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Cellular Repeater
A cellular repeater (also known as cell phone signal booster or cell phone signal amplifier) is a type of bi-directional amplifier used to improve cell phone reception. A cellular repeater system commonly consists of a donor antenna that receives and transmits signal from nearby cell towers, coaxial cables, a signal amplifier, and an indoor rebroadcast antenna. Common components Donor antenna A "donor antenna" is typically installed by a window or on the roof a building and used to communicate back to a nearby cell tower. A donor antenna can be any of several types, but is usually directional or omnidirectional. An omnidirectional antenna (which broadcast in all directions) is typically used for a repeater system that amplify coverage for all cellular carriers. A directional antenna is used when a particular tower or carrier needs to be isolated for improvement. The use of a highly directional antenna can help improve the donor's signal-to-noise ratio, thus improving the qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bi-directional Amplifier
A cellular repeater (also known as cell phone signal booster or cell phone signal amplifier) is a type of bi-directional amplifier used to improve cell phone reception. A cellular repeater system commonly consists of a donor antenna that receives and transmits signal from nearby cell towers, coaxial cables, a signal amplifier, and an indoor rebroadcast antenna. Common components Donor antenna A "donor antenna" is typically installed by a window or on the roof a building and used to communicate back to a nearby cell tower. A donor antenna can be any of several types, but is usually directional or omnidirectional. An omnidirectional antenna (which broadcast in all directions) is typically used for a repeater system that amplify coverage for all cellular carriers. A directional antenna is used when a particular tower or carrier needs to be isolated for improvement. The use of a highly directional antenna can help improve the donor's signal-to-noise ratio, thus improving the qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction
Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Italian scientist Francesco Maria Grimaldi coined the word ''diffraction'' and was the first to record accurate observations of the phenomenon in 1660. In classical physics, the diffraction phenomenon is described by the Huygens–Fresnel principle that treats each point in a propagating wavefront as a collection of individual spherical wavelets. The characteristic bending pattern is most pronounced when a wave from a coherent source (such as a laser) encounters a slit/aperture that is comparable in size to its wavelength, as shown in the inserted image. This is due to the addition, or interference, of different points on the wavefront (or, equivalently, each wavelet) that travel by paths of di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate. There are several different types of repeaters; a telephone repeater is an amplifier in a telephone line, an optical repeater is an optoelectronic circuit that amplifies the light beam in an optical fiber cable; and a radio repeater is a radio receiver and transmitter that retransmits a radio signal. A broadcast relay station is a repeater used in broadcast radio and television. Overview When an information-bearing signal passes through a communication channel, it is progressively degraded due to loss of power. For example, when a telephone call passes through a wire telephone line, some of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave
In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (resting) value at some frequency. When the entire waveform moves in one direction, it is said to be a ''traveling wave''; by contrast, a pair of superimposed periodic waves traveling in opposite directions makes a ''standing wave''. In a standing wave, the amplitude of vibration has nulls at some positions where the wave amplitude appears smaller or even zero. Waves are often described by a ''wave equation'' (standing wave field of two opposite waves) or a one-way wave equation for single wave propagation in a defined direction. Two types of waves are most commonly studied in classical physics. In a '' mechanical wave'', stress and strain fields oscillate about a mechanical equilibrium. A mechanical wave is a local deformation (strain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coverage Noticer
In telecommunications, the coverage of a radio station is the geographic area where the station can communicate. Broadcasters and telecommunications companies frequently produce coverage maps to indicate to users the station's intended service area. Coverage depends on several factors, such as orography (i.e. mountains) and buildings, technology, radio frequency and perhaps most importantly for two-way telecommunications the sensitivity and transmit efficiency of the consumer equipment. Some frequencies provide better regional coverage, while other frequencies penetrate better through obstacles, such as buildings in cities. The ability of a mobile phone to connect to a base station depends on the strength of the signal. That may be boosted by higher power transmissions, better antennas, taller antenna masts or alternative solutions like in-building picocells. Normal Macro-Cell signals need to be boosted to pass through buildings, which is a particular problem designing networks f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Home Node B
