Fiber Optics Illustrated Dictionary - Part 22 potx

One ofthe best applications of computer-aided manufacturing is integrating the production machines with paramet-ric design software usually used with CAD so that objects that are general

Fiber Optics Illustrated Dictionary

of different sizes, and which may take longer to

ex-ecute than the same operation carried out on areduced

instruction set computing(RISC) chip

elscchips are more common on older architectures

A CISC processor command is translated into

micro-code, a series ofsmaller instructions, which are inturn

queued and processed one at a time by a

nano-processor See reduced instruction set computing

Complex Node RepresentationCNR In ATM

net-works, a collection of node-related parameters that

provide state information about a logical node This

information is useful in routing

Complex Text LayoutCTL An IETF Human

Com-puter Interface (HCI) platform standard

Component Object ModelCOM Microsoft's

ap-proach to object-oriented programming The COM

is a means for creating components that are reusable

across a variety of applications, thus reducing

pro-gramming time and increasing interoperability across

applications Microsoft's Object Linking and

Embed-ding (OLE) provided a subset ofthe functionality now

associated with COM See Object Management

Group For a more complete discussion of the basic

concepts associated with programming objects, see

object-oriented programming

Component SoftwareMicrosoft's description for

object-oriented programming components associated

with their Component Object Model See Component

Object Model, object-oriented programming

compositeCombined, bundled, aggregated,

inter-leaved, entwined, mixed

composite videoA color composite video signal is

one in which the luminance (brightness) and

chromi-nance (color) are combined, with the chromichromi-nance

modulated onto the luminance as a subcarrier The

signal may have to be separated by the receiver,

de-pending upon the system Videogame systems that

plug into a TV set send out a composite signal, as

op-posed to an RGB signal that might be sent to a

com-puter monitor

compound modulationA successive modulation

technique in which the modulated wave from one step

becomes the modulating wave in the next step

Comprehensive System AccountingCSA Within

the Open Source Software community, CSA is a set

ofC programs and shell scripts that help administrate

individual online accounts CSA facilitates

account-ing for users, jobs, daemons, and billaccount-ing units and

provides configuration parameters, accounts

sched-uling, and hooks to reporting applications Thus, CSA

makes it easier to monitor usage, frequency, and other

access data for administrating and tuning networks

and for billing purposes

compressCondense, contract, shrink; reduce in size,

transmission time, or byte count

compressionThe act ofreducing, shrinking, or

short-ening items or data in order to store or transmit the

objects or information more easily Data compression

is based on the premise that most files or

transmis-sions include white spaces, noninformational

sec-tions, or redundancies that can be removed without

affecting or significantly degrading the meaning or

quality of the information when it is decompressed Compression is sometimes also based on human per-ceptual characteristics or multiple means ofrepresent-ing the same data, some ofwhich may be more space-conserving than others See data compression, de-compression, lossless de-compression, lossy compres-sion, run length encoding

compression algorithmThe computer logic and code designed to automate the process of saving or transmitting data in less space or less time than ifthe data were stored or transmittedraw(unaltered) Com-pression algorithms are used on many types of data (video, still images, sound, text, etc.) and the degree

of compression is often tied to the type of data and even the specific character of the particular data be-ing compressed A compressed file is not always smaller than the original

Compression algorithms may belossless(the infor-mation can be reconstructed to be the same, or to ap-pear the same, as the original) orlossy(the informa-tion is reconstructed to beessentiallythe same as the original, or perceptually similar, but not identical) Compression Control ProtocolCCP Aprotocol for negotiating data compression at both ends of an es-tablished Point-to-Point Protocol (PPP) link CCP was introduced as a standards track protocol in the mid-1990s as a means to configure, enable, and dis-able data compression and to signal errors in the com-pression/decompression mechanism CCP is similar

to Link Control Protocol (LCP) except that CCP uti-lizes different timeouts, additional codes, and specific PPP Protocol field indicators and may utilize frame format modifications that may have been established with the link See Link Control Protocol, Point-to-Point Protocol, RFC 1962

CompTelCompetitive Telecommunications Associa-tion An association that includes WorldCom and a number ofmedium-sized communications carriers Compton scatteringAform ofphoton scattering that results from stimulation by electromagnetic radiation The scattering effect is small but important, as it oc-curs at a wavelength different from the incident ra-diation, scattering off of loosely bound "stationary" electrons Thus, for light, a particle model is more ef-fective at describing the effect than a wave model

In Compton scattering, the scatter angles and energy levels in the scattered photons may be detected/cal-culated At visible light ranges, the effect is very small, but becomes more apparent at the higher en-ergy levels associated with X-rays or gamma rays This is useful for telescopic radiation detectors.A

Compton scattering telescope typically consists of a scintillating layer that Compton scatters gamma ra-diation The scattered photons then encounter a sec-ond scintillating layer which absorbs them Phototube detectors assessing the two levels can somewhat de-termine interaction between the two layers and the associated amount of energy deposited Unfortu-nately, the Compton relationships don't include in-formation about the angle of incidence ofthe incom-ing photons, so this must be determined or estimated

by other means if the source of the radiant energy is

Thomson scattering.

Compton Scattering

The Compton effect was studied in the early 1920s

by A Compton and may be expressed mathematically

as

Af- Ai=M =(h/mc)*(1- cosS)

where \ is the scattered photon and Ai is the

incom-ing (incident) photon andhis Planck's constant In

terms of understanding the nature of light, this was

important data confirming the hypothesis of a

par-ticle nature oflight.

