ATSC 3.0
ATSC 3.0 is a major version of the ATSC standards for terrestrial television broadcasting created by the Advanced Television Systems Committee.
The standards are designed to offer support for newer technologies, including High Efficiency Video Coding for video channels of up to 4K resolution at 120 frames per second, wide color gamut, high dynamic range, Dolby AC-4 and MPEG-H 3D Audio, datacasting capabilities, and more robust mobile television support. The capabilities have also been foreseen as a way to enable finer public alerting and targeted advertising.
The first major deployment of ATSC 3.0 occurred in South Korea in May 2017, in preparation for the 2018 Winter Olympics. In November 2017, the FCC passed rules allowing American broadcast stations to voluntarily adopt ATSC 3.0, provided that full-power stations preserve the availability of their programming in their city of license via legacy ATSC signals; adoption is being steered by the broadcasting industry, without a mandatory transition as there was from analog NTSC to ATSC. Other adoptions have since occurred in Jamaica and Trinidad and Tobago, while Brazil has proposed a transition from ISDB-T International to standards derived from ATSC 3.0.
Technical details
Bootstrap
ATSC 3.0 uses a bootstrap signal which allows a receiver to discover and identify the signals that are being transmitted. The bootstrap signal has a fixed configuration that can allow for new signal types to be used in the future. The bootstrap signal can also carry information to wake up a receiver so that it can receive an emergency population warning.Physical layer
ATSC 3.0 uses a highly efficient physical layer that is based on orthogonal frequency-division multiplexing modulation with low-density parity-check code forward error correction. With a 6 MHz channel, the bit rate can vary from 1 to 57 Mbit/s depending on the parameters that are used. ATSC 3.0 is limited to 64 physical layer pipes with a recommended 4 simultaneous PLPs per complete delivered product. The PLPs in a channel may each have different robustness levels. An example of how PLPs can be used would be a channel that delivers HD video over a robust PLP and enhances the video to UHD with a Scalable HEVC layer over a higher-bitrate PLP.Audio
ATSC 3.0 supports Dolby AC-4 and MPEG-H 3D Audio.Video
ATSC 3.0 supports three video formats: legacy SD video, interlaced HD video, and progressive video. Legacy SD Video and Interlaced HD Video support frame rates up to 30 fps. Legacy SD Video and Interlaced HD Video are included for compatibility with existing content and can't use HDR, HFR, or WCG.Legacy SD video
Legacy SD video supports resolutions up to 720×480 and supports HEVC Main 10 profile at Level 3.1 Main Tier.Interlaced HD video
Interlaced HD video supports 1080-line interlaced video with 1,920 or 1,440 pixels per line, and supports HEVC Main 10 profile at Level 4.1 Main Tier.Progressive video
Progressive video supports resolutions up to 3840×2160 progressive scan and supports HEVC Main 10 profile at Level 5.2 Main Tier. Progressive video supports frame rates up to 120 fps and the Rec. 2020 color space. Progressive video supports HDR using hybrid log–gamma and perceptual quantizer transfer functions.Security
ATSC 3.0 supports encryption of the signal to protect against intrusion and provide digital rights management. While tuner vendor Nuvyyo stated in 2017 that this was intended "to allow broadcasters to provide value-added services like on-demand and pay-per-view content on a subscription basis" via broadcast signals, major U.S. broadcast groups began to encrypt their ATSC 3.0 broadcast signals in 2023.ATSC 3.0 supports digital watermarking of the audio and video signals.
Public alerting
A U.S.-based coalition known as the Advanced Warning and Response Network Alliance has advocated for the use of ATSC 3.0 features, including datacasting and digital network interoperability, in order to provide an emergency alert system with support for embedded rich media and finer geotargeting.In November 2021, AWARN and ATSC jointly filed comments in response to questions posed about ATSC 3.0 alerting capabilities in the FCC's Further Notice of Proposed Rulemaking as required by the National Defense Authorization Act for Fiscal Year 2021.
