Digital television in the United States

See digital television for more technical details, or DTV transition in the United States for specific information related to the analog-to-digital switchover

In the United States, digital television broadcasts, or DTV, can be received via cable, via internet, via satellite, or via digital terrestrial television - much like analog television broadcasts have been. Full-power analog television broadcasts, however, were required by U.S. federal law to cease by June 12, 2009. Low-power, Class A, and TV Translator stations are not currently required to cease analog broadcasts. Also by law, digital broadcasts - when transmitted as OTA signals - must conform to ATSC standards.;[1] it is unclear whether satellite operators are free to use their own proprietary standards; and many standards exist for Internet television (most are proprietary).


The U.S. opted to adhere to ATSC standards for broadcast digital television. These standards define, among other things, format and transmission criteria that ensure consistency, accessibility, and fairness for consumers and equipment manufacturers alike in the U.S., as well as international compatibility.

Format standards

The five main ATSC formats of DTV currently broadcast in the U.S. are:

Most digital television sets sold in the U.S. use a display with a 16:9 aspect ratio to optimally display HDTV-formatted content. Lower-resolution sources like regular DVDs may be upscaled to the native resolution of the TV.

Transmission standards

Pay television

Most Americans get digital television broadcasts via cable or satellite. Digital cable television systems with an active channel capacity of 750 MHz or greater, are required by the FCC to follow ANSI/SCTE transmission standards with the exception of cable systems that only pass through 8 VSB modulated signals.[2] Digital television sets (equipped with ATSC tuners) are often capable of viewing a baseline set of unencrypted digital programming, known as basic cable or low-tier channels, which typically include local network television affiliates. According to FCC regulations, the remaining encrypted channels must be viewable with a receiver equipped with a CableCARD,.


Digital television transmissions over-the-air (OTA) are available in metropolitan areas in the U.S., often carrying both standard-definition and high-definition (HDTV) transmissions of the same stations.[3] As of the analog shut-off date of June 12, 2009, all full power OTA stations in the U.S. by law either transmitted their broadcasts digitally, or shut down.

Many stations used the switch to digital transmission as an opportunity to transition from 480i broadcasts to digital HD OTA broadcasts (either in 720p or 1080i), though this change is voluntary.

Within a distance of 35 to 40 miles from the broadcast stations, it is possible that a simple antenna (such as "rabbit ears") may be adequate to receive a DTV broadcast signal OTA—at least some of the time for some of the channels. Any television equipped with an ATSC tuner may display DTV broadcasts properly. Some customers discovered that terrain, trees, rain, snow, wind, and movement of people around the room interfere with reception to one degree or another, from signals breaking up to total loss of signal. (Few modern ATSC-equipped televisions or converter boxes have internal antennas, in contrast to analog sets available in years past).

Broadcast TV signals in the United States are horizontally polarized.

Transition from analog to digital terrestrial broadcasts in 2009

It was estimated that as of April 2007, 28% of American households had an HDTV set, a total of 35 million sets, and that 86% of owners were highly satisfied with the HDTV programming[4] All TV stations currently broadcast in both digital and analog and major networks broadcast in HD in most markets.

While many in the industry wanted a flexible or delayed deadline, the FCC forced the issue at the behest of Congress. Congress wanted to reclaim some of the spectrum used for analog and repurpose that for emergency services. They also wanted to auction off bandwidth between 76-88 MHz frequencies (channels 5 and 6) and old analog UHF channels 60 to 69, and channels 52 to 59 by mandating DTV tuners be phased into all new TV sets. Many transition dates were proposed, but Congress finally fixed February 17, 2009 (later extending it until June 12, 2009), in law as the maximum end date for analog television authorizations.[5] Because this date comes after the NCAA's Bowl Championship Series and the NFL's Super Bowl XLIII, there will be less of a chance of an acute hardware shortage from people waiting until the last minute to purchase an ATSC tuner than there would have been with a January 1 cutoff.