A Home Node B, or HNB, is the 3GPP's term for a 3G femtocell or Small Cell. A Node B is an element of a 3G macro Radio Access Network, or RAN. A femtocell performs many of the function of a Node B, but is optimized for deployment in the indoor premises and small coverage public hotspots. The femtocell concept was originally conceived for residential environment. However, it has evolved to include other usages such as enterprise and public hotspots. Home eNode B is an LTE counterpart of the HNB. Architecture Within an HNB Access Network there are three new network elements: the Home Node B (or femtocell), the Security Gateway (SeGW) and the Home Node B Gateway, or HNB-GW. Between the HNB and the HNB-GW is a new interface known as Iu-h. Home Node B (HNB) – Connected to an existing residential broadband service, an HNB provides 3G radio coverage for 3G handsets within a home. HNBs incorporate the capabilities of a standard Node B as well as the radio resource manageme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femtocell
In telecommunications, a femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. A broader term which is more widespread in the industry is '' small cell'', with ''femtocell'' as a subset. It connects to the service provider's network via broadband (such as DSL or cable); current designs typically support four to eight simultaneously active mobile phones in a residential setting depending on version number and femtocell hardware, and eight to sixteen mobile phones in enterprise settings. A femtocell allows service providers to extend service coverage indoors or at the cell edge, especially where access would otherwise be limited or unavailable. Although much attention is focused on WCDMA, the concept is applicable to all standards, including GSM, CDMA2000, TD-SCDMA, WiMAX and LTE solutions. The use of femtocells allows network coverage in places where the signal to the main network cells might be too weak. Furthermore, fem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Station Subsystem
The base station subsystem (BSS) is the section of a traditional cellular telephone network which is responsible for handling traffic and signaling between a mobile phone and the network switching subsystem. The BSS carries out transcoding of speech channels, allocation of radio channels to mobile phones, paging, transmission and reception over the air interface and many other tasks related to the radio network. Base transceiver station The base transceiver station, or BTS, contains the equipment for transmitting and receiving radio signals ( transceivers), antennas, and equipment for encrypting and decrypting communications with the base station controller (BSC). Typically a BTS for anything other than a picocell will have several transceivers (TRXs) which allow it to serve several different frequencies and different sectors of the cell (in the case of sectorised base stations). A BTS is controlled by a parent BSC via the "base station control function" (BCF). The BCF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CE Mark
On commercial products, the letters CE (as the logo ) mean that the manufacturer or importer affirms the good's conformity with European health, safety, and environmental protection standards. It is not a quality indicator or a certification mark. The CE marking is required for goods sold in the European Economic Area (EEA), but is also found on products sold elsewhere that have been manufactured to EEA standards. The mark indicates that the product may be traded freely in any part of the European Economic Area, regardless of its country of origin. It consists of the CE logo and, if applicable, the four digit identification number of the notified body involved in the conformity assessment procedure. "CE" is the abbreviation of (French for "European conformity"). Meaning The mark on a product indicates that the manufacturer or importer of that product affirms its compliance with the relevant EU legislation and the product may be sold anywhere in the European Economi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ofcom
The Office of Communications, commonly known as Ofcom, is the government-approved regulatory and competition authority for the broadcasting, telecommunications and postal industries of the United Kingdom. Ofcom has wide-ranging powers across the television, radio, telecoms and postal sectors. It has a statutory duty to represent the interests of citizens and consumers by promoting competition and protecting the public from harmful or offensive material. Some of the main areas Ofcom presides over are licensing, research, codes and policies, complaints, competition and protecting the radio spectrum from abuse (e.g., pirate radio stations). The regulator was initially established by the Office of Communications Act 2002 and received its full authority from the Communications Act 2003. History On , the Queen's Speech to the UK Parliament announced the creation of Ofcom. The new body, which was to replace several existing authorities, was conceived as a "super-regulator" to ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Phone
A satellite telephone, satellite phone or satphone is a type of mobile phone that connects to other phones or the telephone network by radio through orbiting satellites instead of terrestrial cell sites, as cellphones do. The advantage of a satphone is that its use is not limited to areas covered by cell towers; it can be used in most or all geographic locations on the Earth's surface. The mobile equipment, also known as a terminal, varies widely. Early satellite phone handsets had a size and weight comparable to that of a late-1980s or early-1990s mobile phone, but usually with a large retractable antenna. More recent satellite phones are similar in size to a regular mobile phone while some prototype satellite phones have no distinguishable difference from an ordinary smartphone. Satphones are popular on expeditions into remote areas where terrestrial cellular service is unavailable. A fixed installation, such as one used aboard a ship, may include large, rugged, rack-mounte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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