Compton, Arthur Holly(1892-1962)AnAmerican

physicist and engineer who studied X-rays and

veloped theories and mathematical expressions

de-scribing their behavior, including reflection and

po-larization effects He was also a pioneer in obtaining

the spectra ofX-rays by the use ofruled gratings,

in-formation that was invaluable in determining

elec-tronic charge In 1941, he became chairman of the

National Academy of Sciences

Compton is best remembered for having observed and

mathematically expressed Compton scattering, a

subtle wavelength-shift effect that provided

conftr-matory evidence for a particle nature oflight In 1922,

he published his observations in Secondary

Radia-tions Produced by X-rays.In collaboration with A

Simon, Compton provided further confIrmation ofthe

effect by the coincidence method, describing how

in-dividual scattered photons and the electrons off of

which they recoiled would appear simultaneously, an

idea that required quantum rather than classical

phys-ics concepts to reconcile

In 1927, Compton and C Wilson were coawarded the

Nobel Prize in physics.In1991, NASA named its new

space-based gamma radiation observatory after

Compton See Compton scattering

CompuServe, CompuServHistorically, one of the

earliest large-scale commercial computer service

pro-viders, CompuServe was initiated in 1969 as a

time-share subsidiary of Golden United Life Insurance

under the name CompuServ Network, Incorporated

In 1986, the service was purchased by H&R Block

By the late 1980s, CompuServe was also beginning

to sell services to personal computer users and soon

CompuServe was one ofthe pioneering Internet mail relay carriers and, in the mid-1990s, extended its tra-ditional BBS-style dial-up services to include Inter-net access

CompuServe survived the online services shakeouts

of the 1990s to become a large, commercial dialup Internet Services Provider (ISP) In 1997, it was bought out by America Online, Inc (AOL) and posi-tioned as an interactive service brand In addition to public services, it provides CompuServe-specific ser-vices available only to members, including airline res-ervations, stock listings, chat services, etc

computerAlogic-processing device, which usually includes temporary or long-term storage and input and/or output devices for interaction with the user.It

mayor may not be programmable and mayor may not be constructed with binary architecture (binary computers are prevalent) A computer doesn't have

to be strictly electronic, and researchers have explored biological parts or processes for incorporation into computing devices Quantum computers have been proposed, with science fiction possibilities, but none has yet been devised However, individual quantum processes have been developed successfully and may someday be incorporated into computers

The most common configuration for digital desktop computers consists ofa central processing unit (CPU) for performing mathematical logical instructions, sometimes cooperating with coprocessing chips for graphics and sound; volatile storage, usually in the form of RAM; read/write semi-permanent storage, usually on magnetic or magneto-optical media; user-interaction input/output devices such as monitors, keyboards, mice, microphones, cameras, speakers, and joysticks; and program instructions in the form

of operating systems and applications programs

To enhance the usefulness ofbasic computers, print-ers, scannprint-ers, modems, and network interfaces have been developed, which communicate through a printed circuit board, or various SCSI, IDE, serial, parallel, USB, FireWire and networking ports Many people make the mistake of assuming the software that runs the system, the operating system (OS), is the computer itself While it is true that a particular

OS is usually optimized for a particular platform, op-erating systems can be adapted to run on many sys-tems Early computers ran several operating systems (see TRS-80), and the trend is moving back in that direction Linux, Be, Inc 's BeOS, and Apple Computer's OS X, as examples, are designed to run

on a number of hardware platforms, providing the user the freedom to choose his or her hardware/soft-ware combination

Computer and Business Equipment Manufactur-ers AssociationCBEMA See Information Technol-ogy Industry Council

Computer and Communications Industry Asso-ciationCCIA Atrade organization based in Virginia that represents data processing companies and common carrier service companies The CCIA pro-vides education and lobbying support to its members

Fiber Optics Illustrated Dictionary

Computer and Information Science and

Engineer-ing CISE A U.S National Science Foundation

Di-rectorate that promotes basic research and education

in the fields ofcomputer information sciences and

en-gineering http://www.cise.nsf.gov/

Computer Control CompanyThe company that

originated the Series-16 minicomputers,

washing-machine (and smaller) sized 16-bit-register

comput-ers that were bought out by Honeywell in the

mid-1960s See Honeywell Kitchen Computer

Computer Emergency Response TeamCERT

Es-tablished in the late 1980s by the Advanced Research

Projects Agency (ARPA), based at Carnegie Mellon

University CERT provides assistance to computer

operators wrestling with various network security and

operations issues

computer fraudMisrepresentation or theft

accom-plished on, with, or with regard to computers The

computer data may itselfbe the target of the

fraudu-lent activities or a computer may be used as a tool to

aid in noncomputer-related fraud (as in records theft,

spying, or unauthorized access) Unsecured computer

data, in the form of accounts, confidential business

or investment information, personnel files, etc is

es-pecially subject to tampering

Computer Incident Advisory CapabilityCIAC.An

archive and notices repository posted in conjunction

with the Laurence Livermore National Labs Web site

to inform the network community about security

weaknesses and breaches that might compromise

net-work systems, particularly the Internet This posting

is intended to provide technical assistance to help

se-cure the Department of Energy (DoE)

communica-tions systems, but the posted bulletins are open to the

Internet community CIAC was founded in 1989 and

is a founding member of the Forum of Incident

Re-sponse and Security Teams (FIRST) CIAC provides

training, education, technology watches, and trend,

threat, and vulnerability data collection and analysis

CIAC publications that are transmitted to other

par-ties are signed with a PGP encryption key

Computer Science Telecommunications CST

Apub-lication of the University of Missouri (Kansas City)

School of Interdisciplinary Computing and

Engi-neering

Computer Security InstituteCSI A professional

organization committed to supporting and educating

information technology (IT), computer, and network

security professionals, founded in 1974

http://www.gocsi.com/

computer societies, nationalA complete listing of

the world's computer societies is outside the scope

of this dictionary, but a sampling of some of the

ac-tive and prominent societies that are accessible on the

Web helps illustrate the types of organizations that

exist and their general goals and priorities with

rela-tion to informarela-tion technologies and computing

sci-ence See Computer Societies chart

Computer Supported Telecommunications

Appli-cationsCSTA Acomputer telephony interface

stan-dard published by the European Computer

Manufac-turers Association (ECMA) in 1992 Work on ECMA

telephony standards was carried out by the ECMA Technical Committee TC32 CSTAwas developed for integrating computers and telephone technology into

a unified system, in a process described as Computer Telephone Integration (CTI) CSTAhas been adopted

as an ISO standard and is one of the most important international standards for computer telephony for the predictable future

