ATSC Standards document a digital television format which will replace the analog NTSC television system^[1] by February 17, 2009 in the United States,^[2] and August 31, 2011 in Canada. For the chemical compound see Divinylbenzene. Digital Video Broadcasting ( DVB) is a suite of internationally accepted DVB-S is the original Digital Video Broadcasting forward error coding and modulation standard for Satellite television and dates from 1995 Satellite television is Television delivered by the means of Communications satellites as compared to conventional Terrestrial television and Cable Digital Video Broadcasting - Satellite - Second Generation ( DVB-S2) is an enhanced specification to replace the DVB-S standard developed in 2003 and ratified 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 ( DTTV or DTT) is an implementation of digital technology to provide a greater number of channels and/or better quality of picture and DVB-T is an abbreviation for Digital Video Broadcasting – Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of DVB-C stands for Digital Video Broadcasting - Cable and it is the DVB European consortium standard for the broadcast transmission of Digital television DVB-H ( Digital Video Broadcasting - Handheld) is one of three prevalent mobile TV formats Digital Terrestrial Television ( DTTV or DTT) is an implementation of digital technology to provide a greater number of channels and/or better quality of picture and Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio Satellite television is Television delivered by the means of Communications satellites as compared to conventional Terrestrial television and Cable Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio Digital Terrestrial Television ( DTTV or DTT) is an implementation of digital technology to provide a greater number of channels and/or better quality of picture and Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio Digital Multimedia Broadcasting ( DMB) is a Digital Radio transmission system for sending Multimedia ( Radio, TV DMB-T/H or DTMB ( GB 20600-2006 is the Digital terrestrial television standard applied in the People's Republic of China (PRC including A video Codec is a device or Software that enables Video compression and/or decompression for digital video MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information" MPEG-4 is a collection of methods defining compression of audio and visual (AV digital data Radio frequency ( RF) is a Frequency or rate of Oscillation within the range of about 3 Hz to 300 GHz Very high frequency (VHF is the Radio frequency range from 30 MHz to 300 MHz. Super high frequency (or SHF) refers to radio frequencies (RF in the range of 3  GHz and 30 GHz Digital television (DTV is the sending and receiving of moving images and sound by discrete ( digital) signals in contrast to the analog signals used by NTSC ( National Television System Committee) is the Analog television system used in the United States, Canada, Japan, Mexico Events 1500 - Battle of Hemmingstedt. 1600 - Philosopher Giordano Bruno is burned alive at Campo de' Fiori This article is about the year For the film see 2009 Lost Memories. The United States of America —commonly referred to as the Events 1056 - Byzantine Empress Theodora becomes ill dying suddenly a few days later without children to succeed the Throne 2011 ( MMXI) will be a Common year starting on Saturday of the Gregorian calendar. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page ^[3] It was developed by the 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

The high definition television standards defined by the ATSC produce wide screen 16:9 images up to 1920×1080 pixels in size — more than six times the display resolution of the earlier standard. A widescreen image is a film computer or television image with a wider and shorter aspect ratio than the standard Academy frame developed during the Classical The aspect ratio of an Image is its width divided by its height In Digital imaging, a pixel ( pict ure el ement is the smallest piece of information in an image The display resolution of a Digital television or Computer display typically refers to the number of distinct pixels in each dimension that can be displayed However, a host of different image sizes are also supported, so that up to six standard-definition "virtual channels" can be broadcast on a single 6 MHz TV channel. In Telecommunications, a logical channel number (LCN also known as virtual channel in North America, is a channel designation which differs The hertz (symbol Hz) is a measure of Frequency, informally defined as the number of events occurring per Second. The term television channel generally refers to either a Television station or its cable / satellite counterpart (both outlined below

ATSC also boasts "theater quality" audio because it uses the Dolby Digital AC-3 format to provide 5. Cinemaaustraliajpg|thumb|A movie theater in Australia ]]A movie theater, movie theatre, picture theatre or cinema is a venue Dolby Digital is the marketing name for a series of lossy audio compression technologies developed by Dolby 1-channel surround sound. 51, Multichannel audio, Multichannel music Surround 3D Surround 5 Numerous auxiliary datacasting services can also be provided. Datacasting (data broadcasting is the Broadcasting of Data over a wide area via Radio waves It most often refers to supplemental Information

