Terrestrial television
Encyclopedia
Terrestrial television is a mode of television
broadcasting
which does not involve satellite
transmission or cable
s — typically using radio waves
through transmitting and receiving antennas
or television antenna
aerials. The term is more common in Europe
, while in the United States
it is referred to as broadcast television or sometimes over-the-air television (OTA) and requires a Tuner (television) to view content.
Terrestrial television broadcasting dates back to the very beginnings of the broadcast television system
as a medium itself with the first long-distance public television broadcast from Washington, D.C., on April 7, 1927. The BBC
began broadcasting television to the public in 1929, and had a regular schedule of television program
mes in 1930. Aside from transmission by high-flying planes moving in a loop using a system developed by Westinghouse called Stratovision
, there was virtually no other method of television delivery until the 1950s with the beginnings of cable television
, or community antenna television (CATV). The first non-terrestrial method of delivering television signals that in no way depended on a signal originating from a traditional terrestrial source began with the use of communications satellite
s during the 1960s and 1970s.
. In UK, VHF channels were kept on the old 405-line
system, while UHF was used solely for 625-line broadcasts (which later used PAL
colour). Television broadcasting in the 405-line system continued after the introduction of four analogue programmes in the UHF bands until the last 405-line transmitters were switched off on January 6, 1985. VHF Band III is still used in other countries around Europe for PAL broadcasts, though many have plans to phase it out.
The success of terrestrial analogue television across Europe varies from country to country. Although each country has rights to a certain number of frequencies by virtue of the ST61 plan, not all of them have been brought into
standard for color television
broadcasts in 1953. Later, Europe and the rest of the world either chose between the later PAL
and SECAM
color television standards, or adopted NTSC. Japan also uses a version of NTSC.
In addition to the threat from cable television
, analog terrestrial television is now also subject to competition from satellite television
and distribution of video and film content over the Internet
. The technology of digital terrestrial television
has been developed as a response to these challenges. The rise of digital terrestrial television, especially high-definition television
(HDTV), may mark an end to the decline of broadcast television reception via traditional receiving antennas, which can receive over-the-air HDTV signals.
In North America, terrestrial broadcast television operates on TV channels 2 through 6 (VHF-low band, known as band I
in Europe), 7 through 13 (VHF-high band, known as band III
elsewhere), and 14 through 69 (UHF
television band, elsewhere bands IV
and V
). Channel numbers represent actual frequencies used to broadcast the television signal. Additionally, television translators and boosters can be used to rebroadcast a terrestrial TV signal using an otherwise unused channel to cover areas with marginal reception. A chart showing the North American television bandplan can be found at the North American broadcast television frequencies
page.
NOTE: As of 01/08/2011, analog TV channels 2 through 6, 7 through 13 and 14 through 51 are only used for LPTV translator stations in the U.S. Channels 52 through 69 are still used in exceptional circumstances for LPTV translators in some remote regions of Canada. The Canadian Broadcasting Corporation has received permission to continue analog broadcasting at severely reduced power levels in some mandatory markets until 01/08/2012. It is expected that these transmitters will be shut down rather than converted to digital.
on 15 September 1959 with a small transmitter and a makeshift studio. The regular daily transmission started in 1965 as a part of All India Radio
. The television service was extended to Bombay (now Mumbai
) and Amritsar
in 1972. Up until 1975, only seven Indian cities had a television service and Doordarshan remained the sole provider of television in India. Television services were separated from radio in 1976. National telecasts were introduced in 1982. In the same year, colour TV was introduced in the Indian market. At that time there was only one national channel Doordarshan
, which was government owned. The Ramayana
and Mahabharata
(both being Hindu mythological stories based on religious scriptures of the same names) were the first major television series produced. This serial notched up the world record in viewership numbers for a single program. By the late 1980s more and more people started to own television sets. Though there was a single channel, television programming had reached saturation. Hence the government opened up another channel which had part national programming and part regional. This channel was known as DD 2 later DD Metro
'. Both channels were broadcast terrestrially. Now more than 90 percent of the Indian population can receive Doordarshan DD National
' programmes through a network of nearly 1,400 terrestrial transmitters.
across Europe was such the CEPT
convened the "Chester '97" conference to agree means by which digital television could be inserted into the ST61 frequency plan.
