Fiber Optics Illustrated Dictionary - Part 14 pps

Black operations may be used to tap into communications systems to eavesdrop on conversa-tions or data transfers.. The only practical ways to tap into a fiber optic connection are 1 to b

Fiber Optics Illustrated Dictionary

BITNET, BITNET-NJEBecause It's Time

Net-work.Aninternational, cooperative, academic

net-work established in 1981 by Ira H Fuchs (City

Uni-versity of New York) and Greydon Freeman (Yale

University) It began as a cooperative project at the

City University of New York, with Yale as the first

outside connection through a leased telephone line

It ran originally on ffiMmainframes and Digital

VAXes communicating through EBCDIC formats

From there, it spread across the U.s and became

in-ternational when it was joined by the European

Aca-demic and Research Network (EARN) in 1982 A

grant fromffiMin 1984 helped establish support

ser-vices for BITNET in the U.S

BITNET promoted the noncommercial exchange of

research and education information and was

orga-nized as a nonprofit corporation in 1987 By 1991,

BITNET included almost 1500 organizations in 49

countries and for a while was the world's largest

aca-demic network Participation declined thereafter due

to the rapid growth ofthe Internet and BITNET's

in-herent interactivity limitations In the late 1980s, it

was merged with The Computer+Science Network

(CSNET) to form the Corporation for Research and

Educational Networking (CREN) In the end, CREN

recommended to its members that BITNET

depen-dency be tenninated by December 31, 1996 in favor

of other network systems, primarily the Internet

BITNET is based on anffiMcommunications

pro-tocol called Network Job Entry(NJE),which made

it practical to connect mainframe computers through

telephone circuits.Ituses astore-and-forwardsystem

oftransmitting information through nodes on the

sys-tem See Network Job Entry, RELAY, UUCP

BITNICBITNET Network Information Center A

support center for administering BITNET computer

networks initially established with the aid of

fund-ing from ffiM in 1984 After 1987, fundfund-ing was

mem-ber-based and volunteer-supported See BITNET

BITSSee Base Information Transport System

bits per secondbps A very common means of

de-scribing data transmission per second unit oftime A

megabit per second, or Mbps, represents a million bits

per second Common consumer modems operate at

data rates of about 9600 to 28,800 bits per second

T1, fiber lines, and other higher speed protocols and

media can transmit at much higher rates

BIUSee basic information unit

BL1 bilateral Having two sides 2 See bit line

blackIn politics, a designation for secret and/or

clas-sified information or activities The designation has

significant impact on telecommunications in a

num-ber ofways Black operations may be used to tap into

communications systems to eavesdrop on

conversa-tions or data transfers Computing systems designated

for black operations are typically equipped with

spe-cial encryption systems and code-creating keyboards,

wheels, algorithms and other means of encoding

messages or data

Fiber optic connections are favored over electrical

connections for secured cable installations because

it is harder to tap into fiber optic connections without

detection Wired connections can be tapped with sen-sitive instruments that sense emanations from the wire without necessarily touching the wire A fiber optic transmission doesn't emit electromagnetic radiation

in the same way as electrical connections The only practical ways to tap into a fiber optic connection are (1) to bend the filament to cause the light to escape the reflective cladding layer (in which case the loss ofpower ofthe light beams could be detected beyond the point of the tap) or (2) to insert a clandestine tap segment in the link, which would involve temporary disconnection of the existing link (which may trig-ger an alarm), and would require higher technical ex-pertise and much more precise components than a typical copper wire connection See encryption black bodyA theoretical body which absorbs all in-cident light with no reflection and consequently ap-pears black (without light) at all wavelengths Black BoxAregistered trademark ofThe Black Box Corporation of Pittsburgh, PAl

black box1.colloq.A device whose internal work-ings are obscure or obscured That is, the outside may not indicate what is inside, or how it works 2 A de-vice that is used by a lay person without technical knowledge of its construction or functioning 3 A type of clandestine phone interface device used in a central office to gain unauthorized access to phone services by obscuring the fact that a long-distance call had been answered See blue box, red box

black box designA design model for inputs and out-puts which function independently of the various ways the internal components might be configured For example, a converter or transformer for match-ing two types of signals might be specified, with lee-way given to a manufacturer as to the best lee-way to implement and build the hardware itself

black hole1 A theorized invisible (thus perceived

as dark) region in space with a small diameter in re-lation to its intense gravitational field A black hole could perhaps result from the collapse of a massive star, in which the escape velocity equals the speed of light 2.colloq.A fictional area into which things dis-appear when they can't be found, and those looking for them are sure they should be "right there." 3 In networks and computer systems in general, a point

