View source for ATSC standards

{{Short description|Standards for digital television in the US}}
{{Redirect|ATSC}}
{{Distinguish|NTSC}}
{{Use mdy dates|date=January 2016}}
[[File:Atsc-logo-500px.png|thumb|ATSC standards logo]]
{{Table Digital video broadcast standards}}

'''Advanced Television Systems Committee''' ('''ATSC''') '''standards''' are an international set of standards for broadcast and [[digital television]] transmission over [[Digital terrestrial television|terrestrial]], [[Digital cable|cable]] and [[Satellite television|satellite]] networks. It is largely a replacement for the analog [[NTSC]] standard. Like NTSC, ATSC is used mostly in the [[United States]], [[Mexico]], [[Canada]], [[South Korea]], and [[Trinidad and Tobago]]. Several former NTSC users like [[Japan]] have not used ATSC during their [[digital television transition]], because they adopted other systems like [[ISDB]] developed by Japan and [[DVB]] developed in Europe, for example.

The ATSC standards were developed in the early 1990s by the [[Grand Alliance (HDTV)|Grand Alliance]], a consortium of electronics and telecommunications companies that assembled to develop a specification for what is now known as [[HDTV]]. The standard is now administered by the [[Advanced Television Systems Committee]]. It includes a number of [[patent]]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 [[Terrestrial television|over-the-air]] broadcasts. ATSC 1.0 technology was primarily developed with patent contributions from [[LG Electronics]], which held most of the patents for the ATSC standard.<ref name="atsc-patents" />

ATSC includes two primary high definition video formats, [[1080i]] and [[720p]]. It also includes [[SDTV|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&nbsp;MHz (former NTSC) channel allocation.

== Background ==
{{Update section|reason=No official history|date=September 2024}}

The high-definition television standards defined by the ATSC produce [[widescreen]] [[16:9]] images up to 1920×1080 [[pixel]]s in size{{snd}}more than six times the [[display resolution]] of the earlier standard. However, many different image sizes are also supported. The reduced bandwidth requirements of lower-resolution images allow up to six [[SDTV|standard-definition]] "subchannels" to be broadcast on a single 6&nbsp;[[MegaHertz|MHz]] [[TV channel]].

ATSC standards are marked A/''x'' (''x'' is the standard number) and can be downloaded for free from the ATSC's website at [[#External links|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]] in the United States in 1996. It was revised in 2009. ATSC Standard A/72 was approved in 2008 and introduces [[H.264/MPEG-4 AVC|H.264]]/AVC video coding to the ATSC system.

ATSC supports 5.1-channel [[surround sound]] using [[Dolby Digital]]'s [[Dolby AC-3|AC-3]] format. Numerous auxiliary [[datacasting]] services can also be provided.

Many aspects of ATSC were [[patent]]ed, including elements of the [[MPEG]] video coding, the AC-3 audio coding, and the [[8VSB]] modulation.<ref>{{cite web|url=http://www.chinadaily.com.cn/bizchina/2006-12/27/content_768603.htm|title=TV makers to fight royalties|website=www.chinadaily.com.cn|access-date=March 16, 2018|url-status=live|archive-url=https://web.archive.org/web/20180316151853/http://www.chinadaily.com.cn/bizchina/2006-12/27/content_768603.htm|archive-date=March 16, 2018|df=mdy-all}}</ref> The cost of patent licensing, estimated at up to {{nowrap|$50}} per digital TV receiver,<ref>[http://www.nasdaq.com/aspxcontent/NewsStory.aspx?cpath=20090225\ACQDJON200902251515DOWJONESDJONLINE000741.htm&&mypage=newsheadlines&title=FCC%20Opens%20Inquiry%20Into%20Patent%20Costs%20For%20Digital%20TVs FCC Opens Inquiry Into Patent Costs For Digital TVs]{{dead link|date=May 2018 |bot=SheriffIsInTown |fix-attempted=yes }}, [[Dow Jones & Company|Dow Jones]], February 25, 2009</ref> had prompted complaints by manufacturers.<ref>[http://www.taipeitimes.com/News/biz/archives/2009/02/24/2003436924 Amtran affiliate accuses Funai of unfair competition] {{webarchive|url=https://web.archive.org/web/20090227084231/http://www.taipeitimes.com/News/biz/archives/2009/02/24/2003436924 |date=February 27, 2009 }}, Lisa Wang, [[Taipei Times]], February 24, 2009</ref>

As with other systems, ATSC depends on numerous interwoven standards, e.g., the [[EIA-708]] standard for digital [[closed captioning]], leading to variations in implementation.