The introduction of digital television in the late 1990s and early years of the 21st century led the ITU to call a Regional Radiocommunication Conference to abrogate the ST61 plan and to put a new plan for digital broadcasting only in its place.
In December 2005 the European Union
decided to cease all analog audio and analog video
television transmissions by 2012 and switch all terrestrial television broadcasting to digital audio
and digital video
(all EU countries have agreed on using DVB-T
). The Netherlands completed the transition in December 2006, and some EU member states decided to complete their switchover as early as 2008 (Sweden), and (Denmark) in 2009. While the UK began the switch in late 2007, it will not be complete until mid 2012. Norway ceased all analogue television transmissions on December 1, 2009. Two member states (not specified in the announcement) have expressed concerns that they might not be able to proceed to the switchover by 2012 due to technical limitations; the rest of the EU member states are expected to stop analog television transmissions by 2012.
Many countries are developing and evaluating digital terrestrial television systems.
Australia has adopted the DVB-T standard and the government's industry regulator, the Australian Communications and Media Authority
, has mandated that all analogue transmissions will cease by 2012. Mandated digital conversion commenced early in 2009 with a graduated program. The first centre to experience analog switch-off will be the remote Victorian regional town of Mildura, in 2010. The government will supply underprivileged houses across the nation with free digital set-top DTV converter boxes in order to minimise any conversion disruption. Australia's major free-to-air
television network
s have all been granted digital transmission licences and are each required to broadcast at least one high-definition and one standard-definition channel into all of their markets.
In North America a specification laid out by the ATSC
has become the standard for digital terrestrial television. In the United States the Federal Communications Commission
(FCC) set the final deadline for the switchoff of analog service for June 12, 2009. All television receivers must now include a digital tuner. In Canada, the Canadian Radio-television and Telecommunications Commission (CRTC), has set August 31, 2011 as the date that over-the-air analog transmission service will cease in most parts of the country except in Northern Canada.
to the broadcasters) in the DTV transition in the United States
.
Some US commenters have proposed the closing down of over-the-air TV broadcasting, on the grounds that available spectrum might be better used, and requiring viewers to shift to satellite or cable reception. This would eliminate mobile TV
, which has been delayed several years by the FCC's decision to choose ATSC
and its proprietary 8VSB
modulation
, instead of the worldwide COFDM standard used for all other digital terrestrial broadcasting around the world. Compared to Europe and Asia, this has hamstrung mobile TV in the US, because ATSC cannot be received while in motion (or often even while stationary) without ATSC-M/H
as terrestrial DVB-T
or ISDB-T can even without DVB-H
or 1seg
.
The National Association of Broadcasters
has organized to fight such proposals, and public comment
s are also being taken by the FCC through mid-December 2009, in preparation for a plan
to be released in mid-February 2010.
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
broadcasting
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
which does not involve satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
transmission or cable
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
s — typically using radio waves
Radio waves
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. Like all other electromagnetic waves,...
through transmitting and receiving antennas
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
or television antenna
Television antenna
A television antenna, or TV aerial, is an antenna specifically designed for the reception of over the air broadcast television signals, which are transmitted at frequencies from about 41 to 250 MHz in the VHF band, and 470 to 960 MHz in the UHF band in different countries...
aerials. The term is more common in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, while in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
it is referred to as broadcast television or sometimes over-the-air television (OTA) and requires a Tuner (television) to view content.
Terrestrial television broadcasting dates back to the very beginnings of the broadcast television system
Broadcast television system
Broadcast television systems are encoding or formatting standards for the transmission and reception of terrestrial television signals. There are three main analog television systems in current use around the world: NTSC, PAL, and SECAM...
as a medium itself with the first long-distance public television broadcast from Washington, D.C., on April 7, 1927. The BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
began broadcasting television to the public in 1929, and had a regular schedule of television program
Television program
A television program , also called television show, is a segment of content which is intended to be broadcast on television. It may be a one-time production or part of a periodically recurring series...
mes in 1930. Aside from transmission by high-flying planes moving in a loop using a system developed by Westinghouse called Stratovision
Stratovision
Stratovision was an airborne television transmission relay system from aircraft flying at high altitudes. In 1945 the Glenn L. Martin Co. and Westinghouse Electric Corporation advocated television coverage of small towns and rural areas as well as the large metropolitan centers by fourteen aircraft...
