ATSC 3.0 is a major version of the ATSC standards for television broadcasting created by the Advanced Television Systems Committee (ATSC). ATSC 3.0 comprises around 20 standards covering different aspects of the system and in total will have over 1,000 pages of documentation.
The standards are designed to offer support for newer technologies, including HEVC for video channels of up to 2160p 4K resolution at 120 frames per second, wide color gamut, 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 targeted advertising and finer public alerting.
The first major deployments of ATSC 3.0 occurred in South Korea in 2017, with the country's major television networks launching terrestrial ATSC 3.0 services in May 2017. In November 2017, the United States' Federal Communications Commission approved regulations allowing broadcasters to voluntarily offer ATSC 3.0 services alongside their standard digital signals, but will not be enforcing a mandatory transition as it did with the transition from analog NTSC to ATSC.
Video 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.
Physical layer
ATSC 3.0 uses a physical layer that is based on orthogonal frequency-division multiplexing (OFDM) modulation with low-density parity-check code (LDPC) FEC codes. With a 6 MHz channel the bit rate can vary from 1 Mbit/s to 57 Mbit/s depending on the parameters that are used. ATSC 3.0 can have up to 4 physical layer pipes (PLP) in a channel with different robustness levels used for each PLP. An example of how PLP can be used would be a channel that delivers HD video over a robust PLP and enhances the video to UHD with Scalable Video Coding 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 60 fps and can only use the Rec. 709 color space. 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 High Efficiency Video Coding (HEVC) Main 10 profile at Level 3.1 Main Tier.
- Interlaced HD Video
Interlaced HD Video supports resolutions up to 1920×1080 interlaced video 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 (HLG) and Perceptual Quantizer (PQ).
Watermark
ATSC 3.0 supports digital watermarking of the audio signal and video signal.
Public alerting
A U.S. consortium known as AWARN has advocated for the use of ATSC 3.0 features, including datacasting, and automatically waking up devices, in order to provide emergency alerts with support for embedded rich media and finer geotargeting. These features are defined within the "Advanced Emergency Alerting" portions of the ATSC 3.0 standards.
Maps ATSC 3.0
History
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 original ATSC system. ATSC 3.0 is expected to emerge within the next decade.
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 (4K UHDTV).
In February 2014, a channel-sharing trial began between Los Angeles television stations KLCS (a public television station that is a PBS member) 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 28 Mbit/s to 36 Mbit/s or more of bandwidth 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, will be 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, DC 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 in on January 6, 2016 of ATSC 3.0 with High Dynamic Range (using the Scalable HEVC video codec with HE-AAC audio) 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 (UHF 45).
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 (System Discovery and Signalling) 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 1.0 DTV standards, launched an experimental ATSC 3.0 channel carrying the station's programming in 1080p, as well as a 4K demo loop.
On July 27, 2016, South Korea's Ministry of Science, ICT and Future Planning officially endorsed ATSC 3.0 over DVB-T2 as the country's broadcasting standard for ultra-high-definition television.
2017
On January 6, 2017, LG Electronics announced that their 2017 4K TVs sold in South Korea would include ATSC 3.0 tuners.
On February 2, 2017, the Federal Communications Commission (FCC) released a "Notice of Proposed Rulemaking" which would allow for the deployment of ATSC 3.0 in the United States. The Notice of Proposed Rulemaking seeks comments on issues such as carriage obligations, interference, public interest obligations, simulcasting, and a tuner mandate. Gary Shapiro of the Consumer Technology Association (CTA) has stated that a TV tuner mandate is not necessary and that it should be market-driven and voluntary. On February 24, 2017, the FCC voted unanimously to approve two portions of the NPRM, opening the door for manufacturers to begin producing ATSC 3.0 hardware.
Unlike the transition from NTSC analog broadcast to ATSC 1.0 digital transmission, the FCC will not allocate a second channel to each broadcaster to enable a gradual consumer transition. Instead, it has been suggested that multiple broadcasters in each market cooperate by locating multiple degraded ATSC 1.0 services on a single "lighthouse" transmitter. At the same time, the broadcasters would share the remaining transmitters for ATSC 3.0 transmissions. After sufficient consumer adoption, ATSC 1.0 transmissions would be abandoned, allowing stations to return to operation on their owned transmitters. It is unclear how the complications of this approach would be overcome, especially in light of spectrum allocation in heavily populated markets.
On May 31, 2017, SBS, MBC, and KBS officially launched their full-time ATSC 3.0 services in major South Korean markets such as Seoul and Incheon. The launch had been delayed from February 2017 due to issues obtaining the required equipment.
On November 14, 2017, the Pearl consortium (comprising a number of major broadcasting conglomerates, including Fox Television Stations, Meredith Corporation, Nexstar Media Group, Scripps Media, Tegna Inc., Telemundo, and Univision) announced that it would use Phoenix, Arizona as a test market for an ATSC 3.0 transition in 2018.
Two days later, the FCC voted 3-2 in favor of an order authorizing voluntary deployments of Next Gen TV (ATSC 3.0); stations that choose to deploy ATSC 3.0 services must continue to maintain an ATSC 1.0-compatible signal that is "substantially similar" in programming to their ATSC 3.0 signal (besides "programming features that are based on the enhanced capabilities of ATSC 3.0", and advertising), and covers the station's entire community of license (the FCC stated that it would expedite approval for transitions if the loss in over-the-air coverage post-transition is 5% or less). The "substantially similar" clause will remain in effect for at least five years; permission from the FCC must be obtained before a full-power station can shut down its ATSC 1.0 signal, but low-power stations are exempt from the simulcasting requirement and are allowed to flash-cut to ATSC 3.0 if they choose.
Unlike the original transition to digital television, the FCC will not enforce a mandate on the provision of ATSC 3.0 tuners on new televisions, having deemed this unnecessary. ATSC 1.0 signals will still be subject to mandatory carriage rules for television providers during the five-year simulcasting mandate; the FCC stated that voluntary carriage of 3.0 signals by television providers would be left to the marketplace. The order does require stations to provide sufficient on-air notice about transitions to ATSC 3.0 services.
Concerns
Consumer advocates have noted the opportunity in which ATSC 3.0 can allow advertisers to run targeted advertising. The targeted ads would allow advertisers to track more directly viewer ratings rather than indirectly by companies such as Nielsen ratings. The FCC is expected to defer the decision on targeted ads to be in accordance with Federal Trade Commission's guidelines on privacy.
A consortium of U.S. television providers criticized the domestic plans for the transition, citing the "voluntary" transition, inconsistencies in commitments to simulcasting arrangements for compatibility, potential downgrades in service for ATSC 1.0 viewers, as well as how these signals will factor into retransmission consent negotiations.
See also
- ATSC tuner
- High Efficiency Video Coding
References
External links
- ATSC website
Source of article : Wikipedia
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