The standard describes information interchange among telecommunications and computer devices It

is sufficiently generic to encompass analog and digi-tal private, public, and combination communications signaling systems, switches, and networks Initial applications of the standard tend to focus on tele-phony/database integration and basic automation of services but, since it is a broad-based standard, new types of services and technologies will emerge as it becomes better understood and supported

Computer Systems Policy ProjectA lobbying or-ganization formed in 1991 to represent those who felt national networks were too oriented toward research and science and not enough toward everyday users

In actual fact, statistics show that a great majority of

Internet use is devoted to conventional everyday user

traffic, predominantly business and personal elec-tronic mail and file transfers unrelated to research and science

computer telephony integrationCTI Integration of computer database, dialing, and other features, with voice communications through a headset, handset, or other computer peripheral voice transmitting and re-ceiving device See Computer Supported Telecom-munications Applications, computer telephony computer-aided dispatchCAD A system in which the administration ofservices is aided by a computer For example, emergency or law enforcement systems may track the location ofvehicles and their direction oftravel in order to dispatch calls in an efficient man-ner Similarly, taxi and limousine services can be managed with the aid ofa computer Billing and mile-age factors may also be stored by the system, and sta-tistical measures tracked in order to enable a com-pany to better manage its resources

computer-aided learning, computer-assisted learningSee computer-assisted instruction computer-aided manufacturingThe process ofus-ing a computer to directly control manufacturofus-ing equipment, such as drilling machines, production lines, bottle cappers, saws, chisels, and any ofthe fab-rications equipment which normally may have been driven by manual, electrical, or mechanical machines without the benefit oflogic programming One ofthe best applications of computer-aided manufacturing

is integrating the production machines with paramet-ric design software (usually used with CAD) so that objects that are generally the same, but perhaps dif-ferent in specifics, can be manufactured with the same equipment, under the control of the computer See parametric design

computer-assisted instructionCAl Instructional media and techniques used in conjunction with com-puter software, or entirely by comcom-puter software, in

online mentors and instructors, educational software,

tests, multimedia presentations, etc CAl has been

around for decades as a number of instructors were

quick to grasp the significance of and opportunities

provided by CAl, particularly for individual

learn-ing and distance learnlearn-ing However, the resources and

time to provide good educational programming and

the prohibitive cost of systems up until recently

greatly limited the practical application ofthese ideas

Computer+Science Network CSNET CSNET

merged with BITNET in 1989 to form the

Corpora-tion for Research and EducaCorpora-tional Networking

(CREN); CSNET was discontinued in 1991

computerTVSee telecomputer

Computists InternationalCI A professional

asso-ciation for information science, artificial intelligence,

and computer science researchers CI provides

infor-mation on industry trends, leading edge technologies,

research, andjob opportunities CI publishes a weekly

Computists ' Communique reporting on artificial

in-telligence, neural networks, genetic algorithms,

ma-chine learning, natural language processing, fuzzy

logic, and computational linguistics See artificial

in-telligence

COMSAT Corporation Originally created by the

u.S Congress, COMSAT merged with Continental

Telephone to form COMSAT Corporation, an

inter-national provider of satellite communications and

networking services COMSAT operates through the

INTELSAT and Inmarsat systems and is currently the

largest user of both systems

COMSAT operates the COMSAT Laboratories for

research, development, and technical consultation in

pioneering satellite communications technologies

http://www.comsat.com/

concatenateTo link, chain, or otherwise place

adja-cent objects or structures end-to-end Thus, a female

RCA plug can concatenate two RCA cables with

stan-dard male ends A2-port 25-pin data switcher can be

used to selectively concatenate one or the other oftwo

25-pin cables (e.g., serial cables) A software "join"

utility can concatenate two files, one after the other

(as opposed to merging one file into another) See

daisy chain

concaveDished in, hollowed out, bowl-shaped (on

the inner surface), or otherwise smoothly curving or

arching inwards in two or three dimensions Many

optical components and networking structures have

concave shapes, including resonating cavities, lenses,

reflectors, parabolic antennas, etc See parabola

Con-trast with convex

concentratorA point or device at which a number

of elements are brought together either for

simplic-ity ofcabling and management, or to more efficiently

provide a means to allocate shared resources A star

topology network is a type of concentrated

configu-ration with a hub negotiating communications among

the connected systems A printer room with several

kinds ofprinters available to the general office is

an-other type ofconcentration point for general network

services

router, which processes the incoming infonnation and sends the task or communication to the best destina-tion or it may simply work on a frrst-come, first-serve basis

A patch panel is a type of cable concentrator in the sense that it brings together the connecting points of

a large number of individually cabled systems, usu-ally to facilitate reconnections in different configu-rations Amodem pool is a concentrated assembly of individual modems, brought together in one facility, room, or closet, for easy access, configuration, and maintenance See condenser

concentrator, opticalA device, such as a lens, that concentrates electromagnetic radiation into a higher energy level or smaller physical space This is useful for increasing luminance, collimating beams, or chan-neling light into narrow openings such as the endfaces

of fiber optic lightguides

concentricIn geometry relating to fiber 9ptics, two

or more broadly circular or rotating structures in the same general plane with a common center point or rotational axis Thus, a bull's eye target comprises a series of differently sized concentric circles A shaft within a rotating cylindrical tubing is concentric along the access ofthe shaft Cable assemblies, with layers comprised ofcylindrical fiber-conducting cores, clad-ding, tubing, aramid yam, and outer armoring sheaths are concentric along the perpendicular plane to the axis of the length of the fiber core - incross-section, the assembly will resemble a target

