The United States has moved forward aggressively with the implementation of DTV using the ATSC Digital Television (DTV) Standard, a powerful technology that is transforming the nature of broadcast television service. This new broadcast transmission standard provides broadcasters with many new capabilities to serve the public, such as HDTV and standard resolution pictures, multicasting, data delivery, interactive communication, robust reception modes, and other features. These capabilities provide broadcasters the technical flexibility and options to compete with other digital media such as cable and direct broadcast satellite services. The ATSC DTV standard was developed through a lengthy initial specification process that began in 1987 and its evolution is continuing today, due to the flexibility for extending the digital system to include new capabilities as technology continues to develop. Coincident with the development of the transmission technology, the U.S. Government, through actions by its Federal Communications Commission (FCC) and legislation by the U.S. Congress, has developed public policies under which digital television is being implemented.
The U.S. Government is implementing broadcast DTV service as a replacement technology for the existing analog National Television System Committee (NTSC) technology that has been used for transmission of broadcast television service in the United States since the late 1940s. Under this policy approach, all eligible existing television stations were provided a second channel to be used for DTV service during a transition period from the analog to digital operation. This transition period, which began in 1998, is intended to facilitate an orderly change to the digital television technology while taking account of consumer investments in analog television sets. At the end of this transition period, TV stations will cease analog transmissions so that all broadcast television service will then be in the digital format. The FCC will also recover one of each TV station’s two channels at this time. Because operation with the ATSC standard is very spectrum efficient, it is possible for all of the existing TV stations to operate in a much smaller amount of spectrum bandwidth, thereby allowing a portion of the existing TV channels 2-69 to be recovered for new uses. The U.S. Government plan is for all DTV stations to operate on channels 2-51 (the DTV core spectrum) after the transition ends and to recover channels 52-69 (698 MHz to 806 MHz) for new uses.
After very careful consideration and review in the FCC’s public rule making processes, the Commission afforded broadcasters great flexibility in the use of their DTT channels. Broadcasters were required at least to match the hours of operation of their existing analog station. For example, if the analog station operated
24 hours/day, then the digital station would also be required to operate 24 h/day.
Broadcasters were given almost unlimited flexibility in the services that could be offered over their 6 MHz digital channel. They were required to offer one free-to-air video program service with resolution equivalent to their existing analog service. Beyond this, they could offer whatever other services they chose on the digital channel.
The FCC did not impose any requirement that broadcasters offer HDTV, and there is no legal requirement for U.S. broadcasters to offer HDTV. However, HDTV was the initial focal point of the U.S. transition to DTT broadcasting, and it has remained the centerpiece application throughout the U.S. deployment.
Pay services were explicitly permitted by the FCC, once a single, free, standard-definition program had been provided. If broadcasters do use their DTT channel to offer services for which a subscription fee or charge is required in order to receive service, they are required to pay the U.S. government a spectrum use fee in the amount of 5% of gross revenues from any such service.
The basic transition plan followed in the U.S. was to require stations affiliated with the four largest TV networks in the 30 largest cities to implement DTT first, while allowing more time for stations in smaller cities to make the transition. In addition, public TV stations were given an extra year beyond the deadline that applied to commercial stations. The FCC’s initial plan applied to approximately 1,600 commercial and non-commercial (public) stations. Transition planning for low-power TV stations and for translators was deferred for several years, but has now been completed. Low power TV stations generally will be allowed to transition to DTV operation on their existing channels. In addition, if they so desire and a channel is available, low power stations may request a “companion channel” for DTV operation during the transition. The FCC further stated that it would establish a deadline at the end of the transition for low power stations that would be after the end of the transition for full service stations.
Each station was given a new assignment for its DTT broadcast channel, along with an antenna height, antenna pattern and maximum radiated power level, in an effort to replicate the station’s analog coverage area. Assignments for all 1,600 stations were made shortly after the FCC formally adopted the ATSC Standard and approximately 18 months before the launch of commercial DTT service.
At the request of the FCC, 28 stations in the ten largest cities volunteered to launch DTT service in November 1998, six months ahead of the deadline established by the FCC. Six months later (May 1999) all stations in the top 10 markets that were affiliated with the four largest broadcast networks were required to provide service, and in another six months (November 1999) this requirement was extended to the affiliates of the four largest networks in all of the 30 largest cities. All commercial broadcasters were required to be on the air by May 2002 and all non-commercial broadcasters by May 2003. Broadcasters who could not meet these deadlines were allowed to apply for a six-month extension and in some cases a second six-month extension under certain circumstances.
The U.S. Congress and the FCC are determined to conclude the transition to DTT broadcasting as rapidly as possible for a variety of reasons, most notably to recapture 108 MHz of invaluable nationwide spectrum that will be made available once analog TV transmissions cease. Broadcasters also want to make the conversion as rapidly as possible in order to eliminate the expense of operating two TV stations in parallel.
In early 2006, legislation was enacted by the U.S. Congress requiring broadcasters to terminate their analog transmissions by February 17, 2009. This legislation included provision of up to $1.5 billion to subsidize the purchase by television viewers of digital-to-analog set-top converters that could be used to view DTT signals on existing analog television receivers.
Each television household would be permitted to apply for up to two $40 coupons that could be used to purchase such converters, with only one coupon allowed per converter. The price of these converters is typically about $50 (without a coupon).
The FCC adopted regulations that phased in a requirement for inclusion of ATSC receiving capability starting with the largest TV sets first, in 2004, and for all sets over 13 inches by July 2007. In November 2005 the FCC amended its rules to advance the date for the completion of the phase-in period to March 1, 2007, and to apply the requirement to all receivers regardless of screen size. Thus, every television set sold in the U.S. must now contain ATSC DTT reception and decoding capabilities. The U.S. Consumer Electronics Association predicts that over 100 million integrtaed ATSC DTT receivers per year will be sold in the U.S. alone by 2009.This is ina addition to ATSC HDTV Set-top boxes and digital to analog converters.