in the transmission link where data went in and ap-parently didn't come out Black hole also refers to a metaphorical repository for lost data Disappearing into a black hole may also be jargonistically de-scribed as disappearing into the ether, into the bit-stream, or into the bit bucket

black levelAreference level on a display device cor-responding to the lowest possible luminance setting, which typically appears as black (the absence of il-lumination), or nearly black, depending upon the characteristics of the display device

black matrix tubeAcathode-ray tube in which black fills the spaces between color phosphors on the in-side front coating of the tube The greater contrast between the lit phosphors and the small surrounding area results in a picture that appears to have crisper, brighter colors

tude modulation, black recording is the correlation

between the maximum power ofthe transmission and

the maximum density of the recording device In

re-cording systems employing frequency modulation,

black recording is the correlation of the lowest

fquency received and the maximum density ofthe

re-cording medium The phrase applies to various wired

and wireless facsimile machines, printers, electronic

photocopiers, etc See black transmission

black transmission,AMInan amplitude-modulated

(AM)image transmission, black means that the

great-est divergence in amplitude in the signal represents

the black tones, and the narrowest divergence

repre-sents the lightest tones (or no tone at all) In white

transmission, the opposite is true

black transmission,FM In a frequency-modulated

(FM) transmission, a black transmission means that

the lowest frequency corresponds to black, and the

highest frequency corresponds to white or no tone;

in a white transmission the opposite relationship is

used Black transmission concepts in general can be

applied to image scanners, facsimile machines,

pho-tocopiers, etc See black recording

blackjackWhen Samuel Morse won a contract from

the u.S Congress in the 1800s to build a telegraph

line from Washington, DC to Baltimore, MD, he

ini-tially tried to install the lines underground, alongside

railroad tracks There were problems with the line,

however, and the wires were subsequently suspended

from poles To this day, millions ofmiles

ofcommu-nications cables are installed on utility poles Since

the poles were subject to weathering, they were

coated with creosote, a preservative derived from coal

tar that came to be called blackjack It is still used to

prevent dry rot and insect infestations

Blake, Francis, Jr.(1850-1913)AnAmerican

inven-tor, physicist, and photographer who became

ap-pointed to the u.S Coast Survey in 1866, Blake was

talented in mathematics and became skilled in

tele-graphy, astronomy, and hydrography Upon leaving

the Coast Survey in 1878, he pursued his creative

ideas and invented a better telephone transmitter He

subsequently patented numerous other inventions

Emile Berliner was later to make practical

improve-ments to some of the microphone technology

devel-oped by Blake A number of Blake's papers are

ar-chived by the Massachusetts Historical Society,

Bos-ton See Berliner, Emil; Blake telephone; Blake

trans-mitter; telephone history

Blake telephoneA historic magneto telephone,

known as the Blake Transmitter, which became the

first standard telephone installed by the Bell

Tele-phone Company of Canada It incorporated a

mag-neto generator, which was cranked to ring the

cen-tral switching office, and a better quality transmitter

invented by Francis Blake, Jr Awet battery provided

power to the system The quality of the system was

important to furthering Bell's success as a telephone

company See Blake transmitter

Blake transmitterApioneering telephone transmitter

designed by Francis Blake, Jr., in 1878 so the diaphragm

rent from a battery, rather than generating energy by means of electromagnetic induction, as in earlier models, thus producing a stronger sound He received three related patents for carbon transmitting technolo-gies in 1881

blank1 A transmissions gap, one in which no sig-nal or data is coming through 2 A space or nonprinted area on paper 3 A spacer used to format

a blank area in HTML documents for display on the Web It may be created with (1) a blank image file, (2) a <PRE> (preformatted) tag, or (3) an &nbsp (nonbreaking space) tag 4 An advancing key on a teletype, typewriter, typesetter, label-maker, or other device such that an unprinted area is established The word "space" is often used interchangeably with blank

blankingIn a display device, such as a cathode-ray tube (CRT), the interval during which part or all of the display is suppressed Blanking is used to sup-press artifacts from the display sweep ofan electron gun The sweeping ofa screen is often a repeated zig-zag, but the part of the transmission intended to be seen is displayed on the straight sweep (usually the horizontal sweep), and the beam drops to the next line

as it moves back to the other side, ready to sweep again (horizontal blanking) It is somewhat like the line feed and carriage return on a typewriter; as the carriage sets the typing position back and down to the beginning of the next line, it shouldn't make marks on the page See blanking pulse