Concentric structures are generally not concentric from every viewing angle Just as a flat target has concentric circles only on the front and not on the side, the axis of reference is important Concentric-ity may be associated with stepped or curved struc-tures, as in Fresnel lenses or other types of curved, ridged components However, they are only concen-tric in those planes in which the ridges share a com-mon axis In other words, they are concentric at the points where a knife, slicing down through all the lay-ers, would pass through the shared center of all the reference components along the shared axis Only an assembly oftwo or more perfect spheres of different sizes, with their radii sharing a common center, would

be concentric in any given plane that passes through the center

Technically the structures don't have to be circular

to be concentric A target could be comprised of dif-ferent-sized squares rather than circles, as long as they share a common center point, but in practical appli-cations concentricity is often associated with roughly circular or spherical components, especially those that rotate within one another

concentricity errorIn fiber optic lightguides with two or more component layers (e.g., cladding sur-rounding the core), which may not be perfectly cir-cular at any given point, and thus not perfectly con-centric, the ratio of the cladding to the core, which has fine tolerances for optimum performance, may not be ideal At this point, the reflection of the light beam off the cladding and through the core may be

Fiber Optics Illustrated Dictionary

Computer Societies - Sample List

Australian Computer Society ACS Per capita, one of the world's largest computer societies, established

in 1966 in a merger of state-based computer societies The ACS studies, supports, and promotes professional excellence in information technology See ACSnet http://www.acs.org.au/ British Computer Society BCS A professional society and registered charitable institution for

supporting the field of information systems engineering, founded in

1957 The BCS is also a licensed engineering institution with accreditation-granting authority http://www.bcs.org.uk!

http://www.infj.ulst.ac.uk! bcs/

Computer Society of Bermuda CSB A nonprofit organization for fostering knowledge and applications in

information technologies in Bermuda, founded in 1975 and incorporated in 1986 http://www.csb.bm/

Computer Society of India CSI Founded in 1965, the CSI is committed to promoting the interchange

of information and the advancement of the theory and practice of computer technologies and professions http://www.csi-india.org/ Computer Society of South Africa CSSA A not-for-profit professional corporation dedicated to the support and

education of its members in various chapters throughout the region http://www.cssa.org.za/

Computer Society of Sri Lanka CSSL Formed in 1977 to support and promote research and professionalism

in the information technology field http://www.ccom.lkJcssl/ Jamaica Computer Society JCS A communications and education body of Jamaica which seeks to

promote the efficient and effective use of information technologies in Jamaica http://www.jcs.org.jrnl

Jordan Computer Society JCS A nonprofit organization for promoting the computer profession,

founded in 1986 http://www.nzcs.org.nz/

Hong Kong Computer Society HKCS A nonprofit professional organization promoting education and

applications in information technologies in Hong Kong, founded in

1970 http://www.csb.bm/

IEEE Computer Society IEEE A highly prominent American organization descended from the

Subcommittee on Large-Scale Computing of the American Institute

of Electrical Engineers (AlEE), founded in 1946 The AlEE and the Institute of Radio Engineers merged in 1963 to become the Institute

of Electrical and Electronics Engineers (IEEE) The IEEE has members around the world It promotes education and professionalism in a broad range of computing technologies and is responsible for the development of many telecommunications and computing standards http://www.computer.orgl

http://www.ieee.orgicshome.htm Irish Computer Society ICS The ICS supports and promotes a broad range of information

technologies through education and member services It was founded

in 1967 http://www.ics.ie/

Kuwait Computer Society KCS A Kuwaiti Public Welfare Institution, founded in 1982 as the Kuwaiti

Society of Computers, renamed in 1990 The KCS promotes education and professionalism in computer sciences and information technologies http://www.paaet.edu.kw/Info/HomePage/adel/kcslkcs.hnn Lithuanian Computer Society LIKS An independent society of software users, amateurs, and

professionals in informatics and computing science, officially registered in 1990 http://www.liks.1t/

Malaysian Computer Society MCS A society that promotes computer literacy in Malaysia, founded in

1998 http://www.geocities.com/EurekaiConcourse/2008/

Mauritius Computer Society MCS The MCS promotes personal and professional development and

computer literacy in Mauritius http://ncb.intnet.mu/mcs.htm New Zealand Computer Society Inc NZCS Promotes and fosters education, qualification, and professional

development in information processing http://www.nzcs.org.nz/ Norwegian Computer Society NCS An open, independent, self-financed society for promoting awareness

and the advancement of information technologies for business and society http://dataforeningen.no/ncs/

Singapore Computer Society SCS Singapore's largest information technology professional body,

founded in 1967 The SCS promotes personal development and industry leadership in information technology http://www.scs.org.sg/ Syrian Computer Society SCS Anonprofit national organization of scholars and engineers, based in

