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DVB-T
DVB-T, short for Digital Video Broadcasting – Terrestrial, 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 Singapore in February, 1998. This system transmits compressed digital audio, digital video and other data in an MPEG transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation. It is also the format widely used worldwide (including North America) for Electronic News Gathering for transmission of video and audio from a mobile newsgathering vehicle to a central receive point. It is also used in the US by Amateur television operators. Basics Rather than carrying one data carrier on a single radio frequency (RF) channel, COFDM works by splitting the digital data stream into a large number of slower digital streams, each of which digitally modulates a set of closely spaced adjacent sub-carrier frequencies. In the cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVB-T2
DVB-T2 is an abbreviation for "Digital Video Broadcasting – Second Generation Terrestrial"; it is the extension of the television standard DVB-T, issued by the consortium DVB, devised for the broadcast transmission of digital terrestrial television. DVB has been standardized by ETSI. This system transmits compressed digital audio, video, and other data in "physical layer pipes" (PLPs), using OFDM modulation with concatenated channel coding and interleaving. The higher offered bit rate, with respect to its predecessor DVB-T, makes it a system suited for carrying HDTV signals on the terrestrial TV channel (though many broadcasters still use plain DVB-T for this purpose). , it was implemented in broadcasts in the United Kingdom (Freeview HD, eight channels across two multiplexes, plus an extra multiplex in Northern Ireland carrying three SD channels), Italy ( Europa 7 HD, twelve channels), Finland (21 channels, five in HD), Germany (six HD (1080p50) channels, with 40 in planning), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Terrestrial Television
Digital terrestrial television (DTTV or DTT, or DTTB with "broadcasting") is a technology for terrestrial 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 up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVB-T
DVB-T, short for Digital Video Broadcasting – Terrestrial, 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 Singapore in February, 1998. This system transmits compressed digital audio, digital video and other data in an MPEG transport stream, using coded orthogonal frequency-division multiplexing (COFDM or OFDM) modulation. It is also the format widely used worldwide (including North America) for Electronic News Gathering for transmission of video and audio from a mobile newsgathering vehicle to a central receive point. It is also used in the US by Amateur television operators. Basics Rather than carrying one data carrier on a single radio frequency (RF) channel, COFDM works by splitting the digital data stream into a large number of slower digital streams, each of which digitally modulates a set of closely spaced adjacent sub-carrier frequencies. In the cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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). Transmission DVB systems distribute data using a variety of approaches, including: * Satellite: DVB-S, DVB-S2, and DVB-SH ** DVB-SMATV for distribution via SMATV * Cable: DVB-C, DVB-C2 * Terrestrial television: DVB-T, DVB-T2 ** Digital terrestrial television for handhelds: DVB-H, DVB-SH * Microwave: using DTT ( DVB-MT), the MMDS ( DVB-MC), and/or MVDS standards (DVB-MS) These standards define the physical layer and data link layer of the distribution system. Devices interact with the physical layer via a synchronous parallel interface (SPI), synchronous serial i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthogonal Frequency-division Multiplexing
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G/ 5G mobile communications. OFDM is a frequency-division multiplexing (FDM) scheme that was introduced by Robert W. Chang of Bell Labs in 1966. In OFDM, multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted to carry data in parallel.webe.org - 2GHz BAS Relocation Tech-Fair, COFDM Technology Basics 2007-03-02 Demodula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COFDM
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G/ 5G mobile communications. OFDM is a frequency-division multiplexing (FDM) scheme that was introduced by Robert W. Chang of Bell Labs in 1966. In OFDM, multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted to carry data in parallel.webe.org - 2GHz BAS Relocation Tech-Fair, COFDM Technology Basics 2007-03-02 Demodula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freeview (UK)
Freeview is the United Kingdom's sole digital terrestrial television platform. It is operated by Digital UK Ltd and DTV Services Ltd, a joint venture between the BBC, ITV, Channel 4, Channel 5 and Sky. It was launched on 30 October 2002, taking over the licence from ITV Digital which collapsed that year. The service provides consumer access via an aerial to the seven DTT multiplexes covering the United Kingdom. As of July 2020, it has 85 TV channels, 26 digital radio channels, 10 HD channels, six text services, 11 streamed channels, and one interactive channel. Delivery of standard-definition television and radio is labelled Freeview, while delivery of HDTV is called Freeview HD. Reception of Freeview requires a DVB-T/DVB-T2 tuner, either in a separate set-top box or built into the TV set. Since 2008 all new TV sets sold in the United Kingdom have a built-in Freeview tuner. Freeview HD requires a HDTV-capable tuner. Digital video recorders (DVRs) with a built-in Freevie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVB-H
