a complex configuration of standard and proprietary broadcasting and monitoring techniques.

SYMMETRICAL DIGITAL SUBSCRIBER LINE (SDSL) - SDSL is a type of DSL that uses only one of the two cable pairs for transmission. SDSL allows residential or small office users to share the same telephone for data transmission and voice or fax telephony.

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TOV - (Threshold of visibility) The measurement of digital receiver performance established by the ATSC as an error ratio of 3E-6, or the output BER, for the threshold of visibility system failure point, is 3x10^-6, after viterbi decoding; the measure of sensitivity of a satellite receiver measured in decibels (dB). See section 2.1 http://happy.emu.id.au/lab/rep/rep/9801/9801_071.htm#s7p1

TCOMMERCE - A word based on "ecommerce," this term describes interactive commerce on television. The word "shopping" also suffices.

TELECOMMUNICATIONS ACT OF 1996 - U.S. Legislation passed in 1996, which overhauled the telecommunications industry. This bill also put in place important deadlines for the digital transition affecting every commercial and public TV broadcaster in the country. The final deadline for the transition is February 17th, 2009.

TELETEXT -Teletext is a series of static pages on the television that offer all sorts of text news and community services. Invented by BBC engineers in the 1970's, Teletext remains popular today across all UK television networks. Text pages are offered in carousel in order to keep things fresh. A viewer can request different pages using the number pad on their remote control. Only recently has this technology been upgraded to digital.

TERMINAL - A device that allows user to send commands to a computer that is somewhere else.

TERRESTRIAL - Broadcasting analog or digital signal via a large antenna that stands on the ground.

Threshold - In Audio/Video terms, threshold is the measure of sensitivity of a satellite receiver measured in decibels (dB).

Transponder - This term comes from a combination of the words "transmitter" and "responder". Transponders are used in satellite communications as well as in location, identification and navigation systems. A transponder is a wireless communications device that is usually attached to a satellite. This device is designed to receive as well as convey radio signals at a prescribed frequency range. See Transponders-What are they?

Transponders (Dish Network)

• A transponder is the part of the satellite used to send a signal to the earth using a specific frequency range.
• DISH Network satellites use one transponder to transmit several channels - up to six video channels and four audio channels.
• On average, each of our satellites has 32 transponders.
• Every satellite has a home transponder. A home transponder is a designated transponder which only transmits system information; i.e., Electronic Program Guide (EPG) data, system software, etc.

TRIGGERS "Transport A" & "Transport B" - A command from the host server that notifies the viewer's set-top box that interactive content is available at this point. A trigger shows up as an icon or some kind of clickable text seamlessly within the television broadcast program. Once clicked by using the remote control, the trigger disappears and more content or a new interface appears on the TV screen. Transport A triggers travel over the VBI first and then sends the following content though the Internet (mostly in use now). Transport B triggers and content travel over the digital broadcast signal.

TV ANYTIME FORUM - A commercial consortium developing open standards to take advantage of high volume digital storage devices (most likely digital video recorders). Members companies will derive the benefits from those technologies.

TV Documentaries - http://www.linktv.org/experience/

TV TUNER CARD - The TV tuner card enables the PC user to receive television signals, which are then converted to digital format for viewing on screen.

TWO-WAY - The term used to describe data as it travels both from the broadcaster's headend (cable) or central office (telecommunications) from the viewers location and then back to the headend of central office. Two-way always connotes the presence of an interactive infrastructure.

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Ultra High Frequency (UHF) - designates a range (band) of electromagnetic waves whose frequency is between 300 MHz and 3 GHz. UHF and VHF are the most commonly used frequency bands for transmission of television signals. Modern mobile phones also transmit and receive within the UHF spectrum. UHF is widely used by public service agencies for two-way radio communication

UHF Remote or Ultra High Frequency Remote - Remote control that can operate the satellite receiver from another room. Many manufactures, including DISH, RCA, Hughes and Sony, offer UHF remotes. UHF remotes can control a satellite system from another room, or "hidden" in the same room. Many receivers will have this function built in. (The more common remote is the I/R (Infra Red) remote, which is a line-of-sight remote that needs to be pointed at the receiver or TV in order for the system to operate properly.

UNIFORM RESOURCE LOCATOR (URL) - The address of a document or other resource available on the Internet by clicking a link. A URL has three components, the protocol ("http:"), server domain name ("intel.com"), and the file location on their server.

Upconversion - The term used to describe the conversion of a lower resolution to a higher one. This process uses technology to increase the number of pixels, frame rate or scanning lines.  

Uplink - Uplink refers to the function of a transmission signal being sent from a ground station on Earth to a satellite.

UPSTREAM - Information which travels from the user to the Internet or to a central office or headend.

User Menu - Is the menu that you can access with your remote to adjust the setup of your TV's display.

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VGA - Is a single cable that is used to carry an analog video signal.  This type of connection is capable of carrying the complete resolution of HDTV and NTSC.  It is typically used for connection with a computer.

