Set-top box
Encyclopedia
A set-top box or set-top unit (STU) is an information appliance
Information appliance
In general terms, an information appliance or information device is any machine or device that is usable for the purposes of computing, telecommunicating, reproducing, and presenting encoded information in myriad forms and applications....

 device that generally contains a tuner and connects to a television set
Television set
A television set is a device that combines a tuner, display, and speakers for the purpose of viewing television. Television sets became a popular consumer product after the Second World War, using vacuum tubes and cathode ray tube displays...

 and an external source of signal, turning the signal into content
Content (media and publishing)
In media production and publishing, content is information and experiences that may provide value for an end-user/audience in specific contexts. Content may be delivered via any medium such as the internet, television, and audio CDs, as well as live events such as conferences and stage performances...

 which is then displayed on the television screen or other display
Display
Display may refer to:* Display , an American thoroughbred racehorse* Display , a form of animal behaviour* Display advertising, type that typically contains text, i.e., copy, logos, images, location maps, etc....

 device.

History

Before the mid-1950s, all British television sets tuned only VHF Band I
Band I
Band I is the name of a radio frequency range within the very high frequency part of the electromagnetic spectrum.Band I ranges from 47 to 88 MHz, and it is primarily used for radio and television broadcasting....

 channels. Since all 5 Band I channels were occupied by BBC transmissions, ITV
ITV
ITV is the major commercial public service TV network in the United Kingdom. Launched in 1955 under the auspices of the Independent Television Authority to provide competition to the BBC, it is also the oldest commercial network in the UK...

 would have to use Band III
Band III
Band III is the name of a radio frequency range within the very high frequency part of the electromagnetic spectrum.Band III ranges from 174 to 230 MHz, and it is primarily used for radio and television broadcasting...

. This meant all the TV sets in the country would require Band III converters which converted the Band III signal to a Band I signal. By 1955, when the first ITV stations started transmitting, virtually all new British Televisions had 13-channel tuners, quickly making Band III converters obsolete.

Before the All-Channel Receiver Act of 1962 required US television receivers to be able to tune the entire VHF and UHF range (which in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 was NTSC-M channels 2 through 83
North American broadcast television frequencies
The North American broadcast television frequencies are on designated television channels numbered 2 through 69, approximately between 54 and 806 MHz. Traditionally, the frequencies are divided into two sections, the very high frequency band and the ultra high frequency band. The VHF band is...

 on 54 to 890 MHz), a set-top box known as a UHF converter would be installed at the receiver to shift a portion of the UHF-TV spectrum onto low-VHF channels for viewing. As some 1960s-era twelve-channel TV sets remained in use for many years, and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 were slower than the US to require UHF tuners to be factory-installed in new TV's, a market for these converters continued to exist for much of the 1970s.

Cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...

 represented a possible alternative to deployment of UHF converters as broadcasts could be frequency-shifted to VHF channels at the cable head-end instead of the final viewing location. Unfortunately, cable brought a new problem; most cable systems could not accommodate the full 54-890 MHz VHF/UHF frequency range and the twelve channels of VHF space were quickly exhausted on most systems. Adding any additional channels therefore needed to be done by inserting the extra signals into cable systems on non-standard frequencies, typically either below VHF channel 7
North American broadcast television frequencies
The North American broadcast television frequencies are on designated television channels numbered 2 through 69, approximately between 54 and 806 MHz. Traditionally, the frequencies are divided into two sections, the very high frequency band and the ultra high frequency band. The VHF band is...

 (midband) or directly above VHF channel 13
Channel 13
Channel 13 refers to several television stations:* Channel 13, Lithuania* DZTV-TV, the flagship station of the Intercontinental Broadcasting Corporation in Metro Manila, Philippines* Thirteen WNET, primary public television station of PBS in New York City...

 (superband).

These frequencies corresponded to non-television services (such as two-way radio) over-the-air and were therefore not on standard TV receivers. Before cable-ready TV sets became common in the late 1980s, a set-top box known as a cable converter box
Cable converter box
A cable converter box or television converter box is an electronic tuning device that transposes/converts any of the available channels from a cable television service to an analog RF signal on a single channel, usually VHF channel 3 or 4. The device allows a television set that is not “cable...

 was needed to receive the additional analog cable
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...

