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Advanced Television Systems Committee (ATSC) standards are an American set of standards for
digital television 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 advanc ...
transmission over terrestrial, cable and satellite networks. It is largely a replacement for the analog
NTSC 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 supplement ...
standard and, like that standard, is used mostly in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
,
Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...
,
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...
, and
South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...
. 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. The ATSC standards were developed in the early 1990s by the Grand Alliance, a consortium of electronics and telecommunications companies that assembled to develop a specification for what is now known as
HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the ...
. The standard is now administered by the Advanced Television Systems Committee. It includes a number of
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclo ...
ed elements, and licensing is required for devices that use these parts of the standard. Key among these is the 8VSB modulation system used for over-the-air broadcasts. ATSC technology was primarily developed with patent contributions from LG Electronics, which holds most of the patents for the ATSC standard. ATSC includes two primary high definition video formats, 1080i and
720p 720p (1280×720 px; also called HD ready, standard HD or just HD) is a progressive HDTV signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9, normally known as widescreen HDTV (1.78:1). All major HDTV broadcas ...
. It also includes standard-definition formats, although initially only HDTV services were launched in the digital format. ATSC can carry multiple channels of information on a single stream, and it is common for there to be a single high-definition signal and several standard-definition signals carried on a single 6 MHz (former NTSC) channel allocation.


Background

The high-definition television standards defined by the ATSC produce
widescreen Widescreen images are displayed within a set of aspect ratios (relationship of image width to height) used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than t ...
16:9 images up to 1920×1080
pixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the s ...
s in sizemore than six times the
display resolution The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution i ...
of the earlier standard. However, many different image sizes are also supported. The reduced bandwidth requirements of lower-resolution images allow up to six standard-definition "subchannels" to be broadcast on a single 6  MHz
TV channel A television channel is a terrestrial frequency or virtual number over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the terrestrial or cable band of 54 to 60 MHz, wit ...
. ATSC standards are marked A/''x'' (''x'' is the standard number) and can be downloaded for free from the ATSC's website at ATSC.org. ATSC Standard A/53, which implemented the system developed by the Grand Alliance, was published in 1995; the standard was adopted by the
Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisd ...
in the United States in 1996. It was revised in 2009. ATSC Standard A/72 was approved in 2008 and introduces H.264/AVC video coding to the ATSC system. ATSC supports 5.1-channel
surround sound Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener (surround channels). Its first application was in movie theaters. Prior to sur ...
using
Dolby Digital Dolby Digital, originally synonymous with Dolby AC-3, is the name for what has now become a family of audio compression (data), audio compression technologies developed by Dolby Laboratories. Formerly named Dolby Stereo Digital until 1995 in film, ...
's AC-3 format. Numerous auxiliary datacasting services can also be provided. Many aspects of ATSC are
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclo ...
ed, including elements of the
MPEG The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by ISO and IEC that sets standards for media coding, including compression coding of audio, video, graphics, and genomic data; and transmission and fi ...
video coding, the AC-3 audio coding, and the 8VSB modulation. The cost of patent licensing, estimated at up to per digital TV receiver, had prompted complaints by manufacturers. As with other systems, ATSC depends on numerous interwoven standards, e.g., the EIA-708 standard for digital
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 por ...
, leading to variations in implementation.


Digital switchover

ATSC replaced much of the
analog Analog or analogue may refer to: Computing and electronics * Analog signal, in which information is encoded in a continuous variable ** Analog device, an apparatus that operates on analog signals *** Analog electronics, circuits which use analo ...
NTSC 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 supplement ...
television system in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
on June 12, 2009, on August 31, 2011 in
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...
, on December 31, 2012 in
South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...
, and on December 31, 2015 in
Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...
. Broadcasters who used ATSC and wanted to retain an analog signal were temporarily forced to broadcast on two separate channels, as the ATSC system requires the use of an entire separate channel. Channel numbers in ATSC do not correspond to RF frequency ranges, as they did with
analog television Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog s ...
. Instead,
virtual channel In most telecommunications organizations, a virtual channel is a method of remapping the ''program number'' as used in H.222 Program Association Tables and Program Mapping Tables to a channel number that can be entered via digits on a receiver' ...
s, sent as part of the metadata along with the program(s), allow channel numbers to be remapped from their physical RF channel to any other number 1 to 99, so that ATSC stations can either be associated with the related NTSC channel numbers, or all stations on a network can use the same number. There is also a standard for
distributed transmission system In North American digital terrestrial television broadcasting, a distributed transmission system (DTS or DTx) is a form of single-frequency network in which a single broadcast signal is fed via microwave, landline, or communications satellite to ...
s (DTx), a form of single-frequency network which allows for the synchronised operation of multiple on-channel booster stations.