In March 2008, the FCC requested public comment on turning the bandwidth currently occupied by analog television channels 5 and 6 (76–88 MHz) over to extending the FM broadcast band when the digital television transition was to be completed in February 2009 (ultimately delayed to June 2009).[6] This proposed allocation would effectively assign frequencies corresponding to the existing Japanese FM radio service (which begins at 76 MHz) for use as an extension to the existing North American FM broadcast band.[7]

Ultimately, VHF Channels 5 and 6 were retained for digital broadcast television use after the transition, though the FCC had continued researching the possibility of re-allocating the two channels to an expanded FM band.

On August 22, 2011, the United States' Federal Communications Commission announced a freeze on all future applications for broadcast stations requesting to use channel 51,[8] to prevent adjacent-channel interference to the A-Block of the 700 MHz band. On December 16, 2011, Industry Canada and the CRTC followed suit in placing a moratorium on any future Channel 51 television station applications.[9]

Early rollout of transition

On May 8, 2008, FCC Chairman Kevin J. Martin announced the agency would test run the transition to digital terrestrial television in Wilmington, North Carolina, beginning September 8, 2008. This test run was to work out problems that might have occurred before the complete transition.

See also


  1. ^ FCC. The Digital TV Transition FAQs Archived 2008-04-24 at the Wayback Machine
  2. ^ "76.640 Support for unidirectional digital cable products on digital cable systems". Government Printing Office. 8 Nov 2003. Archived from the original on 2012-10-09.
  3. ^ "Archived copy". Archived from the original on 2012-02-02. Retrieved 2011-11-01.CS1 maint: Archived copy as title (link) AntennaWeb
  4. ^ "WKYC's Director's Cut with Frank Macek: News: HDTV Penetration at 28%". Archived from the original on 9 February 2013. Retrieved 26 April 2018.
  5. ^ 47 USC 309(j)(14)(A) "Archived copy". Archived from the original on 2008-12-06. Retrieved 2006-02-10.CS1 maint: Archived copy as title (link) as amended by section 3002 of S.1932 signed into law February 8, 2006
  6. ^ Federal Communications Commission (2008-05-16). "In the Matter of Promoting Diversification of Ownership in the Broadcasting Services". Archived from the original on 2008-12-27. Retrieved 2008-08-26. Certain commenters have urged the Commission to give a "hard look" to a proposal that the Commission re-allocate TV Channels 5 and 6 for FM broadcasting 73 FR 28400, 28403
  7. ^ Could EXB Band Be Your New Home? Archived 2009-05-06 at the Wayback MachineRadioWorld September 10, 2008
  8. ^ FCCPublic Notice DA-11-1428A1 Archived 2013-02-28 at the Wayback Machine:
  9. ^ Telecommunications, Government of Canada, Industry Canada, National Capital Region, Office of the Deputy Minister, Spectrum, Information Technologies and. "Industry Canada Advisory Letter - Moratorium on the Use of Television Channel 51". Archived from the original on 9 August 2017. Retrieved 26 April 2018.

External links

Advanced Television Systems Committee

The Advanced Television Systems Committee (ATSC) is the group, established in 1982, that developed the eponymous ATSC standards for digital television in the United States. These standards have also been adopted by Canada, Mexico, South Korea and recently Honduras, and are being considered by other countries.


Biotelemetry (or medical telemetry) involves the application of telemetry in biology, medicine, and other health care to remotely monitor various vital signs of ambulatory patients.


CEA-909 is the ANSI standard for 8VSB/ATSC smart antennas. The basic concept is that the smart antenna either physically rotates toward the signal, or is stationary, but has elements pointed in different directions and uses only those elements that maximize the received signal. This is accomplished by feedback from the control device, such as a digital-to-analog converter box, telling the smart antenna when the signal is stronger or weaker.