 TV channel
Television channel
A television channel is a physical or virtual channel over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video and...

s and convert them to analog video
Analog video
Analog video is a video signal transferred by an analog signal. An analog color video signal contains luminance, brightness and chrominance of an analog television image...

 frequencies that could be seen on a regular TV set. These boxes often provided a wired or wireless remote control which could be used to shift one selected channel to a low-VHF frequency (most often channels 3 or 4) for viewing. Block conversion of the entire affected frequency band onto UHF, while less common, was used by some models to provide full VCR compatibility and the ability to drive multiple TV sets, albeit with a somewhat non-standard channel numbering scheme.

Newer television receivers greatly reduced the need for external set-top boxes, although cable converter boxes continue to be used to descramble premium cable channels and to receive digital cable
Digital cable
Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.-Background:...

 channels, along with using interactive services like video on demand
Video on demand
Video on Demand or Audio and Video On Demand are systems which allow users to select and watch/listen to video or audio content on demand...

, pay per view, and home shopping
Home shopping
Home shopping commonly refers to the electronic retailing/home shopping channels industry, which includes such billion dollar television-based and e-commerce companies as HSN, QVC, eBay, ShopNBC, Buy.com, and Amazon.com, as well as traditional mail order and brick and mortar retailers as Hammacher...

 through television. Satellite and microwave-based services also require specific external receiver hardware, so the use of set-top boxes of various formats never completely disappeared.

Cable converter box

A cable converter box or television converter box is type of set-top box that is an electronic tuning device that transposes/converts any of the available channels from a cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...

 service to an analog
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...

 RF
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...

 signal on a single channel, usually VHF channel 3 or 4. The device allows a television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

 set that is not “cable ready” to receive cable channels. While later televisions were "cable ready" with a standard converter built-in, the existence of premium television (aka pay per view) and the advent of digital cable
Digital cable
Digital cable is a generic term for any type of cable television distribution using digital video compression or distribution. The technology was originally developed by Motorola.-Background:...

 have continued the need for various forms of these devices for cable television reception. While not an explicit part of signal conversion, many cable converter boxes include forms of descrambling
Descramble
Descramble in Cable television context is the act of taking a scrambled or encrypted Video Signal one that has been processed by a scrambler and provided by a Cable Television company for Premium television services and is then supplied over a Coaxial cable and delivered to the household where a...

 to manage carrier-controlled access restriction to various channels.

Professional set-top box

Professional set-top boxes are referred to as IRDs or integrated receiver/decoder
Integrated receiver/decoder
An integrated receiver/decoder is an electronic device used to pick-up a radio-frequency signal and convert digital information transmitted in it.-Consumer IRDs:...

s in the professional broadcast audio/video industry. They are designed for more robust field handling and rack mounting
19-inch rack
A 19-inch rack is a standardized frame or enclosure for mounting multiple equipment modules. Each module has a front panel that is wide, including edges or ears that protrude on each side which allow the module to be fastened to the rack frame with screws.-Overview and history:Equipment designed...

 environments, and are also technically superior, IRDs have the distinct feature of outputting uncompressed SDI
Serial Digital Interface
Serial digital interface is a family of video interfaces standardized by SMPTE. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video...

 signals, unlike consumer STBs which don’t mostly because of copyright reasons.

TV signal sources

The signal source might be an ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

 cable, a satellite dish
Satellite dish
A satellite dish is a dish-shaped type of parabolic antenna designed to receive microwaves from communications satellites, which transmit data transmissions or broadcasts, such as satellite television.-Principle of operation:...

, a coaxial cable
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...

 (see cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...

), a telephone
Telephone
The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...

 line (including DSL
Digital Subscriber Line
Digital subscriber line is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term DSL is widely understood to mean Asymmetric Digital Subscriber Line ,...

 connections), Broadband over Power Line, or even an ordinary VHF
Very high frequency
Very high frequency is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted High frequency , and the next higher frequencies are known as Ultra high frequency...

 or UHF
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...

 antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...

. Content, in this context, could mean any or all of video
Video
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...

, audio
Sound
Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

, Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 webpage
Web page
A web page or webpage is a document or information resource that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a monitor or mobile device. This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext...

s, interactive games, or other possibilities.

