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Broadcast Television Systems
Broadcast television systems (or terrestrial television systems outside the US and Canada) are the encoding or formatting systems for the transmission and reception of terrestrial television signals. Analog television systems were standardized by the International Telecommunication Union in 1961, with each system designated by a letter ( A- N) in combination with the color standard used (NTSC, PAL or SECAM) - for example PAL-B, NTSC-M, etc.). These analog systems for TV broadcasting dominated until the 2010s. With the introduction of digital terrestrial television (DTT), they were replaced by four main systems in use around the world: ATSC, DVB, ISDB and DTMB. Analog television systems Every analog television system bar one began as a black-and-white system. Each country, faced with local political, technical, and economic issues, adopted a color television standard which was grafted onto an existing monochrome system such as CCIR System M, using gaps in the video spectrum ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Band III
Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz). It is primarily used for radio and television broadcasting. It is also called high-band VHF, in contrast to Bands I and II. Broadcast Television North America The band is subdivided into seven channels for television broadcasting, each occupying 6 MHz. Europe European Band III allocations vary from country to country, with channel widths of 7 or 8 MHz. The standard channel allocations for European countries that use System B with 7 MHz channel spacing are as follows: The Irish (8 MHz) system is shown below. Oceania Australia has allocated 8 channels in Band III for digital television, each with 7 MHz bandwidth. Russia and other former members of OIRT Russian analog television is transmitted using System D with 8 MHz channel bandwidth. Radio The band came into use for radio broa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrestrial Television
Terrestrial television or over-the-air television (OTA) is a type of television broadcasting in which the signal transmission occurs via radio waves from the terrestrial (Earth-based) transmitter of a TV station to a TV receiver having an antenna. The term ''terrestrial'' is more common in Europe and Latin America, while in Canada and the United States it is called ''over-the-air'' or simply ''broadcast''. This type of TV broadcast is distinguished from newer technologies, such as satellite television (direct broadcast satellite or DBS television), in which the signal is transmitted to the receiver from an overhead satellite; cable television, in which the signal is carried to the receiver through a cable; and Internet Protocol television, in which the signal is received over an Internet stream or on a network utilizing the Internet Protocol. Terrestrial television stations broadcast on television channels with frequencies between about 52 and 600 MHz in the VHF and U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chrominance
Chrominance (''chroma'' or ''C'' for short) is the signal used in video systems to convey the color information of the picture (see YUV color model), separately from the accompanying luma signal (or Y' for short). Chrominance is usually represented as two color-difference components: U = B′ − Y′ (blue − luma) and V = R′ − Y′ (red − luma). Each of these difference components may have scale factors and offsets applied to it, as specified by the applicable video standard. In composite video signals, the U and V signals modulate a color subcarrier signal, and the result is referred to as the chrominance signal; the phase and amplitude of this modulated chrominance signal correspond approximately to the hue and saturation of the color. In digital-video and still-image color spaces such as Y′CbCr, the luma and chrominance components are digital sample values. Separating RGB color signals into luma and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 define the range of Band IV from 470 to 582 MHz. An EICTA paper defines the range as 474 to 602 MHz, whilst the BBC define the range as 470 to 614 MHz. Band IV is primarily used for analogue and digital (DVB-T, ATSC and ISDB) television broadcasting, as well as services intended for mobile devices such as DVB-H. Television Australia In Australia UHF channel allocations are 7 MHz wide. Band IV includes channels 28 to 35, with base frequencies of 529.5 MHz to 578.5 MHz. More details are available on the television frequencies page. New Zealand In New Zealand UHF channel allocations are 8 MHz wide. Band IV includes channels 25 to 35, with base fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Radio And Television Organisation
The International Radio and Television Organisation (official name in French: Organisation Internationale de Radiodiffusion et de Télévision or OIRT (before 1960 International Broadcasting Organization (IBO), official name in French: ''Organisation Internationale de Radiodiffusion'' (OIR)) was an East European network of radio and television broadcasters with the primary purpose of establishing ties and securing an interchange of information between those various organizations responsible for broadcasting services, promoting the interests of broadcasting, seeking by international cooperation a solution to any matter relating to broadcasting, and studying and working out all measures having as their aim the development of broadcasting. History Without British participation, 26 members founded the OIR on 28 June 1946. The next day, at the General Assembly of the International Broadcasting Union (IBU), an attempt was made to dissolve this body, but the motion failed to obtain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
819 Line
819-line was an analog monochrome TV system developed and used in France as television broadcast resumed after World War II. Transmissions started in 1949 and were active up to 1985, although limited to France, Belgium and Luxembourg. It is associated with CCIR System E and F. History When Europe resumed TV transmissions after World War II (i.e. in the late 1940s and early 1950s) most countries standardized on 625-line television systems. The two exceptions were the British 405-line system, which had already been introduced in 1936, and the French 819-line system. During the 1940s René Barthélemy had already reached 1,015 lines and even 1,042 lines. On November 20, 1948, François Mitterrand, the then Secretary of State for Information, decreed a broadcast standard of 819 lines developed by Henri de France; broadcasting began at the end of 1949 in this higher definition format. It was used in France by TF1, and in Monaco by Tele Monte Carlo. Some 819-line TV sets were availa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
