Telecommunications — page 14 of 85

Telecommunications terms

1301. clock tolerance The maximum permissible departure of a clock indication from a designated time reference such as Coordinated Universal Time (UTC).
1302. clock track A track on which a pattern of signals is recorded to provide a timing reference.
1303. clockwise polarized wave Synonym right-hand (or clockwise) polarized wave.
1304. closed captioning In broadcast and cable television, the insertion, into the blank lines between frames, of information that may be decoded and displayed on the screen as…
1305. closed circuit In radio and television transmission, pertaining to an arrangement in which programs are directly transmitted to specific users and not broadcast to the…
1306. closed user group In a network, a group of users permitted to communicate with each other but not with users outside the group.
1307. closed user group with outgoing access A closed user group in which at least one member of the group has a facility that permits communication with one or more users external to the closed user…
1308. closed waveguide An electromagnetic waveguide (a) that is tubular, usually with a circular or rectangular cross section, (b) that has electrically conducting walls, (c)…
1309. closed-loop noise bandwidth The integral, over all frequencies, of the absolute value of the closed-loop transfer function of a phase-locked loop.
1310. closed-loop response integrity In cryptography, the originator's confirmation of the integrity of the entire transaction, i.e.
1311. closed-loop transfer function A mathematical expression (algorithm) describing the net result of the effects of a closed (feedback) loop on the input signal to the circuits enclosed by…
1312. closed-security environment An environment in which special attention is paid (in the form of authorizations, security clearances, configuration controls, etc.
1313. closure In transportation, the process of a unit arriving at a specified location. It begins with the arrival of the first element at a designated location and…
1314. cloud attenuation In the transmission of electromagnetic signals, attenuation caused by absorption and scattering by water or ice particles in clouds.
1315. CMRR Abbreviation for common-mode rejection ratio.
1316. CNR Abbreviation for carrier-to-noise ratio, combat-net radio.
1317. CNS The brain and spinal cord. Also called central nervous system.
1318. CO Code (NXX) Exhaust A point in time at which the quantity of TNs within existing CO codes (NXX) which are "Available for Assignment" equals zero within a switching…
1319. CO Code Administrator left
1320. co-channel interference Interference caused by another signal operating on the same channel.
1321. COAM Acronym for customer owned and maintained equipment. Deprecated term. See customer premises equipment.
1322. coast Earth station An Earth station in the fixed-satellite service or, in some cases, in the maritime mobile-satellite service, located at a specified fixed point on land to…
1323. coast station A land station in the maritime mobile service. [RR]
1324. coasting mode In timing-dependent systems, a free-running operational timing mode in which continuous or periodic measurement of clock error, i.e.
1325. Coating The protective material applied to the outer surface of a material, frequently metalwork.
1326. coax See coaxial cable.
1327. coaxial cable (coax) A cable consisting of a center conductor surrounded by an insulating material and a concentric outer conductor and optional protective covering, all of…
1328. coaxial patch bay See patch bay.
1329. COBOL Acronym for common business oriented language. A programming language designed for business data processing.
1330. CODE See: genetic code
1331. code book Document containing plain text and code equivalents in a systematic arrangement, or a technique of machine encryption using a word substitution technique.
1332. code character A character that (a) is used to represent a discrete value or symbol and (b) is derived in accordance with a code.
1333. code conversion Conversion of signals, or groups of signals, in one code into corresponding signals, or groups of signals, in another code. 2.
1334. code element One of a set of parts of which the characters in a given code may be composed.
1335. code group [A] group of letters, numbers, or both in a code system used to represent a plain text word, phrase, or sentence.
1336. Code Holder An assignee of an NXX code which was allocated by the CO Code Administrator. When an NXX Code becomes pooled, the Code Holder becomes the LERG Assignee
1337. code restriction A service feature by which certain terminals are prevented from accessing certain features of the network.
1338. code set The complete set of representations defined by a particular code and language.
1339. code structure The basic characteristics of a code: its length and generic representation. [T1.238-1994/97] [T1.266-2000]
1340. code vocabulary [A] set of plain text words, numerals, phrases, or sentences for which code equivalents are assigned in a code system. [INFOSEC-99]
1341. code word In a code, a word that consists of a sequence of symbols assembled in accordance with the specific rules of the code and assigned a unique meaning.
1342. code-division multiple access (CDMA) A coding scheme, used as a modulation technique, in which multiple channels are independently coded for transmission over a single wideband channel.
1343. code-excited linear prediction (CELP) An analog-to-digital voice coding scheme.
1344. code-independent data communication Synonym code-transparent data communication.
1345. code-transparent data communication A mode of data communication that uses protocols that do not depend for their correct functioning on the data character set or data code used.
1346. codec Acronym for coder-decoder. 1. An assembly consisting of an encoder and a decoder in one piece of equipment. 2.
1347. coded character set A character set established in accordance with unambiguous rules that define the character set and the one-to-one relationships between the characters of…
1348. coded image A representation of a display image in a form suitable for storage and processing.
1349. coded set A set of elements onto which another set of elements has been mapped according to a code.
1350. coding Litigation Support: Automated or human process through which documents are examined and evaluated using predetermined codes, and the results of those…
1351. coding scheme Synonym code.
