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List of digital television broadcast standards |
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DVB standards (countries) |
ATSC standards (countries) |
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ISDB standards (countries) |
DTMB standards (countries) |
DMB standard (countries) |
Codecs |
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Terrestrial Frequency bands |
Satellite Frequency bands |
Digital multimedia broadcasting (DMB) is a digital radio transmission technology developed in South Korea [1] [2] [3] 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 (DAB) 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, [4] but the technological foundations were laid by Prof. Dr. Gert Siegle and Dr. Hamed Amor at Bosch in Germany. [5] 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 its former competing mobile TV standard, DVB-H. [6]
T-DMB is made for terrestrial transmissions on band III (VHF) and L (UHF) frequencies. DMB is unavailable in the United States because those frequencies are allocated for television broadcasting (VHF channels 7 to 13) and military applications. USA is adopting ATSC-M/H for free broadcasts to mobiles, and for a time, Qualcomm's proprietary MediaFLO system. In Japan, 1seg is the standard, using ISDB.
T-DMB uses MPEG-4 Part 10 (H.264) for the video and MPEG-4 Part 3 BSAC or HE-AAC v2 for the audio. The audio and video is encapsulated in an MPEG transport stream (MPEG-TS). The stream is forward error corrected by Reed Solomon encoding and the parity word is 16 bytes long. There is convolutional interleaving made on this stream, then the stream is broadcast in data stream mode on DAB. In order to diminish the channel effects such as fading and shadowing, the DMB modem uses OFDM-DQPSK modulation. A single-chip T-DMB receiver is also provided by an MPEG transport stream demultiplexer. DMB has several applicable devices such as mobile phone, portable TV, PDA and telematics devices for automobiles.
T-DMB is an [ETSI] standard (TS 102 427 and TS 102 428). As of December 14, 2007, ITU formally approved T-DMB as the global standard, along with three other standards, like DVB-H, 1seg, and MediaFLO. [7]
Smart DMB started in January 2013 in South Korea. Smart DMB has a VOD service and quality has been improved from 240p to 480p. Smart DMB is built in many Korean smartphones starting with the Galaxy Grand in January 2013. [8]
HD DMB started in August 2016 in South Korea. HD DMB has been improved from 240p to 720p. It uses HEVC.5 codec. There are currently[ when? ] 6 HD DMB stations in Seoul. Smartphones integrated Qualcomm Snapdragon 801 or higher received firmware upgrade to support HD DMB.
Currently, DMB is being put into use in a number of countries, although mainly used in South Korea. Also see list of Countries using DAB/DMB.
In 2005, South Korea became the world's first country to start S-DMB and T-DMB service on May 1 and December 1, respectively. [9] [10] In December 2006, T-DMB service in South Korea consists of, 7 TV channels, 12 radio channels, and 8 data channels. These are broadcast on six multiplexes in the VHF band on TV channels 8 and 12 (6 MHz raster). In October 2007, South Korea added broadcasting channel MBCNET to the DMB channel. But in 2010, this channel changed tnN go. In 2009 there were eight DMB video channels in Seoul, and six in other metropolitan cities. As of April 2013, S-DMB service in South Korea consists of 15 TV channels, 2 radio channels and 6 data channels. [11]
South Korea has had Full T-DMB services including JSS (Jpeg Slide Show), DLS (Dynamic Label Segment), BWS, and TPEG since 2006.
S-DMB service in South Korea is provided on a subscription basis through TU Media and is accessible throughout the country. T-DMB service is provided free of charge, but access is limited to selected regions.
Around one million receivers have been sold as of June 2006 [update] . 14 million DMB receivers were sold including T-DMB and S-DMB in South Korea, and 40% of the new cell phones have the capability to see DMB. [12]
Receivers are integrated in car navigation systems, mobile phones, portable media players, laptop computers and digital cameras. In mid-August 2007, Iriver, a multimedia and micro-technology company released their "NV", which utilizes South Korea's DMB service.
Since the advent of smartphones DMBs have been made available on phones with receivers through smartphone applications, most of which come pre-installed in phones made and sold in South Korea.
This article needs to be updated. The reason given is: DMB outside Korea and DVB-H are dead; and in all other standards, there's been heavy movement in since 2008, which seems to be the state of the section..(August 2024) |
Some T-DMB trials are currently available or planned around Europe and other countries:
T-DMB works flawlessly in vehicles traveling up to 300 km/h.[ citation needed ] In tunnels or underground areas, both television and radio broadcast is still available, though DMB may skip occasionally. In South Korea, some long-distance buses adopted T-DMB instead of satellite TV such as Sky TV. It works quite well even though the resolution is 240p, lower than satellite. In comparison, satellite is usually 480p or higher.[ citation needed ]
Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio in contrast to the narrower format (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same bandwidth as a single analog channel, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2000. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widely used standards:
Digital Audio Broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services in many countries around the world, defined, supported, marketed and promoted by the WorldDAB organisation. The standard is dominant in Europe and is also used in Australia, and in parts of Africa and Asia; as of 2022, 55 countries are actively running DAB broadcasts.