Hybrid

In the late 2000s, there has been a significant growth in the adoption of Hybrid IPTV Set-Top Box
Hybrid IPTV Set-Top Box
A hybrid IPTV set-top box enables the aggregation of traditional linear TV broadcasts with video delivered via both managed and unmanaged IP networks...

es in both the pay-TV and free-to-air set-top box markets. A hybrid set-top allows traditional TV broadcast (from terrestrial, satellite, or cable providers) to be brought together with video delivered over the Internet, and with personal multimedia content. This enables television viewers to access a greater variety of content on their TV sets, without needing a separate box for each service.

Hybrid IPTV Set-Top Box
Hybrid IPTV Set-Top Box
A hybrid IPTV set-top box enables the aggregation of traditional linear TV broadcasts with video delivered via both managed and unmanaged IP networks...

es also enable consumers to access a range of advanced interactive services, such as VOD
VOD
VOD may stand for:*Velocity of detonation, the speed of a shock wave through a detonated explosive*Veno-occlusive disease, a complication of bone marrow transplantation*Versant Object Database, a database management system...

 and time-shifting TV, as well as internet applications, including video telephony, surveillance, gaming, shopping, e-government accessed via a television set.

For a pay-TV operator’s perspective, a Hybrid IPTV Set-Top Box
Hybrid IPTV Set-Top Box
A hybrid IPTV set-top box enables the aggregation of traditional linear TV broadcasts with video delivered via both managed and unmanaged IP networks...

 gives them greater long term flexibility by enabling them to deploy a wide variety new services and applications as and when consumers require, most often without the need to upgrade equipment or for an engineer to visit and reconfigure or swap out the device. This minimises the cost of launching new services, increases speed to market and limits disruption for consumers.

One of the leaders in the Hybrid IPTV Set-Top Box market is Advanced Digital Broadcast
Advanced Digital Broadcast
Advanced Digital Broadcast designs, manufactures and deploys solutions to distribute pay-TV and multimedia services to the connected home, for all types of networks. The company has its global headquarters in Geneva, Switzerland and regional headquarters in Denver, USA and Taipei, Taiwan...

 (ADB) – having launched its first hybrid digital terrestrial (DTT) /IPTV set-top box in 2005
that provided Telefónica
Telefónica
Telefónica, S.A. is a Spanish broadband and telecommunications provider in Europe and Latin America. Operating globally, it is the third largest provider in the world...

 with the digital TV platform for its Imagenio service at the end of that year. In 2009, the company also provided Europe’s first three-way hybrid
Three-way hybrid
A three-way hybrid set-top box is a hybrid device typically used by Pay TV operators and Telecommunications service providers to converge content delivered via three different video transport networks – satellite, terrestrial and IP [managed or public Internet]...

 digital TV platform to Polish digital satellite operator n that enables its subscribers to view content delivered via satellite, digital terrestrial, and IP networks.

IPTV

In IPTV
IPTV
Internet Protocol television is a system through which television services are delivered using the Internet protocol suite over a packet-switched network such as the Internet, instead of being delivered through traditional terrestrial, satellite signal, and cable television formats.IPTV services...

 networks, the set-top box is a small computer providing two-way communications on an IP
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...

 network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....

 and decoding the video streaming media
Streaming media
Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a streaming provider.The term "presented" is used in this article in a general sense that includes audio or video playback. The name refers to the delivery method of the medium rather...

. IP set-top boxes have a built in home network
Home network
A home network or home area network is a residential local area network . It is used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices...

 interface which can be Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

 or one of the existing wire home networking technologies such as HomePNA
HomePNA
The HomePNA Alliance is an incorporated non-profit industry association of companies that develops and standardizes technology for home networking over the existing coaxial cables and telephone wiring within homes.-Overview:HomePNA does not manufacture products, although its members do...

 or the ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....

 G.hn
G.hn
G.hn is the common name for a home network technology family of standards developed under the International Telecommunication Union's Standardization arm and promoted by the HomeGrid Forum...

 standard, which provides a way to create a high-speed (up to 1 Gigabit/s) Local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...

 using existing home wiring (power lines
Power line communication
Power line communication or power line carrier , also known as power line digital subscriber line , mains communication, power line telecom , power line networking , or broadband over power lines are systems for carrying data on a conductor also used for electric power transmission.A wide range...

, phone lines, and coaxial cables
Ethernet over coax
Ethernet over Coax is a family of technologies that supports the transmission of Ethernet frames over coaxial cable.- History :The first Ethernet standard, known as 10BASE5 in the family of IEEE 802.3, specified baseband operation over coaxial cable...

).

