Digital broadcasting

Digital broadcasting is the practice of using digital signals rather than analogue signals for broadcasting over radio frequency bands. Digital television broadcasting (especially satellite television) is widespread. Digital audio broadcasting is being adopted more slowly for radio broadcasting where it is mainly used in Satellite radio.

Digital links, thanks to the use of data compression, generally have greater spectral efficiency than analog links. Content providers can provide more services or a higher-quality signal than was previously available.

It is estimated that the share of digital broadcasting increased from 7% of the total amount of broadcast information in 2000, to 25% in 2007.[1] Some countries have completed a Digital television transition.

The premise behind digital broadcasting

''For more information on the premise of digital broadcasting refer to the 2002 edition of the World Radio TV Handbook.''

Digital broadcasting has been helped greatly by the presence of computers. In fact, with the invention of the integrated circuit in the 1960s and the microprocessor in the 1970s, digital broadcasting seems to have taken a footing in the global village that is broadcasting. However, most broadcasters are switching to digital broadcasting mostly because of a lack of frequency space.

  1. In the UK, the FM broadcasting band is extremely limited. It is only possible to fit three BBC services comfortably: BBC Radio 1, BBC Radio 2, and BBC Radio 3. In most areas BBC Radio 4 is also on FM, but for other locations Radio 4 uses AM and longwave because of the lack of space on FM. In fact, this is why BBC Radio Five Live exclusively uses AM. On the commercial radio front, only Classic FM can comfortably fit in FM: TalkSPORT and Virgin Radio use AM. In addition, local radio stations use a mixture of FM and AM. The same can also be said for British television, which exclusively uses the pan-European UHF television band after VHF television (PAL-A) was discontinued in the 1980s. Only BBC1, BBC2, ITV1, and Channel Four could comfortably fit. In addition, Channel Five could broadcast only in a few limited areas because of the strain of the TV band. There are also a few local television stations, but they are mostly low-power and are not affected, if any.
  2. In Canada, the Canadian Broadcasting Corporation/Société Radio-Canada (CBC/Radio-Canada) operates four domestic radio networks: CBC Radio One, CBC Radio 2, Première Chaîne and Espace musique. Originally, Radio One and Première Chaîne used AM and Radio 2 and Espace musique used FM. However, most CBC radio broadcasts use FM now, putting strains on the FM radio band. This has left the AM band almost dry, since most local broadcasters are using FM. However, Canada uses the NTSC television system used in the US, so there aren't any problems with television, yet.
  3. In South Asia, the Sri Lanka Broadcasting Corporation formerly Radio Ceylon, operates a pioneering FM radio station in Colombo.
  4. In addition, there are inherent problems with AM and FM. FM in particular is prone to multipath interference and the need to constantly retune the radio because of problems with the signal. AM, by contrast, doesn't suffer with multipath but when going under bridges or in tunnels, reception is absent. AM in particular (as well as LW and SW) is also prone to conditions on the Sun. RDS, known in the US as RBRS, has alleviated some of the problems with FM, but hasn't been fully implemented in AM.

Thus, because of these problems, most broadcasters are switching to digital techniques.

References

  1. ^ "The World’s Technological Capacity to Store, Communicate, and Compute Information", especially Supporting online material, Martin Hilbert and Priscila López (2011), Science, 332(6025), 60-65; free access to the article through here: martinhilbert.net/WorldInfoCapacity.html

Related links

DVB 3D-TV

DVB 3D-TV is a new standard that partially came out at the end of 2010 which included techniques and procedures to send a three-dimensional video signal through actual DVB transmission standards (Cable, Terrestrial or Satellite). Currently there is a commercial requirement text for 3D TV broadcasters and Set-top box manufacturers, but no technical information is in there.

Nowadays 3D television technology is already in its first steps regarding its standardization, now the major 3D market is in theaters and Blu-ray Disc players with stereoscopic systems, but in the near future it will be extended to diffusion, and later Free viewpoint television will come into our homes, which means the need of new coding and transmission standards.

Digea

Digea is a Greek network operator that provides a digital terrestrial television system in Greece for seven nationwide free-to-air channels (Alpha TV, Alter Channel, ANT1, Makedonia TV, Mega Channel, Skai TV and Star Channel). In addition to these free-to-air nationwide stations, the network is open to any other station choosing to use its services.