, there was virtually no other method of television delivery until the 1950s with the beginnings of cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
, or community antenna television (CATV). The first non-terrestrial method of delivering television signals that in no way depended on a signal originating from a traditional terrestrial source began with the use of communications satellite
Communications satellite
A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...
s during the 1960s and 1970s.
Europe
Following the ST61 conference, UHF frequencies were first used in the UK in 1964 with the introduction of BBC2BBC Two
BBC Two is the second television channel operated by the British Broadcasting Corporation in the United Kingdom. It covers a wide range of subject matter, but tending towards more 'highbrow' programmes than the more mainstream and popular BBC One. Like the BBC's other domestic TV and radio...
. In UK, VHF channels were kept on the old 405-line
405-line
The 405-line monochrome analogue television broadcasting system was the first fully electronic television system to be used in regular broadcasting....
system, while UHF was used solely for 625-line broadcasts (which later used PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...
colour). Television broadcasting in the 405-line system continued after the introduction of four analogue programmes in the UHF bands until the last 405-line transmitters were switched off on January 6, 1985. VHF Band III is still used in other countries around Europe for PAL broadcasts, though many have plans to phase it out.
The success of terrestrial analogue television across Europe varies from country to country. Although each country has rights to a certain number of frequencies by virtue of the ST61 plan, not all of them have been brought into
North America
In North America terrestrial television underwent a revolutionary transformation with the eventual acceptance of the NTSCNTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
standard for color television
Color television
Color television is part of the history of television, the technology of television and practices associated with television's transmission of moving images in color video....
broadcasts in 1953. Later, Europe and the rest of the world either chose between the later PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...
and SECAM
SECAM
SECAM, also written SÉCAM , is an analog color television system first used in France....
color television standards, or adopted NTSC. Japan also uses a version of NTSC.
In addition to the threat from cable television
Cable television
Cable television is a system of providing television programs to consumers via radio frequency signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's property, much like the over-the-air method used in traditional...
, analog terrestrial television is now also subject to competition from satellite television
Satellite television
Satellite television is television programming delivered by the means of communications satellite and received by an outdoor antenna, usually a parabolic mirror generally referred to as a satellite dish, and as far as household usage is concerned, a satellite receiver either in the form of an...
and distribution of video and film content over the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
. The technology of digital terrestrial television
Digital terrestrial television
Digital terrestrial television is the technological evolution of broadcast television and advance from analog television, which broadcasts land-based signals...
has been developed as a response to these challenges. The rise of digital terrestrial television, especially high-definition television
High-definition television
High-definition television is video that has resolution substantially higher than that of traditional television systems . HDTV has one or two million pixels per frame, roughly five times that of SD...
(HDTV), may mark an end to the decline of broadcast television reception via traditional receiving antennas, which can receive over-the-air HDTV signals.
In North America, terrestrial broadcast television operates on TV channels 2 through 6 (VHF-low band, known as band I
Band I
Band I is the name of a radio frequency range within the very high frequency part of the electromagnetic spectrum.Band I ranges from 47 to 88 MHz, and it is primarily used for radio and television broadcasting....
in Europe), 7 through 13 (VHF-high band, known as band III
Band III
Band III is the name of a radio frequency range within the very high frequency part of the electromagnetic spectrum.Band III ranges from 174 to 230 MHz, and it is primarily used for radio and television broadcasting...
elsewhere), and 14 through 69 (UHF
Ultra high frequency
Ultra-High Frequency designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz , also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres...
television band, elsewhere bands IV
Band IV
Band IV is the name of a radio frequency range within the ultra high frequency part of the electromagnetic spectrum.Sources differ on the exact frequency range of the band. For example, the Swiss Federal Office of Communications, the Broadcast engineer's reference book and Ericsson India Ltd all...
and V
Band V
Band V is the name of a radio frequency range within the ultra high frequency part of the electromagnetic spectrum. It is not to be confused with the V band in the extremely high frequency part of the spectrum....