== Digital switchover ==
{{See also|Digital television transition in the United States|Digital television in Canada|Television in Mexico}}
ATSC [[DTV transition in the United States|replaced]] much of the [[analog television|analog]] [[NTSC]] television system<ref>{{cite press release|url=http://www.businesswire.com/news/home/20071017005469/en|title=Best Buy Exits the Analog TV Business, Outlines Plans to Help With Digital Broadcast Transition|website=businesswire.com|access-date=March 16, 2018|url-status=live|archive-url=https://web.archive.org/web/20180316214333/https://www.businesswire.com/news/home/20071017005469/en|archive-date=March 16, 2018|df=mdy-all}}</ref> in the [[United States]]<ref>[http://www.dtvtransition.org/ A New Era in Television Broadcasting] {{webarchive|url=https://web.archive.org/web/20071123122408/http://www.dtvtransition.org/ |date=November 23, 2007 }} – DTVTransition.org</ref><ref>{{cite journal|url=http://features.csmonitor.com/innovation/2009/02/04/congress-delays-dtv-switch/|title=Congress delays DTV switch|date=February 4, 2009|access-date=March 16, 2018|journal=Christian Science Monitor|url-status=live|archive-url=https://web.archive.org/web/20090815051311/http://features.csmonitor.com/innovation/2009/02/04/congress-delays-dtv-switch/|archive-date=August 15, 2009|df=mdy-all}}</ref> on June 12, 2009, on August 31, 2011 in [[Canada]],<ref>{{Cite web |title=Erreur 404/404 Error &#124; CRTC |url=https://crtc.gc.ca/eng/NEWS/RELEASES/2007/r070517.htm |url-status=dead |archive-url=https://web.archive.org/web/20070519082346/http://www.crtc.gc.ca/eng/NEWS/RELEASES/2007/r070517.htm |archive-date=May 19, 2007 |website=crtc.gc.ca}}</ref> on December 31, 2012 in [[South Korea]], and on December 31, 2015 in [[Mexico]].<ref name="dgm 1">{{cite web|url=http://dof.gob.mx/nota_detalle.php?codigo=5157568&fecha=02/09/2010|title=DOF - Diario Oficial de la Federación|website=dof.gob.mx|access-date=March 16, 2018|url-status=live|archive-url=https://web.archive.org/web/20180121000019/http://dof.gob.mx/nota_detalle.php?codigo=5157568&fecha=02%2F09%2F2010|archive-date=January 21, 2018|df=mdy-all}}</ref>

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]].  Instead, [[virtual channel]]s, sent as part of the metadata along with the program(s), allow channel numbers to be remapped from their physical [[Radio frequency|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]]s (DTx), a form of [[single-frequency network]] which allows for the synchronised operation of multiple on-channel [[relay transmitter|booster stations]].

== Audio ==
[[Dolby Digital]] AC-3 is used as the [[audio codec]], 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 so-called "5.1" configuration). In contrast, Japanese [[ISDB]] [[HDTV]] broadcasts use MPEG's [[Advanced Audio Coding]] (AAC) as the audio codec, which also allows 5.1 audio output. [[Digital Video Broadcasting|DVB]] (see [[#Other systems|below]]) allows both.

[[MPEG-2]] audio was a contender for the ATSC standard during the [[Digital Television|DTV]] "[[Grand Alliance (HDTV)|Grand Alliance]]" shootout, but lost out to [[Dolby Digital|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.<ref name="mit">{{citation |url=http://tech.mit.edu/V122/PDF/N54.pdf |title=MIT Getting Millions For Digital TV Deal |author=Keith J. Winsteln |work=The Tech |publisher=[[Massachusetts Institute of Technology]] |date=November 8, 2002 |url-status=live |archive-url=https://web.archive.org/web/20090326004942/http://tech.mit.edu/V122/PDF/N54.pdf |archive-date=March 26, 2009 |df=mdy-all }}</ref>

== Video ==
The ATSC system supports a number of different display resolutions, [[Display aspect ratio|aspect ratio]]s, and [[frame rate]]s. The formats are listed here by resolution, form of scanning ([[progressive scan|progressive]] or [[Interlaced video|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]] systems specification, known as an [[MPEG transport stream]], 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 [[demodulation|demodulate]] and apply [[error correction]] to the signal. Then, the transport stream may be [[demultiplex]]ed 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 video|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 [[megabit]]s of data per second (a fluctuating bandwidth of about 18.3&nbsp;[[Mbit/s]] left after overhead such as error correction, program guide, closed captioning, etc.), compared to a maximum possible MPEG-2 bitrate of 10.08&nbsp;Mbit/s (7&nbsp;Mbit/s typical) allowed in the [[DVD]] standard and 48&nbsp;Mbit/s (36&nbsp;Mbit/s typical) allowed in the [[Blu-ray|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.

"[[Enhanced-definition television|EDTV]]" displays can reproduce progressive scan content and frequently have a 16:9 wide screen format. Such resolutions are 704×480 or 720×480{{citation needed|date=December 2013}}<!-- I've removed this false information twice in the past and keep seeing it re-inserted, usually in the form of an reversion without comment or explanation. 720×480 is NOT a resolution in the ATSC standards. Let's see you cite something that says otherwise.--> in NTSC and 720×576 in PAL, allowing 60 progressive frames per second in NTSC or 50 in PAL.

{|class="wikitable" style="text-align:center;"
|+ ATSC Standard A/53 Part 4:2009 (MPEG-2 Video System Characteristics)
|- style="background:#eee;"

!colspan="2"|Resolution
!rowspan="2"|Aspect ratio
!rowspan="2"|[[Pixel aspect ratio]]
!rowspan="2"|Scanning
!rowspan="2"|Frame rate ([[Hertz|Hz]])
|- style="background:#eee;"
!Vertical
!Horizontal
|-
|rowspan="2"|1080
|rowspan="2"|1920
|rowspan="2"|16:9
|rowspan="2"|1:1
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s)
|-
|720
|1280
|16:9
|1:1
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60
|-
|rowspan="4"|480
|rowspan="2"|704
|rowspan="2"|4:3 or 16:9
|rowspan="2"|10:11 or 40:33
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s)
|-
|rowspan="2"|640
|rowspan="2"|4:3
|rowspan="2"|1:1
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60
|-
|interlaced
|29.97 frames/s (59.94 fields/s) <br /> 30 frames/s (60 fields/s)
|}

ATSC also supports PAL frame rates and resolutions which are defined in ATSC A/63 standard.