Audio

Dolby Digital Dolby Digital, originally synonymous with Dolby AC-3, is the name for what has now become a family of audio compression (data), audio compression technologies developed by Dolby Laboratories. Formerly named Dolby Stereo Digital until 1995 in film, ...
AC-3 is used as the
audio codec An audio codec is a device or computer program capable of encoding or decoding a digital data stream (a codec) that encodes or decodes audio. In software, an audio codec is a computer program implementing an algorithm that compresses and decompres ...
, though it was standardized as A/52 by the ATSC. It allows the transport of up to five channels of sound with a sixth channel for
low-frequency effects The low-frequency effects (LFE) channel is a band-limited audio track that is used for reproducing deep and intense low-frequency sounds in the 3–120 Hz frequency range. This track is normally sent to a subwoofer—a loudspeaker d ...
(the so-called "5.1" configuration). In contrast, Japanese ISDB
HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the ...
broadcasts use MPEG's
Advanced Audio Coding Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves higher sound quality than MP3 encoders at the same bit rate. AAC has been sta ...
(AAC) as the audio codec, which also allows 5.1 audio output. DVB (see
below Below may refer to: *Earth * Ground (disambiguation) * Soil * Floor * Bottom (disambiguation) * Less than *Temperatures below freezing * Hell or underworld People with the surname * Ernst von Below (1863–1955), German World War I general * Fr ...
) allows both.
MPEG-2 MPEG-2 (a.k.a. H.222/H.262 as was defined by the ITU) is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods, w ...
audio was a contender for the ATSC standard during the DTV " Grand Alliance" shootout, but lost out to Dolby AC-3. The Grand Alliance issued a statement finding the MPEG-2 system to be "essentially equivalent" to Dolby, but only after the Dolby selection had been made. Later, a story emerged that MIT had entered into an agreement with Dolby whereupon the university would be awarded a large sum of money if the MPEG-2 system was rejected. Dolby also offered an incentive for Zenith to switch their vote (which they did); however, it is unknown whether they accepted the offer.


Video

The ATSC system supports a number of different display resolutions, aspect ratios, and
frame rate Frame rate (expressed in or FPS) is the frequency (rate) at which consecutive images ( frames) are captured or displayed. The term applies equally to film and video cameras, computer graphics, and motion capture systems. Frame rate may also ...
s. The formats are listed here by resolution, form of scanning (
progressive Progressive may refer to: Politics * Progressivism, a political philosophy in support of social reform ** Progressivism in the United States, the political philosophy in the American context * Progressive realism, an American foreign policy par ...
or interlaced), and number of frames (or fields) per second (see also the TV resolution overview at the end of this article). For transport, ATSC uses the
MPEG The Moving Picture Experts Group (MPEG) is an alliance of working groups established jointly by ISO and IEC that sets standards for media coding, including compression coding of audio, video, graphics, and genomic data; and transmission and fi ...
systems specification, known as an
MPEG transport stream MPEG transport stream (MPEG-TS, MTS) or simply transport stream (TS) is a standard digital container format for transmission and storage of audio, video, and Program and System Information Protocol (PSIP) data. It is used in broadcast syste ...
, to encapsulate data, subject to certain constraints. ATSC uses 188-byte MPEG transport stream packets to carry data. Before decoding of audio and video takes place, the receiver must demodulate and apply error correction to the signal. Then, the transport stream may be demultiplexed into its constituent streams.