DVB-H (Digital Video Broadcasting - Handheld) 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 (EN 302 304) can be downloaded from the official DVB-H website. From March 2008, DVB-H is officially endorsed by the European Union as the "preferred technology for terrestrial mobile broadcasting". The major competitors of this technology are Qualcomm's MediaFLO system, the 3G cellular system based MBMS mobile-TV standard, and the ATSC-M/H format in the U.S. DVB-SH (Satellite to Handhelds) now and DVB-NGH (Next Generation Handheld) in the future are possible enhancements to DVB-H, providing improved spectral efficiency and better modulation flexibility. DVB-H has been a commercial failure, and the service is no longer on-air. Ukraine was the last country with a nationwide broadcast in DVB-H, which began trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-frequency Network
A single-frequency network or SFN is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel. Analog AM and FM radio broadcast networks as well as digital broadcast networks can operate in this manner. SFNs are not generally compatible with analog television transmission, since the SFN results in ghosting due to echoes of the same signal. A simplified form of SFN can be achieved by a low power co-channel repeater, booster or broadcast translator, which is utilized as a gap filler transmitter. The aim of SFNs is efficient utilization of the radio spectrum, allowing a higher number of radio and TV programs in comparison to traditional multi-frequency network (MFN) transmission. An SFN may also increase the coverage area and decrease the outage probability in comparison to an MFN, since the total received signal strength may increase to positions midway between the transmitters. SFN schemes are somewhat analogous to what ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-book
The D-Book is the UK technical specification for digital terrestrial television (DTT). The Digital TV Group (DTG) has published and maintained the D-Book for over a decade and the specification is updated annually to keep up with the pace of development in UK DTT. The D-Book is compiled by DTG Working Groups composed of industry experts from the DTG’s staff and membership of around 150 broadcasters, manufacturers, technology providers and other organisations who continually update and peer-review the specification. Conformance to D-Book standard allows products to use the Digital Tick, Freeview, Freeview + and Freeview HDlogos. The D-Book is only available to members of the Digital TV Group. History The first edition of the D-Book was written in 1996 when the current standard for terrestrial broadcasting DVB-T was new and untried. From the outset, the D-Book was an implementation guideline and referenced fundamental standards where possible. But many of the component parts o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Television
Amateur television (ATV) is the transmission of broadcast quality video and sound reproduction, audio over the wide range of frequencies of radio waves allocated for radio amateur (Ham) use. ATV is used for non-commercial experimentation, pleasure, and public service events. Ham TV stations were on the air in many cities before commercial television stations came on the air. Various transmission standards are used, these include the broadcast transmission standards of NTSC in North America and Japan, and PAL or SECAM elsewhere, utilizing the full refresh rates of those standards. ATV includes the study of building of such transmitters and receiver (radio), receivers, and the study of radio propagation of signals travelling between transmitting and receiving stations. ATV is an extension of amateur radio. It is also called HAM TV or fast-scan TV (FSTV), as opposed to slow-scan television (SSTV). North America In North America, Amateur radio frequency allocations, amateur radio ban ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiplexing
In telecommunications and computer networking, multiplexing (sometimes contracted to muxing) is a method by which multiple analog or digital signals are combined into one signal over a shared medium. The aim is to share a scarce resource - a physical transmission medium. For example, in telecommunications, several telephone calls may be carried using one wire. Multiplexing originated in telegraphy in the 1870s, and is now widely applied in communications. In telephony, George Owen Squier is credited with the development of telephone carrier multiplexing in 1910. The multiplexed signal is transmitted over a communication channel such as a cable. The multiplexing divides the capacity of the communication channel into several logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, extracts the original channels on the receiver end. A device that performs the multiplexing is called a multiplexer (MUX), and a dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