{|class="wikitable" style="text-align:center;"
|+ ATSC Standard A/63:1997 (Standard for Coding 25/50&nbsp;Hz Video)
|- style="background:#eee;"
!colspan="2"|Resolution
!rowspan="2"|Aspect ratio
!rowspan="2"|[[Pixel aspect ratio]]
!rowspan="2"|Scanning
!rowspan="2"|Frame rate ([[Hertz|Hz]])
|- style="background:#eee;"
!Vertical
!Horizontal
|-
|rowspan="2"|1080
|rowspan="2"|1920
|rowspan="2"|16:9
|rowspan="2"|1:1
|interlaced
|25 (50 fields/s)
|-
|progressive
| 25
|-
|720
|1280
|16:9
|1:1
|progressive
|50
|-
|rowspan="8"|576
|rowspan="2"|720
|rowspan="2"|4:3 or 16:9
|rowspan="2"|[[SMPTE 259M]]
|progressive
|25 <br /> 50
|-
|interlaced
|25 (50 fields/s)
|-
|rowspan="2"|544
|rowspan="2"|4:3 or 16:9
|rowspan="2"|[[SMPTE 259M]]<br />three quarters
|progressive
|25
|-
|interlaced
|25 (50 fields/s)
|-
|rowspan="2"|480
|rowspan="2"|4:3 or 16:9
|rowspan="2"|[[SMPTE 259M]]<br />two thirds
|progressive
|25
|-
|interlaced
|25 (50 fields/s)
|-
|rowspan="2"|352
|rowspan="2"|4:3 or 16:9
|rowspan="2"|[[SMPTE 259M]]<br />half
|progressive
|25
|-
|interlaced
|25 (50 fields/s)
|-
|288
|352
|4:3 or 16:9
|[[Common Intermediate Format|CIF]]
|progressive
|25
|}

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&nbsp;Mbit/s for broadcast television, and 38.8&nbsp;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 [[Telecine#Soft and hard telecine|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&nbsp;Hz interlaced (news), 30&nbsp;Hz progressive or [[progressive segmented frame|PsF]] (soap operas), and 24&nbsp;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 ===
{{Disputed section|date=June 2017}}
In July 2008, ATSC was updated to support the [[H.264/MPEG-4 AVC|ITU-T H.264]] video codec. This standard is split in two parts:

* A/72 part 1: Video System Characteristics of AVC in the ATSC Digital Television System<ref>{{cite web|url=http://www.atsc.org/cms/standards/a72/A72-Part-1-2014.pdf |title=Archived copy |access-date=2014-04-03 |url-status=dead |archive-url=https://web.archive.org/web/20140407071216/http://www.atsc.org/cms/standards/a72/A72-Part-1-2014.pdf |archive-date=April 7, 2014 |df=mdy }}</ref>
* A/72 part 2 : AVC Video Transport Subsystem Characteristics<ref>{{cite web|url=http://www.atsc.org/cms/standards/a72/A72-Part-2-2014.pdf |title=Archived copy |access-date=2014-04-03 |url-status=dead |archive-url=https://web.archive.org/web/20140407071209/http://www.atsc.org/cms/standards/a72/A72-Part-2-2014.pdf |archive-date=April 7, 2014 |df=mdy }}</ref>

The standards support [[1080p]] at 50, 59.94 and 60 frames per second; such frame rates require H.264/AVC ''[[H.264/MPEG-4 AVC#Levels|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.{{Dubious|date=June 2017}}

{|class="wikitable" style="text-align:center;"
|+ ATSC Standard A/72 Part 1:2008 (Video System Characteristics of AVC)
|- style="background:#eee;"