Damascus, founded in 1989 The SCS furthers information technologies in Syria http://www.scs-syria.coml

cladding ratio See concentric, total internal

reflec-tion, critical angle

concurrentFunctioning, processing, or operating at

the same time; parallel, in conjunction with;

coexist-ent, simultaneous, synchronous

concurrent programmingTechniques and

associ-ated notation systems for parallel processing

imple-mentation Distribution, synchronization, prioritizing,

and signaling are important aspects ofconcurrent

pro-gramming For example, computer graphics special

effects rendering is computing intensive, and

farm-ing out various objects to various processors or

work-stations, and then combining them in one frame when

each is rendered, can greatly decrease the time it takes

to create each image (calledrender farms). Not all

types ofoperations benefit from concurrent

program-ming The overhead involved in setting up the

distri-bution and coordination of the data must be smaller,

in proportion to the effective processing that occurs,

to make it worth processing in parallel

concurrent site licenseIn the software industry there

are a number ofcommon schemes for assigning

soft-ware use rights Exclusive operation on only one

machine at a time is the most common, but it is also

possible to get concurrent licenses that permit a

speci-fied maximum number ofusers to access the software

at anyone time from a networked server, or that

per-mit up to a specified number of users (five is

com-mon) to install the software on individual

worksta-tions

condenserAn apparatus that concentrates or

con-denses a beam, ray, wave, or collection of particles

In the process ofconcentrating a substance, wave, or

particles, the condenser may also secondarily store

them, as in electrical energy A device that focuses

radiant energy, such as a lens for concentrating light

or a parabolic antenna for concentrating satellite

waves, can be considered a basic type of condenser

See concentrator; condenser, electrical

condenser, electricalCondensers range widely in

complexity and construction They are used with a

variety of types of electrical apparatus, for example,

spark coils Condensers employ a dielectric, that is a

material that doesn't readily conduct direct current

(DC) Dielectrics vary from paper to ceramic or glass,

with the better insulators being used in higher

volt-age applications A Leyden jar is one of the earliest

condensers used for concentrating and storing

elec-trical energy In the Leyden jar, the glass acts as the

dielectric A variation on the same idea, using glass

plates in a rack rather than a jar, were used for early

wireless condensers See capacitor, condenser,

Ley-den jar

conditioningThe processing of current to make it

suitable for specific tasks Some electrical appliances

can tolerate variations in current or noise, while

oth-ers are very sensitive to variations and noise,

particu-larly small electronic components, requiring that the

raw current that may come from a wall socket or other

source frrst be conditioned to meet the needs of the

device See AC to DC converter

disposition of a material or system to carry an elec-trical current, expressed in the practical unitmho