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).
Integrated Services Digital Broadcasting is a Japanese broadcasting standard for digital television (DTV) and digital radio.
Advanced Television Systems Committee (ATSC) standards are an International set of standards for broadcast and digital television transmission over terrestrial, cable and satellite networks. It is largely a replacement for the analog NTSC standard and, like that standard, is used mostly in the United States, Mexico, Canada, South Korea and Trinidad & Tobago. Several former NTSC users, such as Japan, have not used ATSC during their digital television transition, because they adopted other systems such as ISDB developed by Japan, and DVB developed in Europe, for example.
Digital Radio Mondiale is a set of digital audio broadcasting technologies designed to work over the bands currently used for analogue radio broadcasting including AM broadcasting—particularly shortwave—and FM broadcasting. DRM is more spectrally efficient than AM and FM, allowing more stations, at higher quality, into a given amount of bandwidth, using xHE-AAC audio coding format. Various other MPEG-4 codecs and Opus are also compatible, but the standard now specifies xHE-AAC.
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 terrestrial television is a technology for terrestrial television, in which television stations broadcast television content in a digital format. Digital terrestrial television is a major technological advancement over analog television, and has largely replaced analog television broadcasting, which was previously in common use since the middle of the 20th century.
Malaysian television broadcasting was introduced on 28 December 1963. Colour television was introduced on 28 December 1978. Full-time colour transmissions were officially inaugurated on New Year's Day 1982. There are currently 16 national free-to-air terrestrial television channels in Malaysia and 3 national pay subscription television operators in Malaysia.
Datacasting is the transmission of data over a wide area using radio waves. It typically refers to supplemental information sent by television stations alongside digital terrestrial television (DTT) signals. However, datacasting can also be applied to digital data signals carried on analog TV or radio broadcasts.
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. For a few months from March 2008, DVB-H was officially endorsed by the European Union as the "preferred technology for terrestrial mobile broadcasting".
MediaFLO was a technology developed by Qualcomm for transmitting audio, video and data to portable devices such as mobile phones and personal televisions, used for mobile television. In the United States, the service powered by this technology was branded as FLO TV.
S-DMB (Satellite-DMB) was a hybrid version of the Digital Multimedia Broadcasting. The S-DMB used the S band (2170-2200 MHz) of IMT-2000. and delivered around 18 channels at 128 kbit/s in 15 MHz. It incorporated a high power geostationary satellite, the MBSat 1. For outdoor and light indoor coverage is integrated with a terrestrial repeater network for indoor coverage in urban areas.
Mobile television is television watched on a small handheld or mobile device, typically developed for that purpose. It includes service delivered via mobile phone networks, received free-to-air via terrestrial television stations, or via satellite broadcast. Regular broadcast standards or special mobile TV transmission formats can be used. Additional features include downloading TV programs and podcasts from the Internet and storing programming for later viewing.
DTMB is the digital TV standard for mobile and fixed devices, developed in the People's Republic of China. It is used there and in both of their special administrative regions, and also in Cambodia, the Comoros, Cuba, East Timor, Laos, Vietnam, and Pakistan. In Pakistan, as part of the China–Pakistan Economic Corridor Project, ZTE Corporation will provide Pakistan Television Corporation collaboration across several digital terrestrial television technologies, staff training, and content creation, including partnerships with Chinese multinational companies in multiple areas, such as television sets and set top boxes, as a form of "International Cooperation".
IP over DVB implies that Internet Protocol datagrams are distributed using some digital television system, for example DVB-H, DVB-SH, DVB-T, DVB-S, DVB-C or their successors like DVB-T2, DVB-S2, and DVB-C2. This may take the form of IP over MPEG, where the datagrams are transferred over the MPEG transport stream, or the datagrams may be carried in the DVB baseband frames directly, as in GSE.
ETSI Satellite Digital Radio describes a standard of satellite digital radio. It is an activity of the European standardisation organisation ETSI.
The radio technology known as Digital Audio Broadcasting, and its TV sibling, Digital Multimedia Broadcasting (DMB), is being operated in several regions worldwide, either in the form of full services, or as feasibility studies.