). Channel numbers represent actual frequencies used to broadcast the television signal. Additionally, television translators and boosters can be used to rebroadcast a terrestrial TV signal using an otherwise unused channel to cover areas with marginal reception. A chart showing the North American television bandplan can be found at the North American broadcast television frequencies
North American broadcast television frequencies
The North American broadcast television frequencies are on designated television channels numbered 2 through 69, approximately between 54 and 806 MHz. Traditionally, the frequencies are divided into two sections, the very high frequency band and the ultra high frequency band. The VHF band is...
page.
NOTE: As of 01/08/2011, analog TV channels 2 through 6, 7 through 13 and 14 through 51 are only used for LPTV translator stations in the U.S. Channels 52 through 69 are still used in exceptional circumstances for LPTV translators in some remote regions of Canada. The Canadian Broadcasting Corporation has received permission to continue analog broadcasting at severely reduced power levels in some mandatory markets until 01/08/2012. It is expected that these transmitters will be shut down rather than converted to digital.
Asia
Terrestrial television in India started with the experimental telecast starting in DelhiDelhi
Delhi , officially National Capital Territory of Delhi , is the largest metropolis by area and the second-largest by population in India, next to Mumbai. It is the eighth largest metropolis in the world by population with 16,753,265 inhabitants in the Territory at the 2011 Census...
on 15 September 1959 with a small transmitter and a makeshift studio. The regular daily transmission started in 1965 as a part of All India Radio
All India Radio
All India Radio , officially known since 1956 as Akashvani , is the radio broadcaster of India and a division of Prasar Bharati. Established in 1936, it is the sister service of Prasar Bharati's Doordarshan, the national television broadcaster. All India Radio is one of the largest radio networks...
. The television service was extended to Bombay (now Mumbai
Mumbai
Mumbai , formerly known as Bombay in English, is the capital of the Indian state of Maharashtra. It is the most populous city in India, and the fourth most populous city in the world, with a total metropolitan area population of approximately 20.5 million...
) and Amritsar
Amritsar
Amritsar is a city in the northern part of India and is the administrative headquarters of Amritsar district in the state of Punjab, India. The 2001 Indian census reported the population of the city to be over 1,500,000, with that of the entire district numbering 3,695,077...
in 1972. Up until 1975, only seven Indian cities had a television service and Doordarshan remained the sole provider of television in India. Television services were separated from radio in 1976. National telecasts were introduced in 1982. In the same year, colour TV was introduced in the Indian market. At that time there was only one national channel Doordarshan
DoorDarshan
Doordarshan is an Indian public service broadcaster, a division of Prasar Bharati. It is one of the largest broadcasting organizations in India in terms of the infrastructure of studios and transmitters. Recently, it has also started Digital Terrestrial Transmitters. On September 15, 2009,...
, which was government owned. The Ramayana
Ramayan (TV series)
Ramayan is a highly successful Indian television series created, written, and directed by Ramanand Sagar. The 78-episode series originally aired weekly on Doordarshan from January 25, 1987, to July 31, 1988, on Sundays at 9:30 a.m...
and Mahabharata
Mahabharata
The Mahabharata is one of the two major Sanskrit epics of ancient India and Nepal, the other being the Ramayana. The epic is part of itihasa....
(both being Hindu mythological stories based on religious scriptures of the same names) were the first major television series produced. This serial notched up the world record in viewership numbers for a single program. By the late 1980s more and more people started to own television sets. Though there was a single channel, television programming had reached saturation. Hence the government opened up another channel which had part national programming and part regional. This channel was known as DD 2 later DD Metro
DD Metro
DD Metro also known as DD 2 was Doordarshan's Hindi language general entertainment channel. At the time, DD Metro was on air, the channel was kept as a terrestrial channel, instead of exclusive satellite channel. However, it was available on many of the cable operators in India...
'. Both channels were broadcast terrestrially. Now more than 90 percent of the Indian population can receive Doordarshan DD National
DD National
DD National or DD1 is Doordarshan's flagship channel and the most widely available terrestrial television channel in India.-The Early Years:...
' programmes through a network of nearly 1,400 terrestrial transmitters.