VERTICAL BLANKING INTERVAL (VBI) - Part of the TV signal that is not used for video information and left available to transmit other data such as captions, Web data, current stock market prices. Visually the VBI is the black stripe at the top and bottom of a TV picture and physically it constitutes 21 lines' worth of the total 525 lines transmitted per second in the NTSC TV signal. In detail, the Vertical Blanking Interval is a portion of the analog TV signal embedded inside two rectangular fields on the TV screen that are comprised of 262.5 imperceptible horizontal lines. Each line is made of 427 pixels that form the video images on the screen through a process called electron beam called "interlaced scanning". The first 21 lines of each of the two horizontal fields (a black stripe - only seen when the picture loses its vertical hold and rolls) is called the Vertical Blanking Interval. In this interval, data of any kind can be broadcasted, received by any TV set, and interpreted with special software if the TV set is hooked into a set-top box or the data is received by a TV tuner card on a computer. The first 9 lines of the VBI are used for timing information of the shows, but lines 10-20 are pretty much unused. Line 21, however, is used for closed captioning text and now in use for HTML data. See HTML.

VERY HIGH BIT RATE DIGITAL SUBSCRIBER LINE (VDSL) - VDSL is a type of DSL that is primarily intended to be used as the last transmission system section in a network. VDSL can serve as the primary transmission element for video-on-demand (VOD) and Asynchronous Transfer Mode (ATM) applications over the existing infrastructure of twisted copper pairs in the local plant and used to carry multiple television channels, HDTV and ATM to the Home for interactive services (home banking, shopping, remote medical care).

Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF is HF, and the next higher frequencies are known as Ultra high frequency (UHF).

VIDEOPHONE - This future device promises to incorporate real time video transmissions with telephony. Although this technology was promised and available many years ago, it has never been fully realized. Today, Internet Telephony or Cable Telephony may offer this service.

Video-On-Demand (VOD)
This is a multi-channel system allowing a film to be broadcasted immediately if it is requested by an individual viewer.

Viewing angle - A TV's maximum usable viewing range from the center of the screen. The maximum angle that an image can be viewed at from an off-center point without degrading picture quality.

Viterbi decoding - In the receiver the ‘Inner’ coded signal goes through process of Viterbi decoding in which the receiver recognizes the pseudorandom sequence added by the convolutional encoder. The Viterbi decoder has the ability to recognize the distinctive pattern imposed on the data by the sequence even in the presence of errors. In essence, the Viterbi decoder passes the data through a buffer configured with templates shaped by the pseudorandom sequence and attempts to find the best match between the incoming data, with possible errors, and its templates. The Viterbi decoder outputs a decision based on the best match found.

Voltage - Measured in Volts, the difference of electrical potential between two points in an electrical circuit.  http://searchsmb.techtarget.com/sDefinition/0,,sid44_gci213320,00.html

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WALLED GARDEN - A term that appeared in the mid- to late 90's to define interactive content offerings contained or walled-off from direct access to Internet users. Walled garden users may link to the Internet from walled gardens, however, but not vice versa. America Online is an example of a very successful walled garden. Certain interactive TV middleware software solutions enable cable and satellite providers to create their own walled gardens or "portals." Inside an ITV walled garden an interface allows the viewer to have access to news, sports information, one's email on TV, and other applications.

WARNER BROS. - Cable operator that funded the first interactive set-top box network in the mid-1970's called QUBE. QUBE was located in Columbus, Ohio.

Wavelength - The distance between identical points in the adjacent cycles of a waveform signal propagated in space or along a wire (i.e. the distance from one wave crest to the next, or trough to trough . For more see  http://science.hq.nasa.gov/kids/imagers/ems/waves3.html

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.

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Wobulation - A technique originally invented by Hewlett-Packard for its ink jet printers. Texas Instruments, developer of DLP display technology, employs wobulation in some of its image chips used in rear-projection TVs. Like interlacing, wobulation shows half the picture at a time, but displays the two halves so rapidly that our eyes combine the two parts into one. A 1080p DLP TV can display images with 1920 x 1080 pixels, yet its DMD (Digital Micromirror Device) image chip has 960 x 1080 mirrors. Half the image is displayed, then a separate pivoting reflective panel called an "actuator" shifts the display a half pixel's width to the side. This all happens fast enough to generate 60 full frames per second, for a clean progressive-scan image. Texas Instruments calls this technique SmoothPictureT, and it is also often referred to as "pixel-shifting."

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The rule prohibits most restrictions that: (1) unreasonably delay or prevent installation, maintenance or use; (2) unreasonably increase the cost of installation, maintenance or use; or (3) preclude reception of an acceptable quality signal.

Q: Who do I call if my town, community association or landlord is enforcing an invalid restriction?
A: Call the Federal Communications Commission at (888) CALLFCC (888-225-5322), which is a toll-free number, or 202-418-7096, which is not toll-free. Some assistance may also be available from the direct broadcast satellite company, broadband radio service provider, television broadcast station, or fixed wireless company whose service is desired.

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