blanking interval, blanking timeThe period dur-ing which a display is suppressed, usually to enable

an electron gun to return to the next display position See blanking, cathode-ray tube, frame, sweep

blanking pulseA mechanism for suppressing a dis-play, usually on a cathode-ray tube It is sometimes accomplished by means of a positive or negative square wave A series of pulses can be combined to create a blanking signal that is synchronized with the sweep

blazed, blazing1 Characterized by a somewhat pe-riodic bright illumination, that is, sudden orundulat-ing moments of greater light often associated with heat, such as a forest fire, torch, or firing line of mus-kets 2 Illumination associated with sustained, intense heat, such as a well-stoked furnace or the desert sun 3 Having been marked with a short slash, slit, or cut as an identifier, often as part of a group or series, as a line ofblazed trees indicating a path 4 A fabrication with a regular, periodic "sawtooth" struc-ture that facilitates the filtering or concentration of energy through controlled diffraction, as in a blazed grating See blazed grating

blaze angleIn a blazed grating, the incline of the in-dividual "sawtooths" in relation to the mean grating surface The angle is designed to reflect radiant en-ergy of a desired wavelength in controlled ways to serve as a filtering mechanism When "holographi-cally" recorded and etched in an interference grating, the blaze angle can be established within certain tol-erances but is not as precise as a machined grating

• '.,•.,; •.·.1 ·, 1,

li}' ,

~:~

Fiber Optics Illustrated Dictionary

due to the sinusoidal shape of the peaks and troughs

in a photographically etched grating Consistency

of the blaze angles ofindividual facets is usually

de-sirable See Brewster's angle, incidence angle,

Littrow configuration

Blazing creates a sawtooth design in a grating that

selectively reflects wavelengths, thus acting as a

con-centrator orfilter The blaze angle can be designed to

control the angle of incidence of the reflected light

beam, thus enabling the grating to be Htuned" to

cer-tain frequencies In the asymmetric sawtooth

configu-ration, the direction ofthe light source input is

impor-tant for efficient exploitation of the angle of

refrac-tion.

BLISS Broadband Lightwave Sources and System

AnACTS project to bring to maturity key aspects of photonic networks and to demonstrate their practi-cal implementation Specific concerns include de-tailed studies ofoptical crosstalk and dynamic range OEIC receiver chips are studied through PON and ATM ring solutions with verification and compari-son to commercial systems Some key components include photonic ICs, pulse sources, a variety oftypes oflasers, semiconductors, and other relevant devices and technologies Trials were planned for a univer-sal interface for different traffic types and physical media (copper, optical fiber, etc.) to provide ATM access BLISS components are being used in other ACTS projects See BROADBANDLOOP, UP-GRADE, and WOTAN

Bloch, Felix (1905-1983) A Swiss mathematician and physicist, Bloch was associated with a remark-able who's who list of the most renowned physicists

of the early 20th century He did graduate work un-der quantum theorist Werner HeisenberginLeipzig, Germany, where his graduate thesis, published in

1928, made an important contribution to the knowl-edge ofelectron conduction In Zurich, Switzerland, where Bloch worked for Wolfgang Pauli, he made his fIrst unsuccessful attempts to formulate a theory of superconductivity but got a start in understanding dif-ferent ways to approach the problem He then trav-eled to the Lorentz Foundation, where he studied theories ofelectric conductivity, and then studied fer-romagnetism at the University of Leipzig Bloch worked with the highly regarded Niels Bohr as a Fel-low of the 0rsted Foundation While at the Institute

in Copenhagen, he described theoretical relationships between classical and quantum theory

Fermi encouraged Bloch to consider both theory and practice and, in 1934, Bloch moved thousands of miles to Stanford University where he taught theo-retical physics and gave seminars with Robert Oppenheimer

In 1936, Bloch sought to create a neutron source for the research of particle physics Together with Luis Alvarez, he began work with U.S Berkeley) cyclo-tron to determine the magnetic moment of the neu-tron Thus, he resolved to build a cyclotron at Stan-ford, a project initiated in 1939 After a brief tenure

at the Los Alamos Manhattan Project, Bloch worked

on theoretical studies in radar and conducted micro-wave reflectivity research at the Harvard Radio Re-search Laboratory Returning to Stanford in 1945, he had radio equipment built and cooperated with Purcell in dividing up the research This led to progress in nuclear magnetic resonance(NMR)