Analog televisions generally give instant feedback as the signal gets better or worse as you move the antenna. Digital television antennas can be difficult to aim correctly because of the cliff effect and because of delays in decoding and displaying the signal. Smart antennas remove the burden of positioning the antenna for digital TVs and can make the tuning process easier than it was with analog television.

Create (TV network)

Create is an American digital broadcast television network. The network broadcasts how-to, DIY and other lifestyle-oriented instructional programming 24 hours a day.

DTV America

DTV America Corporation is an owner of low-power television stations in the United States.

Majority owned by telecommunications conglomerate HC2 Holdings, DTV America stations have no local operations, and the company relies almost entirely upon the 24-hour feeds of digital subchannel networks for content. DTV America stations typically carry a large number of digital subchannels not carried by any full-power broadcaster in each respective market. Its stations are mostly in small media markets and rural areas on the fringes of another market but too far away to be served by the major network affiliates.

As of 2015, the chief executive officer is John Kyle II.

Digital television transition in the United States

The digital transition in the United States was the switchover from analog to exclusively digital broadcasting of terrestrial television television programming. According to David Rehr, then president and CEO of the National Association of Broadcasters, this transition represented "the most significant advancement of television technology since color TV was introduced." For full-power TV stations, the transition went into effect on June 12, 2009, with stations ending regular programming on their analog signals no later than 11:59 p.m. local time that day.Under the Digital Transition and Public Safety Act of 2005, full-power broadcasting of analog television in the United States was initially planned to have ceased after February 17, 2009. To help U.S. consumers through the conversion, the Act also established a federally sponsored DTV Converter Box Coupon Program.

The DTV Delay Act changed the mandatory analog cutoff date to June 12, although stations were permitted to cease analog transmissions before the new mandatory cutoff date. The legislation was enacted on February 4, 2009, and on February 11, 2009, President Barack Obama signed it into law. The purpose of the extension was to help the millions of households who had not been able to get their coupons for converters because demand for coupons exceeded the funding provided for in the initial bill, leaving millions on a waiting list to receive coupons. Funding for extra coupons was provided by the American Recovery and Reinvestment Act of 2009. By midnight on the original cut-off date of February 17, 2009, 641 stations representing 36 percent of U.S. full-power broadcasters were transmitting exclusively in digital.Analog broadcasting did not cease entirely following the June 12 deadline: under the provisions of the Short-term Analog Flash and Emergency Readiness Act, approximately 120 full-power stations briefly maintained analog "nightlight" service, ending no later than July 12. In a separate category, low power television stations were permitted to continue analog broadcasts for several more years.

On July 15, 2011, the FCC posted the required transition deadlines for low power television. Stations broadcasting on channels 52 to 69 were required to vacate those channels by December 31, 2011, and all analog television transmitters (primarily low-powered (LP), and Class-A low-powered (-CA) stations, and also broadcast translator (TX) repeaters in rural communities) were required to shut down by September 1, 2015. On April 24, 2015, it was announced that the conversion date for standard LPTVs and translators still broadcasting in analog had been suspended until further notice, due to economic problems that may arise from the then-upcoming spectrum auction; however, Class A low-powered stations were still required to convert by the original deadline date of September 1, 2015. After the auction's completion in 2017, the FCC announced on May 17 of that year that all analog low-power stations and transmitters must convert by July 13, 2021.

FM broadcast band

The FM broadcast band, used for FM broadcast radio by radio stations, differs between different parts of the world. In Europe, Australia and Africa ((defined as International Telecommunication Union (ITU) region 1)), it spans from 87.5 to 108 megahertz (MHz) - also known as VHF Band II - while in the Americas (ITU region 2) it ranges from 88 to 108 MHz. The FM broadcast band in Japan uses 76 to 95 MHz. The International Radio and Television Organisation (OIRT) band in Eastern Europe is from 65.8 to 74.0 MHz, although these countries now primarily use the 87.5 to 108 MHz band, as in the case of Russia. Some other countries have already discontinued the OIRT band and have changed to the 87.5 to 108 MHz band.

