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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-DSNG, DVB-S2, DVB-S2X 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ETSI
The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization operating in the field of Information and communications technology, information and communications. ETSI supports the development and testing of global technical standards for ICT-enabled systems, applications and services. Overview and history ETSI was set up in 1988 by the European Conference of Postal and Telecommunications Administrations (European Conference of Postal and Telecommunications Administrations, CEPT) following a proposal from the European Commission (EC). ETSI is the officially recognized body with a responsibility for the standardization of information and communication technologies (ICT). It is one of the three bodies officially recognized by the European Union as a European Standards Organisation (ESO), the others being European Committee for Standardization, CEN and CENELEC. The role of the ESOs is to support EU regulation and policies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVB-C2
Digital Video Broadcasting - Cable (DVB-C) is the DVB European consortium standard for the broadcast transmission of digital television over cable. This system transmits an MPEG-2 or MPEG-4 family digital audio/digital video stream, using a QAM modulation with channel coding. The standard was first published by the ETSI in 1994, and subsequently became the most widely used transmission system for digital cable television in Europe, Asia and South America. It is deployed worldwide in systems ranging from the larger cable television networks (CATV) down to smaller satellite master antenna TV ( SMATV) systems. Technical description DVB-C transmitter With reference to the figure, a short description of the single processing blocks follows. * Source coding and MPEG-2 multiplexing (MUX): video, audio, and data streams are multiplexed into an MPEG program stream (MPEG-PS). One or more MPEG-PSs are joined together into an MPEG transport stream (MPEG-TS). This is the basic digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Link Layer
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer provides the functional and procedural means to transfer data between network entities and may also provide the means to detect and possibly correct errors that can occur in the physical layer. The data link layer is concerned with local delivery of frames between nodes on the same level of the network. Data-link frames, as these protocol data units are called, do not cross the boundaries of a local area network. Inter-network routing and global addressing are higher-layer functions, allowing data-link protocols to focus on local delivery, addressing, and media arbitration. In this way, the data link layer is analogous to a neighborhood traffic cop; it endeavors to arbitrate between parties contending for access to a medium, without c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Layer
In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer: the layer most closely associated with the physical connection between devices. The physical layer provides an electrical, mechanical, and procedural interface to the transmission medium. The shapes and properties of the electrical connectors, the frequencies to transmit on, the line code to use and similar low-level parameters, are specified by the physical layer. At the electrical layer, the physical layer is commonly implemented in a dedicated PHY chip or, in electronic design automation (EDA), by a design block. In mobile computing, the MIPI Alliance *-PHY family of interconnect protocols are widely used. Role The physical layer defines the means of transmitting a stream of raw bits over a physical data link connecting network nodes. The bitstream may be grouped into code words or symbols and converted to a physical signal that is transmitted over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DVB-MS
DVB-MS is a complementary system for digital television multi-point distribution based on the satellite delivery system DVB-S. For cable delivery system DVB-MC is used which is based on DVB-C Digital Video Broadcasting - Cable (DVB-C) is the Digital Video Broadcasting, DVB European consortium standard for the broadcast transmission of digital television over coaxial cable, cable. This system transmits an MPEG-2 or MPEG-4 family digita .... The DVB-MS system uses microwave frequencies above to directly distribute television services from a central point to homes of viewers. To receive the signal a small frequency converter is used instead of a satellite dish for DVB-S. DVB-MC uses frequencies below . read 2012-08-23 References [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MVDS
MVDS is an acronym for terrestrial "Multipoint Video Distribution System". MVDS currently is a part of broader MWS (Multimedia Wireless System) standards. In the European Union MWS works in 10.7–13.5 and 40.5–43.5 GHz frequency bands. Research for 42 GHz frequency has been done under the European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ... EMBRACE (Efficient Millimetre Broadband Radio Access for Convergence and Evolution) initiative. Standards ETSI *EN 300 748 *EN 301 215-3 *EN 301 997-2 UK Standards * MPT 1550 (obsolete) * MPT 1560 (obsolete) CEPT *ERC/DEC/(99)15 *ECC/REC/(01)04 Manufacturers of MVDS equipment *MDS America Inc *Newtec *EF Data *BluWan *Philips Broadband Network *Hughes Network systems *Thales Group (Thomson) *Trophy electronic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MMDS
Multichannel multipoint distribution service (MMDS), formerly known as broadband radio service (BRS) and also known as wireless cable, is a wireless telecommunications technology, used for general-purpose broadband networking or, more commonly, as an alternative method of cable television programming reception. MMDS is used in Australia, Barbados, Belarus, Bolivia, Brazil, Cambodia, Canada, Czech Republic, Dominican Republic, India, Kazakhstan, Kyrgyzstan, Lebanon, Mexico, Nepal, Nigeria, Pakistan, Panama, Portugal (including Madeira), Russia, Slovakia, Sri Lanka, Sudan, Thailand, Ukraine, United States, Uruguay and Vietnam. It is most commonly used in sparsely populated rural areas, where laying cables is not economically viable, although some companies have also offered MMDS services in urban areas, most notably in Ireland, until they were phased out in 2016. Technology The BRS band uses microwave frequencies from 2.3 to 2.5 GHz. Reception of BRS-delivered television and dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300 MHz and 300 GHz, broadly construed. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 30 cm and 3 mm), or between 1 and 3000 GHz (30 cm and 0.1 mm). In all cases, microwaves include the entire super high frequency, super high frequency (SHF) band (3 to 30 GHz, or 10 to 1 cm) at minimum. The boundaries between far infrared, terahertz radiation, microwaves, and ultra-high-frequency (UHF) are fairly arbitrary and differ between different fields of study. The prefix ' in ''microwave'' indicates that microwaves are small (having shorter wavelengths), compared to the radio waves used in prior radio technology. Frequencies in the micr ... [...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. For a few months from March 2008, DVB-H was officially endorsed by the European Union as the "preferred technology for terrestrial mobile broadcasting". The major competitors of this technology were Qualcomm's MediaFLO system, the 3G cellular system based MBMS mobile-TV standard, and the ATSC-M/H format in the U.S. , the recently introduced DVB-SH (Satellite to Handhelds) and anticipated DVB-NGH (Next Generation Handheld) in the future were possible enhancements to DVB-H, providing improved spectral efficiency and better modulation flexibility. DVB-H struggled against resistance from network operators to include the technology in their subs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handheld
A mobile device or handheld device is a computer small enough to hold and operate in hand. Mobile devices are typically battery-powered and possess a flat-panel display and one or more built-in input devices, such as a touchscreen or keypad. Modern mobile devices often emphasize wireless networking, to both the Internet and to other devices in their vicinity, such as headsets or in-car entertainment systems, via Wi-Fi, Bluetooth, cellular networks, or near-field communication. Characteristics Device mobility can be viewed in the context of several qualities: * Physical dimensions and weight * Whether the device is mobile or some kind of host to which it is attached is mobile * What kind of host devices it can be bound with * How devices communicate with a host * When mobility occurs Strictly speaking, many so-called mobile devices are not mobile. It is the host that is mobile, i.e., a mobile human host carries a non-mobile smartphone device. An example of a true mobile computing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