Bloch and Purcell were awarded the 1952 Nobel Prize

in physics Bloch was one of the Stanford members who encouraged the Atomic Energy Commission to support construction ofthe Stanford Linear Accelera-tor Center (SLAC).In his later years he returned to his country ofbirth See Hansen, William · Bloch's theorem of superconductivity The lowest state ofa quantum mechanical system, in the absence

of a magnetic field, can carry no current

B reflectivesurface

Blaze Angle in Fiber Grating

reflective

surface

A

blaze condition In a semiconductor component, a

configuration in which a corrugated blazing structure

is exhibiting diffractive control over incoming

wave-lengths such that they are selectively filtered or passed

through the structure This is, in part, a function of

the shape of the blazed grating along with the layers

associated with the grating See blazed, blazed grating

blazed grating A corrugated selectively reflective

surface in which the grooves are regularly

asymmet-ric The shape of the pattern of grooves or

corruga-tions is sometimes called asawtooth In this type of

grating, the shape of the teeth and their orientation

have higher significance than the grating period

(al-though very fine teeth will effect diffraction

effi-ciency) Blazed gratings can be mechanically or

pho-tographically fabricated but are generally

mechani-cally ruled, since the sinusoidal characteristic of a

photographic interference grating doesn't lend itself

to blazing The Hubble telescope utilizes a blazed

grating See blaze angle, echelle grating, grating,

ruled grating

blaze wavelength For a given blazed grating and its

associated layered components,in a given index

dif-fraction order, the wavelength for which the

relation-ship between diffraction intensity and wavelength is

at its maximum efficiency See Maxwell's equations

BLEU Belgo-Luxembourg Economic Union A

co-operative arrangement between Belgium and

Luxem-bourg, establishedin1921, to support currency bases

and legal tender between the two countries

blind transfer, cold transfer The transfer of a call

without seeking the identity of, or receiving

informa-tion about, the caller

blind zone A zone where there are no transmission

signals.Askip zone is one type of blind zone See

zone of silence

technique developed for early teletypewriters in

which a control character is appended to blocks for

longitudinal checking and CRC In packet

network-ing, as a packet is assembled, the data is processed

to create a BCC, which is then incorporated into the

packet, checked at the receiving end, and

acknowl-edged (ACK) or not acknowlacknowl-edged (NACK) ifit does

not match The data can then be resent until the BCC

matches or until the process is stopped BCC is used

in a variety ofimplementations, including most polled

protocols

block cypherA type of encryption algorithm that

breaks plaintext data into segments (usually ofa fixed

size) and uses the same encryption key to transform

each segment into a segment ofciphertext See

Blow-fish, SKIPJACK

block diagramAtype ofvisual communications aid

that uses simple shapes to symbolize objects,

func-tions, relationships, condifunc-tions, and processes Aflow

diagram or flow chart is a type of block diagram in

which specific shapes have been standardized to have

certain meanings within the context of the diagram

Rectangles, diamonds, and arrows are commonly

used

block transferThe process ofmoving data in a block,

instead of in individual bits Double buffering, in

which a screen ofinformation or block ofdata is built

in the background and then instantly presented or

dis-played by transferring it from one area ofmemory to

another, is a type of block transfer commonly used

to reduce screen display delays Various file transfer

protocols make use of block transfer techniques,

of-ten reducing the size of the block if many errors are

occurring

blocking 1.Preventing entry/exit or transmission

through 2 Holding until time or space is available,

as in a queue, or until the data, person, or object can

be turned back 3 Acircumstance in which a call

can-not be completed (the exchange may be overloaded

or the line busy) See grade ofservice, call abandons

4 Deliberate exclusion of certain parties from

cer-tain numbers (such as prevention of 900 calls,

long-distance calls, etc.) 5 In business, an illegal practice

preventing others from engaging in fair competition

6 In vacuum tubes, creating very high negative grid

bias to lower the plate current to zero

blocking capacitor, blocking condenserA device

in a circuit that blocks direct current (DC) while

per-mitting alternating current (AC) to pass through

blocking probabilityA performance measure

de-scribing the likelihood of data, or of a user, being

re-jected

bloomOn a cathode-ray tube (CRT) display device,

the tendency of a phosphor excitation level to create

a 'halo' effect of extra light that spreads out beyond

the area being targeted This tends to happen at higher

intensity levels with lighter colors

blooper 1.Goof, embarrassing error, bungle 2 In

transmissions through a regenerative relay, an

un-wanted signal created by the relay that is not part of

the desired transmitted communication

gas, e.g., for installing air-blown fiber See blown fi-ber 2 A speaker or blowhom

