Fiber Optics Illustrated Dictionary - Part 13 pot

Fiber Optics Illustrated DictionaryWhile the invention ofthe telephone was not as revo-lutionary as the telegraph in technical terms, it was a highly significant, culture-changing evolut

Fiber Optics Illustrated Dictionary

While the invention ofthe telephone was not as

revo-lutionary as the telegraph in technical terms, it was a

highly significant, culture-changing evolutionary step

that personalized distance communications and

facili-tated commerce in ways not previously possible See

audiometer; Bell System; Berliner, Emil; Edison,

Thomas Alva; Gray, Elisha; Meucci, Antonia; Reis,

Philip; Photophone; telephone history

Bell asynchronous standards Aseries of full duplex

standards developed by AT&T These were widely

supported by other manufacturers in the late 1970s

and early-/mid-1980s Other vendors and standards

bodies began competing with the Bell standards, most

notably Hayes, in the early 1980s The V Series

Recommendations by the ITU-T are now the

domi-nant formats Some Bell standards are shown in the

Bell Serial Communications Standards chart

BelJ Atlantic A holding company created as a result

of the AT&T divestiture in the mid-1980s See Bell

Operating Company

Bell Canada, Bell Telephone Company of Canada

The Canadian arm ofthe Bell system until the 1970s,

when it became separated from the U.S Bell system

Bell Canada was a member of the Stentor

Consor-tium, along with BC Tel Ltd., SaskTel, and others

As companies merged and were bought out, the

Sten-tor alliance dissolved and Bell became mainly

fo-cused on the provinces of Ontario and Quebec Bell

is the major telecommunications carrier and supplier

of telecommunications equipment in Canada

Through mergers, BCT.TELUS Communications

Inc became the second largest telecommunications

company in Canada

In 1997, Bell Canada and TELUS Cable Holdings

Inc both applied to the CRTC for broadcast distri-bution licenses to conduct trials of broadcasting ser-vices, while distributing telecommunications services over the same digital networks In 1999, both Bell and TELUS testified on issues of promoting elec-tronic commerce by protecting personal information related to Bill C-54

Bell Canada Relay Service BCRS A 24-hour ser-vice that allows TTY users, who may be hearing im-paired, to talk to one another or to a hearing person with the help of specially trained operators translat-ing through teletypewriter terminals The TTY equip-ment can signal up to 60 words per minute

As an example of the service, the subscriber calls the BCRS operator and provides his or her name and number and the number of the person to be called The operator requests billing information and then places the call The operator then acts as a translator, conveying a text message by voice to the hearing callee, and a voice message by text to the hearing-impaired caller

The call is kept confidential by the operator, and no record of the conversation is retained BCRS services are billed at the same rate as normal phone charges Bell Communications Research Bellcore.An orga-nization established as a result of the AT&T divesti-ture to provide a variety of central administration, training, standards, documentation, and quality ser-vices to the regional Bell companies who fund Bellcore and their subsidiaries.Itis roughly equiva-lent to the Central Services portion of the pre-dives-titure AT&T organization

Bell Laboratories, Bell Telephone Laboratory, Bell Labs The research arm of the Bell system responsible

Bell Serial Communications Standards

Bell 103 300 Asynchronous full duplex communications standard for transmitting

at speeds up to 300 bps over publicly switched telephone networks (PSTNs) This standard was commonly used with computer modems

in the late 1970s, but was superseded by Bell 212 in the early 1980s Bell 212 1200 An AT&T asynchronous full duplex communications standard for

transmitting at speeds up to 1200 bps over publicly switched telephone networks (PSTNs) This standard was commonly used with computer modems in the early 1980s, but was superseded by Bell 20 I in the mid-1980s

Bell 201 2400 Asynchronous full duplex conmmnicalions standard for transmitting

at speeds up to 2400 bps over publicly switched telephone networks (PSTNs) This standard was commonly used with computer modems

in the mid-1980s Many other vendors began entering the modem manufacturing/standards industry at this time

Bell 208 4800 Asynchronous full duplex communications standard for transmitting

at speeds up to 4800 bps over publicly switched telephone networks (PSTNs) This standard did not particularly catch on in consumer markets Many users leapfrogged from 2400 bps to 9600 bps as vendor participation and competition for faster speeds increased in the mid-1980s

ofthousands oftelecommunications technologies and

devices over the decades The labs were established

as a combined effort of the Western Electric

Com-pany and the AT&T engineering departments in 1907

Itgrew to be the largest industrial research

organiza-tion in the U.S., and, in 1925, the engineering

depart-ment of Western Electric was incorporated as Bell

Laboratories, with the head office in New York City

In 1941, headquarters were moved to Murray Hill,

New Jersey and larger plants were later established

in Denver and Atlanta Smaller field stations and

sat-ellite labs were regularly established over the years

in many parts of the U.S In 1934, AT&T's research

division was merged into Bell Laboratories

Bell Labs MuseumAnonline resource sponsored by

Lucent Technologies You can visit the images and

historical references at the Bell Labs Museum Web

site http://www.lucent.com/museum/

Bell Operating CompanyBOC This is defined in

the Telecommunications Act of 1996 and published

by the Federal Communications Commission (FCC),

as

" any ofthe following companies: Bell Telephone

Company ofNevada, Illinois Bell Telephone

Com-pany, Indiana Bell Telephone ComCom-pany,

Incorpo-rated, Michigan Bell Telephone Company, New

England Telephone and Telegraph Company, New

Jersey Bell Telephone Company, New York

Tele-phone Company, U S West Communications

Com-pany, South Central Bell Telephone ComCom-pany,

Southern Bell Telephone and Telegraph Company,

Southwestern Bell Telephone Company, The Bell

Telephone Company of Pennsylvania, The

Chesa-peake and Potomac Telephone Company, The

Chesapeake and Potomac Telephone Company of

Maryland, The Chesapeake and Potomac Telephone

Company ofVrrginia, The Chesapeake and Potomac

Telephone Company ofWest Vrrginia, The Diamond

State Telephone Company, The Ohio Bell Telephone

Company, The Pacific Telephone and Telegraph

Company, or Wisconsin Telephone Company; and

(B) includes any successor or assign of any

such company that provides wireline

tele-phone exchange service; but

(C) does not include an affiliate of any such

company, other than an affiliate described

in subparagraph (A) or (B)."

