- 行业: 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.
In a transparent material, anisotropism of the refractive index, which varies as a function of polarization as well as orientation with respect to the incident ray. Note 1: The term "birefringence" means, literally, "double refraction. " Note 2: All crystals except those of cubic lattice structure exhibit some degree of anisotropy with regard to their physical properties, including refractive index. Other materials, such as glasses or plastics, become birefringent when subjected to mechanical strain. Note 3: Birefringent materials, including crystals, have the ability to refract an unpolarized incident ray into two separate, orthogonally polarized rays, which in the general case take different paths, depending on orientation of the material with respect to the incident ray. The refracted rays are referred to as the "ordinary," or "O" ray, which obeys Snell's Law, and the "extraordinary," or "E" ray, which does not. Synonym double refraction.
Industry:Telecommunications
In alternating-current power transmission and distribution, the cosine of the phase angle between the voltage and current. Note 1: When the load is inductive, e.g., an induction motor, the current lags the applied voltage, and the power factor is said to be a lagging power factor. When the load is capacitive, e.g., a synchronous motor or a capacitive network, the current leads the applied voltage, and the power factor is said to be a leading power factor. Note 2: Power factors other than unity have deleterious effects on power transmission systems, including excessive transmission losses and reduced system capacity. Power companies therefore require customers, especially those with large loads, to maintain, within specified limits, the power factors of their respective loads or be subject to additional charges.
Industry:Telecommunications
In alphabet coding schemes, a specially designated character, the occurrence of which in the data signifies that one or more of the characters to follow are from a different character code, i.e., have meanings other than normal. 2. In a text-control sequence of characters, a control character that indicates the beginning of the sequence and the end of any preceding text.
Industry:Telecommunications
In aeronautical navigation, an instrument approach landing facility that furnishes vertical guidance information to an aircraft from its approach altitude down to the surface of the runway.
Industry:Telecommunications
In ADPCM coding, a time-varying process that computes an estimate of the input signal from the quantized difference signal.
Industry:Telecommunications
In ADPCM (adaptive differential pulse code modulation,) the sum of the signal estimate from adaptive prediction and the quantized difference signal from inverse adaptive quantization.
Industry:Telecommunications
In ADPCM (adaptive differential pulse code modulation,) the condition in which the internal state variables of the encoder and the decoder are not the same.
Industry:Telecommunications
In ADPCM (adaptive differential pulse code modulation) coding, a process in which the quantizer step size varies as a function of the quantized input signal's variance.
Industry:Telecommunications
In addition and subtraction operations, a mode in which the decimal marker is placed at a predetermined location with respect to the last digit entered.
Industry:Telecommunications
In adaptive high-frequency (HF) radio, the overall process by which measurements of signal quality are made, assessed, and analyzed. Note 1: In LQA, signal quality is determined by measuring, assessing, and analyzing link parameters, such as bit error ratio (BER,) and the levels of the ratio of signal-plus-noise-plus-distortion to noise-plus-distortion (SINAD. ) Measurements are stored at--and exchanged between--stations, for use in making decisions about link establishment. Note 2: For adaptive HF radio, LQA is automatically performed and is usually based on analyses of pseudo-BERs and SINAD readings.
Industry:Telecommunications