BlowfishA 64-bit(8bytes) encryption algorithm developed by Bruce Schneier, Blowfish has become the basis for a number ofencryption schemes, includ-ing Kent Briggs' Puffer, Harvey Parisien's VGP, and Philip Zimmermann's PGP Blowfish uses a variable-length key up to 448 bits in variable-length There may be re-strictions on sales outside the U.S., due to Federal ex-port restrictions See Pretty Good Privacy

blown fiber, air-blown fiber ABF.A fiber optic in-stallation system designed by British Telecommuni-cations PLC that enables faster, more flexible instal-lation and reconfiguration offiber optic cable systems

by literally blowing the fiber lines into a grouped tube cable hose Thus, existing or newly installed conduit can be fitted with fiber optic lines

This system is often combined with point-to-point modular connectors that eliminate splicing Since splicing is an exactingjob in fiber optic installations, modular connectors are a great convenience

blown fuseA fuse with a broken connection, due to some electrical abnormality on the circuit on which

it is installed, which might have endangered other links in the system Fuses typically cannot be reused and must be replaced with another with the appro-priate voltage A blown fuse will sometimes show a blackened area inside the glass Circuit breakers have superseded fuses in many types of electrical wiring, but the phrase has remained and is often used to in-dicate a tripped circuit breaker See circuit breaker, fuse

BLSThe u.S Bureau of Labor Statistics

http://www.bls.gov/

BLSRSee bidirectional line-switched ring

BLUbasic link unit Ageneric term used in a variety

of networks, refering to a basic transmission unit of control and data information

Blue Book standard 1.A document published by Digital Equipment Corporation (DEC), Xerox Cor-poration, and Intel Corporation in 1980 to provide information on the Ethernet protocol standard, ver-sion 1 2 The Blue Book or CD Plus standards are a subset ofthe Orange Book standards originally based upon the Red Book and Yellow Book digital audio and computer data optical recording fonnats Blue Book is a special case of the Orange Book standards

in which multisession data is recorded in two blocks with one session devoted to recording music and one devoted to recording digital data Blue Book formats are supported by a number of major audio and com-puter data vendors Blue Book discs can be played

on audio CD players and on more recent CD-ROM drives Besides their simplicity, the Blue Book stan-dards served another purpose in preventing CD play-ers from misreading the type of data on a disc (Or-ange Book) and trying to create audio from computer data and possibly even damaging the equipment (if you've heard a modem screech over a phone line, you get the general idea) See Orange