See Federal Communications Commission,

Telecom-munications Act of 1996

Bell speakcolloq.Aphrase to describe the

substan-tial body of telephone jargon that grew up over the

decades within the Bell system, particularly among

technicians and scientific researchers

Bell SystemThe original holders of the Bell

tele-phone patents formed by Bell, Sanders, and Hubbard

in 1877, and incorporated in 1878, less than 15 years

after the invention of the telephone The company

thrived and grew under the management ofTheodore

N Vail Since the term of exclusivity granted by a

patent lasted only 17 years, the expiry ofthe Bell

pat-dependent phone companies These gradually were merged and consolidated into the Bell System.Ina

1984 court decision, divestiture of the American Telephone and Telegraph company (AT&T) removed the distinction between the Bell company and inde-pendent phone companies

Bell Telephone Company of Canada Inc Estab-lished in 1880, Bell Canada began by providing ser-vice to the larger centers in eastern Canada, most of which were interconnected within about 10 years Bell Canada is under the jurisdiction ofthe Canadian Radio Television and Telecommunications Commis-sion (CRTC)

Bell Telephonic ExchangeThe first telephone ex-change in Ohio State

BellcoreSee Bell Communications Research Bellingham Antique Radio MuseumSeeAmerican Radio Museum

BellSouth CorporationA large regional holding company created as a result of the AT&T divestiture

in the mid-1980s It is comprised of Southern Bell Telephone and South Central Bell Telephone Com-pany and a number of other companies BellSouth is cooperating with Nippon Telegraph and Telephone

to provide large-scale integration ofresidential fiber multimedia telecommunications services See Bell Operating Company, fiber to the home

benchmark1 Aspecified expression ofperformance based on agreed-upon test criteria 2 A criterion ex-pression, often numeric, against which other systems

or processes are compared Benchmarks are so sys-tem specific that it is hard to translate benchmark per-formance scores to real-life computing situations, and their validity is often hotly contested See benchmark test

benchmark testA criterion test for evaluating the performance of a system, often applied to the speed

of processing Although benchmark tests may be straightforward for simple electronic components, they are sometimes used to evaluate the system per-formance of complex systems, which is difficult to measure in objective units For example, a computer with a 40-MHz CPU will perform more slowly on benchmark tests than a 200 MHz RISC chip CPU, yet aword processor running on one system may have the same apparent speed to the user as one running

on a faster system due to many factors such as load

on the system, user interaction, software optimiza-tion, address bus bottlenecks, amount and type of memory, etc Ina broad sense, benchmarks cannot

be said to provide definitive performance measures, but they are nevertheless often established as a best-efforts way of comparing and contrasting systems with significantly different construction and charac-teristics Even these are often considered "better than nothing" performance indicators See Dhrystone, Rhealstone, Whetstone

bend lossIncabling, attenuation caused by bends and twists in the wires or fibers At each bend there is a tendency, especially in optical fibers, for the signal

to want to continue to radiate in the same direction,

Fiber Optics Illustrated Dictionary

resulting in slight losses through the cladding as the

cable curves See Bend Factors diagram

bend radius In cabling and cabling enclosures, a

description of the bend tolerance ofa certain material

at a certain radius, often under a certain pulling force

This measure is important for manufacturing, for

se-lecting types and sizes ofparts, and for installing

pul-leys, cables, and wires See bend loss

bend-insensitive fiber Fiber optic cable that is

par-ticularly resistant to losses when the fiber is bent

Bend-insensitive fibers were first being developed

and described in the late 1980s

There are various ways to reduce bend-induced loss

in optical fibers The materials, diameter and ratio of

core to cladding, and the numerical aperture can all

influence sensitivity to bend losses For example,

in-creasing the numerical aperture (e.g., NA= 0.16 for

single-mode fiber) can confine the reflected light

more tightly within the conducting core, producing

a more bend-insensitive fiber

Benedicks, MansonAnAmerican researcher who

investigated the electromagnetic-influencing

proper-ties of germanium crystals in the early 1900s and

found that they could be used to convert alternating

current (AC) to direct current (DC)

Benjamin Franklin Instituteof GlobalEducation

A resource and Web center that supports and

pro-motes affordable access to education from global

re-sources through distance education, founded in the

mid-1990s by John Hibbs http://www.bfranklin.edul

bent pipe A description for a communications

con-duit, path, or transmissions medium that reflects an incoming signal at an angle, usually between 20 and

70 degrees, thus following a path that resembles a bent pipe This is a very common configuration for Earth-satellite/satellite-Earth transmissions and for radio transmissions which are channeled by being bounced off the ionosphere

Benton FoundationAnorganization established in

1948 that has promoted diverse and equitable public use of communications technologies for its social benefits since 1981.Itis named after its founder, William Benton (1900-1973), a U.S Senator, UNESCO Ambassador, and publisher of the Ency-clopedia Britannica The Benton Foundation provides news on communications policy and the social use

of technologies; it supports a number of free online newsletters and discussion lists The Foundation op-erates from an endowment along with additional funding from major communications industry ven-dors and philanthropical organizations See Commu-nications Policy Project

BeDS An object-oriented, multitasking, fast,

nonlegacy, microcomputer operating system devel-oped by Be, Inc., under the leadership of Jean-Louis Gassee Programmers claim it is a pleasure to pro-gram and that the environment is powerful and yet easier to learn and use than many others

Bend Factors in Fiber Optic Lightguides

Light is guided thlVugh a fiber optiC cable thlVugh a process called total internal reflection (TIR) in which the outer cladding which has a different refi'active indexfi'om the inlier conducting core (in this case, a multimodefibel), reflects the light beam back into the core This plVcess continues even if the fiber is bent to some extent, which is very useful for network cable installation alld fiber optic plVbes for scielltific or medical purposes However, there are limits to how much a cable call be bent without bend-induced loss ofsignal.

