A set-top box (STB), also colloquially known as a
cable box and historically television decoder, is an
information appliance device that generally contains a
TV-tuner input and displays output to a
television set
A television set or television receiver, more commonly called the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...
and an external source of
signal, turning the source signal into
content
Content or contents may refer to:
Media
* Content (media), information or experience provided to audience or end-users by publishers or media producers
** Content industry, an umbrella term that encompasses companies owning and providing mas ...
in a form that can then be displayed on the
television screen
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal th ...
or other
display device. They are used in
cable television
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...
,
satellite television
Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location. The signals are received via an outdoor parabolic antenna commo ...
, and
over-the-air television
Terrestrial television or over-the-air television (OTA) is a type of television broadcasting in which the signal transmission occurs via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an ant ...
systems as well as other uses.
According to the ''
Los Angeles Times'', the cost to a cable provider in the United States for a set-top box is between $150 for a basic box to $250 for a more sophisticated box. In 2016, the average
pay-TV
Pay television, also known as subscription television, premium television or, when referring to an individual service, a premium channel, refers to subscription-based television services, usually provided by multichannel television providers, bu ...
subscriber paid $231 per year to lease their set-top box from a cable service provider.
TV signal sources
The signal source might be an
Ethernet cable, a
satellite dish, a
coaxial cable
Coaxial cable, or coax (pronounced ) is a type of electrical cable consisting of an inner Electrical conductor, conductor surrounded by a concentric conducting Electromagnetic shielding, shield, with the two separated by a dielectric (Insulato ...
(see
cable television
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...
), a
telephone line (including
DSL connections),
broadband over power lines
Broadband over power lines (BPL) is a method of power-line communication (PLC) that allows relatively high-speed digital data transmission over the public electric power distribution wiring. BPL uses higher frequencies, a wider frequency range an ...
(BPL), or even an ordinary
VHF or
UHF
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...
antenna. Content, in this context, could mean any or all of
video,
audio
Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to:
Sound
*Audio signal, an electrical representation of sound
*Audio frequency, a frequency in the audio spectrum
* Digital audio, representation of sou ...
,
Internet web pages,
interactive video games, or other possibilities. Satellite and microwave-based services also require specific external receiver hardware, so the use of set-top boxes of various formats has never completely disappeared. Set-top boxes can also enhance source signal quality.
UHF converter
Before the
All-Channel Receiver Act
The All-Channel Receiver Act of 1962 (ACRA) (), commonly known as the All-Channels Act, was passed by the United States Congress in 1961, to allow the Federal Communications Commission to require that all television set manufacturers must include ...
of 1962 required US
television receivers to be able to tune the entire
VHF and
UHF
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...
range (which in
North America was
NTSC-M
The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplementa ...
channels
2 through 83 on 54 to 890
MHz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
), 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 12-channel TV sets remained in use for many years, and
Canada and
Mexico were slower than the US to require UHF tuners to be factory-installed in new TVs, a market for these converters continued to exist for much of the 1970s.
Cable converter
Cable television
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...
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. However, 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 nonstandard frequencies, typically either below VHF
channel 7 (midband) or directly above VHF channel 13 (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, an electronic tuning device called a
cable converter box
A cable converter box or television converter box is an electronic tuning device that transposes/converts channels from a cable television service to an analog RF signal on a single channel, usually VHF or 4, or to a different output for di ...
was needed to receive the additional
analog cable TV channels and transpose or convert the selected channel to
analog radio frequency (RF) for viewing on a regular TV set on a single channel, usually
VHF channel 3 or 4. The box allowed an analog non-cable-ready
television set to receive analog encrypted cable channels and was a prototype topology for later date digital encryption devices. Newer televisions were then converted to be analog cypher cable-ready, with the standard converter built-in for selling
premium television
Pay television, also known as subscription television, premium television or, when referring to an individual service, a premium channel, refers to subscription-based television services, usually provided by multichannel television providers, but ...
(aka
pay per view
Pay-per-view (PPV) is a type of pay television or webcast service that enables a viewer to pay to watch individual events via private telecast.
Events can be purchased through a multichannel television platform using their electronic program guid ...
). Several years later and slowly marketed, the advent of
digital cable
Digital cable is the distribution of cable television using digital data and video compression. The technology was first developed by General Instrument. By 2000, most cable companies offered digital features, eventually replacing their previou ...
continued and increased the need for various forms of these devices.
Block conversion of the entire affected frequency band onto
UHF
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...
, while less common, was used by some models to provide full
VCR
A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other source on a removable, magnetic tape videocassette, and can play back the recordin ...
compatibility and the ability to drive multiple TV sets, albeit with a somewhat nonstandard channel numbering scheme.