blue boxcolloq A small handheld device designed

Fiber Optics Illustrated Dictionary

to emit tones in the same frequencies as touchtone

telephones, often used in the 1980s for connecting

long-distance calls illegally through direct tones

rather than dialing Typically a connection was

es-tablished through normal means, usually through a

toll free 800 number and then the blue box was used

to disconnect the remote ringing, without actually

dis-engaging from the long-distance connection A new

connection could then be established within about a

10 second window, by punching in appropriate

op-erator tones from a keypad on the blue box (Some

individuals have even learned to reproduce some of

these tones by whistling, without having to use a blue

box.) Newer systems can move these tones out of

band or use more sophisticated monitoring and

trac-ing of suspected connections to reduce the

possibil-ity of abuse

Blue boxing probably originated in the very early

1960s, and the Bell System first apprehended a blue

box user in 1961 The myth that blue boxing is done

almost entirely by young college students is refuted

by a report by AT&T that almost half of those caught

stealing phone services with blue boxes are

business-men, many of them wealthy, along with a number of

doctors and lawyers

blue gun In a color cathode-ray tube (CRT) using a

red-green-blue (RGB) system, the electron gun

spe-cifically aimed to excite the blue phosphors on the

inside coated surface of the front of the tube

Some-times a shadow mask is used to increase the

preci-sion of this process, so the green and red phosphors

are not affected, resulting in a crisper color image

See shadow mask

blue pages A convention in telephone directories in

which government listings are printed on pages with

a blue background to distinguish them from

residen-tial and business listings Online directories of

gov-ernment information and email addresses are now

sometimes called blue page listings

blue wire A color designation used by mM to

indi-cate patch wires used to correct design or fabrication

errors in situations where it is not practical to

recre-ate the board with the corrections See purple wire,

red wire, yellow wire

Bluetooth Project A combined effort of Ericsson,

mM, Intel, Nokia, and Toshiba, formed in 1998 as a

special interest group, to develop a vision and path

for a single, universal, low-cost wireless

communi-cations system that allows easy access from a wide

variety of wireless consumer devices See Service

Discovery Protocol

Bluetooth Service Discovery Protocol See Service

Discovery Protocol

BLVIBLIAnoperator call wherein the caller requests

information about the busy status ofa line or requests

an interruption of a call on an Exchange Service

BM 1 See benchmark 2 See burst modem

BMEWS Ballistic Missile Early Warning System A

U.S Government long-range warning and tracking

radar network designed to detect missile fire along

the northern approaches

BMP, bmp Afile extension standing for bitmap, often

expressed as a three-character file name extension to maintain backward compatibility with operating sys-tems that can't use a longer file extension Techni-cally, bitmap files are monochrome raster graphics files While bmp is used by some as a generic file extension name for any type of raster graphics file, bitmap also has a specific meaning for a standard-ized file format See bitmap, raster

BN 1 See background noise 2 See border node

3 See bridge number

BNC 1 See bayonet nut connector 2 See British National Corpus

BNCC Base Network Control Center The main ad-ministrative central facility for network operations within an organization or location See Network Op-erations Center

BO 1 body odor See skunkworks 2 See branch of-fice

board See printed circuit board

Boardwatch A good prosumer-Ievel print and Web publication dealing specifically with the telecommu-nications industry, particularly the Internet http://www.boardwatch.com/

bobtail curtain antenna A phased-array, bidirec-tional, vertically-polarized wire antenna, intended for high-frequency transmitting and receiving

BOC See Bell Operating Company

body The main informational portion of a commu-nication, sometimes sandwiched as a block between

headers and trailers Sometimes called the payload.

In a picture file, the body is the portion that carries the object or raster information about the image In a word processed document, the body is the portion that contains the informational text and accompanying il-lustrations Contrast with header

body, type In typography, the main portion of the shapes that constitute a character set (typestyle) The portion from which ascenders and descenders origi-nate Sometimes called x-height

body area network BAN A network based upon a body-worn communications network device It is usu-ally wireless, to enable mobility, but may also be wired ifthe user is stationary (usually seated at a com-puter, telephone, or games terminal) The trend in BANs is to incorporate them into clothing or body-worn harnesses to distribute the weight and decrease their visibility

Boggs, DavidR.Along with Robert Metcalfe, the co-developer and co-builder ofthe first Ethernet systems

in 1973 at Xerox PARCo Metcalfe and Boggs authored a frequently cited article "Ethernet: Distrib-uted packet switching for local computer networks"

in Communications of the ACM in July 1976 See

Ethernet; Metcalfe, Robert

Bohr's correspondence principle In an atomic sys-tem, the behavior of the electrons must increasingly approach that predicted by classical physics the higher the quantum number of the orbit

bolometer A detection instrument for measuring the intensity of radiant energy through a thermal-sensi-tive resistor, a type of actinometer Bolometers may

be assembled in arrays

versal gas constant, R, to the Avogadro constant, Na.