Broadcasters who use ATSC and want to retain an analog signal must broadcast on two separate channels, as the ATSC system requires the use of an entire channel. Virtual channels allow channel numbers to be remapped from their physical RF channel to any other number 1 to 99, so that ATSC stations can either be associated with the related NTSC channel numbers, or all stations on a network can use the same number. In Telecommunications, a logical channel number (LCN also known as virtual channel in North America, is a channel designation which differs Radio frequency ( RF) is a Frequency or rate of Oscillation within the range of about 3 Hz to 300 GHz There is also a standard for distributed transmission (DTx) which allows for booster stations. A single-frequency network or SFN is a Broadcast network where several Transmitters simultaneously send the same signal over the same Frequency

ATSC standards are marked A/x (x is the standard number) and can be downloaded freely from ATSC website (see external links below).

Many aspects of ATSC are patented, including elements of the MPEG video coding, the AC-3 audio coding, and the 8VSB modulation. A patent is a set of Exclusive rights granted by a State to an inventor or his assignee for a fixed period of time in exchange for a disclosure of an The Moving Picture Experts Group, commonly referred to as simply MPEG, is a Working group of ISO / IEC charged with the development of video and 8VSB is the 8-level Vestigial sideband modulation method adopted for terrestrial broadcast of the ATSC digital television standard in the United States, ^[4] As with other systems, ATSC depends on numerous interwoven standards, e. g. the EIA-708 standard for digital closed captioning, leading to variations in implementation. EIA-708 is the standard for Closed captioning for ATSC Digital television streams in the United States and Canada. Closed captioning is a term describing several systems developed to display text on a Television or Video screen to provide additional or interpretive

Resolution

The ATSC system supports a number of different display resolutions, aspect ratios, and frame rates. The aspect ratio of a Shape is the ratio of its longer Dimension to its shorter dimension Frame rate, or frame frequency, is the measurement of the Frequency (rate at which an imaging device produces unique consecutive images called frames The The formats are listed here by resolution, form of scanning (progressive or interlaced), and number of frames (or fields) per second (see also the TV resolution overview at the end of this article). Progressive or noninterlaced scanning is a method for displaying storing or transmitting Moving images in which all the lines of each frame are drawn in For the method of incrementally displaying Raster graphics, see Interlace (bitmaps. The table includes formats from both A/53 Part 4 (MPEG-2 Video System Characteristics) and A/63 (Standard for Coding 25/50 Hz Video).

The different resolutions can operate in progressive scan or interlaced mode, although the highest 1080-line system cannot display progressive images at the rate of 59. Progressive or noninterlaced scanning is a method for displaying storing or transmitting Moving images in which all the lines of each frame are drawn in For the method of incrementally displaying Raster graphics, see Interlace (bitmaps. 94 or 60 frames per second. (Such technology was seen as too advanced at the time, plus the image quality was deemed to be too poor considering the amount of data that can be transmitted. ) A terrestrial (over-the-air) transmission carries 19. 39 megabits of data per second, compared to a maximum possible bitrate of 10. A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) 08 Mbit/s allowed in the DVD standard. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is

"EDTV" displays can reproduce progressive scan content and frequently have a 16:9 wide screen format. Enhanced-definition television, extended-definition television, or EDTV is a CEA marketing shorthand term for certain Digital television Such resolutions are 720×480 in NTSC or 720×576 in PAL, allowing 60 progressive frames per second in NTSC or 50 in PAL.

There are three basic display sizes for ATSC. Basic and enhanced NTSC and PAL image sizes are at the bottom level at 480 or 576 lines. Medium-sized images have 720 scanlines and are 1280 pixels wide. The top tier has 1080 lines 1920 pixels wide. 1080-line video is actually encoded with 1920×1088 pixel frames, but the last eight lines are discarded prior to display. This is due to a restriction of the MPEG-2 video format, which requires the number of coded luma samples (i. e. , pixels) to be divisible by 16.

Codecs

For transport, ATSC uses the MPEG-2 systems specification, known as transport stream, to encapsulate data, subject to certain constraints. MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information" Transport stream ( TS, TP, MPEG-TS, or M2T) is a Communications protocol for audio, video, and data ATSC uses 188-byte MPEG transport stream packets to carry data. Before decoding of audio and video takes place, the receiver must demodulate and apply error correction to the signal. Demodulation is the act of removing the Modulation from an analog signal to get the original Baseband signal back In Mathematics, Computer science, Telecommunication, and Information theory, error detection and correction has great practical importance in Then, the transport stream may be demultiplexed into its constituent streams. For multiplexing in electronics and signal processing see Multiplexer.

