About ATSC : History of the ATSC : Members

Development of the ATSC Digital Television Standard

In 1987, the United States Federal Communications Commission established the Advisory Committee on Advanced Television Service to advise the FCC on technical and public policy issues regarding advanced television. The Advisory Committee consisted of 25 leaders of the television industry, with Richard E. Wiley, a former chairman of the FCC, chosen as its chair with hundreds of industry volunteers serving on numerous Advisory Committee subcommittees.

Initially, 23 different systems were proposed to the Advisory Committee. These systems ranged from "Improved" systems which worked within the parameters of the NTSC system to improve the quality of the video; to "Enhanced" systems which added additional information to the signal to provide an improved wide-screen picture; and finally to "High-Definition Television (HDTV)" systems which were completely new systems with substantially higher resolution, a wider picture aspect ratio and improved sound.

In the midst of this competitive process, a fundamental technological advance occurred when in May of 1990, General Instrument proposed the first all-digital high-definition television system. Within seven months, three additional all-digital HDTV systems had been proposed.

By 1991 the number of competing system proposals had been reduced to six, including the four all-digital HDTV systems. The Advisory Committee developed extensive test procedures to evaluate the performance of the proposed systems, and required the proponents to provide fully implemented real-time operating hardware for the testing phase of the process. From July 1991 to October 1992 the six systems were tested by three independent and neutral laboratories working together, following the detailed test procedures prescribed by the Advisory Committee.

The Advanced Television Test Center, funded by the broadcasting and consumer electronics industries, conducted transmission performance testing and subjective tests using expert viewers. Cable Television Laboratories, a research and development consortium of cable television system operators, conducted an extensive series of cable transmission tests as well. The Advanced Television Evaluation Laboratory within the Canadian Communications Research Centre conducted subject assessment tests using non-expert viewers.

In February 1993, a Special Panel of the Advisory Committee convened to review the results of the testing process, and, if possible, to choose a new transmission standard for terrestrial broadcast television to be recommended by the Advisory Committee to the FCC. After a week of deliberations, the Special Panel determined that there would be no further consideration of analog technology, and that based upon analysis of transmission system performance, an all-digital approach was both feasible and desirable.

Although all of the all-digital systems performed well, each of them had one or more deficiencies that required further improvement.

The Special Panel recommended that the proponents of the four all-digital systems be authorized to implement certain modifications they had proposed, and that supplemental tests of these improvements be conducted. The Advisory Committee adopted this recommendation of the Special Panel, but also expressed its willingness to entertain a proposal by the remaining proponents for a single system that incorporated the best elements of the four all-digital systems.

The Grand Alliance

In response to this invitation, in May 1993, as an alternative to a second round of intense competitive testing, the proponents of the four all-digital systems formed the Digital HDTV Grand Alliance. The members of the Grand Alliance were AT&T (now Lucent Technologies), General Instrument, North American Philips, Massachusetts Institute of Technology, Thomson Consumer Electronics, the David Sarnoff Research Center (now Sarnoff Corporation) and Zenith Electronics Corporation. After a thorough review of the Grand Alliance’s proposal, the Advisory Committee ordered a number of important changes, and the Grand Alliance companies proceeded to build a final prototype system based on specifications approved by the Advisory Committee.

The prototype Grand Alliance system was built in a modular fashion at various locations. The video encoder was built by AT&T and General Instrument, the video decoder by Philips, the multi-channel audio subsystem by Dolby Laboratories, the transport system by Thomson and Sarnoff, and the transmission subsystem by Zenith. The complete system was integrated at Sarnoff. Testing of the complete Grand Alliance system started in April 1995 and was completed in August of that year.

The Advisory Committee testing of the Grand Alliance system was similar to that conducted for the four individual all-digital systems, however, additional tests were conducted to more fully evaluate the proposed system. These new tests included format conversions between the progressive and interlace modes (both directions) and compliance with the MPEG-2 video compression syntax. Subjective audio tests and long form viewing of video and audio programming were also conducted. A second set of field tests was conducted in Charlotte, North Carolina, utilizing the complete Grand Alliance system. (The VSB transmission sub-system had been field-tested alone in Charlotte in 1994.)

Another vitally important organization in this historic process was the Advanced Television Systems Committee, a private sector organization founded in 1982. ATSC is composed of corporations, associations and educational institutions, developing voluntary standards for the entire spectrum of advanced television systems, including high-definition television. All segments of the television industry are represented within the ATSC, including broadcasters, cable companies, satellite service providers, consumer and professional equipment manufacturers, computer and telecommunications companies, and motion picture and other content providers. Working closely with the Advisory Committee throughout the U.S. DTV process, the ATSC was responsible for developing and documenting the detailed specifications for the ATV standard based on the Grand Alliance system. In addition, the ATSC developed the industry consensus around several standard-definition television (SDTV) formats that were added to the Grand Alliance HDTV system to form a complete digital television standard. Among other things, these SDTV video formats provide for interoperability with existing television standards and support the convergence of television and computing devices.

