- 行业: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
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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 tape-relay communications system, a service message, usually sent to a relay station or to a tributary station, that contains a request to the operator to resume transmitting over a specified channel or channels. Synonyms go-ahead message, start message, start notice.
Industry:Telecommunications
In a system or device, any departure of the output signal waveform from that which should result from the input signal waveform's being operated on by the system's specified, i.e., ideal, transfer function. Note: Distortion may result from many mechanisms. Examples include nonlinearities in the transfer function of an active device, such as a vacuum tube, transistor, or operational amplifier. Distortion may also be caused by a passive component such as a coaxial cable or optical fiber, or by inhomogeneities, reflections, etc. , in the propagation path. 2. In start-stop teletypewriter signaling, the shifting of the significant instants of the signal pulses from their proper positions relative to the beginning of the start pulse. Note: The magnitude of the distortion is expressed in percent of an ideal unit pulse length.
Industry:Telecommunications
In a system, the reduction of the power level of an echo or the elimination of an echo. Note: Echo cancellation is usually an active process in which echo signals are measured and canceled or eliminated by combining an inverted signal with the echo signal.
Industry:Telecommunications
In a system, a network that may replace another network without altering the performance of the system. 2. A network with external characteristics that are identical to those of another network. 3. A theoretical representation of an actual network.
Industry:Telecommunications
In a system or device, the ratio of (a) a specified maximum level of a parameter, such as power, current, voltage, or frequency to (b) the minimum detectable value of that parameter. Note: The dynamic range is usually expressed in dB. 2. In a transmission system, the ratio of (a) the overload level, i.e., the maximum signal power that the system can tolerate without distortion of the signal, to (b) the noise level of the system. Note: The dynamic range of transmission systems is usually expressed in dB. 3. In digital systems or devices, the ratio of maximum and minimum signal levels required to maintain a specified bit error ratio.
Industry:Telecommunications
In a system or device, any departure of the output signal waveform from that which should result from the input signal waveform's being operated on by the system's specified, i.e., ideal, transfer function. Note: Distortion may result from many mechanisms. Examples include nonlinearities in the transfer function of an active device, such as a vacuum tube, transistor, or operational amplifier. Distortion may also be caused by a passive component such as a coaxial cable or optical fiber, or by inhomogeneities, reflections, etc. , in the propagation path. 2. In start-stop teletypewriter signaling, the shifting of the significant instants of the signal pulses from their proper positions relative to the beginning of the start pulse. Note: The magnitude of the distortion is expressed in percent of an ideal unit pulse length.
Industry:Telecommunications
In a single-mode optical fiber, the wavelength or wavelengths at which material dispersion and waveguide dispersion cancel one another. Note: In all silica-based optical fibers, minimum material dispersion occurs naturally at a wavelength of approximately 1. 3 m. Single-mode fibers may be made of silica-based glasses containing dopants that shift the material-dispersion wavelength, and thus, the zero-dispersion wavelength, toward the minimum-loss window at approximately 1. 55 m. The engineering tradeoff is a slight increase in the minimum attenuation coefficient. 2. Loosely, in a multimode optical fiber, the wavelength at which material dispersion is minimum, i.e., essentially zero. Synonym minimum-dispersion wavelength.
Industry:Telecommunications
In a system in which two channels share a common interface, a channel that has a lower data signaling rate (DSR) capacity than the primary channel.
Industry:Telecommunications
In a synchronized oscillator, the capability to operate in the absence of a synchronizing signal.
Industry:Telecommunications
In a switched telephone network, a supervisory signal transmitted from one end of a user line or trunk to indicate at the other end that the established connection should be disconnected.
Industry:Telecommunications