MPEG-2

There are four basic display sizes for ATSC, generally known by referring to the number of lines of the picture height. NTSC and PAL image sizes are smallest, with a width of 720 (or 704) and a height of 480 or 576 lines. The third size is HDTV images that have 720 scan lines in height and are 1280 pixels wide. The largest size has 1080 lines high and 1920 pixels wide. 1080-line video is actually encoded with 1920×1088 pixel frames, but the last eight lines are discarded prior to display. This is due to a restriction of the MPEG-2 video format, which requires the height of the picture in luma samples (i.e. pixels) to be divisible by 16. The lower resolutions can operate either in progressive scan or interlaced mode, but not the largest picture sizes. The 1080-line system does not support progressive images at the highest frame rates of 50, 59.94 or 60 frames per second, because such technology was seen as too advanced at the time. The standard also requires 720-line video be progressive scan, since that provides better picture quality than interlaced scan at a given frame rate, and there was no legacy use of interlaced scan for that format. The result is that the combination of maximum frame rate and picture size results in approximately the same number of samples per second for both the 1080-line interlaced format and the 720-line format, as 1920*1080*30 is roughly equal to 1280*720*60. A similar equality relationship applies for 576 lines at 25 frame per second versus 480 lines at 30 frames per second. A terrestrial (over-the-air) transmission carries 19.39 megabits of data per second (a fluctuating bandwidth of about 18.3 
Mbit/s In telecommunications, data-transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mul ...
left after overhead such as error correction, program guide, closed captioning, etc.), compared to a maximum possible MPEG-2 bitrate of 10.08 Mbit/s (7 Mbit/s typical) allowed in the DVD standard and 48 Mbit/s (36 Mbit/s typical) allowed in the Blu-ray disc standard. Although the ATSC A/53 standard limits MPEG-2 transmission to the formats listed below (with integer frame rates paired with 1000/1001-rate versions), the U.S. Federal Communications Commission declined to mandate that television stations obey this part of the ATSC's standard. In theory, television stations in the U.S. are free to choose any resolution, aspect ratio, and frame/field rate, within the limits of Main Profile @ High Level. Many stations do go outside the bounds of the ATSC specification by using other resolutions – for example, 352 x 480 or 720 x 480. " EDTV" displays can reproduce progressive scan content and frequently have a 16:9 wide screen format. Such resolutions are 704×480 or 720×480 in NTSC and 720×576 in PAL, allowing 60 progressive frames per second in NTSC or 50 in PAL. ATSC also supports PAL frame rates and resolutions which are defined in ATSC A/63 standard. The ATSC A/53 specification imposes certain constraints on MPEG-2 video stream: * The maximum bit rate value in the sequence header of the MPEG-2 video stream is 19.4 Mbit/s for broadcast television, and 38.8 Mbit/s for the "high data rate" mode (e.g., cable television). The actual MPEG-2 video bit rate will be lower, since the MPEG-2 video stream must fit inside a transport stream. * The amount of MPEG-2 stream buffer required at the decoder (the vbv_buffer_size_value) must be less than or equal to 999,424 bytes. * In most cases, the transmitter can't start sending a coded image until within a half-second of when it's to be decoded (vbv_delay less than or equal to 45000 90-kHz clock increments). * The stream must include colorimetry information (gamma curve, the precise RGB colors used, and the relationship between RGB and the coded YCbCr). * The video must be 4:2:0 (chrominance resolution must be 1/2 of luma horizontal resolution and 1/2 of luma vertical resolution). The ATSC specification and MPEG-2 allow the use of progressive frames coded within an interlaced video sequence. For example, NBC stations transmit a 1080i60 video sequence, meaning the formal output of the MPEG-2 decoding process is sixty 540-line fields per second. However, for prime-time television shows, those 60 fields can be coded using 24 progressive frames as a base – actually, an 1080p24 video stream (a sequence of 24 progressive frames per second) is transmitted, and MPEG-2 metadata instructs the decoder to interlace these fields and perform 3:2 pulldown before display, as in soft telecine. The ATSC specification also allows 1080p30 and 1080p24 MPEG-2 sequences, however they are not used in practice, because broadcasters want to be able to switch between 60 Hz interlaced (news), 30 Hz progressive or PsF (soap operas), and 24 Hz progressive (prime-time) content without ending the 1080i60 MPEG-2 sequence. The 1080-line formats are encoded with 1920 × 1088 pixel luma matrices and 960 × 540 chroma matrices, but the last 8 lines are discarded by the MPEG-2 decoding and display process.


