A digital television adapter (DTA), commonly known as a converter box or decoder box, is a television tuner that receives a digital television (DTV) transmission, and converts the digital signal into an analog signal that can be received and displayed on an analog television set. Some also have an HDMI output since some TVs with HDMI do not have a digital tuner. The input digital signal may be over-the-air terrestrial television signals received by a television antenna, or signals from a digital cable system. It normally does not refer to satellite TV, which has always required a set-top box either to operate the big satellite dish, or to be the integrated receiver/decoder (IRD) in the case of direct-broadcast satellites (DBS).
In North America and South Korea, these ATSC tuner boxes convert from ATSC to NTSC, while in most of Europe and other places such as Australia and most Asian countries, they convert from Digital Video Broadcasting (DVB) to PAL, and in Japan, the Philippines and almost all countries in Latin America, they convert from ISDB-T to either NTSC or PAL. Because the DTV transition did nothing to reduce the number of broadcast television system standards (and in fact further complicated them), and due to varying frequency allocations and bandplans, there are many other combinations specific to other countries.
On June 12, 2009, all full-power analog television transmissions ended in the United States. Viewers who watch broadcast television on older analog TV sets must use a digital converter box. Since many of the low-power TV stations continued to broadcast in analog for a while, consumers who watch low-power stations needed an adapter with an analog passthrough feature that allows the viewer to watch both digital and analog signals. Viewers who receive their television signals through cable or satellite were not affected by this change and did not need a digital television adapter (however, see the cable TV exception below). Additionally, viewers who have newer televisions with built-in digital ATSC tuners will not need an external digital television adapter.
The United States government had set up a program to offer consumers a $40 "coupon" which could be used toward the purchase of a coupon-eligible converter box; that program ended in July 2009.
At the Consumer Electronics Association's Entertainment Technology Policy Summit in January 2006, Federal Communications Commission (FCC) Commissioner Jonathan Adelstein said many Americans did not know about the February 17, 2006, deadline for ending analog TV. Furthermore, he said, too many people were still buying analog TV sets, meaning more demand for converter boxes. And even if people found out what they would have to do, converter boxes might not do the job adequately. Tribune Broadcasting chief technology officer Ira Goldstone said just buying a converter box did not necessarily mean getting the latest technology. Bob Seidel of CBS said companies (especially in countries other than the US) might use cheaper tuners, and people would need new television antennas for proper reception. Circuit City Chairman Alan McCollough opposed converter boxes, saying people should just buy digital TVs, and television networks should offer only widescreen-format television programming as an incentive to do that. [1]
Prototypes of the first converter boxes appeared at the NAB show in 2006. LG Electronics, which took over Zenith Electronics in 1999, showed its model connected to a Zenith TV from 1980, while Thomson Consumer Electronics used an RCA TV from 1987 for its demonstration. Both boxes shown used electronic program guides using Program and System Information Protocol (PSIP). The devices showed program details, V-chip ratings and signal strength. Thomson's model stored three days of TV listings, allowed parental controls, and could set a VCR. [2]
Cable TV systems are under no deadline to convert to digital TV. However, many Comcast (and some other cable TV) customers are finding all of their non-local and non-shopping networks eliminated on various dates, even though only a few are needed for additional digital cable channels. CECBs (Coupon-eligible converter boxes) will not work on these systems because cable ATSC uses 256QAM modulation instead of 8VSB, and so a separate but similar DTA with a QAM tuner is necessary. If the cable company takes away analog channels, at least two of these adapters must be provided for free by the cable company for at least three years so that customers can continue to watch the same channels with existing equipment.[ citation needed ] Cable companies were required to provide some analog service until December 2015. [3] After that, taking away analog channels allowed faster Internet and more HD channels. An adapter from the cable provider was needed even for digital TVs if the company scrambled its digital signals to prevent piracy. [4]
A digital transport adapter will allow viewing of basic channels, often as many as 99, but not premium channels. It will also not allow video on demand or pay-per-view. DTAs also allow analog sets to receive digital signals using RF output on channel 3 or 4, using coaxial cable. Other versions of the DTA (including with an HDMI output) are available. [5]
Pace plc developed the XiD-P digital transport adapter for Comcast, allowing 4K service and offering the potential to expand the DTA from one-way to two-way. This would involve adding IP capability. [6]
Most countries that have switched to digital TV use DVB-T broadcasting with MPEG-2 MP@ML or H.264 encoding. However, some have considered switching to DVB-T2 such as the UK, being the first to test DVB-T2. This results in a number of different combinations for external digital receivers with the MPEG-2s sold at about €15 to €35 and the MPEG-4 ones reaching €25 to €150. Currently, all set top boxes sold in the EU cannot exceed 0.5 W in standby mode.
Some countries have also introduced digital television and ended analog over-the-air transmissions. Most new TVs feature a digital tuner which allows reception of digital over-the-air TV without need of an external device such a converter box. If using a TV set without a digital tuner, an external converter box must be purchased and used. A converter box takes the digital signal from the antenna and outputs composite video (for SD TVs) or HDMI (for HD TVs). A RF/antenna output, if present on a converter box, is usually just a passthrough ("LOOP OUT" which does not provide the box's output signal, but only provides the raw antenna input signal to watch analog channels via a TV set's tuner if analog broadcasts have not ended yet or to connect another capable device to the same antenna feed) because even older TVs usually have at least composite input; this removes a need for an RF modulator in a converter box.
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 broadcast television, in which the television signal is transmitted over-the-air by radio waves and received by a television antenna ; or satellite television, in which the television signal is transmitted over-the-air by radio waves from a communications satellite and received by a satellite dish on the roof. FM radio programming, high-speed Internet, telephone services, and similar non-television services may also be provided through these cables. Analog television was standard in the 20th century, but since the 2000s, cable systems have been upgraded to digital cable operation.
Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same bandwidth as a single analog channel, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2000. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widely used standards:
A set-top box (STB), also known as a cable box, receiver, or simply box, and historically television decoder or a converter, is an information appliance device that generally contains a TV tuner input and displays output to a television set, turning the source signal into content in a form that can then be displayed on the television screen or other display device. It is designed to be placed alongside or "on top" of a television set.
8VSB is the modulation method used for broadcast in the ATSC digital television standard. ATSC and 8VSB modulation is used primarily in North America; in contrast, the DVB-T standard uses COFDM.
Digital Video Broadcasting - Cable (DVB-C) is the DVB European consortium standard for the broadcast transmission of digital television over cable. This system transmits an MPEG-2 or MPEG-4 family digital audio/digital video stream, using a QAM modulation with channel coding. The standard was first published by the ETSI in 1994, and subsequently became the most widely used transmission system for digital cable television in Europe, Asia and South America. It is deployed worldwide in systems ranging from the larger cable television networks (CATV) down to smaller satellite master antenna TV (SMATV) systems.
Integrated Services Digital Broadcasting is a Japanese broadcasting standard for digital television (DTV) and digital radio.
Advanced Television Systems Committee (ATSC) standards are an international set of standards for broadcast and digital television transmission over terrestrial, cable and satellite networks. It is largely a replacement for the analog NTSC standard and, like that standard, is used mostly in the United States, Mexico, Canada, South Korea and Trinidad & Tobago. Several former NTSC users, such as Japan, have not used ATSC during their digital television transition, because they adopted other systems such as ISDB developed by Japan, and DVB developed in Europe, for example.
A DVD recorder is an optical disc recorder that uses optical disc recording technologies to digitally record analog or digital signals onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in television studios or home theater systems.
Datacasting is the transmission of data over a wide area using radio waves. It typically refers to supplemental information sent by television stations alongside digital terrestrial television (DTT) signals. However, datacasting can also be applied to digital data signals carried on analog TV or radio broadcasts.
QAM is a digital television standard using quadrature amplitude modulation. It is the format by which digital cable channels are encoded and transmitted via cable television providers. QAM is used in a variety of communications systems such as Dial-up modems and WiFi. In cable systems, a QAM tuner is linked to the cable in a manner that is equivalent to an ATSC tuner which is required to receive over-the-air (OTA) digital channels broadcast by local television stations when attached to an antenna. Most new HDTV digital televisions support both of these standards. QAM uses the same 6 MHz bandwidth as ATSC, using a standard known as ITU-T Recommendation J.83 Annex B ("J.83b").
An ATSCtuner, often called an ATSC receiver or HDTV tuner, is a type of television tuner that allows reception of digital television (DTV) television channels that use ATSC standards, as transmitted by television stations in North America, parts of Central America, and South Korea. Such tuners are usually integrated into a television set, VCR, digital video recorder (DVR), or set-top box which provides audio/video output connectors of various types.
Cable-ready is a designation which indicates that a TV set or other television-receiving device is capable of receiving cable TV without a set-top 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 an affordable way to continue receiving free digital terrestrial television services after the nation's television service transitioned to digital transmission and analog transmissions ceased. The specification was developed by the National Telecommunications and Information Administration (NTIA), with input from the broadcast and consumer electronics industries as well as public interest groups.
A free-to-air or FTA Receiver is a satellite television receiver designed to receive unencrypted broadcasts. Modern decoders are typically compliant with the MPEG-4/DVB-S2 standard and formerly the MPEG-2/DVB-S standard, while older FTA receivers relied on analog satellite transmissions which have declined rapidly in recent years.
Digital television in the United States is available via digital terrestrial television (DTT), digital cable, satellite television, and IPTV providers.
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 channel 3 or 4, or to a different output for digital televisions such as HDMI.
When a descrambler is added to the Cable Converter Box in the same chassis, it is referred to as a Converter/Descrambler or sometimes a Combination Unit, and is a type of Set-top box, it allows : local broadcast channels, basic cable channels, authorized premium channels, "Pay-Per-View" (PPV), and “Video On Demand” (VOD) services to be viewed. A Combination Converter/Descrambler is generally called a Set-top box or STB it is a single (one-piece) system installed in a single cabinet and represents a single component that is capable of descrambling premium services, like HBO or Showtime, pay-per-view cable channels., Video on Demand, Games or other specialty pay services, and transposes the cable signal for RF output on channel 3 or 4. This unit contains a converter and a descrambler, enclosed in a common box and outputs the signal directly to a TV, VCR, DVR, PC, DVD or video projector.
Analog passthrough is a feature found on some digital-to-analog television converter boxes. Boxes without the analog passthrough feature only allow older, analog-only TVs to view digital TV. Those with analog pass-through allow both digital and analog television to be viewed on older TVs.
The digital transition in the United States was the switchover from analog to exclusively digital broadcasting of terrestrial television programming. According to David Rehr, then president and CEO of the National Association of Broadcasters, this transition represented "the most significant advancement of television technology since color TV was introduced." For full-power TV stations, the transition went into effect on June 12, 2009, with stations ending regular programming on their analog signals no later than 11:59 p.m. local time that day.
A Digital transport/terminal adapter is a device used by cable companies who are switching to all-digital cable systems. They typically have an RF input for receiving service, and a modulated output on Channel 3 or 4 that allows a TV to be set to channel 3 or 4 and have the tuner change channels. They are also deployed by cable companies who are encrypting digital signals to cut down on cable theft.