High-definition television in the United States

High-definition television in the United States

The FCC has notified U.S. television broadcasters that the standard for transmitting TV over-the-air shall change from analog to digital. While there are many technical, political, and economic reasons for and implications of this change, the end-result for some segments of the American TV audience will be an improvement in picture and sound quality.

From a technical standpoint, this change results in a more efficient management of the portions of the radio spectrum used for television. Even though the ATSC channel uses the same 6 MHz bandwidth as the NTSC channel it replaces, the ATSC channels can be packed in adjacent channel slots, whereas with NTSC transmission technology it is not possible to transmit on adjacent channels in the same geographic area. This allows the U.S. government to implement its plans of removing a portion of the VHF and UHF spectra from television uses and auctioning (resulting in a revenue stream of perhaps billions of dollars) some frequencies off to make them available for commercial voice and data services. Other frequencies will be reserved for government and public service.

From a consumer standpoint, every conventional TV with an antenna will become obsolete, unless connected to a digital tuner. After the switch to digital transmission, TVs will be unable to receive terrestrial analog RF TV broadcasts unless connected to a set-top box or other device that contains a digital tuner. Roughly 20% of viewers receive analog broadcasts over the air, and will be affected by the analog shutoff. The majority of TV watchers will not be affected.Fact|date=March 2008 The 80% of television viewers that use cable or satellite television will not be immediately impacted.Fact|date=March 2008 Virtually all satellite users and an increasing number of cable users already use set top boxes to view programming, and analog cable television is being phased out in many markets. For people unable to buy new digital TVs, Congress is arranging to offer cash vouchers for the purchase of digital tuners.

From a historical standpoint, this is the first time in over half a century that the basic format for TV transmission has changed. The last major change in TV transmission standards took place when compatible color broadcasts began in 1953. That change was engineered to be backwards-compatible, meaning that existing black-and-white TV sets would receive and display "compatible-color" broadcasts (in monochrome) without modification. The impending change to digital from analog is not backwards-compatible.

High definition versus standard or enhanced definition

Digital TV includes HDTV as a subset. The FCC has not mandated HDTV signals be broadcast; it only requires digital TV broadcasts. The prevailing expectation, however, is that native HDTV (i.e., programming recorded with a digital HDTV camera) during primetime will predominate. The great majority of primetime television shows in the United States are available in HDTV at the network level. It is up to the affiliates, not all of which have HDTV broadcast capability, to retransmit these shows at HDTV resolutions. A number of non-primetime shows, including morning news shows and some soap operas, are also available in HDTV.

It is not clear whether broadcasting HDTV or multiple standard definition (SD) channels during non-primetime hours will become common. Many Public Broadcasting Service member stations are now carrying SD multicasts when not broadcasting in HDTV; but unlike many commercial stations, most of these multicasts are suspended while HDTV programs are being broadcast.

The three main types of digital TV set are standard definition ("good", offering the same resolution as the traditional analog system), enhanced definition ("better"), and high definition ("best"). The resolution of viewers' sets does not affect the logistics of the transition to digital TV since all sets with ATSC-compliant tuners will be able to receive and decode all resolutions, even though they might not be able to display the signal at full resolution.

From proposals to introduction

The Federal Communications Commission (FCC) began soliciting proposals for a new television standard for the U.S. in the late 1980s and later decided to ask companies competing to create the standard to pool their resources and work together, forming what was known as the Grand Alliance in 1993.

On July 23 1996, WRAL-TV (the CBS affiliate in Raleigh, North Carolina) was the first television station in the United States to broadcast a digital television signal. Fact|date=March 2008

HDTV sets became available in the U.S. in 1998 and broadcasts began around November 1998. The first public HDTV broadcast was of the launch of the space shuttle Discovery and John Glenn's return to space; that broadcast was made possible in part by Harris Corporation. Fact|date=March 2008 The first major sporting event broadcast in HD was Super Bowl XXXIV on January 30, 2000.

Analog shutoff

Because HDTV requires extra broadcast spectrum during the transition period, it had become a topic of political controversy in the United States. Current stations have received a free channel, usually in the UHF range, on which to broadcast their digital signal, while still maintaining analog service.

According to the original FCC rules, all full power stations were to convert to digital by the beginning of 2007, followed by shutdown of analog broadcasting. An escape clause stipulated that 85% of receivers in the service area must be "capable" of receiving digital signals before the shutdown could occur. At the time of analog shutoff, one of the channels (digital or analog) would then be returned to the government, with the other channel remaining as a digital station; the freed spectrum could then be used for other TV stations, with UHF channels at the high end of the band being decommissioned and sold for other uses. The 2007 deadline could not be satisfied under many interpretations of 85% "capability" of digital signal reception.