In the diagram above, the amount ofloss ill the bend depends upon the bend radius, the relationship ofthe core to the claddillg in tenns ofsize and refractive index, and the allgle at which the beams encounter the cladding Ifa light beam (A) passes the maximum point of bend, it may continue on thlVugh the lightguide In contrast, a beam (B) traveling at a different angle such that it hits the cladding at the bend, beyond the critical angle at which it,can be reflected back into thefiber, would be partly absorbed by the cladding and by any materials outside the cladding and would be lost as far as the fiber core is concerned Commercial mamifacturers design certain cables to minimize bend loss, by balancing cable parameters Thus, bend-insensitive cables often have a higher numerical aperture.

to R&D at Apple Computer, when the Apple II line

was being developed BeDS is aimed at multimedia

audio and visual applications

BeDS was introduced to developers late in 1995 along

with the Be computer About a year later, Be, Inc

dis-continued the hardware, to concentrate on software

development, as their operating system software is

able to run on several hardware platforms by various

vendors See Be, Inc

BEP 1 See back end processor 2 Bureau

Economique de la Province de Namur 3 Bureau of

Engraving and Printing (Federal) 4 Business Enterprise

Program (for minorities and handicapped workers)

BER 1 See Basic Encoding Rules 2 See bit error rate

Berkeley, Edmund Callis(1909-1988) An

Ameri-can educator and pioneer computer developer who

worked on the Mark II construction project in 1942

and developed a lifelong interest in computer

appli-cations Berkeley founded the Eastern Association for

Computing Machinery in 1947, which became the

respected Association for Computing Machinery

(ACM) the following year

In 1948, Berkeley started his own company,

Berke-ley Associates, to market his inventions He authored

many books foreshadowing computer and

telecom-munications history In 1949, Great Brains, Or,

Ma-chines That Thinkwas released with instructions on

how to design computing devices In 1950,

Berke-ley published Computers and Automation, a historic

computing magazine In 1956, he coauthored

Com-puters, Their Operation and Applicationswith L

Wainwright And, in 1959, he authored Symbolic

Logic and Intelligent Machines.

Following up on the ideas in Great Brains, Berkeley

described and constructed one ofthe first desktop

mi-crocomputers that became generally known through

popular publications The Simon (named after

"Simple Simon") was made public in an electronics

magazine in 1950 (as construction plans) Berkeley

was also actively interested in the design and

con-struction ofsmall robots (quite prolific, in fact), which

he marketed through Berkeley Enterprises, Inc

(originally Berkeley Associates)

