- 産業: Telecommunications
- Number of terms: 29235
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ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry.
Any orbit in which an orbiting object has a period equal to the average rotational period of the body being orbited, and in the same direction of rotation as that body. Note 1: A synchronous orbit need not be equatorial, but it usually is, ideally. A body in a nonequatorial synchronous orbit will, when observed from a fixed point on the orbited body, appear to move up and down, i.e., northward and southward. If the synchronous orbit is not perfectly circular, the orbiting body will appear to move back and forth, eastward and westward. The combination of these two motions will produce a figure-8 pattern as seen from the orbited body. Note 2: A synchronous orbit about the Earth that is circular and lies in the equatorial plane is called a geostationary orbit.
Industry:Telecommunications
Any organized assembly of resources and methods used to collect, process, and distribute messages largely by automatic means.
Industry:Telecommunications
Any outside plant facilities subject to the effects of lightning; or to power contacts, power induction, or differences in ground potential any of which exceed 300 Vrms to ground.
Industry:Telecommunications
Any phenomenon in which the velocity of propagation of an electromagnetic wave is wavelength dependent. Note 1: In communication technology, "dispersion" is used to describe any process by which an electromagnetic signal propagating in a physical medium is degraded because the various wave components (i.e., frequencies) of the signal have different propagation velocities within the physical medium. Note 2: In an optical fiber, there are several significant dispersion effects, such as material dispersion, profile dispersion, and waveguide dispersion, that degrade the signal. Note 3: In optical fiber communications, the incorrect terms "multimode dispersion" and "intermodal dispersion" should not be used as synonyms for the correct term "multimode distortion. " Note 4: In classical optics, "dispersion" is used to denote the wavelength dependence of refractive index in matter, (dn/d, where n is the refractive index and is the wavelength) caused by interaction between the matter and light. "Dispersion," as used in fiber optic communications, should not be confused with "dispersion" as used by optical lens designers. Note 5: Three types of dispersion, relating to optical fibers, are defined as follows: material dispersion: In optical fiber communication, the wavelength dependence of the velocity of propagation (of the optical signal) on the bulk material of which the fiber is made. Note 1: Because every optical signal has a finite spectral width, material dispersion results in spreading of the signal. Note 2: Use of the redundant term "chromatic dispersion" is discouraged. Note 3: In pure silica, the basic material from which the most common telecommunication-grade fibers are made, material dispersion is minimum at wavelengths in the vicinity of 1. 27 m (slightly longer in practical fibers. ) profile dispersion: In an optical fiber, that dispersion attributable to the variation of refractive index contrast with wavelength. Profile dispersion is a function of the profile dispersion parameter. Waveguide dispersion: Dispersion, of importance only in single-mode fibers, caused by the dependence of the phase and group velocities on core radius, numerical aperture, and wavelength. Note 1: For circular waveguides, the dependence is on the ratio, a/, where a is the core radius and is the wavelength. Note 2: Practical single-mode fibers are designed so that material dispersion and waveguide dispersion cancel one another at the wavelength of interest.
Industry:Telecommunications
Any phenomenon in which the velocity of propagation of an electromagnetic wave is wavelength dependent. Note 1: In communication technology, "dispersion" is used to describe any process by which an electromagnetic signal propagating in a physical medium is degraded because the various wave components (i.e., frequencies) of the signal have different propagation velocities within the physical medium. Note 2: In an optical fiber, there are several significant dispersion effects, such as material dispersion, profile dispersion, and waveguide dispersion, that degrade the signal. Note 3: In optical fiber communications, the incorrect terms "multimode dispersion" and "intermodal dispersion" should not be used as synonyms for the correct term "multimode distortion. " Note 4: In classical optics, "dispersion" is used to denote the wavelength dependence of refractive index in matter, (dn/d, where n is the refractive index and is the wavelength) caused by interaction between the matter and light. "Dispersion," as used in fiber optic communications, should not be confused with "dispersion" as used by optical lens designers. Note 5: Three types of dispersion, relating to optical fibers, are defined as follows: material dispersion: In optical fiber communication, the wavelength dependence of the velocity of propagation (of the optical signal) on the bulk material of which the fiber is made. Note 1: Because every optical signal has a finite spectral width, material dispersion results in spreading of the signal. Note 2: Use of the redundant term "chromatic dispersion" is discouraged. Note 3: In pure silica, the basic material from which the most common telecommunication-grade fibers are made, material dispersion is minimum at wavelengths in the vicinity of 1. 27 m (slightly longer in practical fibers. ) profile dispersion: In an optical fiber, that dispersion attributable to the variation of refractive index contrast with wavelength. Profile dispersion is a function of the profile dispersion parameter. Waveguide dispersion: Dispersion, of importance only in single-mode fibers, caused by the dependence of the phase and group velocities on core radius, numerical aperture, and wavelength. Note 1: For circular waveguides, the dependence is on the ratio, a/, where a is the core radius and is the wavelength. Note 2: Practical single-mode fibers are designed so that material dispersion and waveguide dispersion cancel one another at the wavelength of interest.
Industry:Telecommunications
Any photomechanical printing surface or the impression therefrom in which detail and tone values are represented by a series of evenly spaced dots in varying size and shape, varying in direct proportion to the intensity of tones they represent.
Industry:Telecommunications
Any physical interface in a fiber optic system. Note: Source to fiber, fiber to fiber, fiber to detector, beam to prism (or lens,) fiber to lens, lens to fiber, are examples of optical junctions.
Industry:Telecommunications
Any portion of a loop that is not in the direct talking path between the central office and the service user's terminating equipment. A bridged tap may be an unused cable pair connected at an intermediate point or an extension of the circuit beyond the service user's location. Note: A bridged tap creates an impedance mismatch within the transmission line, which creates signal reflections. These reflections are generally not noticed in standard (POTS) voicegrade service, but become significant with high frequency (xDSL--which can be ADSL, asynchronous DSL, or SDSL, synchronous DSL, etc. ) and digital transmission (DDS and DS1) services.
Industry:Telecommunications
Any portion of a ringing cycle during which the ringing signal is not being applied.
Industry:Telecommunications
Any private network that uses some or all of the protocols of The Internet. Note: In an intranet, nodes interact in a client-server relationship, nodes are identified by using Internet protocol (IP) addresses, and files are identified by universal resource locators (URLs. ) The data being exchanged are typically formatted using the HTML language, and is controlled and displayed using a browser. The intranet may be connected to The Internet via firewalls, or it may be totally separate.
Industry:Telecommunications