(ohm spelled backward) The reciprocal ofelectrical resistance See conductor

conductivity methodA pioneer experimental

~~~;{~r~;l~~1~;~:~~~:~~~~~~~~~ '.

before Marconi demonstrated practical applications ofwireless communications Terminals ofstrong bat-teries were set up in series from a sending key, grounded at a distance ofabout fifty feet apart Asym-metric arrangement was set up at the receiving end, except that it used a telephone receiver or galvanom-eter Other researchers experimented with this method, but little documentation of their efforts is available See Preece, William; Steinheil, K.A

conductorA material that readily carries an electri-cal current or heat Some metals make especially good conductors (e.g., silver, copper, gold, alumi-num) and are widely used in the manufacture ofwire

Less conductive materials, such as rubber, used in specialized parts such as gaskets and seals, are some-times impregnated with metal to increase their con-ductivity, while still retaining attributes that are dif-ficult to achieve with metal alone The tenn conduc-tororiginates from Desgauliers in the 1730s Con-trast with insulator

conduit1 In its most basic sense, a channel for di-recting physical objects or virtual data along its path

2 A liquid conduit is a pathway often used for tem-perature regulation, dispersion oflubricants, or chan-neling of fluids from one area to another See duct

conduit, wiring1.Atubular, hollow, physical path-way providing a channel for materials installed in-side or directed through its core Plastic, metal, and ceramic are common conduit materials 2 A pipe that provides a protected pathway for wire, cable, or other conductive materials Conduit is commonly used to run wires in a building and may also include insula-tion, color coding, and other attributes to protect or identify its contents Conduit can be a good way to hedge against obsolescence, since it can be rethreaded more easily than cables that have been attached di-rectly to the structure of a building inside its walls

cone of silenceSee zone of silence

Conference Europeenne des Administrations des Postes et des Telecommunications(European Con-ference ofPostal and Telecommunications Adminis-trations) CEPT.Aninternational standards body rep-resenting telecommunications providers in most na-tions other than Japan, Canada, U.S., and Mexico.It

cooperates with CEN/CENELEC See El

configurationSetup, organizational structure, archi-tecture, topology, assemblage, physical and logical parts and interactions taken as a whole

congestion indicatorIn ATM networking, a traffic flow control signal to reduce the allowed cell rate (ACR) in order to reduce the likelihood of increasing congestion The information is contained in the RM cell See cell rate, leaky bucket

Fiber Optics Illustrated Dictionary

Congestion ManagerCM A network end-system

module that enables applications to adapt to network

congestion and enables a suite ofmultiple concurrent

streams from a sender to a receiver with the same

congestion properties to perform congestion

avoid-ance and control Congestion Manager was

submit-ted as a Standards Track RFC by Balakrishnan and

Seshan in June 2001

The framework supplied by Congestion Manager

in-tegrates congestion management across all

applica-tions and transport protocols It maintains parameters

and exports an API with information about network

characteristics and enables applications to pass

infor-mation to the CM, to schedule data transmissions, and

to share congestion information Use of the CM

re-quires explicit consent of the CM through the API

CM may be elected for use on best-effort network

systems that have well-behaved applications with

their own independent per-byte or per-packet

se-quence number information and use the API to

up-date the CM's internal state See RFC 3124

conical array antenn'aAn antenna that can receive

a range ofVHFsignals through a central rod with

re-flector elements extending out at right angles to the

support rod and, at the other end, forward-oriented

driven elements fanned out more or less from a single

connection point on the rod

conical monopole antennaA vertically polarized,

broadband antenna shaped like a cone with the

nar-row end oriented towards the top The frequency

re-sponse is related to the size and angle of the cone

conical scanIn radar antennas, a circular scanning

motion, often used on aircraft, that provides more

complete information on the location and

character-istics of the object of the scan The conical scan can

provide angular information

Connect 918A Macintosh and IBM-licensed

PC-based videoconferencing product from Nuts

Tech-nologies that supports video, audio, whiteboarding,

and screen sharing over analog, Switched 56, ISDN,

and Ethernet networks It uses ITU-T H Series and

G Series Recommendations standards and encoding

See Cameo Personal Video System, CU-SeeMe,

IRIS, MacMICA, ShareView 3000, VISIT Video

Connected, Limited Device ConfigurationCLDC

A Sun Microsystems Java specification used by a

number of major wireless telecommunications

pro-viders as a guideline for manufacturing and

program-ming small Java-enabled communications devices

The audience for the CLDC specification is the Java

Community Process (JCP) expert group and

afore-mentioned developers Participants include

promi-nent network technology companies such as Nokia,

Ericsson, Fujitsu, Sony, America Online, et a1

The "Limited Device" designation applies to

rela-tively slow CPU, limited-resolution, limited-memory

devices that are becoming prevalent as

mass-pro-duced hand-held assistants, including palm-top

com-puters and schedulers, and advanced-feature

cellu-lar phones, etc Thus, CLDC is a

minimum-foot-print specification for connected devices, devices that

can interface with a computer or wireless network

The full specification is downloadable free from Sun Microsystems' Web site

connection 1.Asystem or circumstance ofphysically

or logically joined entities, objects, or processes An electromagnetic connection is one in which current from one system can pass into another, either through

a splice, jack, plug, or other connector, or by a spark

or induction system 2 Awireless connectionis one

in which a signal is transferred without a visible physical connection Wireless connections typically are based upon the transmission of sound or electro-magnetic waves that originate in a transmitter (which commonly includes or is associated with a wave gen-erator) and terminate in a receiver which mayor may not convert the signals into visual or audio forms that may be directly perceived by humans

connection management controllerCMC Works

in conjunction with a broadband integrated gateway (BIG) to take data from incomingATM cells for pro-cessing and routing See broadband integrated gate-way,HFC

connection protocolThe software protocol that ne-gotiates a pathway for a transmissions connection session

connection-orientedA type of communication in which the sender/receiver connection is established prior to transmission, as in a phone call This may sound like a logical way to do things, but a substan-tial amount of network traffic does not follow this model In sending an email message, for example, the message will be sent irrespective of whether the re-ceiver is online at the time the message is sent Then,

if too much time elapses, or a certain number of at-tempts to deliver the message have failed,itwill be returned to sender Modem communications are con-nection-oriented If there is no answering handshake

at the other end ofthe transmission, no transfer ofdata takes place Contrast with connectionless

Connection-Oriented Transport ServiceCOTS.A connection-oriented, end-to-end network communi-cation service COTS involves initializing the service, establishing a connection, transferring data, releas-ing the connection, and general cleanup associated with the release of the connection such that it may

be reused, unbound, or closed When a COTS ses-sion is initialized, it enables the COTS driver and as-sociated application to be bound with a specific trans-port entity Various buffer-handling or status utilities may be used during the connection In the Open Sys-tem Interconnect (OSI) model, connection-oriented network services are implemented by using the Con-nection-Oriented Network Protocol (CONP) and the Connection-Mode Network Service (CMNS) connection-related functionIn ATM networking, a traffic management and policing function related to

