- المجال: 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 high-frequency (HF) radio automatic link establishment, the period between changes in the time-of-day portion of the time-varying randomization data used for encrypting transmissions.
Industry:Telecommunications
In grounding systems, the lightning rod or conductor placed on or above a building, structure, or external conductors for the purpose of intercepting lightning.
Industry:Telecommunications
In graphics, especially computer graphics, that which characterizes an area in which a smooth transition between one color and another, or between black and white (i.e., contrast,) takes place.
Industry:Telecommunications
In graphic display devices, an intentional periodic change in the intensity of one or more display elements or display segments.
Industry:Telecommunications
In geometric optics, at a refractive boundary, the smallest angle of incidence at which total internal reflection occurs. Note 1: The angle of incidence is measured with respect to the normal at the refractive boundary. Note 2: The critical angle is given by where c is the critical angle, n1 is the refractive index of the less dense medium, and n2 is the refractive index of the denser medium. Note 3: The incident ray is in the denser medium. Note 4: If the incident ray is precisely at the critical angle, the refracted ray is tangent to the boundary at the point of incidence.
Industry:Telecommunications
In general, the total power required by a facility. Note: The demand load is the sum of the operational load (including any tactical load) and nonoperational demand loads. It is determined by applying the proper demand factor to each of the connected loads and a diversity factor to the sum total. 2. At a communications center, the power required by all automatic switching, synchronous, and terminal equipment (operated simultaneously on-line or in standby,) control and keying equipment, plus lighting, ventilation, and air-conditioning equipment required to maintain full continuity of communications. 3. The power required for ventilating equipment, shop lighting, and other support items that may be operated simultaneously with the technical load. 4. The sum of the technical demand and nontechnical demand loads of an operating facility. 5. At a receiver facility, the power required for all receivers and auxiliary equipment that may be operated on prime or spare antennas simultaneously, those in standby condition, multicouplers, control and keying equipment, plus lighting, ventilation, and air conditioning equipment required for full continuity of communications. 6. At a transmitter facility, the power required for all transmitters and auxiliary equipment that may be operated on prime or spare antennas or dummy loads simultaneously, those in standby condition, control and keying equipment, plus lighting, ventilation, and air conditioning equipment required for full continuity of communications.
Industry:Telecommunications
In general, key escrow means that a copy of the secret key needed to decrypt something is stored with a third party. This can be a notary or a bank, who will keep it safely for you, in case you lose your key, or when you die, in which case your relatives might need access to your encrypted material. It is also common in business. When an employee has encrypted material on his company computer, and he leaves, gets fired, or dies unexpectedly, the company might not be able to decrypt the material. This can cost them a lot of money, especially when the employee was working on something very important. For this reason, a copy of the secret key is usually kept by one or more supervisors, who can then decrypt the material if necessary. To ensure that a supervisor does not abuse this power, the key can be split amongst several persons, who have to work together to restore the key.
Industry:Telecommunications
In general, extraneous energy, from natural or man-made sources, that impedes the reception of desired signals. 2. A coherent emission having a relatively narrow spectral content, e. G. , a radio emission from another transmitter at approximately the same frequency, or having a harmonic frequency approximately the same as, another emission of interest to a given recipient, and which impedes reception of the desired signal by the intended recipient. Note: In the context of this definition, interference is distinguished from noise in that the latter is an incoherent emission from a natural source (e. G. , lightning) or a man-made source, of a character unlike that of the desired signal (e. G. , commutator noise from rotating machinery) and which usually has a broad spectral content. 3. The effect of unwanted energy due to one or a combination of emissions, radiation, or inductions upon reception in a radiocommunication system, manifested by any performance degradation, misinterpretation, or loss of information which could be extracted in the absence of such unwanted energy. 4. The interaction of two or more coherent or partially coherent waves, which interaction produces a resultant wave that differs from the original waves in phase, amplitude, or both. Note: Interference may be constructive or destructive, i.e., it may result in increased amplitude or decreased amplitude, respectively. Two waves equal in frequency and amplitude, and out of phase by 180°, will completely cancel one another. In phase, they create a resultant wave having twice the amplitude of either interfering beam.
Industry:Telecommunications
In frequency-division multiplexing, a specific number of associated voice channels, either within a supergroup or as an independent entity. Note 1: In wideband systems, a group usually consists of 12 voice channels and occupies the frequency band from 60 kHz to 108 kHz. Note 2: this is ITU-T group B (formerly CCITT group B. ) Note 3: ITU-T Basic Group A, for carrier telephone systems, consists of 12 channels occupying upper sidebands in the 12-kHz to 60-kHz band. Basic Group A is no longer mentioned in ITU-T Recommendations. Note 4: A supergroup usually consists of 60 voice channels, i.e., 5 groups of 12 voice channels each, occupying the frequency band from 312 kHz to 552 kHz. Note 5: A mastergroup consists of 10 supergroups or 600 voice channels. Note 6: The ITU-T standard mastergroup consists of 5 supergroups. The U. S. Commercial carrier standard mastergroup consists of 10 supergroups. Note 7: The terms "supermaster group" or "jumbo group" are sometimes used to refer to 6 mastergroups. 2. A set of characters forming a unit for transmission or cryptographic treatment.
Industry:Telecommunications
In frequency-division multiplexing, the rank of frequency bands occupied: 12 channels group 5 groups (60 channels) super group 5 super groups (300 channels) master group (CCITT--now, ITU-T) 10 super groups (600 channels) master group (U. S. Standard) 6 U. S. Master groups (3600 channels) jumbo group.
Industry:Telecommunications