!colspan="2"|Resolution
!rowspan="2"|Aspect ratio
!rowspan="2"|[[Pixel aspect ratio]]
!rowspan="2"|Scanning
!rowspan="2"|Frame rate ([[Hertz|Hz]])
!rowspan="2"|Level
|- style="background:#eee;"
!Vertical
!Horizontal
|-
|rowspan="6"|1080
|rowspan="3"|1920
|rowspan="3"|16:9
|rowspan="3"|1:1
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 25
|4
|-
|progressive
|59.94 <br /> 60 <br /> 50
|4.2
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s) <br /> 25 (50 fields/s)
|4
|-
|rowspan="3"|1440
|rowspan="3"|16:9
|rowspan="3"|HDV <br />(4:3)
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 25
|4
|-
|progressive
|59.94 <br /> 60 <br /> 50
|4.2
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s) <br /> 25 (50 fields/s)
|4
|-
|720
|1280
|16:9
|1:1
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60 <br /> 25 <br /> 50
|3.2, 4
|-
|rowspan="12"|480
|rowspan="2"|720
|rowspan="2"|4:3 or 16:9
|rowspan="2"|[[SMPTE 259M]] <br /> (10:11 or 40:33)
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60 <br /> 25 <br /> 50
|3.1, 4
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s) <br /> 25 (50 fields/s)
|3
|-
|rowspan="2"|704
|rowspan="2"|4:3 or 16:9
|rowspan="2"|[[SMPTE 259M]] <br /> (10:11 or 40:33)
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60 <br /> 25 <br /> 50
|3.1, 4
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s) <br /> 25 (50 fields/s)
|3
|-
|rowspan="2"|640
|rowspan="2"|4:3
|rowspan="2"|1:1
|progressive
|23.976 <br /> 24 <br /> 29.97 <br /> 30 <br /> 59.94 <br /> 60 <br /> 25 <br /> 50
|3.1, 4
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 30 (60 fields/s) <br /> 25 (50 fields/s)
|3
|-
|rowspan="2"|544
|rowspan="2"|4:3
|rowspan="2"|[[SMPTE 259M]] <br /> three quarters <br /> (40:33)
|progressive
|23.976 <br /> 25
|rowspan="2"|3
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 25 (50 fields/s)
|-
|rowspan="2"|528
|rowspan="2"|4:3
|rowspan="2"|[[SMPTE 259M]] <br /> three quarters <br /> (40:33)
|progressive
|23.976 <br /> 25
|rowspan="2"|3
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 25 (50 fields/s)
|-
|rowspan="2"|352
|rowspan="2"|4:3
|rowspan="2"|[[SMPTE 259M]] <br /> half <br /> (20:11)
|progressive
|23.976 <br /> 25
|rowspan="2"|3
|-
|interlaced
|29.97 (59.94 fields/s) <br /> 25 (50 fields/s)
|-
|240
|352
|4:3
|[[Common Intermediate Format|SIF]] <br /> (10:11)
|progressive
|23.976 <br /> 25
|3
|-
|120
|176
|4:3
|[[Common Intermediate Format|SIF]] half <br /> (10:11)
|progressive
|23.976 <br /> 25
|1.1
|}

== Transport stream (TS) ==
{{Main|MPEG transport stream}}

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 ==
{{Main|8VSB|QAM tuner}}

ATSC signals are designed to use the same 6&nbsp;MHz [[Bandwidth (signal processing)|bandwidth]] as analog [[NTSC]] 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 [[modulation|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&nbsp;Mbit/s, sufficient to carry several video and audio programs and [[metadata]].
* [[Cable television]] stations can generally operate at a higher [[signal-to-noise ratio]] and can use either the [[16VSB]] as defined in ATSC or the [[256-QAM]] defined in [[SCTE]], to achieve a throughput of 38.78&nbsp;Mbit/s, using the same 6&nbsp;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]] systems, making it harder to find duplicate 6&nbsp;MHz channels for local broadcasters on uncompressed "basic" cable.

Currently, the [[Federal Communications Commission]] 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]] 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, [http://www.scte.org/documents/pdf/Standards/ANSISCTE072006.pdf ANSI/SCTE 07 2006: Digital Transmission Standard For Cable Television] {{Webarchive|url=https://web.archive.org/web/20100705154402/http://www.scte.org/documents/pdf/Standards/ANSISCTE072006.pdf |date=July 5, 2010 }}. 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 network]]s{{Citation needed|date=June 2010}}. Very few [[Earth station|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]] systems; in the U.S. and Canada these have long used either [[DVB-S]] (in standard or modified form) or a proprietary system such as [[Digital Satellite Service|DSS]] or [[DigiCipher 2]].

== Other systems ==
{{See also|Digital terrestrial television}}
[[File:Digital broadcast standards.svg|560px|[[Digital terrestrial television]] broadcasting systems. Countries using ATSC are shown in orange.]]

ATSC coexists with the [[DVB-T]] 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,<ref>{{cite web|url=http://nsayer.blogspot.com/2008/10/atsc-vs-dvb-for-north-american-amateurs.html|title=ATSC vs DVB for North American amateurs|last=Nick|date=October 16, 2008|website=nsayer.blogspot.com|access-date=March 16, 2018|url-status=live|archive-url=https://web.archive.org/web/20180316084839/http://nsayer.blogspot.com/2008/10/atsc-vs-dvb-for-north-american-amateurs.html|archive-date=March 16, 2018|df=mdy-all}}</ref> 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]] conditions than [[DVB-T]] and [[ISDB-T]]. It also lacks true [[hierarchical modulation]], which would allow the SDTV part of an [[HDTV]] 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]] and have a much lower [[population density]], thereby requiring larger [[transmitter]]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]] in the United States. In [[metropolitan area]]s, 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 system|distributed transmission]] mode, using multiple synchronized on-channel transmitters, has been shown to improve reception under similar conditions. Thus, it may not require more [[spectrum]] allocation than [[DVB-T]] using SFNs. A comparison study found that ISDB-T and DVB-T performed similarly, and that both were outperformed by [[DVB-T2]].<ref>Julian Clover [http://www.broadbandtvnews.com/2010/11/02/dvb-t-far-superior-to-isdb-dvb-t2-beats-them-both/ ''DVB-T far superior to ISDB, DVB-T2 beats them both''] {{webarchive|url=https://web.archive.org/web/20130612025400/http://www.broadbandtvnews.com/2010/11/02/dvb-t-far-superior-to-isdb-dvb-t2-beats-them-both/ |date=June 12, 2013 }}, in ''broadbandtvnews'' November 2, 2010</ref>