In the US and Europe, telephone companies use IPTV (often on ADSL or optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...

 networks) as a means to compete with traditional local cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...

 monopolies.

Ambiguities in the definition

With the advent of flat-panel televisions, set-top boxes are now deeper in profile than the tops of most modern TV sets. Because of this, set-top boxes are often placed beneath televisions, and the term set-top box has become something of a misnomer
Misnomer
A misnomer is a term which suggests an interpretation that is known to be untrue. Such incorrect terms sometimes derive their names because of the form, action, or origin of the subject becoming named popularly or widely referenced—long before their true natures were known.- Sources of misnomers...

, possibly helping the adoption of the term digibox. Additionally, newer set-top boxes that sit at the edge of IP based distribution networks are often called Net-Top-Boxes or NTB
NTB
NTB may refer to:* Non-tariff barriers to trade* Norsk Telegrambyrå, the leading news agency in Norway* The IATA code for Notodden Airport, Tuven, in Norway* National Tire and Battery* Nusa Tenggara Barat, Indonesian province of West Nusa Tenggara...

s. This is to differentiate between devices with IP or RF inputs.

In Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, a set-top box does not necessarily contain a tuner of its own. A box connected to a television (or VCR
Videocassette recorder
The videocassette recorder , is a type of electro-mechanical device that uses removable videocassettes that contain magnetic tape for recording analog audio and analog video from broadcast television so that the images and sound can be played back at a more convenient time...

) set's SCART
SCART
SCART is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment together...

 connector is fed with the baseband
Baseband
In telecommunications and signal processing, baseband is an adjective that describes signals and systems whose range of frequencies is measured from close to 0 hertz to a cut-off frequency, a maximum bandwidth or highest signal frequency; it is sometimes used as a noun for a band of frequencies...

 television signal from the set's tuner, and can ask the television to display the returned processed signal instead.

This SCART feature had been used for connection to analogue decoding equipment by pay TV
Pay TV
Pay television, premium television, or premium channels refers to subscription-based television services, usually provided by both analog and digital cable and satellite, but also increasingly via digital terrestrial and internet television...

 operators in Europe, and in the past was used for connection to teletext
Teletext
Teletext is a television information retrieval service developed in the United Kingdom in the early 1970s. It offers a range of text-based information, typically including national, international and sporting news, weather and TV schedules...

 equipment before the decoders became built-in. The outgoing signal could be of the same nature as the incoming signal, or RGB
YPbPr
' is a color space used in video electronics, in particular in reference to component video cables. is the analog version of the YCBCR color space; the two are numerically equivalent, but YPBPR is designed for use in analog systems whereas YCBCR is intended for digital video. cables are also...

 component video
Component video
Component video is a video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video information that is transmitted or stored as three separate signals...

, or even an "insert
Local insertion
In broadcasting, local insertion is the act or capability of a broadcast television station, radio station, or cable TV system to insert or replace part of a broadcast network feed with content unique to the local station or system...

" over the original signal, thanks to the "fast switching" feature of SCART.

In case of analogue pay-TV, this approach avoided the need for a second remote control
Remote control
A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

. The use of digital television
Digital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...

 signals in more modern pay-TV schemes requires that decoding take place before the digital-to-analogue conversion step, rendering the video outputs of an analogue SCART connector no longer suitable for interconnection to decryption hardware. Standards such as DVB's Common Interface
Common Interface
In Digital Video Broadcasting, the Common Interface is an extensible digital interconnect found in the digital TV market. It is also known as DVB-CI for Digital Video Broadcast Common Interface....

 and ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....

's CableCARD
CableCARD
CableCARD is a special-use PCMCIA card that allows consumers in the United States to view and record digital cable television channels on digital video recorders, personal computers and television sets without the use of other equipment such as a set top box provided by a cable television company...

 therefore use a PCMCIA-like card inserted as part of the digital signal path as their alternative to a tuner-equipped set-top box.

The distinction between external tuner or demodulator boxes (traditionally considered to be "set-top boxes") and storage devices (such as VCR, DVD, or disc-based PVR units) is also blurred by the increasing deployment of satellite and cable tuner boxes with hard discs, network or USB interfaces built-in.

Devices with computer terminal
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...

-like capabilities, such as the WebTV thin client
Thin client
A thin client is a computer or a computer program which depends heavily on some other computer to fulfill its traditional computational roles. This stands in contrast to the traditional fat client, a computer designed to take on these roles by itself...