Newer television receivers greatly reduced the need for external set-top boxes, although
cable converter box
A cable converter box or television converter box is an electronic tuning device that transposes/converts channels from a cable television service to an analog RF signal on a single channel, usually VHF or 4, or to a different output for di ...
es continue to be used to
descramble
In telecommunications, a scrambler is a device that transposes or inverts signals or otherwise encodes a message at the sender's side to make the message unintelligible at a receiver not equipped with an appropriately set descrambling device. Wher ...
premium cable channels according to carrier-controlled access restrictions, and to receive digital cable channels, along with using interactive services like
video on demand, pay per view, and
home shopping through television.
Closed captioning box
Set-top boxes were also made to enable
closed captioning
Closed captioning (CC) and subtitling are both processes of displaying text on a television, video screen, or other visual display to provide additional or interpretive information. Both are typically used as a transcription of the audio port ...
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
Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to:
Sound
*Audio signal, an electrical representation of sound
*Audio frequency, a frequency in the audio spectrum
* Digital audio, representation of sou ...
(or replace it with noise) when
profanity is detected in the captioning, where the offensive word is also blocked. Some also include a
V-chip
V-chip is a technology used in television set receivers in Canada, Brazil and the United States, that allows the blocking of programs based on their ratings category. It is intended for use by parents to manage their children's television view ...
that allows only programs of some
television content ratings. A function that limits children's time watching TV or playing
video games may also be built in, though some of these work on main electricity rather than the video signal.
Digital television adapter
The
transition to
digital terrestrial television after the turn of the millennium left many existing
television receivers unable to tune and display the new signal directly. In the United States, where
analog shutdown
The digital television transition, also called the digital switchover (DSO), the analogue switch/sign-off (ASO), the digital migration, or the analogue shutdown, is the process in which older analogue television broadcasting technology is conv ...
was completed in 2009 for full-service broadcasters, a federal subsidy was offered for
coupon-eligible converter box
A coupon-eligible converter box (CECB) was a digital television adapter that met eligibility specifications for subsidy "coupons" from the United States government. The subsidy program was enacted to provide terrestrial television viewers with ...
es with deliberately limited capability which would restore signals lost to digital transition.
Professional set-top box
Professional set-top boxes are referred to as IRDs or
integrated receiver/decoders in the professional broadcast audio/video industry. They are designed for more robust field handling and
rack mounting environments. IRDs are capable of outputting uncompressed
serial digital interface signals, unlike consumer STBs which usually don't, mostly because of copyright reasons.
Hybrid box
Hybrid set-top boxes, such as those used for
Smart TV programming, enable viewers to access multiple TV delivery methods (including terrestrial, cable, internet, and satellite); like IPTV boxes, they include
video on demand,
time-shifting
In broadcasting, time shifting is the recording of programming to a storage medium to be viewed or listened to after the live broadcasting. Typically, this refers to TV programming but it can also refer to radio shows via podcasts.
In recent year ...
TV, Internet applications,
video telephony, surveillance, gaming, shopping, TV-centric
electronic program guides, and e-government. By integrating varying delivery streams, hybrids (sometimes known as "TV-centric") enable pay-TV operators more flexible application deployment, which decreases the cost of launching new services, increases speed to market, and limits disruption for consumers.
As examples,
Hybrid Broadcast Broadband TV (HbbTV) set-top boxes allow traditional TV broadcasts, whether from
terrestrial (DTT), satellite, or cable providers, to be brought together with video delivered over the Internet and personal multimedia content.
Advanced Digital Broadcast
Advanced Digital Broadcast (ADB) is a company which provides software, system and services to pay-TV and telecommunication operators, content distributors and property owners around the world. The company specializes also in the development of dig ...
(ADB) launched its first hybrid DTT/IPTV set-top box in 2005, which provided
Telefónica
Telefónica, S.A. () is a Spanish multinational telecommunications company headquartered in Madrid, Spain. It is one of the largest telephone operators and mobile network providers in the world. It provides fixed and mobile telephony, broadb ...
with the digital TV platform for its
Movistar TV
Movistar TV is a subscription television service operated by Telefónica. Currently, the service is available in Chile, Perú, Colombia, El Salvador, Venezuela and Argentina. In Spain, this service merged with the satellite platform Canal+, resul ...
service by the end of that year. In 2009, ADB provided Europe's first
three-way hybrid digital TV platform to Polish digital satellite operator
n, which enables subscribers to view integrated content whether delivered via satellite, terrestrial, or internet.
UK based
Inview Technology
Inview Technology (Inview Technology Ltd or simply Inview) is a UK-based digital TV software company. It specialises in advanced EPGs, interactive broadcast, IP services and solutions for Pay-TV and analogue switch off markets. Their OTT TV ...
has over 8M STBs deployed in the UK for
Teletext and an original push
VOD service for Top Up TV.