Digital television
By the mid 1990s, the interest in digital televisionDigital television
Digital television is the transmission of audio and video by digital signals, in contrast to the analog signals used by analog TV...
across Europe was such the CEPT
European Conference of Postal and Telecommunications Administrations
The European Conference of Postal and Telecommunications Administrations was established on June 26, 1959, as a coordinating body for European state telecommunications and postal organizations...
convened the "Chester '97" conference to agree means by which digital television could be inserted into the ST61 frequency plan.
The introduction of digital television in the late 1990s and early years of the 21st century led the ITU to call a Regional Radiocommunication Conference to abrogate the ST61 plan and to put a new plan for digital broadcasting only in its place.
In December 2005 the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
decided to cease all analog audio and analog video
Analog video
Analog video is a video signal transferred by an analog signal. An analog color video signal contains luminance, brightness and chrominance of an analog television image...
television transmissions by 2012 and switch all terrestrial television broadcasting to digital audio
Digital audio
Digital audio is sound reproduction using pulse-code modulation and digital signals. Digital audio systems include analog-to-digital conversion , digital-to-analog conversion , digital storage, processing and transmission components...
and digital video
Digital video
Digital video is a type of digital recording system that works by using a digital rather than an analog video signal.The terms camera, video camera, and camcorder are used interchangeably in this article.- History :...
(all EU countries have agreed on using DVB-T
DVB-T
DVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998...
). The Netherlands completed the transition in December 2006, and some EU member states decided to complete their switchover as early as 2008 (Sweden), and (Denmark) in 2009. While the UK began the switch in late 2007, it will not be complete until mid 2012. Norway ceased all analogue television transmissions on December 1, 2009. Two member states (not specified in the announcement) have expressed concerns that they might not be able to proceed to the switchover by 2012 due to technical limitations; the rest of the EU member states are expected to stop analog television transmissions by 2012.
Many countries are developing and evaluating digital terrestrial television systems.
Australia has adopted the DVB-T standard and the government's industry regulator, the Australian Communications and Media Authority
Australian Communications and Media Authority
The Australian Communications and Media Authority is an Australian government statutory authority within the Department of Broadband, Communications and the Digital Economy portfolio...
, has mandated that all analogue transmissions will cease by 2012. Mandated digital conversion commenced early in 2009 with a graduated program. The first centre to experience analog switch-off will be the remote Victorian regional town of Mildura, in 2010. The government will supply underprivileged houses across the nation with free digital set-top DTV converter boxes in order to minimise any conversion disruption. Australia's major free-to-air
Free-to-air
Free-to-air describes television and radio services broadcast in clear form, allowing any person with the appropriate receiving equipment to receive the signal and view or listen to the content without requiring a subscription or one-off fee...
television network
Television network
A television network is a telecommunications network for distribution of television program content, whereby a central operation provides programming to many television stations or pay TV providers. Until the mid-1980s, television programming in most countries of the world was dominated by a small...
s have all been granted digital transmission licences and are each required to broadcast at least one high-definition and one standard-definition channel into all of their markets.
In North America a specification laid out by the ATSC
Advanced Television Systems Committee
The Advanced Television Systems Committee is the group, established in 1982, that developed the eponymous ATSC Standards for digital television in the United States, also adopted by Canada, Mexico, South Korea, and recently Honduras and is being considered by other countries.-See also:*ATSC...
has become the standard for digital terrestrial television. In the United States the Federal Communications Commission
Federal Communications Commission
The Federal Communications Commission is an independent agency of the United States government, created, Congressional statute , and with the majority of its commissioners appointed by the current President. The FCC works towards six goals in the areas of broadband, competition, the spectrum, the...
(FCC) set the final deadline for the switchoff of analog service for June 12, 2009. All television receivers must now include a digital tuner. In Canada, the Canadian Radio-television and Telecommunications Commission (CRTC), has set August 31, 2011 as the date that over-the-air analog transmission service will cease in most parts of the country except in Northern Canada.
