WASHINGTON—The Advanced Television Systems Committee achieved a significant milestone last week with the elevation of the ATSC 3.0 Physical Layer to Candidate Standard status. TV Technology asked ATSC President Mark Richer to provide more details on the technology and the process of developing this latest transmission standard for over-the-air broadcast television in the United States.
TV Technology:Ten proposals from 19 organizations were submitted in the physical layer call for proposals:
- Coherent Logix and Sinclair Broadcast Group
- Communications Research Centre and Electronics & Telecommunications Research Institute
- Digital Video Broadcasting Project
- LG Electronics, Zenith and Harris Broadcast
- Allen Limberg
- National Engineering Research Center of Digital Television, Shanghai Jiao Tong University, Shanghai Advance Research Institute, and Bell Labs, Alcatel-Lucent
- Power Broadcasting
- Qualcomm and Ericsson
- Samsung and Sony
- Technicolor
TV Technology: Which one represents the physical layer, or is it a combination of submitted technologies?
Richer: The development of the physical layer is a process that involved many volunteers and many companies working in a collaborative fashion to come up with the best possible solution: A transmission system that is both very robust and flexible to meet the demands of broadcasters for next-generation television.
TV Technology: TV Technology received separate statements from LG and ONE Media about their own and their partner companies’ technology used in the standard. Does ATSC have to abide by a policy of not identifying companies contributing to the standard?
Richer: ATSC does not have a formal policy concerning identification of contributors to our standards. In situations such as the development of the ATSC 3.0 Physical Layer, there were many contributors. Participants in our meetings are required to abide by our Patent Policy, which is available on the ATSC Website.
TV Technology:Describe what this technology does and how it works.
Richer:Our overall goal with ATSC 3.0 is to make it highly configurable, scalable, efficient, interoperable, and adaptable.
Drafted by the S-32 Physical Layer specialists group capably chaired by Sony’s Luke Fay, the ATSC 3.0 Physical Layer is intended to offer far more flexibility, robustness and spectrum efficiency than the ATSC 1.0 standard, which was adopted two decades ago.
The ATSC 3.0 Physical Layer uses OFDM modulation with low-density parity check (LDPC) forward-error correction similar to other advanced terrestrial broadcast standards. ATSC 3.0 also uses new more robust LDPC along with non-uniform constellations to provide improved transmission and reception performance.
TV Technology:We’ve already heard several times about flexibility and robustness. But why and how so, and what is it about the technologies that assures this?
Richer: The ATSC 3.0 physical layer allows television broadcasters to choose from a wide variety of transmission parameters so that each station can tailor its signal to best serve its local market by providing the combination of services and coverage area best suited for the market and its terrain.
TV Technology:What do you mean by “transmission parameters” here?
Richer: These flexible parameters include options for coding rates, modulation types, guard intervals, and time interleavers.
As an example, the ATSC 3.0 Physical Layer provides the ability for broadcasters to provide services in a robust mode for mobile services and a less robust but higher bitrate services to serve content to large screens in the home. Broadcasters can configure their transmission to provide simultaneous mixture of types of services using either Time Division Multiplexing or Layer Division Multiplexing, or both.
In other words, it’s not “one size fits all.” Broadcasters can change parameters to send different types of content to different types of receivers throughout the day— including simultaneous transmission of content for both big screens and handheld mobile devices of the future.
The system will allow high-capacity, low-robustness modes and also lower-capacity, high-robustness modes in the same transmission. That flexibility means that we’re likely to see both 4K Ultra HD broadcasts running side-by-side with robust mobile broadcasts to handheld devices.
TV Technology:OK, that’s fairly straightforward, but how is this achieved? Adaptive bit-rate capability? Compression? Also, what types of compression will it support?
Richer: The physical layer delivers bits of any type. Video and audio compression are defined by the presentation layer of ATSC 3.0. See graphic:
Technologies can be selected for various “use cases” like Single Frequency Networks, Multiple Input/Multiple Output channel operation, channel-bonding and more, well beyond a single transmitting tower.
TV Technology:So? What’s the big deal about that?
Richer: These technologies provide network architectures that can be used to improve coverage for services such as mobile. There is also a large range of selections for data protection including a wide range of guard intervals, forward-error correction code lengths and code rates.
TV Technology:Again, what for? Why is this notable?
Richer: Broadcasters can use these parameters to optimize the balance of performance and throughput for each service. Work continues on the other parts of the suite of ATSC 3.0 standards. They include Video and Audio Compression, Closed Captioning, Advanced Emergency Alerting, Security, Companion Devices, Personalization, Applications & Interactivity, Watermarking and Fingerprinting, and Internet Protocol Delivery. All told, some 20 standards are expected to be part of ATSC 3.0
TV Technology: What is meant here by “companion devices,” and in what way does this standard envision accommodating these devices?
Richer: Companion devices include “second screen” such as a tablet or phone. ATSC 3.0 will enable hybrid broadcast and broadband applications.
TV Technology:Noted. What can we expect with regard to video and audio compression? HEVC? Multiple codecs?
Richer: Video and audio compression systems are under consideration. Stay tuned!
TV Technology:The “bootstrap signal” component of this technology was elevated to Candidate Standard in May. Is it now a part of this Candidate Standard?