H.264/MPEG-4 AVC

In July 2008, ATSC was updated to support the ITU-T H.264 video codec. The new standard is split in two parts: * A/72 part 1: Video System Characteristics of AVC in the ATSC Digital Television System * A/72 part 2 : AVC Video Transport Subsystem Characteristics The new standards support 1080p at 50, 59.94 and 60 frames per second; such frame rates require H.264/AVC '' High Profile Level 4.2'', while standard HDTV frame rates only require Levels 3.2 and 4, and SDTV frame rates require Levels 3 and 3.1.


Transport stream (TS)

The file extension ".TS" stands for "transport stream", which is a media container format. It may contain a number of streams of audio or video content multiplexed within the transport stream. Transport streams are designed with synchronization and recovery in mind for potentially lossy distribution (such as over-the-air ATSC broadcast) in order to continue a media stream with minimal interruption in the face of data loss in transmission. When an over-the-air ATSC signal is captured to a file via hardware/software the resulting file is often in a .TS file format.


Modulation and transmission

ATSC signals are designed to use the same 6 MHz bandwidth as analog
NTSC 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 supplement ...
television channels (the interference requirements of A/53 DTV standards with adjacent NTSC or other DTV channels are very strict). Once the digital video and audio signals have been compressed and multiplexed, the transport stream can be modulated in different ways depending on the method of transmission. * Terrestrial (local) broadcasters use 8VSB modulation that can transfer at a maximum rate of 19.39 Mbit/s, sufficient to carry several video and audio programs and metadata. *
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 bro ...
stations can generally operate at a higher
signal-to-noise ratio Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in d ...
and can use either the 16VSB as defined in ATSC or the 256-QAM defined in SCTE, to achieve a throughput of 38.78 Mbit/s, using the same 6 MHz channel. The proposals for modulation schemes for digital television were developed when cable operators carried standard-resolution video as uncompressed analog signals. In recent years, cable operators have become accustomed to compressing standard-resolution video for
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 previo ...
systems, making it harder to find duplicate 6 MHz channels for local broadcasters on uncompressed "basic" cable. Currently, the
Federal Communications Commission The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisd ...
requires cable operators in the United States to carry the analog or digital transmission of a terrestrial broadcaster (but not both), when so requested by the broadcaster (the " must-carry rule"). The
Canadian Radio-television and Telecommunications Commission The Canadian Radio-television and Telecommunications Commission (CRTC; french: Conseil de la radiodiffusion et des télécommunications canadiennes, links=) is a public organization in Canada with mandate as a regulatory agency for broadcasti ...
in Canada does not have similar rules in force with respect to carrying ATSC signals. However, cable operators have still been slow to add ATSC channels to their lineups for legal, regulatory, and plant & equipment related reasons. One key technical and regulatory issue is the modulation scheme used on the cable: cable operators in the U.S. (and to a lesser extent Canada) can determine their own method of modulation for their plants. Multiple standards bodies exist in the industry: the SCTE defined 256-QAM as a modulation scheme for cable in a cable industry standard
ANSI/SCTE 07 2006: Digital Transmission Standard For Cable Television
Consequently, most U.S. and Canadian cable operators seeking additional capacity on the cable system have moved to 256-QAM from the 64-QAM modulation used in their plant, in preference to the 16VSB standard originally proposed by ATSC. Over time 256-QAM is expected to be included in the ATSC standard. There is also a standard for transmitting ATSC via satellite; however, this is only used by TV networks. Very few teleports outside the U.S. support the ATSC satellite transmission standard, but teleport support for the standard is improving. The ATSC satellite transmission system is not used for
direct-broadcast satellite 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 comm ...
systems; in the U.S. and Canada these have long used either
DVB-S Digital Video Broadcasting – Satellite (DVB-S) is the original DVB standard for Satellite Television and dates from 1995, in its first release, while development lasted from 1993 to 1997. The first commercial applications was by Star TV in Asia ...
(in standard or modified form) or a proprietary system such as DSS or DigiCipher 2.