The name Digea is a word play in Greek: composed of the words "Digital" and "Gaea" (the Greek name for Gaia, the ancient goddess who was the personification of the Earth), literally translated as "Digital Earth". It symbolizes a union of the digital era and the basis for life in our world. The company’s main area of activity is the provision of networking and multiplexing services, both to the above-mentioned shareholders as well as to any legal entity opting to use the company’s services.

Digital Video Broadcasting

Digital Video Broadcasting (DVB) is a set of international open standards for digital television. DVB standards are maintained by the DVB Project, an international industry consortium, and are published by a Joint Technical Committee (JTC) of the European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC) and European Broadcasting Union (EBU).

Digital multimedia broadcasting

Digital multimedia broadcasting (DMB) is a digital radio transmission technology developed in South Korea as part of the national IT project for sending multimedia such as TV, radio and datacasting to mobile devices such as mobile phones, laptops and GPS navigation systems. This technology, sometimes known as mobile TV, should not be confused with Digital Audio Broadcasting which was developed as a research project for the European Union. DMB was developed in South Korea as the next generation digital technology to replace FM radio, but the technological foundations were laid by Prof. Dr. Gert Siegle and Dr. Hamed Amor at Robert Bosch GmbH in Germany. The world's first official mobile TV service started in South Korea in May 2005, although trials were available much earlier. It can operate via satellite (S-DMB) or terrestrial (T-DMB) transmission. DMB has also some similarities with the main competing mobile TV standard, DVB-H.

Digital radio

Digital radio is the use of digital technology to transmit or receive across the radio spectrum. Digital transmission by radio waves includes digital broadcasting, and especially digital audio radio services.

Digital television

Digital television (DTV) is the transmission of television signals, including the sound channel, using digital encoding, in contrast to the earlier television technology, analog television, in which the video and audio are carried by analog signals. It is an innovative advance that represents the first significant evolution in television technology since color television in the 1950s. Digital TV transmits in a new image format called high definition television (HDTV), with greater resolution than analog TV, in a widescreen aspect ratio similar to recent movies in contrast to the narrower screen of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit multiple channels, up to 7, in the same bandwidth occupied by a single channel of analog television, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2006. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widely used standards:

Digital Video Broadcasting (DVB) uses coded orthogonal frequency-division multiplexing (OFDM) modulation and supports hierarchical transmission. This standard has been adopted in Europe, Africa, Asia, Australia, total about 60 countries.

Advanced Television System Committee (ATSC) uses eight-level vestigial sideband (8VSB) for terrestrial broadcasting. This standard has been adopted by 6 countries: United States, Canada, Mexico, South Korea, Dominican Republic and Honduras.

Integrated Services Digital Broadcasting (ISDB) is a system designed to provide good reception to fixed receivers and also portable or mobile receivers. It utilizes OFDM and two-dimensional interleaving. It supports hierarchical transmission of up to three layers and uses MPEG-2 video and Advanced Audio Coding. This standard has been adopted in Japan and the Philippines. ISDB-T International is an adaptation of this standard using H.264/MPEG-4 AVC that been adopted in most of South America and is also being embraced by Portuguese-speaking African countries.

Digital Terrestrial Multimedia Broadcasting (DTMB) adopts time-domain synchronous (TDS) OFDM technology with a pseudo-random signal frame to serve as the guard interval (GI) of the OFDM block and the training symbol. The DTMB standard has been adopted in the People's Republic of China, including Hong Kong and Macau.

Digital Multimedia Broadcasting (DMB) is a digital radio transmission technology developed in South Korea as part of the national IT project for sending multimedia such as TV, radio and datacasting to mobile devices such as mobile phones, laptops and GPS navigation systems.

Digital terrestrial television

Digital terrestrial television (DTTV or DTT) is a technology for broadcast television in which land-based (terrestrial) television stations broadcast television content by radio waves to televisions in consumers' residences in a digital format. DTTV is a major technological advance over the previous analog television, and has largely replaced analog which had been in common use since the middle of the 20th century. Test broadcasts began in 1998 with the changeover to DTTV (aka Analog Switchoff (ASO) or Digital Switchover (DSO)) beginning in 2006 and is now complete in many countries. The advantages of digital terrestrial television are similar to those obtained by digitising platforms such as cable TV, satellite, and telecommunications: more efficient use of limited radio spectrum bandwidth, provision of more television channels than analog, better quality images, and potentially lower operating costs for broadcasters (after the initial upgrade costs).

