Telecommunications terms starting with A

604 terms

acknowledge character (ACK) A transmission control character transmitted by the receiving station as an affirmative response to the sending station.
acknowledgement A response sent by a receiver to indicate successful receipt of a transmission.
acknowledgement delay period Synonym [loosely] sliding window.
acoustic coupler An interface device for coupling electrical signals by acoustical means--usually into and out of a telephone instrument. 2.
acoustic delay line A device that introduces a delay in the propagation of an electrical signal by (a) employing a transducer to convert the signal into an acoustic wave, (b)…
acoustic noise An undesired audible disturbance in the audio frequency range. 2. Any undesired acoustic wave or signal, or undesired component of a desired acoustic…
acoustic wave A longitudinal wave that (a) consists of a sequence of pressure pulses or elastic displacements of the material, whether gas, liquid, or solid, in which…
acoustics The branch of science and technology that is devoted to the production, transmission, control, processing, transformation, reception, and effects of…
acousto-optic effect A variation of the refractive index of a material caused by interaction with acoustic energy in the form of a wave or pulse.
acousto-optics The discipline devoted to the interactions between acoustic waves and light waves in a material medium.
acquisition If a company buys another company outright, or accumulates enough shares to take a controlling interest, the deal is described as an acquisition.
acquisition and tracking orderwire See ATOW.
acquisition time In a communications system, the time interval required to attain synchronism. 2.
ACR alkali-carbonate reaction.
Action Case, cause, suit or controversy disputed or contested before a court.
Active Central Office Code A Central Office code assigned by the CO Code Administrator and implemented in the PSTN for specific routing and rating requirements as of the LERG…
active device A device that requires a source of energy for its operation and has an output that is a function of present and past input signals.
active key state A condition of readiness for a key to be used to secure information from the originator, and to process received secure information. [After X9.17]
active laser medium Within a laser, the material that emits coherent radiation or exhibits gain as the result of electronic or molecular transitions to a lower energy state…
active satellite A satellite carrying a station intended to transmit or retransmit radio communication signals.
Active Sensor One that illuminates a target, producing return secondary radiation, which is then detected to track and/or identify the target. An example is radar.
active signaling link A signaling link that has successfully completed the initial alignment procedures and carries (or is ready to carry) signaling traffic. [T1.226-1992]
active star See star coupler, multiport repeater.
active threat 1. Any threat of a deliberate unauthorized change to the state of a data processing system.
active video frame identification The process of comparing each output video frame with its preceding frame(s) in sequence and quantifying the extent of correspondence between each pair…
activity factor For a communications channel during a specified time interval, such as the busy hour, the percentage of time that a signal is present in the channel in…
ACU Abbreviation for automatic calling unit.
ad clicks Synonym click-through.
Ada® The official, high-level computer language of DOD for embedded-computer, real-time applications as defined in MIL-STD-1815.
adaptive channel allocation In communications system traffic flow control, channel allocation in which information-handling capacities of channels are not predetermined but are…
adaptive communications Any communications system, or portion thereof, that automatically uses feedback information obtained from the system itself or from the signals carried by…
adaptive compression In computer science, a software-oriented compression process based on continuous analysis of the data stream, and depending on the type and content of the…
adaptive differential pulse-code modulation (ADPCM) Differential pulse-code modulation in which the prediction algorithm is adjusted in accordance with specific characteristics of the input signal.
adaptive equalization Equalization (a) that is automatically accomplished while traffic is being transmitted and (b) in which signal characteristics are dynamically adjusted to…
adaptive prediction In ADPCM coding, a time-varying process that computes an estimate of the input signal from the quantized difference signal. [T1.310-1991]
adaptive predictive coding (APC) Narrowband analog-to-digital conversion that uses a one-level or multilevel sampling system in which the value of the signal at each sampling instant is…
adaptive quantization In ADPCM (adaptive differential pulse code modulation) coding, a process in which the quantizer step size varies as a function of the quantized input…
adaptive radio A radio that (a) monitors its own performance, (b) monitors the path quality through sounding or polling, (c) varies operating characteristics, such as…
adaptive routing Routing that is automatically adjusted to compensate for network changes such as traffic patterns, channel availability, or equipment failures.
adaptive system A system that has a means of monitoring its own performance, a means of varying its own parameters, and uses closed-loop action to improve its performance…
ADC Analog to Digital converter. Converts analog data to a digital format.
ADCCP Abbreviation for Advanced Data Communication Control Procedures.
add mode 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.
add-on conference A service feature that allows an additional party to be added to an established call without attendant assistance.
add/drop multiplexing A multiplexing function offered in connection with SONET that allows lower level signals to be added or dropped from a high-speed optical carrier channel…
added bit A bit delivered to the intended destination user in addition to intended user information bits and delivered overhead bits. Synonym extra bit.
added block Any block, or other delimited bit group, delivered to the intended destination user in addition to intended user information bits and delivered overhead…
adder A device whose output data are a representation of the sum of the numbers represented by its input data.
adder-subtracter A device that acts as an adder or subtracter depending upon the control signal received; the adder-subtracter may be constructed so as to yield a sum and…
additive white gaussian noise (AWGN) Synonym white noise.
address Addresses using a number of different protocols are commonly used on the Internet.
address field The portion of a message that contains the source-user address and the destination-user addresses.
address message A message sent in the forward direction that contains (a) address information, (b) the signaling information required to route and connect a call to the…
address message sequencing In common-channel signaling, a procedure for ensuring that address messages are processed in the correct order when the order in which they are received…
address part A part of an instruction that usually contains only an address or part of an address.
address pattern A prescribed structure of data used to represent the destination(s) of a block, message, packet, or other formalized data structure.