== Mobile TV ==
{{Main|ATSC-M/H}}

Mobile reception of digital stations using ATSC has, until 2008, been difficult to impossible, especially when moving at vehicular speeds.{{why|date=September 2024}} To overcome this, there are several proposed systems that report improved mobile reception: [[Samsung]]/[[Rhode & Schwarz]]'s [[A-VSB]], [[Harris Broadcast|Harris]]/[[LG]]'s MPH, and a recent{{When|date=July 2023}} proposal from [[Thomson SA|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 compatibility|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 [[Television antenna|larger antennas]] for reception, and is more prone to [[electromagnetic interference]] from [[engine]]s and rapidly changing [[Multipath propagation|multipath]] conditions.{{Citation needed|date=January 2008}}

== 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]] services, and the ability to store information on new receivers, including Non-realtime (NRT) content.<ref name=ATSC2013>[http://www.atsc.org/cms/pdf/ATSC2013_PDF.pdf 2013_electronic.indd] {{webarchive |url=https://web.archive.org/web/20130509104358/http://www.atsc.org/cms/pdf/ATSC2013_PDF.pdf |date=May 9, 2013 }}. (PDF) . Retrieved on May 11, 2014.</ref><ref>George Winslow. "[http://www.broadcastingcable.com/article/469231-With_ATSC_2_0_Broadcasting_Gets_Facelift.php With ATSC 2.0, Broadcasting Gets Facelift] {{webarchive|url=https://web.archive.org/web/20130301044634/http://www.broadcastingcable.com/article/469231-With_ATSC_2_0_Broadcasting_Gets_Facelift.php |date=March 1, 2013 }}". ''Broadcasting & Cable'', June 6, 2011.</ref><ref>{{cite web |url=http://atsc.org/wp-content/uploads/2015/03/Non-Real-Time-Content-Delivery.pdf|title=A/103:2012, Non-Real-Time Content Delivery |website=atsc.org |access-date=March 16, 2018 |url-status=live |archive-url=http://archive.wikiwix.com/cache/20150405202329/http://atsc.org/wp-content/uploads/2015/03/Non-Real-Time-Content-Delivery.pdf |archive-date=April 5, 2015 |df=mdy-all }}</ref>

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.<ref>{{Cite web |url=https://www.digitaltrends.com/home-theater/atsc-3-0-ota-broadcast-standard-4k-dolby-atmos/ |title=ATSC 3.0: Everything You Need to Know About Broadcast TV's Next Big Thing |date=July 24, 2020 }}</ref>

=== ATSC 3.0 ===
{{Main|ATSC 3.0}}
{{See also|List of ATSC standards#ATSC 3.0}}
ATSC 3.0 will provide even more services to the viewer and increased bandwidth efficiency and compression performance, which requires breaking backward 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.<ref>{{Cite web |url=https://www.fcc.gov/document/fcc-authorizes-next-gen-tv-broadcast-standard |title=FCC Authorizes Next Gen TV Broadcast Standard |website=Federal Communications Commission |date=November 16, 2017 |access-date=November 18, 2017 |url-status=live |archive-url=https://web.archive.org/web/20171201011846/https://www.fcc.gov/document/fcc-authorizes-next-gen-tv-broadcast-standard |archive-date=December 1, 2017 |df=mdy-all }}</ref>

[[LG Electronics]] tested the standard with [[4K UHDTV|4K]] on February 23, 2016. With the test considered a success, [[South Korea]] announced that ATSC 3.0 broadcasts would start in February 2017.<ref>{{cite journal|title=ATSC 3.0 Passes Key Test, But Is It Ready to Graduate?|last=Tribbey|first=Chris|journal=[[Broadcasting & Cable]]|date=March 7, 2016|pages=16–17}}</ref>

On March 28, 2016, the Bootstrap component of ATSC 3.0 (System Discovery and Signalling) was upgraded from candidate standard to finalized standard.<ref>{{cite web|url=http://www.tvtechnology.com/news/0002/first-element-of-atsc-30-approved-for-standard/278263|title=First Element of ATSC 3.0 Approved for Standard|website=tvtechnology.com|date=March 28, 2016|access-date=March 16, 2018|url-status=live|archive-url=https://web.archive.org/web/20170302205029/http://www.tvtechnology.com/news/0002/first-element-of-atsc-30-approved-for-standard/278263|archive-date=March 2, 2017|df=mdy-all}}</ref>

On June 29, 2016, [[NBC]] affiliate [[WRAL-TV]] in [[Raleigh, North Carolina]], 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.<ref name="tvnc-atsc3">{{cite web|title=WRAL Launches ATSC 3.0 Service|url=http://www.tvnewscheck.com/article/95854/first-again-wral-launches-atsc-30-service|website=TVNewsCheck|access-date=13 February 2023|url-status=dead|archive-url=https://web.archive.org/web/20171117122543/http://www.tvnewscheck.com/article/95854/first-again-wral-launches-atsc-30-service|archive-date=November 17, 2017|df=mdy-all}}</ref>