MPEG-2 video is used as the video codec, also with certain constraints. A video Codec is a device or Software that enables Video compression and/or decompression for digital video

For more details on this topic, see MPEG-2#ATSC_and_ISDB-T. MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information"

Dolby Digital AC-3 is used as the audio codec, though it was officially standardized as A/52 by the ATSC. Dolby Digital is the marketing name for a series of lossy audio compression technologies developed by Dolby An audio codec is a Hardware device or a Computer program that compresses/decompresses Digital audio data according to a given Audio file It allows the transport of up to five channels of sound with a sixth channel for low-frequency effects (the so-called "5. 1" configuration). In contrast, Japanese ISDB HDTV broadcasts use MPEG's Advanced Audio Coding (AAC) as the audio codec, which also allows 5. Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio Advanced Audio Coding ( AAC) is a standardized lossy compression and encoding scheme for Digital audio. 1 audio output. DVB (see below) allows both. For the chemical compound see Divinylbenzene. Digital Video Broadcasting ( DVB) is a suite of internationally accepted

Modulation and transmission

Main articles: 8VSB and QAM tuner

ATSC signals are designed to use the same 6 MHz bandwidth as NTSC television channels (the interference requirements of A/53 DTV standards with adjacent NTSC or other DTV channels are very strict). 8VSB is the 8-level Vestigial sideband modulation method adopted for terrestrial broadcast of the ATSC digital television standard in the United States, In North American Digital video, a QAM tuner is a device present in some Digital televisions and similar devices which enables direct reception of NTSC ( National Television System Committee) is the Analog television system used in the United States, Canada, Japan, Mexico Once the video and audio signals have been compressed and multiplexed, the transport stream can be modulated in different ways depending on the method of transmission. In Telecommunications, modulation is the process of varying a periodic Waveform, i

• Terrestrial (local) broadcasters use 8VSB modulation that can transfer at a maximum rate of 19. 8VSB is the 8-level Vestigial sideband modulation method adopted for terrestrial broadcast of the ATSC digital television standard in the United States, 39 Mbit/s, sufficient to carry several video and audio programs and metadata. A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) Metadata ( meta data, or sometimes metainformation) is "data about data" of any sort in any media
• Cable television stations can generally operate at a higher signal-to-noise ratio and can use 16VSB or 256-QAM to achieve a throughput of 38. Signal-to-noise ratio (often abbreviated SNR or S/N) is an Electrical engineering concept also used in other fields (such as scientific Measurements 78 Mbit/s, using the same 6 MHz channel.

In recent years, cable operators have become accustomed to compressing standard-resolution video for digital cable systems, making it harder to find duplicate 6 MHz channels for local broadcasters on uncompressed "basic" cable. Digital cable is a type of Cable television distribution using Digital Video compression.

Currently, the Federal Communications Commission requires cable operators in the United States to carry the analog or digital transmission of a terrestrial broadcaster (but not both), when so requested by the broadcaster (the "must-carry rule"). In Cable television, governments apply a must-carry regulation stating that locally-licensed television stations must be carried on a cable provider's system The Canadian Radio-television and Telecommunications Commission in Canada has similar rules in force with respect to carrying ATSC signals. CRTC may also stand for Cathode Ray Tube Controller. Canadian Radio-television and Telecommunications Commission ( CRTC, in French Conseil

However, cable operators in the US (and to a lesser extent Canada) can determine their own method of modulation for their plants.

• Consequently, most North American cable operators have added 256-QAM to the 16VSB standard originally used.
• Cable operators have still been slow to add ATSC channels to their lineups for legal, regulatory, and plant & equipment related reasons.
• 256 QAM is a cable standard, not an ATSC standard; however, over time it is expected to be included in the ATSC standard

There is also a standard for transmitting ATSC via satellite; however, this is only used by TV networks. A television network is a distribution network for Television content whereby a central operation provides programming for many Television stations Very few teleports outside the US support the ATSC satellite transmission standard, but teleport support for the standard is improving.

• The ATSC satellite transmission system is not used for direct broadcast satellite systems, which in North America have long used a system similar to DVB-S. Direct broadcast satellite (DBS is a term used to refer to Satellite television broadcasts intended for home reception also referred to more broadly as direct-to-home DVB-S is the original Digital Video Broadcasting forward error coding and modulation standard for Satellite television and dates from 1995

Other systems

Digital terrestrial television broadcasting systems. Digital Terrestrial Television ( DTTV or DTT) is an implementation of digital technology to provide a greater number of channels and/or better quality of picture and Countries using ATSC are shown in orange.