Berkeley sought to bring computing concepts to

hob-byists through the GENIAC computing device

Un-fortunately, after disputes with his business partners,

Berkeley lost the legal right to use the name, so he

gave the name Brainiac to essentially the same

tech-nology and his former business partner used the

Geniac name to market tube-shaped calculators

The archival legacy of Edmund Berkeley from 1923

to 1988 has been donated to the Charles Babbage

in-stitute by Berkeley Enterprises, Inc and the

Berke-ley family See Brainiac, Charles Babbage Institute,

GENIAC, Simon

Berkeley Internet Name DomainBIND A

popu-lar implementation of the Internet domain name

ser-vice (DNS) originally developed and distributed by

the University of California in Berkeley There have

been numerous commercial implementations of

BIND As of2001, BIND 4.9.8 (for older systems),

on the Internet as free software However, the pur-chase of support contracts aids in the continued de-velopment of the Internet Software Consortium's

~~~:r~~!~:~=~:~~~~~~~Fty~ef:~a1974, adapted to the Digital VAX and PDP-II, andr:.

now widely ported to many systems BSD was fur-ther developed by Bill Joy and ofur-thers at the Univer-sity ofCalifornia in Berkeley, who released it in 1978

Joy subsequently wrote the well-known vi editor, and

co-founded Sun Microsystems

BSD flourished with the development of the ARPA-NET, the forerunner to the Internet, and the Computer Systems Research Group (CSRG) enhanced BSD with 32-bit addressing, virtual memory, and a fast file system supporting long filenames They further in-troduced BSD Lite which was BSD without the li-censed AT&T code, which could be freely distributed

The CSRG disbanded in 1992, and the community

at large adopted BSD and developed FreeBSD See FreeBSD, Unix, UNIX

Berliner, EmU(later Emile) (1851-1929) AGerman-born American/Canadian inventor and musician who was keenly interested in acoustics, electricity, and physics as telephone technology began to emerge

Berliner is best known for music technologies, but also made some significant contributions to historic telephone technology In April 1877, he filed a ca-veat for a patent on a telephone transmitter and six months later is reported to have demonstrated sev-eral telephone devices at the Smithsonian Institution

In 1878, he received a patent for a transfonner Ber-liner joined the Bell Company and later founded Deutsche Grammophon and Gramophone Co., Ltd

F Barraud's painting of a dog listening to a gramophone (trademarked "His Master's Voice") became the popular "Nipper and the Gramophone"

trademark registered May 1900 by Berliner RCA adopted the popular symbol, which is still recognized more than 100 years later Berliner also founded the Esther Berliner fellowship to support women pursu-ing scientific research See Gramophone

Berners-Lee, Tim(1955- ) A British physicist and programmer, Berners-Lee gained a spot in the his-tory books with his Web project proposal introduced

in March 1989, and his demonstration ofWorld Wide Web software in the winter of 1989 The rapid accep-tance and growth ofthe Web is a tribute to the viabil-ity of this concept Prior to that, Berners-Lee devel-oped Enquire, while at CERN in 1980, a hypertext system that no doubt formed the seed for his Web project In 1994, he joined the Laboratory for Com-puter Science at MIT He has won many awards of distinction for his work, including the 1998 MacArthur Fellowship He is the coauthor, with Mark

Fischetti, of Weaving the Web, a book about the

ori-gins and development of the World Wide Web See World Wide Web

Bernoulli, Daniel (1700-1782) Bernoulli was a Swiss mathematician born in the Netherlands, who

Fiber Optics Illustrated Dictionary

pioneered the principles offluid dynamics, now used

broadly in aeronautics, electronics, and other fields

The Bernoulli principle is derived from his writings

in Hydrodynamica which described basic properties

of fluid pressure, density, and flow

Bernoulli box Anelectronic, high-speed data mass

storage and retrieval device based upon technology

pioneered by Daniel Bernoulli.Ingeneral, the

Ber-noulli effectoccurs as pressure acts upon a fluid

me-dium in relation to the volume of the fluid These

forces will equal changes in kinetic energy

associ-ated with the fluid (whether liquid or gaseous) In

general, as fluid flow slows, pressure increases, and

vice versa As applied to storage technology,

in-creased rotational speed in a magnetic disk creates a

cushion of air that controls the distance of the read!

write head from the storage medium

Daniel Bernoulli

One of the earlier removable computer storage

media, called Bernoulli drives, were named after

Daniel Bernoulli, a mathematician.

Bernoulli-Euler lawIn a homogenous bar, the

cur-vature of its central fiber is proportional to the

bend-ing movement It is a general concept, applicable to

many fields including elastic theory and mechanical

engineering

Bernoulli's Theorem in a Field of FlowAt every

point in a steadily flowing fluid, the sum ofthe

pres-sure head, the velocity head, and the height is

con-stant

Berry, Clifford Edward(1918-1963)Anintelligent

and mechanically gifted American who collaborated

withJ.V Atanasoff in the development ofone of the

world's first digital computers Atanasoff and Berry

began working together on the project soon after

Berry completed his Bachelor's degree in electrical

engineering The completion ofa prototype computer

led to a small grant to build a working version, in

December 1939, while Berry continued his graduate

studies Berry then subsequently worked in corporate

positions and applied for more than 40 patents in the

areas of spectrometry and electronics, 30 of which had been granted before his untimely death See Atanasoff-Berry computer

BERTbit error rate test/tester; block error rate test! tester A diagnostic device that is used to test data in-tegrity by transmitting a known pattern of bits and evaluating the subsequent bit error rate (BER), usu-ally on a cable segment See bit error rate

BERTSSee Basic Exchange Radio Telecommuni-cations Service

bespoken, bespokeCustom-made, made to order, made by engagement, requested item

Bessel beamAnondiffracting optical beam, a recent technology that began showing some exciting prac-tical results by the end of the 1990s The potential for infinitely propagating beams for manipulating particles or transmitting information are exciting new fields of experimentation

By 2001, U.K researchers had demonstrated Bessel beam "tweezers" for manipulating, stacking, and aligning a variety of silica and biological structures The linear momentum oflight and its interaction with matter were exploited to trap particles They also demonstrated the use of a laser beam as an optical particle guide, moving 1 Ilm spheres upward within the microscope slide medium within which the par-ticles were held.Inaddition to applications in biol-ogy and medical imaging, this technolbiol-ogy may have significant practical applications in optical fiber-based telecommunications

Bessel beams can be generated with a glass element called an axicon See acousto-optic deflector, axicon, laser

Best Current PracticeBCP Aprocess similar to the Internet Standards process, in that specifications are submitted to the IESG for review, but streamlined to provide industry leaders with a more flexible, and often quicker, consensual alternative to the Standards Track specifications for resolving individual policy and operations issues See Internet Standards process Best EffortSee available bit rate