Different countries have adopted different digital broadcasting standards; the major ones are:

ATSC DTV – Advanced Television Standards Committee (System A)

ATSC-M/H – Advanced Television Systems Committee Mobile & Handheld

ChinaDTV

DVB-H – Digital Video Broadcasting Handheld

DVB-T/DVB-T2 – Digital Video Broadcasting Terrestrial (System B)

ISDB-T – Integrated Services Digital Broadcasting Terrestrial (System C)

DMB-T/H

ISDB-TSB – Integrated Services Digital Broadcasting-Terrestrial Sound Broadcasting – (System F)

FLO – Forward Link Only (System M)

France 5

France 5 (pronounced [fʁɑ̃s sɛ̃k]) is a French free-to-air public television channel, part of the France Télévisions group. Principally featuring educational programming, the channel's motto is la chaîne de la connaissance et du savoir (the knowledge network). In contrast to the group's two main channels, France 2 and France 3, France 5 concentrates almost exclusively on factual programming, documentaries, and discussions – 3925 hours of documentaries were broadcast in 2003 – with fiction confined to one primetime slot of around two hours' duration on Monday evenings.

France 5 is today available around the clock. Earlier – before completion of the switchover to digital broadcasting on 29 November 2011 – the channel's analogue frequencies had carried the programmes of the Franco-German cultural channel Arte between 19.00 each evening and 3.00 the following morning.

ISDB

The Integrated Services Digital Broadcasting (ISDB; Japanese: 統合デジタル放送サービス, Tōgō dejitaru hōsō sābisu) is a Japanese standard for digital television (DTV) and digital radio used by the country's radio and television networks. ISDB replaced NTSC-J analog television system and the previously used MUSE Hi-vision analogue HDTV system in Japan, and will be replacing NTSC, PAL-M and PAL-N in South America and the Philippines. Digital Terrestrial Television Broadcasting (DTTB) services using ISDB-T started in Japan in December 2003 and in Brazil in December 2007 as a trial. Since then, many countries have adopted ISDB over other digital broadcasting standards.

ITV Digital

ITV Digital was a British digital terrestrial television broadcaster which launched a pay-TV service on the world's first digital terrestrial television network. Its main shareholders were Carlton Communications plc and Granada plc, owners of two franchises of the ITV network. Starting as ONdigital in 1998, the service was re-branded as ITV Digital in July 2001. Low audience figures, piracy issues and an ultimately unaffordable multi-million pound deal with the Football League led to the broadcaster suffering massive losses, forcing it to enter administration in March 2002. Pay television services ceased permanently on 1 May 2002, and the remaining free-to-air channels such as BBC One and Channel 4 had ceased when the company was liquidated in October. The terrestrial multiplexes were subsequently taken over by Crown Castle and the BBC to create Freeview later that month.

KBOP-LD

KBOP-LD is an independent television station serving the Dallas / Fort Worth Metroplex, licensed in Dallas, Texas, owned and operated by D.T.V., LLC. This station holds a construction permit for digital broadcasting on RF channel 20. It is not available on Time Warner Cable, Charter Communications, or Verizon Fios at this time.

KYCW-LD

KYCW-LD, virtual and UHF digital channel 25, is a low-powered CW-affiliated television station serving Springfield, Missouri, United States that is licensed to Branson. Owned by Gray Television, it is a sister station to Springfield-licensed NBC affiliate KYTV (channel 3) and ABC affiliate KSPR-LD (channel 33). The three stations share studios on West Sunshine Street in Springfield, where KYCW and KSPR also share transmitter facilities.

KYCW-LD's low-powered digital broadcasting radius does not reach the entire market. Therefore, it is simulcast in standard definition on KYTV's third digital subchannel (UHF channel 44.5, mapped to virtual channel 33.2 via PSIP) from a transmitter north of Fordland. KYCW is also simulcast on the second digital subchannel of low-power K17DL-D.

Media of the Republic of Ireland

The Media of Ireland includes all the media and communications outlets of Ireland.

STV (Philippines)

Social TV (STV) is a mainstream digital television channel in the Philippines.

STV features social media contents and creations such as Do It Yourself (DIY) videos, short films, educational vlogs, documentaries, animation, tutorial, hobbies, music, entertainment and technology trends.

It allows its viewers to interact with the TV network and let amateur content producers to share their own content not only on social media but also on free-to-air television.