A majority of the world's nations have chosen to adopt the DVB standard, as can be seen on the status list on the DVB Project website. For the chemical compound see Divinylbenzene. Digital Video Broadcasting ( DVB) is a suite of internationally accepted

ATSC coexists with the DVB-T standard, and with ISDB-T being implemented in Japan. DVB-T is an abbreviation for Digital Video Broadcasting – Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio (ISDB modulation also serves as a basis of the SBTVD-T standard in Brazil. SBTVD, short for Sistema Brasileiro de Televisão Digital (Brazilian Digital Television System or SBTVD-T (Sistema Brasileiro de Televisão Digital Terrestre |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld ) A similar standard called ADTB was developed for use as part of China's new DMB-T/H dual standard. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National DMB-T/H or DTMB ( GB 20600-2006 is the Digital terrestrial television standard applied in the People's Republic of China (PRC including While China has officially chosen a dual standard, there is no requirement that a receiver work with both standards and there is no support for the ADTB modulation from broadcasters or equipment and receiver manufacturers. Taiwan has chosen DVB-T COFDM as its official modulation. REPUBLIC OF CHINA ARTICLE GUIDELINES DVB-T is an abbreviation for Digital Video Broadcasting – Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of Orthogonal frequency-division multiplexing ( OFDM) — essentially identical to Coded OFDM ( COFDM) and Discrete multi-tone modulation (

Because of potential use outside of existing NTSC areas, the ATSC system includes the capability to carry PAL and SECAM formatted video (576 displayable lines, 50 fields or 25 frames per second) along with NTSC (486 displayable lines, 60 x 1000/1001 fields or 30 x 1000/1001 frames per second) and film (24 frames per second). PAL, short for Phase Alternating Line, is a colour -encoding system used in Broadcast television systems in large parts of the world SECAM, also written SÉCAM ( Séquentiel couleur à mémoire, French for "Sequential Color with Memory" is an analog color television system

Comparison

While the ATSC system has been criticized as being complicated and expensive to implement and use, both broadcasting and receiving equipment are now comparable in cost with that of DVB.

The ATSC signal is more susceptible to changes in radio propagation conditions than DVB-T and ISDB-T. Radio propagation is a term used to explain how Radio waves behave when they are Transmitted, or are propagated from one point on the Earth DVB-T is an abbreviation for Digital Video Broadcasting – Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of Integrated Services Digital Broadcasting (ISDB is a Japanese standard for Digital television (DTV and Digital radio used by the country's radio If ATSC were able to dynamically change its error correction modes, code rates, interleaver mode, and randomizer, the signal could be more robust even if the modulation itself did not change. It also lacks true hierarchical modulation, which allows the SDTV part of an HDTV signal to be received even in fringe areas where signal strength is low. Link adaptation, or adaptive modulation and coding (AMC, is a term used in wireless communications to denote the matching of the Modulation, Coding and In Telecommunications, particularly in Radio, signal strength refers to the magnitude of the Electric field at a reference point that is a significant distance For this reason, an additional modulation mode, enhanced-VSB (E-VSB) has been introduced, allowing for a similar benefit. E-VSB or Enhanced VSB is an optional enhancement to the original ATSC Standards that use the 8VSB Modulation system used for transmission

In spite of ATSC's fixed transmission mode, it is still a robust signal under various conditions. 8VSB was chosen over COFDM in part because many areas of North America are rural and have a much lower population density, thereby requiring larger transmitters and resulting in large fringe areas. Orthogonal frequency-division multiplexing ( OFDM) — essentially identical to Coded OFDM ( COFDM) and Discrete multi-tone modulation ( Rural areas can be large and isolated (also referred to as "the country" and/or "the countryside over the course of time Population density (in agriculture standing stock and Standing crop) is a measurement of Population per unit area or unit volume For biologic transmitters see Transmitter substance. A transmitter is an electronic device which usually with the aid of an antenna In these areas, 8VSB was shown to perform better than other systems.