Named after Ludwig Boltzmann

Boltzmann, Ludwig (1844-1906)An Austrian

ex-perimenter who built on the ideas of James

Clerk-Maxwell, studying electromagnetism,

thermodynam-ics, and statistical mechanics Boltzmann

demon-strated a number ofMaxwell's predictions,

confrrm-ing them, and published his results in1875 The

Ludwig Boltzmann Institute for Urban Ethology in

Vienna is named after him

BOM 1 BASIC operations monitor A monitoring,

debugging tool for BASIC programs 2 beginning of

medium Aphrase applied to the start ofa tape or other

serial storage media 3 See Beginning ofMessage

BONAPARTEBroadband Optical Network using

ATM PON Access Facilities in Realistic

Telecommu-nications Environments.AnACTS project to

dem-onstrate the viability of broadband ATM PON as a

cost-effective communications system and to

dem-onstrate interoperability between ATMmcisland

through the Pan European ATM Network See

BROADBANDLOOP, BOURBON

bondn. 1 To join, adhere, or unite into a combined

unit or system Bond usually implies a

semiperma-nent or permasemiperma-nent adherence, as opposed to

wrap-ping a wire, which would not be considered a bond

A bond is often accomplished with a bonding agent

such as glue, weld, or solder See fusion splicing

bond, electricalTo form an electrical connection by

joining two conductive surfaces, usually metal, to

provide a low-resistance path for the circuit In

elec-tronics, wires are often bonded to a small metallic pad

on a circuit board See bonding

bonding1 Joining two or more items with adhesive,

weld or solder In PC boards, there may be a

bond-ing pad on the board or on a chip for the express

pur-pose ofproviding sufficient space and electrical

con-tact for a potential bond (usually solder) 2.An

in-verse multiplexing specification described by

BOND-ING See BONDBOND-ING

BONDINGBandwidth On Demand Interoperability

Group A set of protocols, known as the BONDING

specification, developed by a consortium ofdata

com-munications consultants and suppliers BONDING

arose from efforts to create a standardized inverse

multiplexing protocol in order to improve

interoper-ability among multiplexers from various vendors

The BONDING specification describes a number of

modes of interoperability for switched networks, so

a sideband signal can be subdivided into multiple56

Kbps or64Kbps channels, and recombined at the

receiving end

bongA tone transmitted through a phone line to

in-dicate to the listener that additional information is

required The information is usually entered through

a touchtone key pad or by speaking clearly

Boole, George (1815-1864) AnEnglish-born

math-ematician, son of a maid and a shoemaker, Boole set

up a school at the age of only19.He taught himself

mathematics and began publishing his ideas,

intro-ducing Invariant Theory Hist854publication "The

applicable to computing operations and earned him the sobriquet of"father of symbolic logic." Boolean logic is named after him

Boolean expressionAtype of expression often used

in programming to control binary relational opera-tions that may be executed or may express true or false Boolean algebra in a broader sense in set theory involves the intersection and union of sets and ele-ments of sets It also provides a practical means for implementing logic in digital computers Boolean al-gebra works readily on binary computing systems boom1 Vertical spar, beam, pole, or suspended pip-ing 2 In video, a vertical bar, rod, or other support for microphones, cameras, or other equipment that need to be suspended over or near a source with a minimum ofvisual obstruction 3 The horizontal sup-porting rods for many common antennas from which there may be secondary protruberances to increase transmission or reception

boom poleA long pole with a spike on the end used

by crews of boomers (telephone line installers) to

guide a long telephone pole into a deep hole Aboom pole is sometimes called a pike pole

boom truck rollerSee stringing roller

boomercolloq. Telephone line installer The name

is derived from the boom poles installers used to hand guide telephone poles into their holes before machin-ery for this job became prevalent

bootabbrev., v.To start, to power up, to get a ma-chine going, to 'kick' something into operation

De-rived from bootstrap, which is further deDe-rived from

the phrase "pulling yourself up by your bootstraps." This term aptly describes how a computer has to launch its basic lower processes so it can recognize its own hardware and capabilities in order to further launch the higher level processes See bootstrap boot ROMAread-only computer memory chip usu-ally located on the motherboard as an essential part

of a basic system This chip provides the minimum necessary information for bringing the computer hardware online and may include diagnostic routines that test systems before bringing the whole system up

In simple terminals, the boot ROM may include all basic operating software needed or, as is the case on most self-contained desktop systems, it may include only the essentials and will seek a floppy diskette, hard drive, or other boot information for further in-structions and parameters for launching the operat-ing system, device drivers, and sometimes user ap-plications

On many Intel-based desktop computers, the infor-mation for accessing devices may be transferred to the BIOS during system startup See BIOS

BOOTPSee Bootstrap Protocol

bootstrapIn a computing system, to bring up basic hardware and software systems in stages that are par-tially or wholly dependent upon the success of pre-vious stages For example, to bootstrap a computer from a power-off state, low-level hardware and soft-ware systems are brought online to the point where self tests can be performed and devices recognized