On February 8 2006, President Bush signed into law the "Digital Transition and Public Safety Act of 2005", a section of the "Deficit Reduction Act of 2005". This law mandated a hard shut-off date of February 17 2009 for the end of all full power [http://www.fcc.gov/cgb/consumerfacts/DTVandLPTV.html] analog (NTSC) TV transmissions in the U.S., thus ending this uncertainty. The act also provided for the auctioning off of the frequencies associated with UHF channels 52 to 69, and set aside funds to subsidize consumers who would need digital-to-analog converter boxes. [http://www.ntia.doc.gov/otiahome/dtv/PL_109_171_TitleIII.pdf] Coupons can now be requested by households in the U.S. for qualifying standard-definition ATSC converter boxes [ [http://www.dtv2009.org TV Converter Box Coupon Program Website ] ]

Availability of HDTV sets

As of March 2006, all 25 inch and larger TVs for sale were required to have ATSC tuners capable of receiving the 8VSB modulation used for free terrestrial digital broadcasts in the United States. The final conversion step was a mandate that all televisions and TV-tuning devices have ATSC tuners by March 2007. Many of these are not capable of displaying HDTV signals at their full resolution, but they are capable of decoding and displaying these signals.

atellite and cable

Satellite television companies in the United States, such as Dish Network and DirecTV, started to carry HD programming in 2002. Satellite transmissions in the U.S. use various forms of PSK modulation. A separate tuner is required to receive HD satellite broadcasts.

Cable television companies in the U.S. generally prefer to use 256-QAM to transmit HDTV. Many of the newer HDTVs with integrated digital tuners include support for decoding 256-QAM in addition to 8VSB. Some cable television companies, such as Comcast, started carrying HDTV in 2003. As of September 2005, HD programming is carried by all major television networks in at least some broadcast markets, including ABC, CBS, NBC, FOX, PBS, The CW, and MyNetworkTV.

List of satellite and cable high-definition channels

Basic services

*ABC Family HD
*Animal Planet HD
*Big Ten Network HD
* Bio HD
* Bravo HD
* Cartoon Network HD
* CBS College Sports Network HD
*Chiller HD
* Discovery Channel HD
* Disney Channel HD
*E! HD - will be launched on December 8, 2008 [ [http://comcastnetworks.com comcastnetworks.com] ]
*ESPNU HD - launched August 28, 2008
*Fuel HD
*Food Network HD
* Fox Business HD
* Fox HD
* Fox News HD
*G4HD - will be launched on December 8, 2008 [ [http://comcastnetworks.com comcastnetworks.com] ]
*Hallmark Movie Channel HD
*HDNet Movies
*HD Theater
*The History Channel HD
*Lifetime Movie HD
*National Geographic Channel HD
*NFL Network HD
*NHL Network HD
* Nick HD
*Outdoor Channel HD
*Palladia (formerly MHD)
* Sci Fi HD
* The Science Channel HD
*Smithsonian Channel HD
* Soapnet HD
* Spike HD
*Style Network HD - will launch on December 8, 2008 [ [http://comcastnetworks.com comcastnetworks.com] ]
* Tennis Channel HD
*The Golf Channel HD - currently shares HD channel space with Versus. Separate HD feeds for both channels will be launched on December 8, 2008 [ [http://comcastnetworks.com comcastnetworks.com] ]
*Toon Disney HD
* Travel Channel HD
*Universal HD
*Versus HD - currently shares HD channel space with The Golf Channel. Separate HD feeds for both channels with be launched on December 8, 2008 [ [http://comcastnetworks.com comcastnetworks.com] ]
* VH1 HD
*Wealth TV HD
*WGN America HD
*The Weather Channel HD

Regional public broadcasting services

*WXXI-TV HD in Rochester, NY [http://www.wxxi.org/about/index.html]

Regional sports networks

*Channel 4 San Diego (San Diego Padres)
*Altitude Sports and Entertainment (Denver)
*Comcast SportsNet HD (Bay Area, Chicago, Mid-Atlantic [Baltimore/Washington] , New England, Northwest [Portland] , Philadelphia, and West [Sacramento] )
*MSG Network in HDTV (New York, New Jersey, Connecticut, Pennsylvania)
*NESN HD (New England area)
*YES-HD (New York Yankees)
*SportsNet New York (New York Mets)
*SportsTime Ohio (Cleveland Indians)

Premium services

*Max HD
*Movie Channel HD
*Showtime HD
*Showtime Too HD
*Starz HD
*Starz Comedy HD
*Starz Edge HD
*Starz Kids and Family HD


Of those TVs with built-in QAM tuners, a subset also have CableCARD support. CableCARD enables the subscriber to access encrypted channels (generally premium channels), and ultimately (with a future version of the standard), interactive services such as video on demand, pay-per-view, and the cable operator's interactive program guide. This eliminates the need for a separate, free standing cable box.

The broadcast flag rule

The FCC also instituted the broadcast flag rule through administrative rulemaking, which required that HDTV sets manufactured in July 2005 or later to include technology which would restrict the ability of viewers to record or time-shift broadcasts that the provider has flagged with a special signal, the broadcast flag. The mandate was highly controversial, with consumer and civil liberties advocates arguing that it stripped consumers of rights they had enjoyed in the past. In May 2005, the United States Court of Appeals for the District of Columbia Circuit struck down the Broadcast Flag mandate in a unanimous ruling, holding that the FCC overstepped its statutory authority when it asserted control of any device capable of receiving an HDTV signal.


ee also

*Digital-to-Analog Converter Box Coupon Program

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