<!-- Deleted image removed: [[File:ATSC 3.0 layers.png|thumb|right|ATSC 3.0's multiple layers.  The standards within ATSC 3.0 are rolled into each of the layers.  {{FFDC|ATSC 3.0 layers.png|log=2022 March 24}}]] -->
;Structure/ATSC 3.0 system layers<ref>{{cite web |url=http://www.tvtechnology.com/portals/0/ATSC30Layers.png |title=Overview - ASTC 3.0 System Layers |format=PNG |access-date=2016-05-18 |url-status=dead |archive-url=https://web.archive.org/web/20161004185359/http://www.tvtechnology.com/portals/0/ATSC30Layers.png |archive-date=October 4, 2016 |df=mdy-all }}</ref>
# Bootstrap: System Discovery and Signalling
# Physical Layer: Transmission ([[OFDM]])
# Protocols: [[Internet Protocol|IP]], [[MPEG media transport|MMT]]
# Presentation: Audio and Video standards (to be determined), [[Ultra HD]] with [[High-definition video|High Definition]] and [[standard-definition]] multicast,  Immersive Audio
# Applications: Screen is a web page

==== ATSC 3.0 advantages ====

# Better image quality. ATSC 3.0 allows [[Ultra-high-definition television|UHD]] transmission, including [[high-dynamic-range television]] (HDR-TV), [[wide color gamut]] (WCG), and [[high frame rate]] (HFR).
# Reception upgrades. ATSC 3.0 allows the same [[Television antenna|aerial]] to receive more channels with better quality.
# Portable devices such as mobile phones, tablets, and car infotainment systems can receive TV signals.
# Enhanced emergency alerts. Emergency signals can be geographically oriented and inform only the specific areas where they are required.
# Audience measure. Telecommunication companies can easily take audience data gatherings.
# [[Targeted advertising]] with the assistance of local network [[Wi-Fi]].
# Content variety and diversification.

==== ATSC 3.0 disadvantages ====

# [[Digital rights management]] encryption being used on ATSC 3.0 stations, preventing many DVRs from being able to access them and limiting the functionality of the remaining that can access them.<ref>{{cite web|url=https://www.techhive.com/article/2250871/drm-remains-a-stumbling-block-for-dvrs-embracing-atsc-3-0.html|title=DRM remains a stumbling block for DVRs embracing ATSC 3.0|publisher=TechHive|last=Newman|first=Jared|date=2024-02-29|access-date=2025-06-26}}</ref>
# Usage of the [[Dolby AC-4]] audio codec, which has very limited support and is not supported by many [[Media player software|media players]].

== Countries and territories using ATSC ==
The following countries use the ATSC broadcast standard: neighbouring countries may also pick up ATSC signals due to [[signal overspill]].