Frequency modulation radio originated in the United States during the 1930s; the system was developed by the American electrical engineer Edwin Howard Armstrong. However, FM broadcasting did not become widespread, even in North America, until the 1960s.

Frequency-modulated radio waves can be generated at any frequency. All the bands mentioned in this article are in the very high frequency (VHF) range, which extends from 30 to 300 MHz.

Game show

A game show is a type of radio, television, or stage show in which contestants, individually or as teams, play a game which involves answering questions or solving puzzles, usually for money or prizes. Alternatively, a gameshow can be a demonstrative program about a game [while usually retaining the spirit of an awards ceremony]. In the former, contestants may be invited from a pool of public applicants. Game shows often reward players with prizes such as cash, trips and goods and services provided by the show's sponsor prize suppliers.

Google Fiber

Google Fiber is part of the Access division of Alphabet Inc. It provides fiber-to-the-premises service in the United States, providing broadband Internet and IPTV to a small and slowly increasing number of locations. In mid-2016, Google Fiber had 68,715 television subscribers and was estimated to have about 453,000 broadband customers.The service was first introduced to the Kansas City metropolitan area, including 20 Kansas City area suburbs within the first 3 years. Initially proposed as an experimental project, Google Fiber was announced as a viable business model on December 12, 2012, when Google executive chairman Eric Schmidt stated "It's actually not an experiment, we're actually running it as a business," at the New York Times' DealBook Conference.Google Fiber announced expansion to Austin, Texas, and Provo, Utah, in April 2013, and subsequent expansions in 2014 and 2015 to Atlanta, Charlotte, the Triangle, Nashville, Salt Lake City, and San Antonio.On August 10, 2015, Google announced its intention to restructure the company moving less central services and products into a new umbrella corporation, Alphabet Inc. As part of this restructuring plan, Google Fiber would become a subsidiary of Alphabet and may become part of the Access and Energy business unit. In October 2016, all expansion plans were put on hold and some jobs were cut. Google Fiber will continue to provide service in the cities where it is already installed.

Headend in the Sky

Headend in the Sky (HITS) is Comcast's satellite multiplex service that provides cable channels to cable television operations.

At a traditional cable television headend, multitudes of satellite dishes and antennas are used to grab cable stations from dozens of communication satellites. In contrast, HITS combines cable stations into multiplex signals on just a few satellites; cable television companies can then pull in hundreds of channels at the local headend with relatively little equipment; the HITS feed effectively replaces the more complex traditional headend operations.

HITS was founded in 1994 and its namesake product is commonly recognized as the pioneer of digital television in the United States. HITS was launched by TCI before their later 1999 purchase by the old AT&T, then merged with the smaller Comcast in 2002 as part their purchase of AT&T Broadband (formerly TCI). The HITS headquarters in Centennial, Colorado, formerly known as the National Digital Television Center, is now called the Comcast Media Center.

As of 2010, HITS offers 6 standard-definition multiplexes on SES Americom's SES-1, 12 standard-definition multiplexes and 8 HD multiplexes on AMC-18, 1 standard-definition multiplex on AMC-10, and 1 standard definition multiplex on Intelsat's Galaxy 17. As of 2010, HITS delivers more than 280 digitally compressed video and audio television programming signals to more than 2000 cable operation sites across the US.

High-definition television in the United States

High-definition television (HDTV) in the United States was introduced in 1998 and has since become increasingly popular and dominant in the television market. Hundreds of HD channels are available in millions of homes and businesses both terrestrially and via subscription services such as satellite, cable and IPTV. HDTV has quickly become the standard, with about 85% of all TVs used being HD as of 2018. In the US, the 720p and 1080i formats are used for linear channels, while 1080p is available on a limited basis, mainly for pay-per-view and video on demand content.