Best Effort CapabilityAcapability offered on some ATM networks that tries to provide transmission but provides no guarantees ofthroughput Might be used between two routers, for example See ATM traffic descriptor, RFC 1633

beta1 In electronics, the current gain of a bipolar transistor in a grounded-emitter amplifier 2 A ver-sion ofsoftware that is mostly complete, has been in-house tested, but requires wider input and trials from testers and users outside the company See beta test

3 (symb - B) quartz 4 (symb.-~)The second let-ter in the Greek alphabet, sometimes used to denote

a specific angle in a geometric diagram

BETABusiness Equipment Trade Association Arep-resentative for many ofthe large hardware manufac-turers in the computing industry

beta siteA location or group ofpeople designated to test and use a piece of nearly completed, internally tested software in working conditions more nearly like those in which the software will eventually be used

ing a nearly complete software or hardware product

to try to detennine if there are still bugs or problems

ofusability, consistency, continuity, and ergonomics

Beta testing can take months or years, depending

upon the state of readiness and the complexity of the

software Some developers use automatedmonkeys,

programs that systematically climb through the

soft-ware, to identify bugs or flow problems.Itis a good

process to use in conjunction with human testing

In the author's experience, as much as 85% of

soft-ware may be commercially introduced without

suf-ficient beta testing Because computing is confusing

to the average user, users are hesitant to complain,

thinking the fault is in their use of the product rather

than the product itself, and sometimes this is true But,

upper managers often insist the product has to ship

(whether it's ready or not) in order to generate

rev-enues to stay in business even though, in most cases,

it's bad economy The cost of testing and correcting

bugs before the product ships is almost always lower

than the cost of repeated patches, upgrades,

techni-cal support, and loss ofbusiness due to consumer

dis-satisfaction when firefighting and corrections are

done after the product ships

Ifcars were sold with the same number of defects as

many software products, consumer rights

organiza-tions would boycott the manufacturers The author

of this dictionary has contributed many hundreds of

hours to beta testing and once found more than 300

bugs in two days of testing in a software product that

the manufacturer insisted was "complete, ready to

ship, and absolutely bug-free." There are responsible

software houses that engage in extensive testing and

quality control, and their efforts should be recognized

and rewarded For those that don't, caveat emptor or

get your money back See alpha testing, gamma

test-ing, upgrade, user acceptance testing

BETRSSee Basic Exchange Telecommunications

Radio Service

beyond visual rangeBVR Something that is

out-side human sight, or in some contexts, out of sight of

human vision with binoculars.Ina very general sense,

itcan mean something distant or obstructed In

tele-communications contexts it is more often used to

in-dicate objects, communications means, or antennas

that require 'line of sight' distances or unimpeded

pathways to be effective See line of sight

bezelThe rim or edge ofa tool or piece ofequipment,

often angled or sloped On a computer monitor, the

housing edge around the cathode-ray tube

BFASee Brocade Fabric Aware program

BFI 1 See Bad Frame Indicator 2 See British Film

Institute 3 Buckminster Fuller Institute

BFOSee beat frequency oscillator

BFOC, bayonet FOC bayonet fiber optic

connec-tor A quick-connect device without a screw thread

BFTSee binary file transfer

BG, BGNDbackground

BGP 1 See Border Gateway Protocol 2 See

Byz-antine Generals problem

BHLISee Broadband High Layer Information

of outlook 2 Deviation from expected value, sys-tematic error 3 In an electron tube, the fixed volt-age that is applied between the control grid and the cathode

bias distortionInconsistencies or aberrations in the linearity of a signal In finely tuned equipment, bias distortion is usually an undesirable property bias stabilizationA means of controlling the bias in

a circuit so that it does not fluctuate Heat or signal variations can throw offbias, resulting in damage to components See bias, bias distortion

biasingTo apply a small amount ofpositive or nega-tive stimulus to a circuit, as in an electron tube, to shift it in one direction or the other

BIBSee backward indicator bit

BIBObounded input, bounded output Input and/or output falling between specified values or other boundaries A concept used in linear mathematics theory and calculations andin data networking analy-sis of traffic flow While many models for network traffic are based on unlimited or scalable queues, for the purposes of modeling, testing, or design, it is of-ten practical to establish bounds for input and output BICEPSee bit-interleaved parity

biconical antennaA balanced broadband antenna which resembles a bowtie in the sense thatithas two metal cones mounted in the same axis, that meet at the narrow ends where the feed line is attached The orientation of the assembly affects its polarity It is suitable for transmissions in the VHF range BICSIAnot-for-profit international telecommunica-tions association headquartered in Tampa, Florida There are regional offices in Australia, Brazil, and the U.K.

BICSI provides educational resources, technical pub-lications, and support for cabling distribution design and installation.Itwas originally established in the early 1970s as the Building Industry Consulting Ser-vices, International, but is now formally known as

BleSI: A Telecommunications Association.

http://www.bicsi.org/

BIDbridge identification code See bridge BIDDSSee Base Information Digital Distribution System

BiDibidirectional 1 Capable of communicating in two directions either alternately or simultaneously

2 Oriented or pointing in two directions, as direc-tional antenna components with two main receiving

or transmitting elements

bidirectional reflectance distribution func-tion BRDF A function describing light reflectance from a surface at a given orientation from a source

of illumination incident from a given direction See Lambert's law

bidirectional line-switched ringBLSR Afault-tol-erant topology for SONET that overcomes some of the problems associated with breaks in basic point-to-point ring topologies In most ring topologies a secondary ring is in place, in case of a failure in the primary ring In local area networks, this is a practi-cal solution, but on long-haul phone networks, for

Fiber Optics Illustrated Dictionary

example, it involves the costly installation of a

sec-ondary cable that is rarely used In BLSR, if a failure

occurs, the bidirectional portion of the link is

en-gaged, and the traffic is routed in the opposite

direc-tion around the secdirec-tion that has failed In fiber optic

cables, this is a very fast transition and wouldn't be

noticed by endusers under most conditions

BIDS Broadband Infrastructures for Digital TV and

Multimedia Services.AnACTS project to provide a

comprehensive analysis of future broadband digital

television and interactive multimedia services for

European users BIDS has established a database of