Other systems

ATSC coexists with the
DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in Singapore in Feb ...
standard, and with ISDB-T. A similar standard called ADTB-T was developed for use as part of China's new DMB-T/H dual standard. While China has officially chosen a dual standard, there is no requirement that a receiver work with both standards and there is no support for the ADTB modulation from broadcasters or equipment and receiver manufacturers. For compatibility with material from various regions and sources, ATSC supports the 480i video format used in the NTSC analog system (480 lines, approximately 60 fields or 30 frames per second), 576i formats used in most PAL regions (576 lines, 50 fields or 25 frames per second), and 24 frames-per-second formats used in film. While the ATSC system has been criticized as being complicated and expensive to implement and use, both broadcasting and receiving equipment are now comparable in cost with that of DVB. The ATSC signal is more susceptible to changes in
radio propagation Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected ...
conditions than
DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in Singapore in Feb ...
and ISDB-T. It also lacks true hierarchical modulation, which would allow the SDTV part of an
HDTV High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the ...
signal (or the audio portion of a television program) to be received uninterrupted even in fringe areas where signal strength is low. For this reason, an additional modulation mode, enhanced-VSB ( E-VSB) has been introduced, allowing for a similar benefit. In spite of ATSC's fixed transmission mode, it is still a robust signal under various conditions. 8VSB was chosen over COFDM in part because many areas are
rural In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry typically are descri ...
and have a much lower
population density Population density (in agriculture: Stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical ...
, thereby requiring larger
transmitter In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to ...
s and resulting in large fringe areas. In these areas, 8VSB was shown to perform better than other systems. COFDM is used in both DVB-T and ISDB-T, and for 1seg, as well as DVB-H and
HD Radio HD Radio (HDR) is a trademark for an in-band on-channel (IBOC) digital radio broadcast technology. It generally simulcasts an existing analog radio station in digital format with less noise and with additional text information. HD Radio is used ...
in the United States. In metropolitan areas, where population density is highest, COFDM is said to be better at handling multipath propagation. While ATSC is also incapable of true single-frequency network (SFN) operation, the
distributed transmission In North American digital terrestrial television broadcasting, a distributed transmission system (DTS or DTx) is a form of single-frequency network in which a single broadcast signal is fed via microwave, landline, or communications satellite to ...
mode, using multiple synchronized on-channel transmitters, has been shown to improve reception under similar conditions. Thus, it may not require more
spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of color ...
allocation than
DVB-T DVB-T, short for Digital Video Broadcasting – Terrestrial, is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in Singapore in Feb ...
using SFNs. A comparison study found that ISDB-T and DVB-T performed similarly, and that both were outperformed by DVB-T2.


Mobile TV

Mobile reception of digital stations using ATSC has, until 2008, been difficult to impossible, especially when moving at vehicular speeds. To overcome this, there are several proposed systems that report improved mobile reception:
Samsung The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
/ Rhode & Schwarz's A-VSB, Harris/ LG's MPH, and a recent proposal from Thomson/Micronas; all of these systems have been submitted as candidates for a new ATSC standard, ATSC-M/H. After one year of standardization, the solution merged between Samsung's AVSB and LGE's MPH technology has been adopted and would have been deployed in 2009. This is in addition to other standards like the now-defunct MediaFLO, and worldwide open standards such as DVB-H and T-DMB. Like DVB-H and ISDB 1seg, the proposed ATSC mobile standards are backward-compatible with existing tuners, despite being added to the standard well after the original standard was in wide use. Mobile reception of some stations will still be more difficult, because 18 UHF channels in the U.S. have been removed from TV service, forcing some broadcasters to stay on VHF. This band requires larger antennas for reception, and is more prone to
electromagnetic interference Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrost ...
from
engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...
s and rapidly changing
multipath In radio communication, multipath is the propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. Causes of multipath include atmospheric ducting, ionospheric reflection and refraction, and ref ...
conditions.


Future


ATSC 2.0

ATSC 2.0 was a planned major new revision of the standard which would have been backward compatible with ATSC 1.0. The standard was to have allowed interactive and hybrid television technologies by connecting the TV with the Internet services and allowing interactive elements into the broadcast stream. Other features were to have included advanced video compression, audience measurement, targeted advertising, enhanced programming guides,
video on demand Video on demand (VOD) is a media distribution system that allows users to access videos without a traditional video playback device and the constraints of a typical static broadcasting schedule. In the 20th century, broadcasting in the form of ...
services, and the ability to store information on new receivers, including Non-realtime (NRT) content.2013_electronic.indd
. (PDF) . Retrieved on May 11, 2014.
However, ATSC 2.0 was never actually launched, as it was essentially outdated before it could be launched. All of the changes that were a part of the ATSC 2.0 revision were adopted into ATSC 3.0.