Richer:No, it’s a separate document and that part of the physical layer was elevated to Candidate Standard earlier.
TV Technology:There were five total components to the physical layer—system discovery and signaling (bootstrap); modulation; error correction algorithms and constellations….
Richer: To put the entire standard-setting process into context, this piece from Dr. Rich Chernock, who chairs the ATSC’s Technology Group 3, is a good description of what the final standard will look like.
TV Technology:Is the modulation scheme based on orthogonal frequency-division multiplexing?
Richer: Yes, the physical layer uses OFDM.
TV Technology:Does it bear a resemblance to DVB-T2?
Richer: There are some elements that are similar to DVB-T2, but also some new ingredients.
TV Technology:Elements such as… ?
Richer: OFDM, some coding rates, modulation types, and guard interval parameters are common with DVB-T2.
TV Technology:Are you on schedule with your timetable?
Richer: Yes, we are on schedule. The Candidate Standard status for the physical layer will continue for six months, during which time manufacturers will build prototype equipment and test to the proposed standard. Final tweaks will be made, and then the physical layer will face a ballot to recognize the technologies as part of the finished ATSC 3.0 Standard.
TV Technology:When do you expect the standard to be complete? What is the timetable for approval?
Richer: In the first quarter of 2017.
TV Technology:When does the Federal Communications Commission get involved?
Richer: While the standards-setting process continues at the ATSC, the FCC will presumably be asked by broadcasters to review the outcome of ATSC 3.0 at some point.
TV Technology:ATSC 3.0 will not be compatible with any existing television receivers, and TV stations do not have extra spectrum this time to make the switch as they did in the 2009 digital transition. In other words, they would all have to flash cut to the new standard. What is the vision and developing strategic plan for receiver deployment?
Richer: ATSC is not directly involved in receiver development plans. Some broadcasters are working with consumer electronics companies to plan a 3.0 strategy.
TV Technology:What is the vision and developing strategic plan for deployment of the ATSC 3.0 transmission scheme itself?
Richer: I believe ATSC 3.0 will provide broadcasters with compelling business opportunities that will drive the implementation of new services.
Also see…
September 29, 2015
“ATSC 3.0 Physical Layer Elevated to Candidate Standard”
The ATSC 3.0 Physical Layer is intended to offer far more flexibility, robustness and spectrum efficiency than the ATSC 1.0 standard, which was adopted two decades ago.
September 21, 2015
“ATSC 3.0 Tested With 4K, Mobile in Korea by LG, SBS”
Korean broadcaster SBS partnered with LG Electronics for the country's first live over-the-air broadcast of 4K Ultra HD signals using technologies behind the ATSC 3.0 TV broadcast standard.
September 2, 2015
“Voting on ATSC 3.0 Physical Layer Standard Begins“
Ballots were sent out on Aug. 31 and over the next four weeks members of the TG3 Technology Group will vote on whether to approve or not approve the Physical Layer to Candidate Standard status.
May 15, 2015
“Samsung and ONE Media Drive ATSC 3.0 Candidate Standard��
Samsung and ONE Media proposed a hierarchical framework comprised of the ‘bootstrap,’ preamble and data framing to meet broadcasters unique requirements.
May 7, 2015
“ATSC 3.0 Bootstrap Signal Becomes Candidate Standard“
The first of five components in the Physical Layer transmission standard for ATSC 3.0 has been elevated to “Candidate Standard” status.
August 27, 2013
“TV Tomorrow: ATSC 3.0 Advances”
The ATSC announced that 10 proposals have been submitted for the foundation of 3.0 known as the “physical layer.” This physical layer includes the modulation scheme, which defines how the signal information is carried by a radio frequency—in this case, the TV channel.
March 28, 2013
“ATSC Seeks Next-Gen TV Physical Layer Proposals”
It appears some of the requirements could be a bit of a stretch, but that may not be such a bad idea, considering that ATSC 3.0 will be replacing a terrestrial DTV standard that’s survived for 15 years.
March 27, 2013
“ATSC Seeks Proposals for ATSC 3.0 Physical Layer”
Glenn Reitmeier, ATSC chairman, noted that, “the ATSC 3.0 effort is a crucial time for broadcasters, professional equipment manufacturers, consumer device manufacturers and all stakeholders to collaborate and create the future capabilities of over-the-air broadcasting.”
February 22, 2013
“HPA 2013: ATSC 3.0 Update”
The current standard was developed 20 years ago and implemented around 15 years ago. The Internet was on baby legs, processor speeds were measured in megahertz, storage in megabytes, and networks in kilobytes.
January 22, 2013
“New ATSC Implementation Teams to Focus on Commercialization of ATSC 2.0 and M-EAS”
The Advanced Television Systems Committee has formed new Implementation Teams for two new emerging standards -- ATSC 2.0 and the Mobile Emergency Alert System.
February 15, 2012,
“HPA Tech Retreat: The State of ATSC 2.0”
ATSC 2.0 will provide a variety of interactive capabilities to broadcasters not now available.
September 6, 2011
“New ATSC 3.0 Technology Group Formed To Anticipate TV of the Future
ATSC 3.0 is anticipated to be a series of voluntary technical standards and recommended practices for the next digital terrestrial television broadcast system.