Broadcast Positioning System
A backup to GPS called Broadcast Positioning System has been proposed as part of ATSC 3.0, to provide location services in broadcast areas in the event of GPS failure. This would use ATSC 3.0 to transmit timing signals terrestrially; the service could be deployed on existing infrastructure and would not be vulnerable to GPS jamming or spoofing.Analog audio fallback
Unlike ATSC 1.0, ATSC 3.0 as defined makes possible the continued use of an analog audio subcarrier in addition to the digital signal—colloquially called a "Franken FM"—by narrowing the bandwidth of the channel to 5.5 MHz wide. On June 10, 2021, the FCC granted KBKF-LD in San Jose, California, a special temporary authority to transmit an analog FM audio subcarrier at 87.75 MHz, the same frequency as what would be the audio subcarrier on an NTSC analog video signal. KBKF-LD's sister station WRME-LD was granted a similar special temporary authority shortly before the end of low-power analog television on July 13, 2021. The STA has implications for the dozens of remaining analog low-power television stations on physical channel 6, which operate as FM radio stations using that NTSC subcarrier and face a July 13 deadline to convert to digital; a digital signal is not compatible with standard FM radio nor with the American digital radio standard, HD Radio. KBKF must report any interference issues to the FCC twice during the STA's term, once at 90 days and again at 180 days. The initial 90-day filings demonstrated that the shared channel space was a success. The FCC has proposed as of July 2023 that those operating under STA would continue to be allowed to use the analog audio service under a grandfather clause but would disallow the addition of analog audio to any other television licenses.History
On March 26, 2013, the Advanced Television Systems Committee announced a call for proposals for the ATSC 3.0 physical layer which states that the plan is for the system to support video with a resolution of 3840×2160 at 60 fps.In February 2014, a channel-sharing trial began between Los Angeles television stations KLCS and KJLA, a commercial ethnic broadcaster owned-and-operated by LATV, with support from the CTIA and approval of the Federal Communications Commission. The test involved multiplexing multiple HD and SD subchannels together, experimenting with both current MPEG-2/H.262 and MPEG-4 AVC/H.264 video codecs. Ultimately, it has been decided that H.264 would not be considered for ATSC-3.0, but rather the newer MPEG-H HEVC/H.265 codec would be used instead, with OFDM instead of 8VSB for modulation, allowing for data rates of 28 Mbit/s to 36 Mbit/s or more on a single 6 MHz channel.
In May 2015, and continuing on for six months afterward, the temporary digital transition transmitter and antenna of Cleveland, Ohio's Fox affiliate, WJW, was used by the National Association of Broadcasters to test the "Futurecast" ATSC 3.0 standard advanced by LG Corporation and GatesAir. In September 2015 further tests in the Baltimore and Washington, D.C. area were announced by Sinclair Broadcast Group's Baltimore station, WBFF, which is also a Fox affiliate. The Futurecast system had previously been tested in October 2014 during off-air hours through Madison, Wisconsin ABC affiliate WKOW. Unlike ATSC 1.0/2.0's Distributed Transmission System's pseudo-single-frequency network operations, WI9XXT's two transmitters operate as a true Single-Frequency Network.
Further tests began on January 6, 2016, of ATSC 3.0 with high dynamic range from Las Vegas independent station, KHMP-LD on UHF 18. It would later be joined in these tests by Sinclair's CW affiliate, KVCW simulcasting on a temporary test frequency.
On January 20, 2016, a working group in South Korea led by LG Electronics and others performed the first "end-to-end" broadcast of 4K resolution programming via an ATSC 3.0 signal, using an IP transmission from the Seoul Broadcasting System's Mok-dong studio to feed a transmitter on Gwanak Mountain. The broadcaster's technical director stated that the successful test "highlights the potential for Korea's launch of terrestrial UHD TV commercial services using ATSC 3.0 in February 2017." Following the test broadcast, South Korean broadcasters announced that they planned to launch ATSC 3.0 services in February 2017.
On March 28, 2016, the bootstrap component of ATSC 3.0 was upgraded from candidate standard to finalized standard.
On June 29, 2016, NBC affiliate WRAL-TV in Raleigh, North Carolina, a station known for its pioneering roles in testing the original ATSC standards, launched an experimental ATSC 3.0 channel carrying the station's programming in 1080p, as well as a 4K demo loop. WRAL-EX has also carried 4K coverage of the 2016 Summer Olympics and 2018 Winter Olympics in an experimental manner.