Following completion of its work to document the U.S. ATV standard, the ATSC membership approved it as the ATSC Digital Television Standard (A/53) on September 16, 1995. On November 28, 1995 the FCC Advisory Committee issued its Final Report, providing the following conclusions:

• The Grand Alliance system meets the Committee's performance objectives and is better than any of the four original digital ATV systems
• The Grand Alliance system is superior to any known alternative system
• The ATSC Digital Television Standard fulfills all of the requirements for the U.S. ATV broadcasting standard

Accordingly, the FCC Advisory Committee recommended that the ATSC DTV Standard be adopted as the standard for digital terrestrial television broadcasts in the U.S.

After receiving the Advisory Committee’s recommendation, the FCC released a Notice of Proposed Rule Making announcing its intention to adopt the ATSC standard. The notice stated:

"We believe that the ATSC DTV Standard embodies the world's best digital television technology and promises to permit striking improvements to today's television pictures and sound; to permit the provision of additional services and programs; to permit integration of future substantial improvements while maintaining compatibility with initial receivers; and to permit interoperability with computers and other digital equipment associated with the national information initiative. It was developed and tested with the unparalleled cooperation of industry experts…"

DTV Standard Adopted by the FCC

On December 24, 1996, the U.S. FCC adopted the major elements of the ATSC Digital Television (DTV) Standard, mandating its use for digital terrestrial television broadcasts in the U.S. (The FCC did not mandate use of the specific HDTV and SDTV video formats contained in the ATSC Standard, but these have been uniformly adopted on a voluntary basis by broadcasters and receiver manufacturers.)

In 1997 the FCC adopted companion DTV rules assigning additional 6 MHz channels to approximately 1,600 full-power broadcasters in the U.S. to permit them to offer digital terrestrial broadcasts in parallel with their existing analog services during a transition period while consumers made the conversion to digital receivers or set-top boxes. The FCC also adopted a series of rules governing the transition to digital television, including a rather aggressive schedule for the transition. Under the FCC’s timetable, stations in the largest U.S. cities would be required to go on the air first with digital services, while stations in smaller cities would make the transition later.

Under the FCC’s plan, more than half of the U.S. population would have access to terrestrial broadcast DTV signals within the first year, all commercial stations would have to be on the air within five years, and all public TV stations would have to be on the air within six years. Analog broadcasts would cease after nine years, assuming that the public had embraced digital TV in adequate numbers by that time. Part of the FCC’s motivation in mandating a rapid deployment of digital TV was to hasten the day when it could recapture 108 MHz of invaluable nationwide spectrum that would be freed up by the use of more spectrum-efficient digital television technology.

In accordance with the FCC plan, digital television service was launched in the U.S. November 1, 1998, and more than 50 percent of the U.S. population had access to terrestrial DTV signals within one year. As of March 1, 2003, there were more than 750 DTV stations on the air in the U.S.

The ATSC DTV Standard was submitted to Task Group 11/3 of the ITU-R, and it was included as System A in ITU Recommendations BT.1300 and BT.1306.

When the ATSC DTV Standard was first adopted by the ATSC in 1995, the ATSC was strictly a United States organization with approximately 50 members, although Mexican and Canadian organizations played a significant role throughout the entire Advisory Committee process in developing what was always expected to be a standard for all of North America, at least. In January 1996 the ATSC modified its charter to become an international organization, and the ATSC began to work with a variety of countries around the world to explore the possibility of using the ATSC Standard for their DTV services. Since that time, the ATSC DTV Standard has been adopted by the governments of Canada (November 8, 1997), South Korea (November 21, 1997), Taiwan (May 8, 1998), and Argentina (October 22, 1998), and many other countries are now considering the ATSC Standard for possible use in their countries. Today, the ATSC has approximately 170 members from a variety of countries in North America, South America, Europe, Asia and Australia.

Ongoing Work of the ATSC

Since the primary ATSC DTV Standard was adopted in 1995, the ATSC has conducted an ever greater and more varied program for developing supplemental DTV and DTV-related standards, and for addressing important implementation issues that have arisen in the countries that have adopted the ATSC DTV Standard. Highlights of this work include a standard for program and system information protocol (PSIP), a conditional access standard to permit restricted or pay services, a data broadcasting standard, a standard for return channel protocols to support interactive services, a standardized software environment for digital receivers (DASE), standards for satellite contribution and distribution services as well as direct-to-home satellite services, and support for non-alphabetic languages. ATSC members from the computer industry have played a central role in leading much of this work, helping to ensure that the full range of potential information services can be achieved using digital television technology.

In conclusion, key organizations that contributed to the development of digital television and to the ATSC DTV Standard specifically include the U.S. Congress and FCC, the FCC’s Advisory Committee consisting of hundreds of volunteers from all corners of the television industry, the Digital HDTV Grand Alliance, the ATSC itself, and the ITU-R. The huge, coordinated effort to create this Standard is, in itself, a momentous achievement. Fortunately, most of the people responsible for this achievement are continuing their efforts under the banner of the ATSC.