information gathered from interactive digital TV

tri-als and has analyzed a number of case studies See

BBL, BLISS, BONAPARTE, BOURBON,

BROAD-BANDLOOP, BTl, UPGRADE, WOTAN

bifurcated routing A routing technique that splits

data traffic so that it continues through multiple routes

(technically it would be two routes, as bifurcated

means split into two branches)

BIG See broadband integrated gateway

big-endian Stored or transmitted data in that the most

significant bit or byte precedes the least significant

bit or byte Many file incompatibilities between

com-puter systems, in which the file formats are otherwise

almost identical, are due to platform conventions

about whether the data is stored in big-endian or

little-endian form

BIGA Bus Interface Gate Array Technology built

into Cisco Catalyst systems to receive and transmit

frames from packet-switching memory to its MAC

local buffer memory external to the host processor

Bll base information infrastructure The

communi-cations foundation for military establishments

bilateral antenna An antenna whose maximum

transmitting or receiving poles are diametrically

op-posite, that is 1800 apart in a plane

Bildshirmtext[trans! picture screen text] A German

interactive videotext system from the German

Bundespost.It is similar to the French Telecom

Minitel service, except that the German Bundespost

did not provide the terminal free See Minitel

billboard array antenna An antenna array that

re-sembles a billboard in that it uses a large sheet metal

reflector behind the stacked bipole arrays

Billing Account Number BAN An identifier that

enables telephone carriers to bill individual

custom-ers or each ofmultiple accounts belonging to the same

customer

Billing Telephone Number, Billed Telephone

Num-ber BTN.Insome situations, the telephone number

billed may be one of several associated numbers but,

for simplicity, all the calls are billed to one This

sys-tem is sometimes done with extension numbers.In

other situations, the main number used may be

dif-ferent from the number to which the calls are billed,

again, usually to simplify accounting or billing

state-ments

billionInNorth America and France, one thousand

million (109

- 1,000,000,000) In the U.K and parts

of Europe, one million million (1012

-1,000,000,000,000) (It used to be a huge number.)

BINAC Binary Automatic Computer Ajoint project

of1.Mauchly and 1. P Eckert who founded the Eckert-Mauchly Computer Corporation The BINAC was developed under contract with the Northrop Air-craft Corporation, unveiled in 1949, and was histori-cally significant not only as a successortoENIAC but for its ability to store data programmed using C-l 0 code on magnetic tapes rather than on paper tape or punch cards See ENIAC; Hopper, Grace Murray; UNIVAC

binaries, binary files Files that have been compiled

or assembled into machine-readable codes, usually 32-bit executable files, that are inscrutable to most human beings Source code is higher level code (as

in BASIC, C, or Perl) that can more easily be read and modified by a programmer Binary files can be edited directly with a hexadecimal (base 16) editor See attachment

binary, base 2 A system of numeric concepts and numerals representing quantities in terms ofones and zeros with the smaller units on the right Thus, two

in the base 10 decimal system is written as "2." The same quantity expressed in binary is "10" or

"00000010" with the one in the 'twos' position, sec-ond from the right The columns from righttoleft are thought of as the "ones column," "twos column,"

"fours column," "eights column," etc so that a digit

in a specific column indicates the presence or absence

of that amount Thus, the following numeral in bi-nary: 00 II 0 I0 can be transposed to decimal by add-ing its values: 0+0+ 16+8+0+2+0=26

In electronics, binary values can be variously repre-sented by pulses of unequal length, by amplitudes of specified magnitudes, by power on or offconditions,

or by different tones

Because most computers are two-state systems, the binary number system is used for programming and storage of data Thus, zero and one can represent states such asonoroff, yesorno,etc

binary asymmetric channel BAC A concept used

in information theory related to Markov channels As

an example, images can be modeled as binary asym-metric Markov sources for transmission over com-munication channels In mathematical descriptions of the capacity of physical or theoretic structures, the concept of BAC is useful for surface area calcula-tions

binary coded decimal BCD I.A system wherein each decimal digit is coded into a four-bit word 2 A system wherein each octet within an ATM cell has each bit set to one of two allowable states, i.e., one

or zero 3 A system of coding high and low power transmissions For example, BCD is used by the Na-tional Institute of Standards and Technology (NIST)

to represent decimal numbers in order to dissemi-nate time code information At the start of each sec-ond of the 60-kHz broadcast, the carrier power is re-duced 10 dB, putting the leading edge of each nega-tive-going pulse on time To create a binary zero (0), full power is restored 0.2 seconds later Alternately,

to create a binary one (I), full power is restored 0.5 seconds later Position markers are signaled

Binary Phase-Shift Keying

A " " if'i" iA

cyfl!.~*l:"~~l!.~ ,Cl~f+-ercl~

: :

'.&

'~

A wave can be altered in a variety ofways to repre-sent information By using two wave phases, with one ofthe phases shifted by halfcompared to the preced-ing reference wave, it is possiblefor the linear modu-lation ofa wave to represent two values, zero (0) and one(1)which, in turn, can be transmitted in sequences ofpatterns to represent data values (e.g., ASCII char-acters) Note that the length ofthe period and the am-plitude remain the same, only the phase is changed.

Biocomputing Office ProtocolBOP.An Internet transaction protocol for transmitting command line and file data, somewhat analogous to SMTP-POP, but designed specifically to send command-line plus data input file block from the client to the server where it

is analyzed and passed back to the client upon request BOP was developed as an easier way for nontechnical professionals to access biocomputing resources The server designed to implement BOP requests is called

hopper, with SeqPup used as the initial client BOP

can be used with anonymous or password access and provides both deferred and interactive processing modes See bopper

biometricAnobjective measure or representation of

a biological attribute, which may be a physical char-acteristic or the output of certain physical character-istics (e.g., handwriting) In technology applications, biometrics that are specific to an individual, such as fingerprints, iris or retina patterns, brain waves, and voice prints, are of interest for developing access, login, and authentication systems

Fiber optic faceplates are being developed for use as biometric light-guiding surfaces in conjunction with

tool that can be used to convert an 8-bit binary file into a 7-bit ASCII file through run-length encoding,

so that it can be handled by 7-bit systems that may use different protocols but understand ASCII Many email clients use BinHex internally to handle binary attachments to text messages At the receiving end, the file must be converted back to its original fonn before it can be executed or otherwise used as origi-nally intended BinHex is a very widely used appli-cation on many platfonns but is especially prevalent