COFDM is used in both DVB-T and ISDB-T, and for ISDB-H, as well as DVB-H and HD Radio in the United States. is a mobile terrestrial digital audio/video and data broadcasting service in Japan and Brazil DVB-H ( Digital Video Broadcasting - Handheld) is one of three prevalent mobile TV formats HD Radio is the name used by iBiquity for a system of digital transmission for audio broadcast stations In metropolitan areas, where the great and increasing majority of North Americans live, COFDM is said to be better at handling multipath. A metropolitan area is a large population center consisting of a large Metropolis and its adjacent zone of influence or of more than one closely adjoining neighboring central In Wireless Telecommunications multipath is the propagation phenomenon that results in Radio signals reaching the receiving While ATSC is also incapable of true single-frequency network (SFN) operation, the distributed transmission mode, using on-channel repeaters, has been shown to improve reception under similar conditions. A single-frequency network or SFN is a Broadcast network where several Transmitters simultaneously send the same signal over the same Frequency Thus, it may not require more spectrum allocation than DVB-T using SFNs. A spectrum (plural spectra or spectrums) is a condition that is not limited to a specific set of values but can vary infinitely within a continuum. DVB-T is an abbreviation for Digital Video Broadcasting – Terrestrial; it is the DVB European-based consortium standard for the broadcast transmission of

Mobile TV

Mobile reception of digital stations using ATSC has (until now) been difficult to impossible, especially when moving at vehicular speeds. To overcome this, there are several proposed systems that report improved mobile reception: Samsung/Rohde & Schwarz's A-VSB, Harris/LG's MPH, and a recent proposal from Thomson/Micronas; all of these systems are expected to be submitted as candidates for a new ATSC standard, ATSC-M/H. The Samsung Group ( Korean:, Samsung Guerup) is South Korea 's largest company or Chaebol and the world's largest conglomerate Rohde & Schwarz (ʁoːdə ʊnt ʃvaʁts in German; anglicized pronunciation ənd ʃwɔ(ɹts is an independent group of companies specializing in electronics A-VSB or Advanced VSB is a modification of the 8VSB Modulation system used for transmission of Digital television using the ATSC Harris Corporation ( is an international communications equipment company that produces Wireless equipment electronic systems and both terrestrial and spaceborne antennas MPH or Mobile-Pedestrian-Handheld is the Trademark of a modification of the 8VSB Modulation system used for transmission of Digital ATSC-M/H is a future standard currently ( As of 2008) under consideration to allow ATSC Digital television broadcast signals to be received by Mobile This is in addition to other proprietary standards like MediaFLO, and worldwide open standards such as DVB-H and DMB-T. MediaFLO is Qualcomm 's new technology to broadcast data to portable devices such as cell phones and PDAs. DVB-H ( Digital Video Broadcasting - Handheld) is one of three prevalent mobile TV formats Like DVB-H and ISDB 1seg, the proposed ATSC mobile standards are backward-compatible with existing tuners, despite being added to the standard well after the original standard was in wide use. is a mobile terrestrial digital audio/video and data broadcasting service in Japan and Brazil In Technology, especially Computing (irrespective of platform a product is said to be backward compatible when it is able to take the place of an older product

Mobile reception of some stations will still be more difficult, because 18 UHF channels in the U. S. have been removed from TV service, forcing some broadcasters to stay on VHF. This band requires larger antennas for reception, and is more prone to electromagnetic interference from engines and rapidly-changing multipath conditions. An engine is a mechanical device that produces some form of output from a given input In Wireless Telecommunications multipath is the propagation phenomenon that results in Radio signals reaching the receiving

Countries and territories using ATSC

Americas

•  Argentina (experimental)^[5]
•  Bahamas
•  Bermuda
•  Canada (To be completely transformed by 8/31/11)
•  Colombia (experimental, not defined)
•  Chile (experimental, dropped by the nationwide TV stations in favor of ISDB-T)
•  Guatemala (experimental)
•  Honduras
•  Mexico
•  Peru (experimental only in Lima)
•  United States (To begin be completely transformed by 2/19/09)
  •  Puerto Rico
  •  U.S. Virgin Islands

Asia/Pacific

•  American Samoa
•  Guam
•  Northern Mariana Islands
•  South Korea

References

See also

• Advanced Television Systems Committee
• ATSC tuner
• List of ATSC standards
• broadcast flag
• Digital terrestrial television
• DMB-T - Digital Multimedia Broadcast-Terrestrial
• Digital Video Broadcasting
• ISDB - Integrated Services Digital Broadcasting
• EIA-708
• OpenCable
• Broadcast safe

External links

• ATSC website
• ATSC standards download page