Light TV

Light TV is an American digital broadcast television network owned by MGM Television that launched on December 22, 2016. The network features family-friendly and faith-based entertainment programming. Light TV is headed by the husband-and-wife team of Mark Burnett and Roma Downey; Burnett is the CEO of MGM TV, while Downey is best known as an actress and star of Touched by an Angel. Both Burnett and Downey consider themselves deeply religious, and have teamed in the past on producing several religious- or family-oriented projects (most notably the 2013 History miniseries The Bible) through the MGM subsidiary Downey leads, Lightworkers Media.

Mobile Emergency Alert System

The Mobile Emergency Alert System (M-EAS) is an information distribution system that utilizes existing digital television spectrum and towers to provide information in emergency situations using rich media. The system can push text, web pages, and video to compatible equipment, such as mobile DTV devices. M-EAS is different than existing 90-character Wireless Emergency Alerts (WEA) available to cellphones, as it allows video, audio, photos and graphics, too.

Proponents of the technology point to modern reliance on mobile communication technologies and failures of the cellular network due to overload, power outage or other emergency-related damage. M-EAS does not rely on the network of cellular towers, instead making use of existing digital television broadcast equipment.

M-EAS is being standardized by the Advanced Television Systems Committee as part of ATSC-M/H, the mobile digital TV standard. WRAL-TV in Raleigh, North Carolina, was the first commercial broadcaster in the United States to demonstrate the system in 2012.A similar system in Japan is credited with saving many lives ahead of the 2011 Tōhoku earthquake and tsunami.


RabbitEars is a website dedicated to providing information on over-the-air digital television in the United States, its territories and protectorates, and border areas of Canada and Mexico. Aside from merely listing network affiliations and technical data, notations of stations carrying Descriptive Video Service, TVGOS, UpdateTV, Sezmi, Mobile DTV, and MediaFLO are also now covered on the site. RabbitEars also maintains a spreadsheet of current television stations.

RabbitEars.Info has been cited by The New York Times, The Washington Post, the Los Angeles Times, the Columbus Dispatch, and the Gotham Gazette for news stories, the Electric Pi Journal, CEOutlook, Sony's eSupport, and Crutchfield websites for additional technical information, and WCCB-TV,WOLO-TV, and WGHP television stations in relation to the digital television transition.

Short-term Analog Flash and Emergency Readiness Act

The Short-term Analog Flash and Emergency Readiness Act, or SAFER Act, is a U.S. law that required the Federal Communications Commission (FCC) to allow the continuation of full-power analog TV transmissions in 2009 for an additional 30 days for the purpose of broadcasting public service announcements regarding the DTV transition in the United States and emergency information. It is also commonly known as the "DTV nightlight bill" or "analog nightlight", referring to a small nightlight that is left on after all of the other lights are out. Despite the analog shutoff deadline being extended to June 12, 2009 as part of the DTV Delay Act, stations that signed off before the deadline were still permitted to participate in the SAFER Act.

This was allowed for such broadcasts, in both English and Spanish, until July 12, 2009, while normal programming ceased on that date. It was passed by both houses of the U.S. Congress, originating in the U.S. Senate as S. 3668, and approved by the U.S. House in mid-December 2008. Such broadcasts were not required, and for stations which changed from analog to digital broadcasts on the same frequency (known as a flash-cut) this would have been impossible. Only stations signing off early or in the "core spectrum" (channels 2 to 51) were allowed to participate so that channels 52 to 69 could be cleared from the TV broadcasting spectrum. At least one station above 51, Fox affiliate WPGH-TV in Pittsburgh (channel 53), signed off its analog signal on the original February deadline, thereby allowing it to participate in the SAFER Act.The act was signed into law by President George W. Bush on December 23, 2008 and the FCC was given until January 15, 2009 to finalize the related rules and regulations. The initial FCC-generated list of eligible stations was published on December 29, 2008. Other stations were encouraged to apply, especially in media markets where no station was listed. Stations only required a special temporary authority (STA) from the FCC to be a part of the service.