in Unix and Macintosh environments

binary file transferBFT Binary files are those that

have been translated into a base 2 system to be more

readily used by a computer Binary files cannot be

readily transported over 7-bit systems that typically

use ASCII (or EBCDIC on some older systems)

en-coding unless they are encoded Due to the

encod-ing, binary files cannot be directly read by (most)

humans or directly edited by most text editors,

al-though a hexadecimal editor is sometimes used to

make limited changes to binary files

Binary file transfers are usually accomplished by (1)

encoding the file into ASCII with a utility such as

BinHex, (2) transmitting the file, and (3)

re-encod-ing it at the destination Most email clients now

au-tomatically convert binary file attachments

Multipur-pose Internet Mail Extension (MIME) is one of the

protocols used with mail clients to handle

transpar-ently the encoding and decoding of attached files

binary phase-shift keyingBPSK A type of linear

modulation in which the phase of a constant

ampli-tude carrier signal represents two values through 1800

shift reversals When there is no phase change, a value

of zero (0) is represented, while a phase change

rela-tive to the preceding wave period represents a value

of one (1)

This basic modulation scheme is effective for

ama-teur high-frequency radio transmissions and

LowFER- and MedFER-band operations BPSK is

used in the SLOWBPSK program developed by

Pawel Jalocha The system was updated as PSK31

(phase-shift keying 31 baud) by Peter Martinez to

function over a narrow 160-Hz phase-shift mode

binary signalingSignaling based upon two states,

whether it be digital or analog Binary signaling is a

common fonn ofmodulation with a variety

ofimple-mentations, including arbitrary binary signaling,

syn-chronous binary signaling, antipodal binary

signal-ing (spread spectrum, Manchester), binary

noncoher-ent signaling, binary orthogonal signaling (codewords

placed at orthogonal axes) See binary phase shift

keying

binauralRelated to two sound sources or two sound

receiving sources, as human ears Since humans are

accustomed to using two sound sources to distinguish

the quality and directionality of sound, monaural

music tends to sound somewhat flat Thus, stereo

(binaural) sound systems have evolved to provide a

more natural representation of sound

BIND See Berkeley Internet Name Domain

bind triangleIn an International Business Machines

(ffiM) SNA implementation, a session setup message

sequence

binding postIn electrical installations, a screw

ter-minal with a corresponding nut around which

U-shaped lugs or wrapped wires can be wound and

secured with the nut Sometimes there are two nuts,

close together so the wire can be secured between the

two screws Binding posts tend to be used in

tempo-rary circuits, or in small installations In medium- and

large-scale telephone installations, mounting blocks

and punchdown tools are much faster

Fiber Optics Illustrated Dictionary

detectors/sensors This has good potential for 3D

bio-metric imaging, remote biobio-metric sensing, and larger

sensing/scanning areas See faceplate

BIOSbasic input/output system A system in read

only memory (ROM) on some Intel-based desktop

computers, that supports the central processing unit

(CPU) by supplying access to a variety of

input/out-put devices, such as serial ports, joysticks, monitors,

keyboards, etc.Asthese peripherals are basic to the

functioning ofthe computer, they are frequently used

and loaded from ROM into RAM for fast access as a

system comes online during the powerup sequence

Biot, Jean-Baptiste(1774-1862) A French

profes-sor ofmathematics and astronomy, Biot collaborated

with Arago in studying the refractive properties of

gases, and discovered, in collaboration with Felix

Savart, fundamental relationships in electromagnetic

theory The Royal Society awarded him the Rumford

Medal for his work in the chemical polarization of

light A crater on the moon is named after Biot See

Biot-Savart law

Biot-Savart lawIn electromagnetics, the magnetic

field produced by a current flowing through a

con-ductor may be described as a vector product inversely

related to the distance ofa point in the magnetic field

to the source current It is similar to Coulomb's law

for electrical relationships Using integrals, the

com-putation may be applied to various arrangements of

conducting sources by breaking the system down into

smaller components See Ampere's law, Coulomb's

law, Gauss's law, right-hand rule

BIPSee bit interleaved parity

biphase codingAnetworking bipolar coding scheme

in which clocking information is carried in the

syn-chronous data stream without separate clocking leads

biphase-shift keyingBPSK Asimple type

ofmodu-lation scheme used in digital satellite transmissions

In BPSK, each phase of the carrier wave is shifted

once with each complete cycle, with a shift

indicat-ing the change of the value (from one to zero or zero

to one) See binary phase-shift keying

bipolar1 Having two mutually opposing or

repel-ling forces, characteristics, or viewpoints 2 Having

two poles 3 A circuit with both positive and

tive polarity or alternating between positive and

nega-tive polarity 4 In electronics, a structure prevalent

in integrated circuits (ICs) 5 A device having both

majority and minority carriers 6 Having

electromag-netic characteristics alternating between two poles

7 Atype ofsignaling in digital transmissions in which

a binary value represents a signal amplitude ofeither

polarity, and no value represents zero amplitude

bipolar receiverA type of telephone receiver used

extensively in the Bell System It improved on

ear-lier technology by using new magnetic alloys and

employing a different acoustical system for the

dia-phragm See ring-armature receiver

bipolar signalA signal with two nonzero polarities;

it can represent two states or three states in a binary

coding scheme See bipolar

bipolar transistorAsemiconductor commonly used

in oscillators, switches, and amplifiers

birdie 1 Twittering, squealing, or whistling noise, often high-pitched Birdie is a descriptive term for auditory interference associated with electrical cir-cuits In older analog phone circuits, overloading sometimes caused crosstalk (conversations bleeding into one another) or, more commonly, birdies In amateur radio systems, birdies may result from ra-dio frequency (RF) leakage from nearby devices In studios with both amateur radio and computer equip-ment close together, it may be necessary to power down everything to a skeleton system and gradually add them back in to locate sources of birdies Moni-tors, cables, and unshielded devices are common cul-prits; even a computer keyboard can cause birdies

In circuit boards, birdies may result from improper grounding Homemade or commercial radio fre-quency (RF) sniffers or more sophisticated spectrum analyzers can help locate sources of radio frequency leakage Proper shielding and grounding, line filters, and toroids can help reduce birdies Ifthe birdies can-not be easily eliminated,itmay be necessary to note the frequencies at which they occur and work around them 2 A lightweight cable or wire installation ac-cessory device Once the conduit has been installed for a wiring/cabling installation, a birdie, attached to the wire by a long lead, can be blown with a com-pressed air tool so that it "flies" through the conduit, with the wire subsequently pulled through using the birdie as a lead See pulling eye, snake