IPTV receiver
In
IPTV
Internet Protocol television (IPTV) is the delivery of television content over Internet Protocol (IP) networks. This is in contrast to delivery through traditional terrestrial, satellite, and cable television formats. Unlike downloaded medi ...
networks, the set-top box is a small computer providing two-way communications on an
IP network
Network, networking and networked may refer to:
Science and technology
* Network theory, the study of graphs as a representation of relations between discrete objects
* Network science, an academic field that studies complex networks
Mathematic ...
and decoding the video
streaming media. IP set-top boxes have a built-in
home network
A home network or home area network (HAN) is a type of computer network that facilitates communication among devices within the close vicinity of a home. Devices capable of participating in this network, for example, smart devices such as netwo ...
interface that can be
Ethernet, Wireless (802.11 g,n,ac), or one of the existing wire home networking technologies such as
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, so new wires do not need to be ...
or the
ITU-T G.hn standard, which provides a way to create a high-speed (up to 1Gbit/s)
local area network using existing home wiring (
power lines
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is d ...
, phone lines, and
coaxial cables).
In the US and Europe, telephone companies use IPTV (often on
ADSL
Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. ...
or
optical fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means t ...
networks) as a means to compete with traditional local
cable television
Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with broadc ...
monopolies.
This type of service is distinct from
Internet television
Streaming television is the digital distribution of television content, such as TV shows, as streaming media delivered over the Internet. Streaming television stands in contrast to dedicated terrestrial television delivered by over-the-air a ...
, which involves third-party content over the public Internet not controlled by the local system operator.
Features
Programming features
Electronic program guide
Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying
broadcast programming
Broadcast programming is the practice of organizing or ordering (scheduling) of broadcast media shows, typically radio and television, in a daily, weekly, monthly, quarterly or season-long schedule.
Modern broadcasters use broadcast automation ...
or scheduling information for current and upcoming programming. Some guides, such as
ITV, also feature backward scrolling to promote their catch-up content.
Favorites
This feature allows the user to choose preferred channels, making them easier and quicker to access; this is handy with the wide range of digital channels on offer. The concept of favourite channels is superficially similar to that of the "
bookmark
A bookmark is a thin marking tool, commonly made of card, leather, or fabric, used to keep track of a reader's progress in a book and allow the reader to easily return to where the previous reading session ended. Alternate materials for book ...
" function offered in many Web browsers.
Timer
The
timer
A timer is a specialized type of clock used for measuring specific time intervals.
Timers can be categorized into two main types.
The word "timer" is usually reserved for devices that counts down from a specified time interval, while devices th ...
allows the user to program and enable the box to switch between channels at certain times: this is handy to record from more than one channel while the user is out. The user still needs to program the VCR or DVD recorder.
Convenience features
Controls on the box
Some models have controls on the box, as well as on the
remote control. This is useful should the user lose the remote or if the batteries age.
Remote controls that work with other TVs
Some
remote controls can also control some basic functions of various brands of TVs. This allows the user to use just one remote to turn the TV on and off, adjust volume, or switch between digital and analog TV channels or between
terrestrial and
internet channels.
Parental locks
The
parental lock or
content filters allow users over 18 years old to block access to channels that are not appropriate for children, using a
personal identification number. Some boxes simply block all channels, while others allow the user to restrict access to chosen channels not suitable for children below certain ages.
Software alternatives
As complexity and potential programming faults of the set-top box increase, software such as
MythTV,
Select-TV
Select-TV is a Malaysian based company specializing in the IPTV (Internet Protocol television) technology for the hospitality and telecommunication sectors. Since its inception, it has delivered several IPTV projects to the Middle East and South ...
and
Microsoft's
Media Center have developed features comparable to those of set-top boxes, ranging from basic DVR-like functionality to
DVD
The DVD (common abbreviation for Digital Video Disc or Digital Versatile Disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kin ...
copying,
home automation
Home automation or domotics is building automation for a home, called a smart home or smart house. A home automation system will monitor and/or control home attributes such as lighting, climate, entertainment systems, and appliances. It ma ...
, and housewide music or video playback.
Firmware update features
Almost all modern set-top boxes feature automatic
firmware update
A patch is a set of changes to a computer program or its supporting data designed to update, fix, or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually being called bugfixes or bug fixes. Patche ...
processes. The firmware update is typically provided by the service provider.
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
A misnomer is a name that is incorrectly or unsuitably applied. Misnomers often arise because something was named long before its correct nature was known, or because an earlier form of something has been replaced by a later form to which the name ...
, 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 NTBs, to differentiate between IP and RF inputs. The Roku LT is around the size of a pack of cards and delivers Smart TV to conventional sets.
The distinction between external tuner or
demodulator
Demodulation is extracting the original information-bearing signal from a carrier wave. A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated ...
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 disk
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magneti ...