Competition for radio spectrum
In late 2009, US competition for the limited available radio spectrum led to debate over the possible re-allocation of frequencies currently occupied by television, and the FCC began asking for comments on how to increase the bandwidth available for wireless broadband. Some have proposed mixing the two together, on different channels that are already open (like White Spaces), while others have proposed "repacking" some stations and forcing them off certain channels, just a few years after the same thing was done (without compensationRegulatory taking
Regulatory taking refers to a situation in which a government regulates a property to such a degree that the regulation effectively amounts to an exercise of the government's eminent domain power without actually divesting the property's owner of title to the property.-United States law:In common...
to the broadcasters) in the DTV transition in the United States
DTV transition in the United States
The DTV transition in the United States was the switchover from analog to exclusively digital broadcasting of free over-the-air television programming...
.
Some US commenters have proposed the closing down of over-the-air TV broadcasting, on the grounds that available spectrum might be better used, and requiring viewers to shift to satellite or cable reception. This would eliminate mobile TV
Mobile TV
Mobile television usually means television watched on a small handheld device. It may be a pay TV service broadcast on mobile phone networks or received free-to-air via terrestrial television stations from either regular broadcast or a special mobile TV transmission format...
, which has been delayed several years by the FCC's decision to choose ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....
and its proprietary 8VSB
8VSB
8VSB is the modulation method used for broadcast in the ATSC digital television standard. ATSC and 8VSB modulation is used primarily in North America; in contrast, the DVB-T standard uses COFDM....
modulation
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...
, instead of the worldwide COFDM standard used for all other digital terrestrial broadcasting around the world. Compared to Europe and Asia, this has hamstrung mobile TV in the US, because ATSC cannot be received while in motion (or often even while stationary) without ATSC-M/H
ATSC-M/H
ATSC-M/H is a standard in the USA for mobile digital TV, that allows TV broadcasts to be received by mobile devices.....
as terrestrial DVB-T
DVB-T
DVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998...
or ISDB-T can even without DVB-H
DVB-H
DVB-H is one of three prevalent mobile TV formats. It is a technical specification for bringing broadcast services to mobile handsets. DVB-H was formally adopted as ETSI standard EN 302 304 in November 2004. The DVB-H specification can be downloaded from the official DVB-H website...
or 1seg
1seg
is a mobile terrestrial digital audio/video and data broadcasting service in Japan, Argentina, Brazil, Chile and Peru. Service began experimentally during 2005 and commercially on April 1, 2006. In Brazil, the broadcast started in late 2007 in just a few cities, with a slight difference from...
.
The National Association of Broadcasters
National Association of Broadcasters
The National Association of Broadcasters is a trade association, workers union, and lobby group representing the interests of for-profit, over-the-air radio and television broadcasters in the United States...
has organized to fight such proposals, and public comment
Public comment
-Introduction:Public comment is a specific term of art used by various government agencies in the United States, a constitutional democracy, in several circumstances. It is sometimes called "vox populi". Generally these circumstances are open public meetings of government bodies which set aside...
s are also being taken by the FCC through mid-December 2009, in preparation for a plan
National Broadband Plan (United States)
Connecting America: The National Broadband Plan, unveiled March 16, 2010, is a FCC plan which deals with improving broadband Internet access throughout the United States. One goal was providing 100 million American households with access to 100 Mbit/s connections by 2020...
to be released in mid-February 2010.
See also
- Broadcast television systemBroadcast television systemBroadcast television systems are encoding or formatting standards for the transmission and reception of terrestrial television signals. There are three main analog television systems in current use around the world: NTSC, PAL, and SECAM...
s - Lists of television channels for lists by country and language.
- Television channel frequenciesTelevision channel frequenciesThe following tables show the frequencies assigned to broadcast television channels in various regions of the world, along with the ITU letter designator for the system used. The frequencies shown are for the video and audio carriers. The channel itself occupies several megahertz of bandwidth....
- DVB-TDVB-TDVB-T is an abbreviation for Digital Video Broadcasting — Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of digital terrestrial television that was first published in 1997 and first broadcast in the UK in 1998...
- ATSC tunerATSC tunerAn ATSC tuner, often called an ATSC receiver or HDTV tuner is a type of television tuner that allows reception of digital television television channels transmitted by television stations in North America, parts of Central America and South Korea that use ATSC standards...
External links
- TVRadioWorld TV stations directory
- W9WI.com (Terrestrial repeater and TV hobbyist information)
- TV Coverage maps and Signal Analysis