=== North America ===

*{{flagcountry|Bermuda}} March 9, 2016,<ref>[[ZFB-TV#cite note-bernews.com-1]]</ref>{{Circular reference|date=February 2025}} after initially announcing [[DVB-T]] (on 10 July 2007)<ref>{{cite web|url=http://www.dvb.org/about_dvb/dvb_worldwide/bermuda/index.xml|title=About – DVB|access-date=26 June 2016|archive-url=https://web.archive.org/web/20130901023746/http://dvb.org/about_dvb/dvb_worldwide/bermuda/index.xml|archive-date=1 September 2013|url-status=dead}}</ref>
*{{flagcountry|Antigua & Barbuda|Antigua}} 2018
*{{flagcountry|Bahamas}} 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.<ref>[http://www.thebahamasinvestor.com/2011/bahamas-national-tv-to-get-multi-million-dollar-digital-upgrade-video/ Bahamas national TV to get multi-million dollar digital upgrade – video] {{webarchive|url=https://web.archive.org/web/20140413131013/http://www.thebahamasinvestor.com/2011/bahamas-national-tv-to-get-multi-million-dollar-digital-upgrade-video/ |date=April 13, 2014 }}. The Bahamas Investor. Retrieved on May 11, 2014.</ref>
*{{flagcountry|Barbados}} opened in digital television on December 4, 2024.
*{{flagcountry|Canada}} [[Digital television in Canada|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 [[Canadian Broadcasting Corporation|CBC]] only converted its originating stations to digital; it was given permission to operate its repeaters in mandatory markets (such as [[CBKST]] in [[Saskatoon]]) 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.<ref name=CRTC_2012>{{cite web|date=August 16, 2011|title=CRTC allows CBC to continue broadcasting analog television signals in 22 markets until August 2012|url=http://www.crtc.gc.ca/eng/com100/2011/r110816.htm|work=News Releases|publisher=Canadian Radio-television and Telecommunications Commission|access-date=June 4, 2013|url-status=dead|archive-url=https://web.archive.org/web/20130529235153/http://www.crtc.gc.ca/eng/com100/2011/r110816.htm|archive-date=May 29, 2013|df=mdy-all}}</ref> 
*{{flagcountry|Dominica}}
*{{flagcountry|Dominican Republic}} 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.<ref>''Advanced Television Systems Committee'', [http://www.atsc.org/cms/index.php/communications/press-releases/225-dominican-republic-adopts-atsc-digital-television-standard Dominican Republic Adopts ATSC Digital Television Standard] {{webarchive |url=https://web.archive.org/web/20100823142941/http://www.atsc.org/cms/index.php/communications/press-releases/225-dominican-republic-adopts-atsc-digital-television-standard |date=August 23, 2010 }}, August 12, 2010</ref>
*{{flagcountry|Grenada}}
*{{flagcountry|Haiti}}
*{{flagcountry|Jamaica}} Will convert to ATSC 3.0 instead of 1.0. The conversion will begin in 2022 and is expected to be completed by 2023.<ref>{{cite news |title=Digital Television Switchover in Jamaica set to begin in 2022 |url=https://jamaica-gleaner.com/article/news/20211207/digital-television-switchover-jamaica-set-begin-2022 |work=[[The Gleaner]] |publisher=[[Gleaner Company]] |date=December 7, 2021 |access-date=January 8, 2021 }}</ref>
*{{flagcountry|Mexico}} [[Television in Mexico|began converting]] to ATSC in 2013;<ref name=Dibble_2013>{{cite news|last=Dibble|first=Sandra|title=New turn for Tijuana's transition to digital broadcasting|url=http://www.utsandiego.com/news/2013/may/30/new-turn-for-tijuanas-transition-to-digital-broac/|access-date=June 4, 2013|newspaper=San Diego Union-Tribune|date=May 30, 2013|url-status=live|archive-url=https://web.archive.org/web/20130906225915/http://www.utsandiego.com/news/2013/may/30/new-turn-for-tijuanas-transition-to-digital-broac/|archive-date=September 6, 2013|df=mdy-all}}</ref> a full transition was scheduled for December 31, 2015,<ref name="dgm 1" /> but due to technical and economic issues for some transmitters, the full transition was extended to December 31, 2016.
*{{flagcountry|Saint Lucia}} opened on Saint Lucia on ATSC on March 5, 2024.
*{{flagcountry|Trinidad and Tobago}} will convert to ATSC 3.0 instead of ATSC 1.0. The conversion process will begin in March 2023 and is expected to be completed by 2026.<ref name="TT ATSC 3.0">{{cite web |title=Notice |url=https://tatt.org.tt/Home/Announcements4/ReadMore/tabid/350/ArticleId/677/Notice-22.aspx |website=Telecommunications Authority of Trinidad and Tobago |access-date=2022-01-26 |archive-date=January 26, 2023 |archive-url=https://web.archive.org/web/20230126050836/https://tatt.org.tt/Home/Announcements4/ReadMore/tabid/350/ArticleId/677/Notice-22.aspx |url-status=dead }}</ref>
*{{flagcountry|United States}} Full-power television stations in the [[Digital television in the United States|United States]] ended analog television service on June 12, 2009. Analog [[Low-power broadcasting|low-power]] stations and translators were all wound down by July 13, 2021.<ref name="US LPTV trans">{{citation |url=http://www.fcc.gov/guides/low-power-television-lptv-service |title=Low Power Television (LPTV) Service |work=CDBS Database |date=May 17, 2011 |publisher=[[Federal Communications Commission]] |access-date=April 3, 2013 |url-status=live |archive-url=https://web.archive.org/web/20130401214127/http://www.fcc.gov/guides/low-power-television-lptv-service |archive-date=April 1, 2013 |df=mdy-all }}</ref><ref>[https://apps.fcc.gov/edocs_public/attachmatch/DA-17-442A1.pdf FCC Public Notice: "THE INCENTIVE AUCTION TASK FORCE AND MEDIA BUREAU ANNOUNCE PROCEDURES FOR LOW POWER TELEVISION, TELEVISION TRANSLATOR AND REPLACEMENT TRANSLATOR STATIONS DURING THE POST-INCENTIVE AUCTION TRANSITION", May 17, 2017]</ref>

*{{flagcountry|Guyana}} As of August 2025, the [[Guyana Learning Channel]] is broadcasting a multiplex in the ATSC standard. On March 19, 2025, it launched a campaign for the delivery of digital receivers to households which only receive analog signals.<ref>{{cite news |title=Guyana Learning Channel Expands Network, Launches Digital TV Box Distribution |url=https://education.gov.gy/en/index.php/media2/news-events/8023-guyana-learning-channel-expands-network-launches-digital-tv-box-distribution |work=Ministry of Education (Guyana)}}</ref> In early 2025, the [[National Communications Network, Guyana|National Communications Network]] began digital terrestrial broadcasts of its channels,  [[NCN Television (Guyana TV channel)|NCN HD]] and NCN Sports in 1080p using the ATSC standard.<ref>{{cite news |title=NCN nears completion of digital broadcasting transition |url=https://ncnguyana.com/2023/ncn-nears-completion-of-digital-broadcasting-transition/ |work=NCN Guyana |date=2023}}</ref> CTV19 also officially launched its digital feed on August 4, 2025.<ref>{{cite web |title=CTV19 Digital Feed Launch |url=https://www.facebook.com/share/p/16LGMcbf48/ |website=Facebook |access-date=2025-08-06}}</ref>
*{{flagcountry|Suriname}} Suriname has undergone transitioning from analogue NTSC broadcasts to digital ATSC broadcasts. Channel [[ATV (Suriname)|ATV]] started with ATSC broadcasts in the [[Paramaribo]] 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 (Suriname)|ATV]] (i.e., ATV and TV2) and [[STVS]].<ref name="TAS">{{cite news|title=FAQ digitale telivisie (DTC)|url=http://www.tas.sr/|access-date=July 9, 2015|publisher=Telecommunication Authority of Suriname}}</ref> In 2016 all channels in Suriname had already made the switch to ATSC.