ATSC 3.0

ATSC 3.0 will provide even more services to the viewer and increased bandwidth efficiency and compression performance, which requires breaking backwards compatibility with the current version. On November 17, 2017, the FCC voted 3–2 in favor of authorizing voluntary deployments of ATSC 3.0, and issued a Report and Order to that effect. ATSC 3.0 broadcasts and receivers are expected to emerge within the next decade. LG Electronics tested the standard with 4K on February 23, 2016. With the test considered a success,
South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...
announced that ATSC 3.0 broadcasts would start in February 2017. On March 28, 2016, the Bootstrap component of ATSC 3.0 (System Discovery and Signalling) was upgraded from candidate standard to finalized standard. On June 29, 2016, NBC affiliate
WRAL-TV WRAL-TV (channel 5) is a television station licensed to Raleigh, North Carolina, United States, serving as the NBC affiliate for the Research Triangle area. It is the flagship station of the locally based Capitol Broadcasting Company, which h ...
in
Raleigh, North Carolina Raleigh (; ) is the capital city of the state of North Carolina and the seat of Wake County in the United States. It is the second-most populous city in North Carolina, after Charlotte. Raleigh is the tenth-most populous city in the South ...
, a station known for its pioneering roles in testing the original DTV standards, launched an experimental ATSC 3.0 channel carrying the station's programming in 1080p, as well as a 4K demo loop. ;Structure/ATSC 3.0 System Layers # Bootstrap: System Discovery and Signalling # Physical Layer: Transmission ( OFDM) # Protocols: IP, MMT # Presentation: Audio and Video standards (to be determined), Ultra HD with
High Definition High definition or HD may refer to: Visual technologies *HD DVD, discontinued optical disc format *HD Photo, former name for the JPEG XR image file format *HDV, format for recording high-definition video onto magnetic tape * HiDef, 24 frames-pe ...
and standard-definition multicast, Immersive Audio # Applications: Screen is a web page


ATSC 3.0 advantages

# Better image quality. ATSC 3.0 allows
4K UHD 4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 38402160 (4K UHD) is the dominan ...
transmission, including
high-dynamic-range television High-dynamic-range television (HDR or HDR-TV) is a technology that improves the quality of display signals. It is contrasted with the retroactively-named standard dynamic range (SDR). HDR changes the way the luminance and colors of videos and i ...
(HDR-TV), wide color gamut (WCG), and high frame rate (HFR). # Reception upgrades. ATSC 3.0 allows the same aerial to receive more channels with better quality. # Portable devices such as mobile phones, tablets, and car infotainment systems can receive TV signals. # Emergency alerts. Emergency signals can be geographically oriented and inform about evacuation plans to areas where they are required. # Audience measure. Telecommunication companies can easily take audience data gatherings. # Targeted advertising. # Content variety and diversification.


Countries and territories using ATSC


North America

* 2018 * On December 14, 2011, the Bahamas' national public broadcaster ZNS-TV announced that it would adopt ATSC, in line with the United States and its territories. * * adopted ATSC, with full-power analog stations in specified "mandatory markets" (which included provincial capitals, and cities with a population of 300,000 or higher) shutting down on August 31, 2011. The CBC only converted its originating stations to digital; it was given permission to operate its repeaters in mandatory markets (such as
CBKST CBKST, VHF analogue channel 11, was a CBC Television owned-and-operated station licensed to Saskatoon, Saskatchewan, Canada, which operated from 1971 to 2012. The station was owned by the Canadian Broadcasting Corporation. CBKST's master contro ...
in
Saskatoon Saskatoon () is the largest city in the Canadian province of Saskatchewan. It straddles a bend in the South Saskatchewan River in the central region of the province. It is located along the Trans-Canada Yellowhead Highway, and has served as ...
) for an additional year, but later announced that it would shut down all of its analog repeaters on July 31, 2012—citing budget issues and their distribution network as being obsolete. * * The Dominican Republic announced its adoption on August 10, 2010, completing the transition on September 24, 2015, but most companies were not able to meet the deadline and the government had to move it forward to the year 2021. * * * Will convert to ATSC 3.0 instead of 1.0. The conversion will begin in 2022 and is expected to be completed by 2023. * began converting to ATSC in 2013; a full transition was scheduled for December 31, 2015, but due to technical and economic issues for some transmitters, the full transition was extended to December 31, 2016. * * Full-power television stations in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
ended analog television service on June 12, 2009. Analog low-power stations and translators were all wound down by July 13, 2021.