,
network
Network, networking and networked may refer to:
Science and technology
* Network theory, the study of graphs as a representation of relations between discrete objects
* Network science, an academic field that studies complex networks
Mathematic ...
or
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply ( interfacing) between computers, peripherals and other computers. A broad ...
interfaces built-in.
Devices with the capabilities of
computer terminals, such as the
WebTV
MSN TV (formerly WebTV) was a web access product consisting of a thin client device that used a television for display (instead of using a computer monitor), and the online service that supported it. The device design and service was developed ...
thin client, also fall into the grey area that could invite the term "NTB".
Europe
In Europe, a set-top box does not necessarily contain a
tuner of its own. A box connected to a television (or VCR)
SCART
SCART (also known as or , especially in France, 21-pin EuroSCART in marketing by Sharp in Asia, Euroconector in Spain, EuroAV or EXT, or EIA Multiport in the United States, as an EIA interface) is a French-originated standard and associated 2 ...
connector is fed with the
baseband
In telecommunications and signal processing, baseband is the range of frequencies occupied by a signal that has not been modulated to higher frequencies. Baseband signals typically originate from transducers, converting some other variable into a ...
television signal from the set's tuner, and can have the television display the returned processed signal instead.
This SCART feature had been used for connection to analogue decoding equipment by
pay TV
Pay television, also known as subscription television, premium television or, when referring to an individual service, a premium channel, refers to subscription-based television services, usually provided by multichannel television providers, b ...
operators in Europe, and in the past was used for connection to teletext equipment before the decoders became built-in. The outgoing signal could be of the same nature as the incoming signal, or
RGB
The RGB color model is an additive color model in which the red, green and blue primary colors of light are added together in various ways to reproduce a broad array of colors. The name of the model comes from the initials of the three additi ...
component video
Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Compon ...
, or even an "
insert Insert may refer to:
*Insert (advertising)
*Insert (composites)
*Insert (effects processing)
*Insert (filmmaking)
*Insert key on a computer keyboard, used to switch between insert mode and overtype mode
*Insert (molecular biology)
*Insert (SQL)
*Fi ...
" over the original signal, due to the "fast switching" feature of SCART.
In case of analogue pay-TV, this approach avoided the need for a second
remote control. The use of
digital television 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
In Digital Video Broadcasting, the Common Interface (also called DVB-CI) is a technology which allows decryption of pay TV channels. Pay TV stations want to choose which encryption method to use. The Common Interface allows TV manufacturers to ...
and
ATSC's CableCARD
CableCARD is a special-use PC Card device that allows consumers in the United States to view and record digital cable television channels on digital video recorders, personal computers and television sets on equipment such as a set-top box not pr ...
therefore use a
PCMCIA-like card inserted as part of the digital signal path as their alternative to a tuner-equipped set-top box.
Energy use
In June 2011 a report from the American National Resources Defense Council brought attention to the energy efficiency of set-top boxes, and the
US Department of Energy
The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United States ...
announced plans to consider the adoption of energy efficiency standards for set-top boxes. In November 2011, the National Cable & Telecommunications Association announced a new energy efficiency initiative that commits the largest American cable operators to the purchase of set-top boxes that meet
Energy Star
Energy Star (trademarked ''ENERGY STAR'') is a program run by the U.S. Environmental Protection Agency (EPA) and U.S. Department of Energy (DOE) that promotes energy efficiency. The program provides information on the energy consumption of prod ...
standards and the development of
sleep modes that will use less energy when the set-top box is not being used to watch or record video.
See also
*
AllVid AllVid was a proposal to develop technology enabling smart broadband-connected video devices to access the content on the managed networks of cable operators, telcos, and satellite-TV operators. It was initially proposed in the U.S. Federal Communic ...
*
CableCARD
CableCARD is a special-use PC Card device that allows consumers in the United States to view and record digital cable television channels on digital video recorders, personal computers and television sets on equipment such as a set-top box not pr ...
*
Comparison of digital media players A digital media player is a home entertainment consumer electronics device that can connect to a home network to stream digital media (such as music, pictures, or video).
Standalone streaming players
''This list does not include discontinued or l ...
*
DTV receiver
*
Digital media player
A digital media player (also sometimes known as a streaming device or streaming box) is a type of consumer electronics device designed for the storage, playback, or viewing of digital media content. They are typically designed to be integra ...
*
Microconsole
*
Over-the-top media service
An over-the-top (OTT) media service is a media service offered directly to viewers via the Internet. OTT bypasses cable, broadcast, and satellite television platforms: the types of companies that traditionally act as controllers or distributors ...
References
External links
"What Is a Set Top Box or STB Working and Architecture?"at Headendinfo.com
{{DEFAULTSORT:Set-Top Box
Cable television technology
Consumer electronics
Satellite broadcasting
Television terminology