=== Asia/Pacific ===
*{{flagcountry|South Korea}} 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]].<ref name=Yonhap_2013>{{cite news|title=N. Korea in the process of introducing digital TV broadcasting|url=http://english.yonhapnews.co.kr/northkorea/2013/03/19/2/0401000000AEN20130319005400315F.HTML|access-date=June 4, 2013|newspaper=Yonhap News Agency|date=March 19, 2013|url-status=live|archive-url=https://web.archive.org/web/20131001182546/http://english.yonhapnews.co.kr/northkorea/2013/03/19/2/0401000000AEN20130319005400315F.HTML|archive-date=October 1, 2013|df=mdy-all}}</ref><ref>{{cite web|title=North Korean television sets still receive South Korean signals|url=http://newfocusintl.com/north-korean-television-sets/|website=News Focus International|access-date=July 12, 2015|url-status=live|archive-url=https://web.archive.org/web/20150614041031/http://newfocusintl.com/north-korean-television-sets/|archive-date=June 14, 2015|df=mdy-all}}</ref> 
*{{flagcountry|United States}} territories in the Pacific, including [[American Samoa]], [[Guam]], and the [[Northern Mariana Islands]] have adopted ATSC, as with the mainland.<ref name="US LPTV trans" />

== Patent holders ==
The following organizations held [[patent]]s for the development of ATSC 1.0 technology, as listed in the [[patent pool]] administered by [[MPEG LA]]. The latest patents expired on 16 September 2024.<ref name="atsc-patents">{{cite web |title=ATSC Patent List |url=https://www.via-la.com/wp-content/uploads/Final-July-1-2024-ATSC-Attachment-1.pdf |website=[[MPEG LA]] |archive-url=https://web.archive.org/web/20240801130217/https://www.via-la.com/wp-content/uploads/Final-July-1-2024-ATSC-Attachment-1.pdf |access-date=21 September 2024|archive-date=August 1, 2024 }}</ref>

{| class="wikitable"
!Organizations<ref>{{cite web |title=Licensors Included in the ATSC Patent Portfolio License |url=https://www.mpegla.com/programs/atsc/licensors/ |website=[[MPEG LA]] |access-date=11 July 2019}}</ref>
!Total patents (all expired)<ref name="atsc-patents" />
|-
|[[LG Electronics]]
|354
|-
|[[Zenith Electronics]]
|54
|-
|[[Panasonic]]
|50
|-
|[[Samsung Electronics]]
|25
|-
|[[Columbia University]]
|16
|-
|[[Mitsubishi Electric]]
|14
|-
|[[JVC Kenwood]]
|6
|-
|[[Cisco Systems|Cisco Technology, Inc.]]
|4
|-
|Vientos Alisios Co., Ltd.
|1
|-
|[[Philips]]
|1
|}

Patents for ATSC 3.0 are still active.<ref name="atsc-3.0-patents">{{cite web |title=ATSC 3.0 Patent List |url=https://www.via-la.com/licensing-2/atsc-3-0/atsc-3-0-patent-list/ |website=[[MPEG LA]] |access-date=21 September 2024}}</ref>

== See also ==
* [[Advanced Television Systems Committee]]
* [[ATSC tuner]]
* [[List of ATSC standards]]
* [[Broadcast flag]]
* [[Broadcast-safe]]
* [[Digital terrestrial television]] (DTT)
* [[DVB|Digital Video Broadcasting]] (DVB)
* [[CTA-708]]
* [[ISDB]] – Integrated Services Digital Broadcasting
* OpenCable
* [[Standard-definition television]]
* [[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 ==
{{Reflist|35em}}

== Further reading ==
* [[Joel Brinkley]] (1998), ''Defining Vision:  The Battle for the Future of Television'', New York: [[Harcourt Brace]].

== External links ==
*[https://www.atsc.org ATSC website]
*[https://www.expway.com/ ATSC-MH Platform for testing and deploying Mobile TV in the US]
*[https://web.archive.org/web/20170724043744/http://www.decontis.com/ ATSC Mobile DTV (ATSC-MH) Analysis, Monitoring, Measurement]
*[https://web.archive.org/web/20140113150024/http://mobile-dtv-viewer.com/ ATSC Mobile DTV (ATSC-MH) Mobile DTV Viewer]
*[https://www.enensys.com/technologies/atsc3-0/ ATSC 3.0 Overview]
*[http://www.enensys.com/solutions/atsc-3.0-/atsc-scheduler.html ATSC 3.0 Scheduler]

{{TV resolution}}
{{Video formats}}
{{High-definition}}
{{North American DTV}}
{{Telecommunications}}
{{Authority control}}

{{DEFAULTSORT:Atsc}}
[[Category:ATSC standards| ]]
[[Category:MPEG]]
[[Category:Digital television]]
[[Category:High-definition television]]
[[Category:Television transmission standards]]