1352. codress message In military communications systems, a message in which the entire address is encrypted with the message text.
1353. COG Abbreviation for centralized ordering group.
1354. coherence area Pertaining to an electromagnetic wave, the area of a surface perpendicular to the direction of propagation, over which the electromagnetic wave maintains…
1355. coherence degree See degree of coherence.
1356. coherence length The propagation distance from a coherent source to a point where an electromagnetic wave maintains a specified degree of coherence.
1357. coherence time For an electromagnetic wave, the time over which a propagating wave may be considered coherent.
1358. coherent Pertaining to a fixed phase relationship between corresponding points on an electromagnetic wave.
1359. coherent bundle Synonym aligned bundle.
1360. coherent differential phase-shift keying (CDPSK) Phase-shift keying (a) that is used for digital transmission, (b) in which the phase of the carrier is discretely modulated in relation to the phase of a…
1361. coherent pulse operation In pulsed carrier transmission, a method of operation in which a fixed phase relationship of the carrier wave is maintained from one pulse to the next.
1362. coherent radiation See coherent.
1363. cold standby Pertaining to spare electronic equipment that is available for substitute use, but is not powered or warmed up and ready for use.
1364. cold start [In security, a] procedure for initially keying crypto-equipment. [INFOSEC-99]
1365. collective address Synonym group address.
1366. collective routing Routing in which a switching center automatically delivers messages to a specified list of destinations.
1367. collimation The process by which a divergent or convergent beam of electromagnetic radiation is converted into a beam with the minimum divergence or convergence…
1368. collimator A device that renders divergent or convergent rays more nearly parallel. Note: The degree of collimation (parallelism) should be stated.
1369. collinear antenna array An array of dipole antennas mounted in such a manner that every element of each antenna is in an extension, with respect to its long axis, of its…
1370. Collision This benefit pays to repair damage to your car as a result of an accident. Most banks or lenders require you to buy this coverage to receive a car loan.
1371. color balancing In color television technology, a calibration process involving adjustment of the relative amplitudes of the signal levels representing the tristimulus…
1372. color bar test signal The color bar test signal shown in the associated figure, consists of discrete steps of chroma and luminance levels that produce eight different colors…
1373. color bars 1. In color television technology, any of several electronically generated video test patterns displayed as vertical bars of usually equal width, and of…
1374. color burst In analog color television technology, a signal consisting of several (8 to 10 in NTSC) cycles of unmodulated color subcarrier, superimposed at a…
1375. color coordinate transformation Computation of the tristimulus values of colors in terms of one set of primaries.
1376. color correction In television and computer graphics, the electronic adjustment of a color reproduction process to improve the perceived-color conformity of the…
1377. color decoder In color television technology, of a receiver, the circuitry that separates the chroma information from the video (gray-scale) information and processes…
1378. color errors In video systems, distortion of hues in all or a portion of the received image.
1379. color keying Synonym chroma keying.
1380. color phase In color television technology, the instantaneous phase of the chroma signal with respect to that of the color burst signal.
1381. color processing In color television technology, electronic alteration of the color information content to effect a change in the color balance of the video signal.
1382. color subcarrier In analog color television technology, a signal superimposed upon the picture (gray scale) information for the purpose of conveying the associated color…
1383. Color Temperature The color of the light source. By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an…
1384. color-difference signal The chrominance vectors carrying the color information in a composite format. Note: The color-difference signals have been defined by the ITU-R for…
1385. color-matching functions The tristimulus values corresponding to monochromatic stimuli of equal radiant power.
1386. colorimetry Measurement of colors based on a set of conventions. [After SMPTE] 2. The science of, or body of techniques employed in, (a) the measurement or…
1387. combat-net radio (CNR) A radio operating in a network that (a) provides a half-duplex circuit and (b) uses either a single radio frequency or a discrete set of radio frequencies…
1388. combinational logic element A device having at least one output channel and one or more input channels, all characterized by discrete states, such that at any instant the state of…
1389. combined communications The common use of communications facilities by two or more military services, each belonging to a different nation.
1390. combined distribution frame (CDF) A distribution frame that combines the functions of main and intermediate distribution frames and contains both vertical and horizontal terminating blocks.
1391. combined link set A load-sharing collection of more than one link set to the same message destination. [T1.226-1992]
1392. combined station In high-level data-link control (HDLC) operation, the station that is usually responsible for performing balanced link-level operations and that generates…
1393. combiner See maximal-ratio combiner.
1394. COMINT Communications Intelligence.
1395. comm center Synonym communications center.
1396. comma-free code A code constructed so that any partial code word, beginning at the start of a code word but terminating prior to the end of that code word, is not a valid…
1397. command For command-oriented functions, the authorization required to perform command operations. 55
1398. command and control (C2) The exercise of authority and direction by a properly designated commander over assigned forces in the accomplishment of the mission.
1399. command and control (C2) system The facilities, equipment, communications, procedures, and personnel essential to a commander for planning, directing, and controlling operations of…
1400. command and control warfare (C2W) The integrated use of operations security (OPSEC), military deception, psychological operations (PSYOP), electronic warfare (EW), and physical…