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Distribution Frame
In telecommunications, a distribution frame is a passive device which terminates cables, allowing arbitrary interconnections to be made. For example, the Main Distribution Frame (MDF) located at a telephone exchange, telephone central office terminates the cables leading to subscribers on the one hand, and cables leading to active equipment (such as DSLAMs and telephone switches) on the other. Service is provided to a subscriber by manually wiring a twisted pair (called a jumper wire) between the telephone line and the relevant DSL or Plain old telephone service, POTS line circuit. In broadcast engineering, a distribution frame is a location within an apparatus room through which all signals (Sound, audio, video, or data) pass, with the ability to arbitrarily route and connect sources and destinations between studios and other internal and external points. Connections can either be Solder, soldered, or made using terminal blocks. Because the frame may carry live broadcast signal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Distribution Frame
In telephony, a main distribution frame (MDF or main frame) is a signal distribution frame for connecting equipment (inside plant) to cables and subscriber carrier equipment ( outside plant). Overview The MDF is a termination point within the local telephone exchange where exchange equipment and terminations of local loops are connected by jumper wires at the MDF. All cable copper pairs supplying services through user telephone lines are terminated at the MDF and distributed through the MDF to equipment within the local exchange e.g. repeaters and DSLAM. Cables to intermediate distribution frames (IDF) terminate at the MDF. Trunk cables may terminate on the same MDF or on a separate trunk main distribution frame (TMDF). Like other distribution frames the MDF provides flexibility in assigning facilities, at lower cost and higher capacity than a patch panel. The most common kind of large MDF is a long steel rack accessible from both sides. On one side, termination blocks a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wall
A wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or serves a decorative purpose. There are various types of walls, including border barriers between countries, brick walls, defensive walls in fortifications, and retaining walls that hold back dirt, stone, water, or noise. Walls can also be found in buildings, where they support roofs, floors, and ceilings, enclose spaces, and provide shelter and security. The construction of walls can be categorized into framed walls and mass-walls. Framed walls transfer the load to the foundation through posts, columns, or studs and typically consist of structural elements, insulation, and finish elements. Mass-walls are made of solid materials such as masonry, concrete, adobe, or rammed earth. Walls may also house utilities like electrical wiring or plumbing and must conform to local building and fire codes. Walls have historically served defensive purp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gigabit Ethernet
In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use in 1999, and has replaced Fast Ethernet in wired local networks due to its considerable speed improvement over Fast Ethernet, as well as its use of cables and equipment that are widely available, economical, and similar to previous standards. The first standard for faster 10 Gigabit Ethernet was approved in 2002. History Ethernet was the result of research conducted at Xerox PARC in the early 1970s, and later evolved into a widely implemented Physical layer, physical and Data link layer, link layer protocol. Fast Ethernet increased the speed from 10 to 100 megabits per second (). Gigabit Ethernet was the next iteration, increasing the speed to . The initial standard for Gigabit Ethernet was produced by the IEEE in June 1998 as IEEE 802.3z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Loop (electricity)
In an electrical system, a ground loop or earth loop occurs when two points of a circuit are intended to have the same ground reference potential but instead have a different potential between them. This is typically caused when enough current is flowing in the connection between the two ground points to produce a voltage drop and cause the two points to be at different potentials. Current may be produced in a ground loop by electromagnetic induction. Ground loops are a major cause of noise, hum, and interference in audio, video, and computer systems. Wiring practices that protect against ground loops include ensuring that all vulnerable signal circuits are referenced to one point as ground. The use of differential signaling can provide rejection of ground-induced interference. The removal of ground connections to equipment in an effort to eliminate ground loops will also eliminate the protection the safety ground connection is intended to provide. Description A ground l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television Station
A television station is a set of equipment managed by a business, organisation or other entity such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the earth's surface to any number of tuned Television sets, receivers simultaneously. Overview The ''Fernsehsender Paul Nipkow'' (''TV Station Paul Nipkow'') in Berlin, Germany, was the first regular television service in the world. It was on the air from 22 March 1935, until it was shut down in 1944. The station was named after Paul Gottlieb Nipkow, the inventor of the Nipkow disk. Most often the term "television station" refers to a station which broadcasts structured content to an audience or it refers to the organization that operates the station. A terrestrial television transmission can occur via analog television signals or, more recently, via digital television signals. Television stations are differentiated from cable television or other video ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Station
Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio station, while in '' satellite radio'' the radio waves are broadcast by a satellite in Earth orbit. To receive the content the listener must have a broadcast radio receiver (''radio''). Stations are often affiliated with a radio network that provides content in a common radio format, either in broadcast syndication or simulcast, or both. The encoding of a radio broadcast depends on whether it uses an analog or digital signal. Analog radio broadcasts use one of two types of radio wave modulation: amplitude modulation for AM radio, or frequency modulation for FM radio. Newer, digital radio stations transmit in several different digital audio standards, such as DAB (Digital Audio Broadcasting), HD radio, or DRM ( Digital Ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Router (computing)
A router is a computer and networking device that Packet forwarding, forwards data packets between computer networks, including internetworks such as the global Internet. Routers perform the "traffic directing" functions on the Internet. A router is connected to two or more data lines from different IP networks. When a data packet comes in on a line, the router reads the network address information in the packet header to determine the ultimate destination. Then, using information in its routing table or routing policy, it directs the packet to the next network on its journey. Data packets are forwarded from one router to another through an internetwork until it reaches its destination Node (networking), node. The most familiar type of Internet Protocol, IP routers are Residential gateway, home and small office routers that forward IP packet (other), IP packets between the home computers and the Internet. More sophisticated routers, such as enterprise routers, conne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixing Console
A mixing console or mixing desk is an electronic device for Audio mixing (recorded music), mixing audio signals, used in sound recording and reproduction and sound reinforcement systems. Inputs to the console include microphones, signals from electric or electronic instruments, or recorded sounds. Mixers may control analog or Digital signal (signal processing), digital signals. The modified signals are summation, summed to produce the combined output signals, which can then be broadcast, amplified through a sound reinforcement system or recorded. Mixing consoles are used for applications including recording studios, public address systems, sound reinforcement systems, nightclubs, broadcasting, and post-production. A typical, simple application combines signals from microphones on stage into an amplifier that drives one set of loudspeakers for the audience. A DJ mixer may have only two channels, for mixing two record players. A coffeehouse's small stage might only have a six-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits, enabling telephone calls between subscribers. The term "central office" can also refer to a central location for fiber optic equipment for a fiber internet provider. In historical perspective, telecommunication terminology has evolved with time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. A central office is defined as the telephone switch controlling connections for one or more central office prefixes. However, it also often denotes the building used to house the inside plant equipment for multiple telephone exchange areas. In North America, the term ''wire center'' may be used to denote a central office location, indicating a facility that provides a telephone with a dial tone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Ground
In electrical engineering, ground or earth may be a reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground for several reasons. Exposed conductive parts of electrical equipment are connected to ground to protect users from electrical shock hazards. If internal insulation fails, dangerous voltages may appear on the exposed conductive parts. Connecting exposed conductive parts to a "ground" wire which provides a low-impedance path for current to flow back to the incoming neutral (which is also connected to ground, close to the point of entry) will allow circuit breakers (or RCDs) to interrupt power supply in the event of a fault. In electric power distribution systems, a protective earth (PE) conductor is an essential part of the safety provided by the earthing system. Connection to ground also limits the build-up of static el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