Address Resolution Protocol (ARP) A TCP/IP protocol used to obtain a node's physical address.
address separator A character that separates the different addresses in a selection signal.
address signaling A process used to convey address information; two address signaling methods, dial pulse (DP) and dual tone multifrequency (DTMF), are used in telephone…
address-indicating group (AIG) A station or address designator, used to represent a set of specific and frequently recurring combinations of action or information addresses.
addressability In computer graphics, the capability of a display surface or storage device to accommodate a specified number of uniquely identifiable points. 2.
addressable point In computer graphics, any point of a device that can be addressed.
ADH Abbreviation for automatic data handling.
adiabatic computer circuit A circuit that avoids loss or gain of heat. For example, a computer could clear a "1" in a register by subtracting the "1" instead of erasing it, thereby…
adjacent signaling points Two signaling points that are directly interconnected by one or more signaling links. [T1.226-1992]
adjacent-channel interference Extraneous power from a signal in an adjacent channel. Note 1: Adjacent channel interference may be caused by inadequate filtering, such as incomplete…
adjunct service point (ASP) An intelligent-network feature that resides at the intelligent peripheral equipment and responds to service logic interpreter requests for service…
administration (ad-MIH-nih-STRAY-shun) In medicine, the act of giving a treatment, such as a drug, to a patient.
administrative management complex (AMC) In network management, a complex that is controlled by a network provider, and is responsible for and performs network management functions such as…
Administrative Numbers: Administrative numbers are numbers used by telecommunications carriers to perform internal administrative or operational functions necessary to maintain…
Administrative Operating Company Number A four character numeric or alphanumeric that identifies the administrator of one (or more) data record contained in BIRRDS.
ADP Abbreviation for adenosine diphosphate.
ADP system Synonym computer system.
ADPCM Abbreviation for adaptive differential pulse-code modulation.
ADPE Automated Data Processing Equipment.
Advanced Data Communication Control Procedures (ADCCP) A bit-oriented Data-Link-Layer protocol used to provide point-to-point and point-to-multipoint transmission of data frames that contain error-control…
advanced intelligent network (AIN) A telecommunications network architecture that uses databases to facilitate call processing, call routing, and network management, allowing carriers to…
advanced television (ATV) A family of television systems that is intended to be improvements over current commercial-quality television.
AECS Abbreviation for Aeronautical Emergency Communications System. See Aeronautical Emergency Communications System Plan.
aerial cable A communications cable designed for installation on, or suspension from, a pole or other overhead structure.
aerial insert In a direct-buried or underground cable run, a cable rise to a point above ground, followed by an overhead run, e.g.
aeronautical advisory station An aeronautical station used for advisory and civil defense communications primarily with private aircraft stations. Synonym UNICOM station. [NTIA]
aeronautical broadcast station An aeronautical station which makes scheduled broadcasts of meteorological information and notices to airmen.
aeronautical Earth station An Earth station in the fixed-satellite service, or, in some cases, in the aeronautical mobile-satellite service, located at a specified fixed point on…
Aeronautical Emergency Communications System (AECS) Plan The AECS Plan provides for the operation of aeronautical communications stations, on a voluntary, organized basis, to provide the President and the…
aeronautical fixed service A radiocommunication service between specified fixed points provided primarily for the safety of air navigation and for the regular, efficient and…
aeronautical fixed station A station in the aeronautical fixed service. [NTIA][RR]
aeronautical mobile (OR) [off-route] service An aeronautical mobile service intended for communications, including those relating to flight coordination, primarily outside national or international…
aeronautical mobile (R) [route] service An aeronautical mobile service reserved for communications relating to safety and regularity of flight, primarily along national or international civil…
aeronautical mobile service A mobile service between aeronautical stations and aircraft stations, or between aircraft stations, in which survival craft stations may participate…
aeronautical mobile-satellite (OR) [off-route] service An aeronautical mobile-satellite service intended for communications, including those relating to flight coordination, primarily outside national and…
aeronautical mobile-satellite (R) [route] service An aeronautical mobile-satellite service reserved for communications relating to safety and regularity of flight, primarily along national or…
aeronautical mobile-satellite service A mobile-satellite service in which mobile Earth stations are located on board aircraft; survival craft stations and emergency position-indicating…
aeronautical multicom service A mobile service not open to public correspondence, used to provide communications essential to conduct activities being performed by or directed from…
aeronautical radionavigation service A radionavigation service intended for the benefit and for the safe operation of aircraft. [NTIA] [RR]
aeronautical radionavigation-satellite service A radionavigation-satellite service in which Earth stations are located on board aircraft. [NTIA] [RR]
aeronautical station A land station in the aeronautical mobile service. In certain instances, an aeronautical station may be located, for example, on board ship or on a…
AF acre-feet.
AFNOR Acronym for Association Francaise de Normalisation. France's national standards-setting organization.
AGC automatic generation control.