- Industry: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
- Company Profile:
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.
One tenth of the common logarithm of the ratio of relative powers, equal to 0. 1 B (bel. ) Note 1: The decibel is the conventional relative power ratio, rather than the bel, for expressing relative powers because the decibel is smaller and therefore more convenient than the bel. The ratio in dB is given by where P1 and P2 are the actual powers. Power ratios may be expressed in terms of voltage and impedance, E and Z, or current and impedance, I and Z, since Thus dB is also given by If Z1 = Z2, these become Note 2: The dB is used rather than arithmetic ratios or percentages because when circuits are connected in tandem, expressions of power level, in dB, may be arithmetically added and subtracted. For example, in an optical link, if a known amount of optical power, in dBm, is launched into a fiber, and the losses, in dB, of each component (e.g., connectors, splices, and lengths of fiber) are known, the overall link loss may be quickly calculated with simple addition and subtraction.
Industry:Telecommunications
Ongoing disturbances of the ionosphere that scatter incident electromagnetic waves. Note: Ionospheric turbulence results in irregularities in the composition of the ionosphere that change with time. This causes changes in reflection properties. These, in turn, cause changes in skip distance, fading, local intensification, and distortion of the incident waves.
Industry:Telecommunications
Operating and testing of a communication system, subsystem, or component, to ensure that the specified performance characteristics have been met.
Industry:Telecommunications
Operating method in which transmission is possible simultaneously, in both directions of a telecommunication channel. Note 1: This definition is not limited to radio transmission. Note 2: In general, duplex operation and semi-duplex operation require two frequencies in radiocommunication; simplex operation may use either one or two. Synonyms full-duplex operation, two-way simultaneous operation.
Industry:Telecommunications
Operating method in which transmission is possible simultaneously, in both directions of a telecommunication channel. Note 1: This definition is not limited to radio transmission. Note 2: In general, duplex operation and semi-duplex operation require two frequencies in radiocommunication; simplex operation may use either one or two. Synonyms full-duplex operation, two-way simultaneous operation.
Industry:Telecommunications
Operation in which certain components, such as nodes, facilities, circuits, or equipment, are in an operational state at all times. Note: Continuous operation usually requires that there be fully redundant configuration, or at least a sufficient X out of Y degree of redundancy for compatible equipment, where X is the number of spare components and Y is the number of operational components. 2. In data transmission, operation in which the master station need not stop for a reply from a slave station after transmitting each message or transmission block.
Industry:Telecommunications
Operation in which communication between two terminals occurs in either direction, but in only one direction at a time. Note: Half-duplex operation may occur on a half-duplex circuit or on a duplex circuit, but it may not occur on a simplex circuit. Synonyms one-way reversible operation, two-way alternate operation.
Industry:Telecommunications
Operation in which data are transmitted from a transmitter to a receiver in only one direction.
Industry:Telecommunications
Operation in which data circuit terminating equipment (DCE,) data terminal equipment (DTE,) and transmitting circuits are all operated in bit synchronism with a clock. Note 1: In bit synchronous operation, clock timing is usually delivered at twice the modulation rate, and one bit is transmitted or received during each clock cycle. Note 2: Bit synchronous operation is sometimes erroneously referred to as digital synchronization.
Industry:Telecommunications