, also fall into the grey area
Grey area
Grey area or gray area is a concept or topic that is unclear.Grey area may also refer to:*Grey Area *"The Grey Area", a song by Miss Kittin & The Hacker from the EP Champagne...

 that could be catered for by the term NTB.

Set-top boxes were also made to enable closed captioning
Closed captioning
Closed captioning is the process of displaying text on a television, video screen or other visual display to provide additional or interpretive information to individuals who wish to access it...

 on older sets in North America, before this became a mandated inclusion in new TV sets. Some have also been produced to mute the audio
Sound recording and reproduction
Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording...

 (or replace it with noise) when profanity
Profanity
Profanity is a show of disrespect, or a desecration or debasement of someone or something. Profanity can take the form of words, expressions, gestures, or other social behaviors that are socially constructed or interpreted as insulting, rude, vulgar, obscene, desecrating, or other forms.The...

 is detected in the captioning, where the offensive word is also blocked. Some also include a V-chip
V-chip
V-chip is a generic term for technology used in television set receivers in the USA, Canada, and Brazil which allows the blocking of programs based on their ratings category. It is intended for use by parents to manage their children's television viewing...

 that allows only programmes of some television content ratings. A function that limits child
Child
Biologically, a child is generally a human between the stages of birth and puberty. Some vernacular definitions of a child include the fetus, as being an unborn child. The legal definition of "child" generally refers to a minor, otherwise known as a person younger than the age of majority...

ren's time watching TV or playing video games may also be built in, though some of these work on the mains electricity
Mains electricity
Mains is the general-purpose alternating current electric power supply. In the US, electric power is referred to by several names including household power, household electricity, powerline, domestic power, wall power, line power, AC power, city power, street power, and grid power...

 rather than the video signal.

Software quality

As complexity of the set-top box increases, the software quality practices of the industry become obvious and many systems have bugs.
However, users of software-based solutions such as Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

's Media Center, MythTV
MythTV
MythTV is a free and open source home entertainment application with a simplified "10-foot user interface" design for the living-room TV, and turns a computer with the necessary hardware into a network streaming digital video recorder, a digital multimedia home entertainment system, or home theater...

 and Select-TV
Select-TV
Select-TV is a Malaysian based company specializing on the IPTV technology for the hospitality and telecommunication sectors. Since its inception, it has delivered several IPTV projects, which the company named as CXS, to the Middle East and South East Asian region...

 have a very flexible list of possible features ranging from basic Digital video recorder
Digital video recorder
A digital video recorder , sometimes referred to by the merchandising term personal video recorder , is a consumer electronics device or application software that records video in a digital format to a disk drive, USB flash drive, SD memory card or other local or networked mass storage device...

 (DVR)-like functionality to features such as DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....

 copying, home automation
Home automation
Home automation is the residential extension of "building automation". It is automation of the home, housework or household activity. Home automation may include centralized control of lighting, HVAC , appliances, and other systems, to provide improved convenience, comfort, energy efficiency and...

, and house-wide music/video file playing.

Energy Use

In 2011, set-top boxes received attention for their energy consumption. The average set-top box configuration (one HD-DVR
Digital video recorder
A digital video recorder , sometimes referred to by the merchandising term personal video recorder , is a consumer electronics device or application software that records video in a digital format to a disk drive, USB flash drive, SD memory card or other local or networked mass storage device...

 and one HD cable box
Cable converter box
A cable converter box or television converter box is an electronic tuning device that transposes/converts any of the available channels from a cable television service to an analog RF signal on a single channel, usually VHF channel 3 or 4. The device allows a television set that is not “cable...

) uses 446 kWh per year -- more than a new 21 cubic foot Energy Star
Energy Star
Energy Star is an international standard for energy efficient consumer products originated in the United States of America. It was first created as a United States government program during the early 1990s, but Australia, Canada, Japan, New Zealand, Taiwan and the European Union have also adopted...

 refrigerator, which uses 415 kWh a year. Currently, there are no federal appliance standards
National Appliance Energy Conservation Act
The National Appliance Energy Conservation Act is a 1975 piece of legislation by the United States Congress which regulates energy consumption of specific household appliances in the United States. Though minimum Energy Efficiency Standards were first established by the United States Congress in...

in place to regulate the energy efficiency of set-top boxes, though in June 2011 the U.S. Department of Energy announced plans to include them in future regulations.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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