birefringentA material with a molecular structure patterned the same along two axes but differently along the third In a light-admitting material, this anisotropic structure will influence properties such

as the index of refraction, which will vary depend-ing upon the angle of incidence of any light that en-counters the substance

Observe a pebble in a bowl of water and one pebble will be visible, a little offset from its actual location The offset is due to theindex ofrefractionof the wa-ter compared to the adjacent air If you look at a pebbIe through a translucent birefringent material, de-pending upon the angle, you may see two pebbles be-cause birefringent materials are doubly refractive Calcium carbonate (CaC03)is an example ofa com-mon natural substance with birefringent properties See anisotropic, Iceland spar, index ofrefraction, re-fraction

birefringent filterA mechanism for filtering wave-lengths using intrinsic birefringent properties ofma-terials used in the filtering component

Birmington Wire Gauge Agauge standard for de-scribing the diameter ofiron wires (nonferrous wires are described with American Wire Gauge) The thin-ner the wire, the higher the number from 1 to20, ex-clusive of the coating See American Wire Gauge bisSecond, update, revision, encore.Inthe V Series Recommendations of the ITU-T related to telecom-munications,hisindicates a second version or update

to a previously numbered standard This was prob-ably substituted for a revision number to prevent con-fusion between the series number and revision level Similarly,terdesignates three, or third

der immediate system.

BISDNSee B-ISDN

BISSIBroadband Inter-Switching System Interface

BISTbuilt-in self-test Testing capabilities included

with a system Many consumer laser printers have test

modes that will create a printout detailing the

oper-ating parameters, settings, status, and problems, if

there are any that can be reported on paper Some of

the newer printers also have LED screens or

Ether-net links so test results can be reported on a built-in

monitor or connected computer system

Bisync(pron. bye-sink) Binary Synchronous

Com-munication Protocol A character-oriented serial

net-work protocol that was developed in the 1960s, at a

time when IBM dominated the network market It is

now mainly supported as a legacy protocol

bisynchronous transmissionAtransmission that can

flow in two directions on the same line or channel,

usually at the same time Traditional wireline

tele-phones are bisynchronous, whereas some types of

radios or intercoms transmit only in one direction, or

in one direction at a time

bitbinary digit A basic unit of digital information

with two (bi-) states Many schemes for signaling

binary states have been developed: on/off(early

tele-graphs), high/low, one or zero (mark or space, data

bits), black/white, dot/dash, etc

bit-interleaved parityBICEP InATM networks, an

error-monitoring method implemented at the

physi-cal (PHY) layer The link overhead contains a check

bit or word for the previous frame to flag errors

bit-orientedData communications that can encode

control information in single-bit data units

bit-oriented protocolBOP In general, a network

control protocol functioning at the data link layer

There are variations on bit-oriented protocols

typi-cally used for synchronous transmissions, including

Synchronous Data Link Control (SDLC), Advanced

Data Communication Control Procedures (ADCCP),

and High Level Data Link Control (HDLC) See

Transparent Bit-Oriented Protocol

bit bucketslangA mythical container into which

unwanted or unused code, email, chad from punch

cards, or other computer information is discarded or

lost Infonnation may also be deliberately discarded

by sending it to the null device (dev/null) bit bucket

See chad, leaky bucket

bit errorA fault condition in which the value of an

individual bit is changed by transmission or data

in-terpretation errors

bit error rateBER Ameasure oftransmission

qual-ity, usually expressed as a ratio of error bits to total

bits received.A high bit error rate does not

necessar-ily result in a faulty transmission Error-detecting and

correcting algorithms are incorporated into most

cur-rent transmissions protocols However, a high BER

may result in slower transmissions, smaller packets,

a higher percentage of retries, and perhaps even the

necessity to connect several times to complete a file

transfer, for example

bit interleaved parityBIP In ArM networking, a

ror performance ofthe link Acheck bit or check word

is sent in the link overhead covering the previous block or frame Bit errors in the payload will be de-tected and may be reported as maintenance

In ATM trunking, when the BFrame is created on in-gress, a BIP is generated and remains until the cell is extracted on egress ofa switch Cells may be dropped ifa BFrame parity error is detected Payload data may

be BIP-checked separately and does not necessarily result in dropped cells

In SONET implementations, distinctions are made between section (BIP-B 1), line (BIP-B2), and path (BIP-B3) overhead, depending upon which part ofthe path is specified Layers are hierarchical in SONET such that ifsection parity is correct, the layers beneath

it should also be correct

BIP is described more fully in Bellcore documents and in ANSI Tl.105 See coding violation

bit lineBL A concept in array-based memory tech-nologies to designate the location of a specific bit, often in conjunction with a word line(WL).The word and bit information may be combined into a binary address to indicate the row and column of an array element, especially in a 20 array

bit pipe1 A generic descriptor for the physical or data transmission line ofa digital circuit Awider pipe

is considered to have more capacity than a narrow pipe or pipeline A bit pipe need not connect sepa-rate devices or systems; a pipe may be established between two processes on one device 2 Atelephone circuit used to transmit digital data packets

bit robbingA process of commandeering bits in a transmission for something other than their usual purpose Extra bits may be robbed to convey signal-ing information, especially ifthe signals are only oc-casionally needed See robbed-bit signaling

bit stuffingSee zero bit insertion

bitmap1 Apoint-by-point digital encoding ofgraph-ics data for transmission, storage, or display The dis-played image does not necessarily reflect the format

of the image file For example, a vector file may be represented as a bitmap or pixmap image on a printer

or computer monitor, or a pixmap file may be con-verted to a continuous tone image when printed to a dye sublimation printer 2 A pixelated image An image (picture or font) represented by discrete dots

on a monochrome display, which is typically white, green, or amber (technically a multicolor image is called apixmaprather than a bitmap) Grayscale im-ages, with varying degrees of intensity on a monitor

or varying sizes of monochromatic dots on a printed page, are often referred to as bitmap images, although they may be closer to pixmaps Abit in computer data does not map directly to a point on the output device (in fact, several bits are usually needed to encode one image point) In the context ofa bitmap, the term bit

is used in its lay meaning to indicate a small amount,

a section, or an individual point of the displayed im-age See raster, pixels, vector