Although it is not required by the government, all DTV receivers available in the United States are capable of decoding all ATSC specified video formats. All-format decoding is essential to permit the introduction of HDTV – later, if not initially.
While there are no government requirements for DTT receiver performance, on a voluntary basis (and upon the recommendation of the FCC) the ATSC has adopted a recommended practice giving performance parameter guidelines for DTT receivers.
The United States is now in the final stages of its DTV transition and there have been many challenges that have been faced and overcome in the period since 1997. In recent years the desire of the U.S. Government to recover TV channels 52-69 for new uses has given rise to greater emphasis on completing the transition as rapidly as possible. The FCC has taken a variety of steps to achieve a rapid conclusion to the transition and to ensure that the benefits and services of DTV broadcasting are available to all Americans. The U.S. Congress has also enacted legislation that mandates the end of analog television transmissions on February 17, 2009.
DTT broadcasting is moving ahead at a feverish pace. More than 1,700 DTV stations are on the air in
211 metropolitan areas, reaching 99.99% of U.S. television households with at least one digital signal. More than 90% of households have access to at least five digital signals, and more than 80% have access to at least eight. In the largest U.S. cities, as many as 23 digital stations are on the air.
HDTV programming is widely available, not only via DTT broadcasts, but over cable and satellite systems as well. Most network primetime and sports programming is now produced in HDTV. Local TV stations are beginning to offer their local news in HDTV.
Manufacturers throughout the world have responded to this demand by developing and marketing more than 750 different models of HDTV and other ATSC DTT consumer products, using a wide variety of new display technologies. Competition is frenzied, with prices continuing to fall rapidly and sales skyrocketing. Since late 1998 when the service was launched and March 31, 2006, more than 30 million units of DTT consumer products worth more than $50 billion have been sold in the U.S. alone. Moreover, sales are continuing to grow exponentially, with projected sales for all of 2006 of approximately 20 million units worth $30 billion.
Standard-definition (SDTV) integrated 27” ATSC receivers are now available for as little as US$299, and integrated 27” HDTV receivers for as little as US$430. Indeed, prices for HDTVs are converging rapidly with those for analog color TVs. It is no longer possible to purchase a large-screen analog color TV in the U.S. They have all been replaced by digital HDTVs. This trend will accelerate and spread to smaller screen sizes over the next few years as prices continue to fall and as the phase-in of the FCC’s tuner mandate is completed. Under this regulation, all television receivers sold in the U.S. must have ATSC tuning and decoding capability by March 2007. As a result, by 2007 an estimated 34 million ATSC receivers per year will be sold in the U.S. alone, with cumulative sales reaching 152 million by 2009. Such massive sales volumes will further drive down the price of ATSC receivers, such that many experts believe that within three or four years, virtually all TV sets sold in the U.S. will be HDTVs, because they will cost no more than analog color TVs by that time, even at the smaller screen sizes.
In addition to HDTV, broadcasters in the U.S. are using DTT to provide innovative packages of new services. Some broadcasters are providing multiple simultaneous programs of SDTV. This is especially important for public broadcasters in achieving their goals to support public education, providing multiple education programs instead of just one program at one time. Many commercial broadcasters are now offering a main program in HDTV, plus another SDTV program such as 24-hour news or weather. Some broadcasters are also pooling their excess capacity to offer basic pay-TV platforms in competition with cable and satellite systems.
Broadcasters are also beginning to offer various data services using the ATSC family of standards, including interactive information services.
The U.S. government is planning to complete the transition to DTT broadcasting by February 2009, in order to free up extremely valuable nationwide spectrum that can be used to promote public safety and national security, and to support new wireless services that will be engines of economic growth for decades to come. To support its decision to end analog television transmissions, the U.S. Congress urged the development of an inexpensive digital-to-analog set-top converter box to permit consumers to view DTT signals on their existing analog TV sets. Several manufacturers responded, demonstrating prototype converters that are expected to cost US$50 by 2008, if sold in large quantities.
With respect to reception by portable hand-held receivers or in fast-moving vehicles, the ATSC Standard was not originally designed to provide this type of reception. Rather, the goal was to deliver the largest possible payload data rate to the largest service area, to ensure that broadcasters could reach the largest possible audience with high-quality HDTV images and associated surround sound.
Now that HDTV is firmly in hand, however, U.S. broadcasters are showing increasing interest in receiving DTV signals in moving vehicles and by pedestrians with hand-held devices. A number of companies have been working on adding such applications to the ATSC Standard.
The implementation of digital television service based on the ATSC family of standards is moving ahead dramatically in the U.S. (.HDTV is firmly entrenched, and is replacing analog color television at a rapid pace. SDTV multicasting and information services are also important and are being expanded, as broadcasters learn to take full advantage of the rich possibilities of DTT broadcasting using the ATSC family of standards. A cornucopia of dazzling new consumer products is available, at rapidly falling prices that make DTT receivers affordable for all socio-economic classes. Continuing improvements in ATSC receivers and further extensions and new additions to the ATSC family of standards are laying the groundwork for additional new services and applications in the future.
The U.S. is now in the final stages of its transition to digital television broadcasting, with a hard date set for the end of analog transmissions. Ending analog transmissions will mark the end of the transition to DTT broadcasting, which will permit the recovery of extremely valuable spectrum that will support new wireless services that will be engines of economic growth for decades to come.