South America

* * Suriname has undergone transitioning from analogue NTSC broadcasts to digital ATSC broadcasts. Channel
ATV ATV may refer to: Broadcasting * Amateur television *Analog television Television stations and companies * Ràdio i Televisió d'Andorra * ATV (Armenia) * ATV (Aruba), NBC affiliate * ATV (Australian TV station), Melbourne * ATV (Austria) * AT ...
started with ATSC broadcasts in the
Paramaribo Paramaribo (; ; nicknamed Par'bo) is the capital and largest city of Suriname, located on the banks of the Suriname River in the Paramaribo District. Paramaribo has a population of roughly 241,000 people (2012 census), almost half of Suriname's ...
area in June 2014, which was followed by ATSC broadcasts from stations in Brokopondo, Wageningen and Albina. The stations in Brokopondo, Wageningen and Albina broadcast both the channels of
ATV ATV may refer to: Broadcasting * Amateur television *Analog television Television stations and companies * Ràdio i Televisió d'Andorra * ATV (Armenia) * ATV (Aruba), NBC affiliate * ATV (Australian TV station), Melbourne * ATV (Austria) * AT ...
(i.e., ATV and TV2) and STVS. In 2016 all channels in Suriname had already made the switch to ATSC.


Asia/Pacific

* South Korea completed its transition to ATSC on December 31, 2012, although it still operates some analog signals along its northern border for reception in
North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and ...
. * territories in the Pacific, including
American Samoa American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is centered on . It is east of the Internation ...
,
Guam Guam (; ch, Guåhan ) is an organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. It is the westernmost point and territory of the United States (reckoned from the geographic ce ...
, and the
Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI; ch, Sankattan Siha Na Islas Mariånas; cal, Commonwealth Téél Falúw kka Efáng llól Marianas), is an unincorporated territory and commonwe ...
have adopted ATSC, as with the mainland.


Patent holders

The following organizations hold
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclo ...
s for the development of ATSC technology, as listed in the patent pool administered by MPEG LA. Actual in July 2021 there are about 75% expired.


See also

* Advanced Television Systems Committee * ATSC tuner * List of ATSC standards * Broadcast flag * Broadcast-safe *
Digital terrestrial television Digital terrestrial television (DTTV or DTT, or DTTB with "broadcasting") is a technology for terrestrial television in which land-based (terrestrial) television stations broadcast television content by radio waves to televisions in consume ...
(DTT) *
Digital Video Broadcasting Digital Video Broadcasting (DVB) is a set of international open standards for digital television. DVB standards are maintained by the DVB Project, an international industry consortium, and are published by a Joint Technical Committee (JTC) ...
(DVB) *
CTA-708 Consumer Technology Association, CTA-708 (formerly EIA-708 and CEA-708) is the standard for closed captioning for ATSC Standards, ATSC digital television (DTV) streams in the United States and Canada. It was developed by the Consumer Electronics ...
* ISDB – Integrated Services Digital Broadcasting * OpenCable *
Standard-definition television Standard-definition television (SDTV, SD, often shortened to standard definition) is a television system which uses a resolution that is not considered to be either high or enhanced definition. "Standard" refers to it being the prevailing sp ...
* T-DMB – South Korean terrestrial mobile digital broadcasting system * Digital Terrestrial Multimedia Broadcast (DMB-T/H) Chinese terrestrial digital broadcasting system * Ultra-high-definition television (UHDTV) – Digital video formats with resolutions of 3840×2160 and 7680×4320


References


Further reading

*
Joel Brinkley Joel Graham Brinkley (July 22, 1952 – March 11, 2014) was an American syndicated columnist. He taught in the journalism program at Stanford University from 2006 until 2013, after a 23-year career with ''The New York Times''. He won the Pulitze ...
(1998), ''Defining Vision: The Battle for the Future of Television'', New York: Harcourt Brace.


External links


ATSC websiteATSC standards download pageATSC-MH Platform for testing and deploying Mobile TV in the USATSC Mobile DTV (ATSC-MH) Analysis, Monitoring, MeasurementATSC Mobile DTV (ATSC-MH) Mobile DTV ViewerATSC 3.0 Overview
{{DEFAULTSORT:Atsc MPEG Digital television High-definition television Television transmission standards