Limited presence of advertising and sponsorship was permitted, insofar as it is needed to allow news broadcasts from the main digital station to be simulcast onto the nightlight channel during an emergency. Commercial activity was otherwise limited to mere identification of sponsors. An updated FCC list of eligible stations, released January 15, 2009, identified twenty-eight stations nationwide which have expressed interest in conducting these broadcasts. The cost per station to operate the transmitters for one month has been estimated at $3500 to $15,000, depending on the frequency, power level, and local electric rates.

Low-power TV (LPTV) stations are not required to transition to digital broadcasting, thus the bill does not affect them. Because of this exception, several stations throughout the nation, such as Washington, D.C.'s WJLA (ABC) and WDJT-TV (CBS) in Milwaukee, took advantage of the loophole by moving network programming from their former analog full-power stations to purchased or leased LPTV stations in order to continue to provide some form of analog network programming and local news to their market area until such time as digital adoption has been deemed sufficient by the stations. WJLA ended their extended service shortly after the nightlight period, while the special dispensation by CBS for WDJT to air the network on their station ended on December 31, 2009, at which time it began to transmit Me-TV station WBME-TV's main signal until Weigel's low-power analog signals in Milwaukee were turned off at the beginning of 2013.

After June 12, 2009, a low-power analog station in Chicago, not required to shut down after 30 days like other nightlight stations, aired newscasts that otherwise could not be seen by a number of people after the transition while stations attempted to solve technical and reception problems.The FCC reported 121 stations providing nightlight service in 87 markets after the June 12, 2009 transition.All of the stations were supposed to be off the air by July 12, 2009, and David Fiske of the FCC said no investigation was planned to ensure compliance. Fiske said someone would have to report a full-power station for violating the rule. Continuation of full-power broadcasting beyond this date was considered to be unlikely, as the stations would have to incur the costs of operating two transmitters.

While Nielsen estimated that 1.7 million people still could not pick up a digital signal as of July 1, 2009, former acting FCC chair Michael Copps said giving nightlight stations more time was not planned.

Smart antenna

Smart antennas (also known as adaptive array antennas, digital antenna arrays, multiple antennas and, recently, MIMO) are antenna arrays with smart signal processing algorithms used to identify spatial signal signatures such as the direction of arrival (DOA) of the signal, and use them to calculate beamforming vectors which are used to track and locate the antenna beam on the mobile/target. Smart antennas should not be confused with reconfigurable antennas, which have similar capabilities but are single element antennas and not antenna arrays.

Smart antenna techniques are used notably in acoustic signal processing, track and scan radar, radio astronomy and radio telescopes, and mostly in cellular systems like W-CDMA, UMTS, and LTE.

Smart antennas have many functions: DOA estimation, beamforming, interference nulling, and constant modulus preservation..

TV Red Puerto Rico

TV Red de Puerto Rico, Inc. is a local owner of low-power television stations in Puerto Rico and the U.S. Virgin Islands. These stations carry programming from English-language and Spanish-language television networks. Headquartered in San Juan, TV Red is one of the largest station groups in Puerto Rico in terms of numbers of stations owned.

Tentative channel designation

Tentative channel designation is a term used by the Federal Communications Commission to refer to TV channel assignments that represent the channels that TV stations must use after the analog cutoff, completing the transition to Digital television in the United States. These channels are determined through a multiple round procedure involving elections by the TV stations themselves, usually either their original analog channel, or their transitional digital channel. The FCC accepts or rejects these elections depending on conflicts that may exist. The FCC has published periodic Report and Order documents with attachments listing the Tentative Channel Designations as of that date.


USDTV, an acronym for U.S. Digital Television, was an over-the-air, pay television service in the United States. Based in Draper, Utah near Salt Lake City, it was founded in 2003 and started service there in 2004. The company ceased operations March 12, 2007.

USDTV leased subchannel space from local TV stations for its subscription TV service. USDTV ended services in 2007.

Digital television in North America
Satellite TV
Technical issues
Network topology
and switching

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