claddingOf an optical fiber, one or more layers of material of lower refractive index, in intimate contact with a core material of higher refractive index. 2.
cladding diameterIn the cross section of a realizable optical fiber, ideally circular, but in practice assumed to a first approximation to be elliptical, the average of…
cladding modeAn undesired mode that is confined to the cladding of an optical fiber by virtue of the fact that the cladding has a higher refractive index than the…
cladding mode stripperIn an optical fiber, anything used to convert cladding modes to radiation modes, thus removing them from the fiber.
classArticle I, section 3 of the Constitution requires the Senate to be divided into three classes for purposes of elections.
class d addressSynonym (in Internet protocol) multicast address.
class of emissionThe set of characteristics of an emission, designated by standard symbols, e.g.
class of officeA ranking, assigned to each switching center in a communications network, determined by the center switching functions, interrelationships with other…
class of serviceA designation assigned to describe the service treatment and privileges given to a particular terminal. 2.
Classificationpatents are classified (organized) in the U.S. by a system using a 3 digit class and a 3 digit subclass to describe every similar grouping of patent art.
classmarkA designator used to describe the service feature privileges, restrictions, and circuit characteristics for lines or trunks that access a switch.
clearTo cause one or more storage locations to be in a prescribed state, usually that corresponding to a zero or that corresponding to the yyspace character.
clear channelIn radio broadcasting, a frequency assigned for the exclusive use of one entity. 2.
clear channel capability (CCC)A characteristic of a transmission path in which the bit position allocated for customer data may represent any combination of zeros and ones.
clear collisionContention that occurs when a DTE and a DCE simultaneously transfer a clear request packet and a clear indication packet specifying the same logical…
clear confirmation signalA call control signal used to acknowledge reception of the data-terminal-equipment (DTE) clear request by the data circuit-terminating equipment (DCE) or…
clear message1. A message that (a) is sent in the forward direction and the backward direction, (b) contains a circuit-released signal or circuit-released…
clear textUnencrypted, non-machine dependent, ASCII text in readable form.
ClearanceClearance is the first half of the process that completes your order to buy or sell a security.
ClearingThe registration and settlement of a trade that includes provisions for margin requirement and performance guarantee.
cleaveTo break phosphodiester bonds of double-stranded DNA, usually with a type II restriction endonuclease. Synonyms: cut; digest.
CLECAbbreviation for competitive local exchange carrier. The new local exchange carrier that is attempting to compete outside its traditional operating…
click dataData obtained by analyzing the log file containing information regarding who has accessed the Web page or the banner under consideration.
click rateOf a Web page menu item, especially an advertisement, the ratio of (a) the number of time it is selected ("clicked") to (b) the number of times it is…
Click throughThe process of clicking on a link in a search engine output page to visit an indexed site.
clientAny computer system that requests a service of another computer system. A workstation requesting the contents of a file from a file server is a client of…
client IDA unique identification number used when sending data to a specific client. Clients that are standardized for use in generic applications are allocated…
client-server architectureThe structural basis of Exchange. The client sends requests to a server, and the server carries out the instructions. [Exchange 5.5]
Client/ServerAn architecture whereby a computer system consists of one or more server computers and numerous client computers (workstations).
cliff effectIn the digital transmission of analog signals, including analog television and digital audio broadcasting (DAB), a signal-quality effect in which the…
clipThe spatial extraction of those features from one coverage that reside entirely within a boundary defined by features in another coverage (called the clip…
clipper1. A circuit or device that limits the instantaneous output signal amplitude to a predetermined maximum value, regardless of the amplitude of the input…
clippingIn telephony, the loss of the initial or final parts of a word, words, or syllable, usually caused by the nonideal operation of voice-actuated devices. 2.