a network element (NE) where connection-specific functions are carried out

connectionlessA type of network transmissions architecture in which the data is sent without first es-tablishing that the receiver is connected and available

to receive transmissions Large distributed comput-ing environments frequently employ connectionless

transfers are connection-oriented end-to-end

commu-nications Contrast with connection-oriented

Connectionless Broadband Data Service CBDS In

ATM networking, a high-speed packet-based

con-nectionless service similar to SMDS (Bellcore) that

is defined by the European Telecommunications

Stan-dards Institute (ETSI) CBDS is appropriate for

net-works requiring high-volume, high-speed

transmis-sion rates and thus is favored for high-end graphics

and publishing, videoconferencing and streaming,

and scientific research applications CBDS is favored

over private lines or permanent virtual circuits (e.g.,

Frame Relay) for some inter-business

communica-tion needs

Commercial implementations of SMDS or CBDS

support multicasting and most major network

proto-cols(TCP/IP,SNA, AppleTalk, etc.) CBDS can be

integrated with existing Ethernet, Token-Ring or

FDDI local area networks (LANs) At the present

time, CBDS is more widely installed in Europe than

North America Refer to the ETSI ETS 300 series

documents for specifications

Connectionless Transport Protocol CTP A

proto-col that provides a means to send to a recipient that

mayor may not be connected to the network at the

time the data is transported CLP allows end-to-end

transmission addressing and error control, but does

not guarantee delivery

connectivityAproperty ofmechanical and electronic

systems that allows them to interconnect with other

devices or systems for the purposes of transmitting

or relaying information or signals While

connectiv-ity generally refers to physical connectivconnectiv-ity, the

in-creasing importance of data in communications and

hardware configuration has extended the term to

soft-ware as well When systems or devices can be readily

interconnected in terms of hardware and software,

they are said to becompatible.See connection

connector 1 Adevice to join or combine two or more

objects When circuits are coupled with a connector,

the two systems or obj ects are usually intended to

communicate in the same way (otherwise the

connec-tor is usually referred to as anadapter).The connector

may be incorporated into the device being connected

or may be a separate item See adaptor, gender

changer, jack 2.In a flow chart, a connector is a

sym-bol that can be used to indicate ajoin in a flow, or the

divergence of the flow into additional paths See

ST-connector

Connon, John R (1862-1931) A Canadian

inven-tor and hisinven-torian who devised various innovative

mechanisms, including a type of dynamo, and who

was granted a first patent for a cinematic camera in

the late 1880s Connon worked together with

Rudolph Stirn, a German inventor, to develop

pan-oramic technology Connon's innovative camera

could photograph a continuous image, without seams,

while rotating 360 degrees (a similar camera was

pat-ented by M Garella in England in 1857 but the

au-thor wasn't able to determine ifthe earlier camera was

seamless) See panoramic camera

Sampling of Standardized Connectors

A variety ofcommon, standardized computer, phone, and video connectors.

1 9- to IS-pin D-shaped computer data adapter

2 25-pin D-shaped null modem data adapter

3 RJ-II phone line splitter/joiner

4 and 5 stereo sound adapters

6 and 7 coax F and BNC video adapters I

8 RCA video/audio splitter/joiner

9 RCA video/audio cross connector

A selection of video and data connectors, oriented

to show the connecting pins.

1 6-pin mini-DIN computer connector

2 RJ-45 1OBase-T computer network connector

3 video BNC coaxial cable connector

4 audio or composite video RCA connector

5 Super-VHS (S-Video) video connector

6 SCSI-2 50-pin computer data connector

7 25-pin D-shaped computer data connector

8 50-pin flat SCSI data connector

Conrad, Frank (1874-1941)AnAmerican broad-caster who began as callsign 8XK in his Pennsylva-nia garage, which was later licensed as the history-making KDKA radio broadcast station Conrad was also an avid inventor, with dozens of patents to his credit His interests ranged from telegraphy to mov-ing picture technologies In 1919, he patented a ra-diotelegraph device (U.S #1,314,789), followedby

a wireless telephone (#1,528,047) in 1925 By the late 1920s, Conrad was designing various types of tele-phones, and in the mid-1930s his interests turned to television and motion picture electronics The Frank Conrad Garage (where it all began) is an official pres-ervation project of the Save America's Treasures ef-fort See KDKA

consecutive Continued presentation ofobjects, data,

or actions one after the other; successive, sequential,

•

Fiber Optics Illustrated Dictionary

following A distinction may be made between

sequential and consecutive in that sequential implies

that there are no gaps between succeeding steps,

whereas consecutive implies there may be gaps or

de-lays in successive presentations, depending upon the

nature of the information of actions For example, it

would not be unusual to say a person was working

on the computer on consecutive weekends, but the

phrase "sequential weekends" would not normally be

used, as there is a weekday gap between each

week-end Sequential events are always consecutive, but

consecutive events are not always sequential If this

is confusing, think of the fact that a square is always

a rectangle, but a rectangle is not always a square

See concurrent, parallel, sequential, serial

Consent Decree, DellA late 1990s judicial decree

barring Dell Computer Corporation from

telemarketing computer systems bundled with

soft-ware that wasn't ready to ship The proceeding was

important because software was relatively new and

established legal protections were still being worked

out for new technologies In this case, Dell promoted

the Dell Software Suite as being bundled with

Dimen-sion computer systems Consumers on the whole

re-ceived the system without software and were not

of-fered the opportunity to consent to the delay or

can-cel orders for a prompt refund The Federal

Commu-nications Commission (FCC) charged that Dell

vio-lated the Mail Order Rule

Since Dell is considered a major personal computer

vendor, and vendors are focused on being

first-to-market (which can be influenced by the readiness

level of the software), this ruling can potentially

af-fect many communications technology vendors, as

they increasingly rely on software operating systems

and utilities to promote their hardware products

Consent Decree, MCI and British TelecomA 1994

decree in which British Telecom's acquisition of an

interest in MCI Gointly called Concert

Communica-tions Corporation) were addressed as to the

competi-tive effects ofthe merger A modified decree was

en-tered into in 1997, as a result of British Telecom's

plans to acquire the remaining assets ofMCI When

British Telecom sold its interest in MCI to WorldCom,

and MCI sold Concert Communications Corporation

to British Telecom, a motion to terminate the consent

decree was tendered in 1998

Consent Decree, MicrosoftA 1995 decree with a

78-month duration involving Microsoft Corporation

Microsoft is a significant software vendor alleged by

a number of competing vendors as engaging in

mo-nopolistic and unfair business practices In this

de-cree, Microsoft was enjoined not to enter into license

agreements for operating system-related products

with a duration exceeding one year and license

agree-ments which would restrict OEMs from licensing,

selling, or distributing non-Microsoft operating

sys-tem software products In later competition for

mar-ket dominance ofWeb browser software, the antitrust

division ofthe Justice Department alleged that

Micro-soft was not keeping to the terms of the previous

agreements The result was a long and complex

anti-trust investigation against Microsoft in the late 1990s continuing into the 2000s

Consent Decree, SprintA decree in 2000 between the Federal Communications Commission (FCC) and Sprint Communications Company, LP, regarding the illegal practice ofslamming -switching consumers' long-distance telephone services without their con-sent Sprint voluntarily notified the FCC of the prac-tice, after a number ofslamming enforcement actions taken earlier the same year by the FCC against other companies, and agreed to a voluntary monetary con-tribution in addition to returning consumers to their preselected carriers, terminating the agents involved, and implementing a stronger slamming prevention and detection program in the firm