It is a subchannel of UNTV News and Rescue, the network's carrier on free-to-air digital terrestrial television (DTT). It broadcasts 24 hours a day on Ultra High Frequency (UHF) Channel 38 (617.143 MHz) in Metro Manila, Rizal, Bulacan, Pampanga, Laguna, Cavite and some parts of Tarlac.

Its studios in the Philippines are located at the UNTV Broadcast Center, 907 Brgy. Philam, EDSA Quezon City.

Its digital transmitter is located at Emerald Hills, Sumulong Highway in Antipolo, Rizal.

STV is known for its broadcast of behind-the-scenes of UNTV's morning show "Good Morning Kuya" led by broadcast journalist and UNTV CEO Daniel Razon.

STV claims to be the first and only social mainstream media channel in the Philippines.

TVB Jade

TVB Jade (Chinese: 無綫電視翡翠台), or simply Jade, is a Hong Kong Cantonese-language free-to-air television channel owned and operated by Television Broadcasts Limited (TVB) as its flagship service, alongside its sister network, the English-language TVB Pearl. Broadcasting started on Nov 19, 1967. It is headquartered at TVB City at the Tseung Kwan O Industrial Estate in Tseung Kwan O, in the Sai Kung District. Primarily broadcasting entertainment programming, TVB Jade has historically been the most dominant television channel in the region in terms of viewership, with its closest competitor having been the now-defunct ATV Home.Jade primarily broadcasts in the Cantonese language; it has also offered programs with alternative audio tracks in Mandarin, English, and other foreign languages. Some shows also offer subtitles in multiple languages.

Television in Russia

Television is the most popular medium in Russia, with 74% of the population watching national television channels routinely and 59% routinely watching regional channels. There are 3300 television channels in total. 3 channels have a nationwide outreach (over 90% coverage of the Russian territory): Channel One, Russia-1 and NTV.

Tokyo Tower

Tokyo Tower (東京タワー, Tōkyō tawā, officially called 日本電波塔 Nippon denpatō "Japan Radio Tower") is a communications and observation tower in the Shiba-koen district of Minato, Tokyo, Japan. At 332.9 metres (1,092 ft), it is the second-tallest structure in Japan. The structure is an Eiffel Tower-inspired lattice tower that is painted white and international orange to comply with air safety regulations.

Built in 1958, the tower's main sources of income are tourism and antenna leasing. Over 150 million people have visited the tower. FootTown, a four-story building directly under the tower, houses museums, restaurants and shops. Departing from there, guests can visit two observation decks. The two-story Main Deck (formerly known as the Main Observatory) is at 150 metres (490 ft), while the smaller Top Deck (formerly known as the Special Observatory) reaches a height of 249.6 metres (819 ft). The names were changed following renovation of the top deck in 2018.The tower acts as a support structure for an antenna. Intended for television broadcasting, radio antennas were installed in 1961, but the tower now broadcasts signals for Japanese media outlets such as NHK, TBS and Fuji TV. Japan's planned digital television transition by July 2011 was problematic, however; Tokyo Tower's height, 332.9 m (1,092 ft) was not high enough to support complete terrestrial digital broadcasting to the area. A taller digital broadcasting tower, known as Tokyo Skytree, was completed on 29 February 2012. Every five years Tokyo Tower is repainted. It takes one year to repaint it.

Since its completion in 1958, Tokyo Tower has become a prominent landmark in the city, and frequently appears in media set in Tokyo.

WLMF-LD

WLMF-LD is a low-powered television station licensed to Miami, Florida. Founded in 1987 and owned by Paging Systems, Inc., a company based in Burlingame, California, WLMF airs programs from the first channel of SCOLA, a service offering European television news and information .

WLMF moved from channel 53 to channel 51 upon transitioning to digital broadcasting, and has an application for a low-powered digital service that would air on channel 39. Earlier attempts to move to channel 3 were dismissed. The move to channel 51 was required because channels 52 through 59 were discontinued as part of the 2009 digital television transition and sold off as blocks of UHF spectrum.

WPLN-FM

WPLN-FM (90.3 FM), is a National Public Radio-affiliated station in Nashville, Tennessee. Since June 2011, the station has employed exclusively a news and talk format; until then, the station carried at least some classical music. The station maintains studios on Mainstream Drive north of downtown Nashville, studios that some consider among the finest radio production facilities in the U.S.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.