CLLI™A CLLI⢠Location Identification Code is an eleven-character alphanumeric descriptor used to identify switches, points of interconnection, and…
clockA reference source of timing information. 2. A device providing signals used in a transmission system to control the timing of certain functions such as…
clock accuracyThe level of agreement of the frequency of a clock with the ideal frequency. This is specified as the magnitude of the fractional frequency offset from…
clock errorThe difference between local clock time or value and a designated reference clock time or value.
clock fast modeAn operating condition of a clock in which it is locked to an external reference and is using time constants that are altered to quickly bring the local…
clock free-run modeAn operating condition of a clock in which its local oscillator is not locked to an external synchronization reference, and is using no storage techniques…
clock holdover modeAn operating condition of a clock that has lost its controlling input and is using stored data, acquired while in normal operation, to control its output.
clock normal modeAn operating condition of a clock in which the output signals are controlled by an external input reference. It is the expected mode.
clock phase slewThe rate of relative phase change between a given clock signal and a stable reference signal.
clock rateThe rate at which a clock issues timing pulses. Note: Clock rates are usually expressed in pulses per second, such as 4.96 Mp/s (megapulses per second).
clock toleranceThe maximum permissible departure of a clock indication from a designated time reference such as Coordinated Universal Time (UTC).
clock trackA track on which a pattern of signals is recorded to provide a timing reference.
closed captioningIn broadcast and cable television, the insertion, into the blank lines between frames, of information that may be decoded and displayed on the screen as…
closed circuitIn radio and television transmission, pertaining to an arrangement in which programs are directly transmitted to specific users and not broadcast to the…
closed user groupIn a network, a group of users permitted to communicate with each other but not with users outside the group.
closed user group with outgoing accessA 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…
closed waveguideAn electromagnetic waveguide (a) that is tubular, usually with a circular or rectangular cross section, (b) that has electrically conducting walls, (c)…
closed-loop noise bandwidthThe integral, over all frequencies, of the absolute value of the closed-loop transfer function of a phase-locked loop.
closed-loop response integrityIn cryptography, the originator's confirmation of the integrity of the entire transaction, i.e.
closed-loop transfer functionA mathematical expression (algorithm) describing the net result of the effects of a closed (feedback) loop on the input signal to the circuits enclosed by…
closed-security environmentAn environment in which special attention is paid (in the form of authorizations, security clearances, configuration controls, etc.
closureIn 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…
cloud attenuationIn the transmission of electromagnetic signals, attenuation caused by absorption and scattering by water or ice particles in clouds.
CNRAbbreviation for carrier-to-noise ratio, combat-net radio.
CNSThe brain and spinal cord. Also called central nervous system.
CO Code (NXX) ExhaustA point in time at which the quantity of TNs within existing CO codes (NXX) which are "Available for Assignment" equals zero within a switching…
COAMAcronym for customer owned and maintained equipment. Deprecated term. See customer premises equipment.
coast Earth stationAn 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…
coast stationA land station in the maritime mobile service. [RR]
coasting modeIn timing-dependent systems, a free-running operational timing mode in which continuous or periodic measurement of clock error, i.e.
CoatingThe protective material applied to the outer surface of a material, frequently metalwork.
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…
code bookDocument containing plain text and code equivalents in a systematic arrangement, or a technique of machine encryption using a word substitution technique.
code characterA character that (a) is used to represent a discrete value or symbol and (b) is derived in accordance with a code.
code conversionConversion of signals, or groups of signals, in one code into corresponding signals, or groups of signals, in another code. 2.
code elementOne of a set of parts of which the characters in a given code may be composed.
code group[A] group of letters, numbers, or both in a code system used to represent a plain text word, phrase, or sentence.
Code HolderAn 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
code restrictionA service feature by which certain terminals are prevented from accessing certain features of the network.
code setThe complete set of representations defined by a particular code and language.
code structureThe basic characteristics of a code: its length and generic representation. [T1.238-1994/97] [T1.266-2000]
code vocabulary[A] set of plain text words, numerals, phrases, or sentences for which code equivalents are assigned in a code system. [INFOSEC-99]
code wordIn 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.
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.
code-transparent data communicationA mode of data communication that uses protocols that do not depend for their correct functioning on the data character set or data code used.
codecAcronym for coder-decoder. 1. An assembly consisting of an encoder and a decoder in one piece of equipment. 2.
coded character setA character set established in accordance with unambiguous rules that define the character set and the one-to-one relationships between the characters of…
coded imageA representation of a display image in a form suitable for storage and processing.
coded setA set of elements onto which another set of elements has been mapped according to a code.