Slamming was not a new problem at the time In an earlier consent decree in 1996, MCI agreed to vol-untary contributions for slamming, indicating that the practice and the problems of its enforcement are longstanding

Consent Decree of 1956A historic agreement be-tween the Justice Department and American Tele-phone and Telegraph (AT&T) to separate Northern Electric (later Northern Telecom) from Western Elec-tric In spite of the limited settlement, the Federal Communications Commission (FCC) received many complaints from manufacturers over the next two decades about AT&T refusing to buy or refusing to permit their subscribers to buy new improved tele-phone technologies This situation lead to the Con-sent Decree of 1982

Consent Decree of 1982A landmark historic pro-ceeding, this consent decree involved the divestiture ofAT&T that took place in the mid-1980s under the direction ofJudge Greene It is now more commonly known as the Modified Final Judgment (MFJ), since

itwas a modification ofthe Consent Decree of 1956 See Modified Final Judgment for a fuller description console1 Floor-standing cabinet, typically holding consumer broadcast receivers (radio, TV) 2 A pri-mary operations physical unit that holds main elec-tronic controls and monitors (such as lab equipment, medical monitors, industrial plant operations equip-ment, etc.)

console, computer operationsAcomputer terminal for monitoring/controlling computer operations, printers, etc On a secure network, the operating con-sole is often password-protected to control access and may even be locked in a separate room to prevent access or physical theft The main server sometimes serves also as the console, although on larger systems the server and the console may be separate systems console, telephoneA primary multiline telephone unit used by an operator to answer and route calls (a replacement for the old physical cord-and-stereo-jack-style switchboards) These come in a wide va-riety of configurations Some are programmable by entering letters, features, and numbers through the keypad, which may further be displayed on a small character display See PBX

consoleless operationAutomated operations or rout-ing, an option for companies whose needs are simple

without the expertise ofan operator See PBX.

Consortium for Audiographics Teleconferencing

StandardsCATS Anonprofit organization, based in

California, that promotes acceptance and

develop-ment of audiographics teleconferencing standards

Audiographics teleconferencing in its ideal form is

the simultaneous realtime use of images and sound,

in a cooperative environment, by participants in

dif-ferent locations

constant angular velocityCAV A playback mode

for magnetic and optical discs in which the disc

ro-tates at a constant speed A CAV disc generally

re-quires more space on the disc to hold the same

infor-mation as can be stored on a constant linear velocity

(CLV) disc, but CAV format has the advantage of

providing frames that can be viewed individually in

'freeze frame' mode as still images See constant

lin-ear velocity

constant bit rateCBR InATM networks, a cell rate

traffic flow class of service (CoS) category that

sup-ports a constant or guaranteed rate of transport, and

circuit emulation Constant bit rates are important for

types of communications that require

synchroniza-tion ofsignals at the receiving end For example,

syn-chronization ofsound and audio in a

videoconferenc-ing application is important, as unacceptable delays

might occur ifrelated cells are not arriving at the same

time See cell rate

constellation 1 A group related by proximity and

physical or conceptual connectivity (such as

work-stations, celestial bodies) 2 In GPS, the set of

satel-lites used in a position calculation or all the satelsatel-lites

within communications range of a GPS receiver at a

specific time See Global Positioning Service

Constellation Communications, Inc.AU.S.-based

commercial provider ofsatellite communications

ser-vices Constellation is developing a low Earth orbit

(LEO) system comprising 46 satellites called the

ARIES satellite system Eleven ARIES satellites will

be placed in circular equatorial orbits at 2000

kilo-meters, and 35 will be divided into seven circular

in-clined orbits at the same altitude

consultTo seek advice, opinion, or information from

reference materials, or from another person,

presum-ably with expertise in the area of inquiry

consultantProfessional or other expert offering

ad-vice or infonnation serad-vices, usually specialized

Consultation HoldA surcharge phone service or

multiline subscriber service that enables the

opera-tor to put an incoming call on hold while engaged in

another call

Consultative Committee Telecommunications

CCT A three-nation industry trade association that

promotes trade expansion and the evolution of

tele-communications equipment and services within

NAFTA and North and South America The CCT

rep-resents more than 50 industry telecommunications

equipment and services suppliers, as well as

regula-tory and certification agencies CCT liaises with

CITEL and serves as industry advisor to the NAFTA

Telecommunications Standards Subcommittee

sory CommitteeC/DTAC ACommittee ofbusiness, academic, public, disability, and minority represen-tatives established by the Federal Communications Commission (FCC) in November 2000 under the pro-visions ofthe Federal Advisory Committee Act Three

working groups focus on Consumer Protection and Education, Access by People with Disabilities, and Availability andAffordability ofTelecommunications Products and Services.

C/DTAC frrst met in an open meeting in March 2001

to discuss the telecommunications needs ofconsum-ers and various undofconsum-erserved populations, with the meeting set up to be broadcast on the Internet http://www.fcc.gov/cib/cdtac

contactA point in a circuit, usually at a junction, binding post, or terminal, where other parts ofthe cir-cuit interconnect or are attached

contentionCompetition for the same space or re-sources; disagreement over the allocation ofresources with the implication that each ofthe disagreeing par-ties has some desire for or stake in the resources Contention can be a problem on systems where the demand for resources outstrips supply, especially if there is no mechanism for resolving contention, but contention is not always unexpected or undesirable

On networks, there is constant contention for re-sources, including computing power, routes, Internet access, printers, monitors, scanners, and modems This is considered part of the normal operation of a network and is managed by a variety of strategies, including prioritization, overflow handling, buffer-ing, pollbuffer-ing, queubuffer-ing, batch processbuffer-ing, packet rerout-ing, and timeouts

Inboth linear and parallel processing systems, dif-ferent resources may be assigned to difdif-ferent servers

or groups ofsystems to prevent contention delays and facilitate arbitration of limited resources

Contention mechanisms may be deliberately initiated

in situations where there are multiple backup systems For example, if a printer on a network fails, the re-maining printers may compete for permission to com-plete the task and the original printer may stand down (or not participate at all if it has failed or been dis-connected) See queue, queuing theory

continuation of messageCOM In AIM networks,

a status indicator used in the asynchronous transfer mode (AIM) adaptation layer (ATM AL or AAL) to indicate that the cell is a continuation of a communi-cation that has been segmented, that is, broken up and sent in different sections, sometimes over different pathways See asynchronous transfer mode Continuous Redial Asubscriber surcharge or bundled telephone service that enables the caller to redial a number that was found to be busy while mak-ing or receivmak-ing other calls If a number is busy, the caller hangs up and dials *66 (in N.A.) The phone service will continue to try to connect with the busy number for up to 30 minutes Ifthe call connects, the caller is notified with a distinctive ring and can pick

up the phone and take the call Dialing *86 will ter-minate the continuous redial