Fiber Optics Illustrated Dictionary

These basic systems are then used to "pull the

sys-tem up by its bootstraps" to the next level of

operat-ing system capabilities for processoperat-ing input from the

user, network configurations, and basic applications

parameters

Bringing a system online from a power-off state is

called acold boot A warm boot is a reset from a

power-on state during which the system typically

re-reads theboot ROM and restores basic operating

pa-rameters without powering off the system or

rerun-ning the low-level self-tests and device intitialization

operations Stable operating systems rarely crash or

hang, but there are some microcomputer operating

systems that do crash, and a cold boot is sometimes

the only way to bring the system back into full

oper-ating mode See device drivers

User Datagram Protocol (IPfUDP) client/server

pro-tocol for storing and providing configuration

infor-mation for a network

BOOTP evolved in the ARPANET days to enable

diskless client machines and other machines that

might not know their own Internet addresses to

dis-cover the IP address, the address of a server host, and

the name of a file to be loaded into memory and

ex-ecuted It is accomplished in two phases: address

de-termination and bootfile selection; and file transfer,

typi-cally with TFTP

BOOTP has since evolved into Dynamic Host

Con-figuration Protocol (DHCP) See Address Resolution

Protocol, Dynamic Host Configuration Protocol,

Re-verse Address Resolution Protocol, RFC 951

BOP 1 beginning of packet 2 See Biocomputing

Office Protocol 3 See bit-oriented protocol

server developed by Don Gilbert, based onpopper, a

Post Office Protocol server Bopper provides

biocomputing services to BOP-compatible clients It

was initially released for Solaris2 in June 1996

gateway routing protocol which is superseding

Ex-terior Gateway Protocol (EGP) BGP is used on the

Internet See Exterior Gateway Protocol, RFC 1163,

RFC 1267, RFC 1268

ver-sion ofBGP which uses route aggregation to reduce

the size of routing tables, and which supports

Class-less Inter-Domain Routing (CIDR)

a specified peer group that has at least one link that

crosses the peer group boundary

between networks of distinct topologies while

limit-ing the flow of topology data across subnetwork

boundaries Thus, subnets with different NETIDs or

defined clusters will have subnetwork boundaries

Border Node was defined originally as Peripheral

Border Node (PBN) with a later release as Extended

Border Node (EBN), described in 1997 by

Interna-tional Business Machines (IBM) for Advanced

Peer-to-Peer Networks (APPNs)

EBN was developed to enable connectivity of

mul-tip Ie subnets It facilitates interoperability, topology isolation, subnet partitioning, route calculation, op-tional security, opop-tional exit access controls, and other functions

Interior Border Node (IBN) and HPR border node (HBN) are subsets ofEBN IBN supports intermedi-ate network routing, usually on the same APPN, but does not support APPN Interchange Node or SSE(CP) functions HBN supports cross subnet path switching, ANR routing, and end-to-end routing

in-dustry to aid in remembering the components of a subscriber line interface (SLI)

B - battery (power source)

o-overvoltage protection R- ringing

S - signaling and signaling detection

C - codec (analog/digital conversions)

H - hybrid (two-/four-wire conversions)

T - test access

largest computer user groups in the world, with a membership of over 25,000 at its peak, the Society served users of a variety of types of computer plat-forms Jonathan Rotenberg, who was 13 at the time

it was founded, ca 1977, is credited with starting the organization Despite a large and enthusiastic membership, the Society officially ceased to operate

in September 1996

describe software robots that manage tasks on behalf

of users and operators, especially in Internet Relay Chat (IRC) channels Since IRC is an interactive so-cial medium, these software programs have fre-quently been given personalities by their respective programmers and thus take on anthropomorphic char-acteristics not usually attributed to applications pro-grams, hence the term bot instead of application See avatar, robot

transmis-sion link that slows the rate of communication be-low the expected efficiency or bebe-low the capabilities

of other links in the system For example, a computer with a CPU capable of 64-bit processing may be im-peded by a 32- or 16-bit data bus As another example, you may have a fast serial card and an ISP with a Tl line, but your 9600 baud modem creates a bottleneck, limiting the upper speed of the transmission of data Bottlenecks may be a constant limitation of a system

or may be a limitation occurring only during times ofpeak traffic

mathemati-cian, inventor, and author, Bouguer carried out mea-surements in astronomical photometry in the 1720s Beginning in 1727, he was a multiple winner of the grand prize of the Academie Royale des Sciences In

1748, he invented photometric and heliophotometric instruments

Bouguer's significant 1729 essay on optics describes the relationahip between the absorption of radiant energy and the associated absorbing medium, now

Gradation de La Lumiere,his treatise on photometry,

was posthumously published as a first edition in 1760

In addition to his observations ofabsorption

proper-ties of radiant energy in atmospheric optics, it

de-scribes a number of types of photometers, including

a method of goniophotometry See Bouguer's law

Bouguer's lawA description of the relationship

be-tween an absorbing medium and the radiant energy

absorbedinterms of the ratio of the transmitted and

incident radiant energy intensity to the mass of the

absorbing medium

Bouguer studied illumination on two surfaces from

light sources ofthe same kind One was set at a fixed

distance from the illuminated surface but had an

ab-sorptive material interposed between the light source

and the illuminated surface, the other was set up the

same way, but without the absorptive materials and

with the light source set at varying distances from the

illuminated surface The intensity ofthe illumination

on the first surface would vary depending upon the

thickness of the intervening materials and the

inten-sity ofthe illumination on the second would vary

ac-cording to distance By visually assessing the

inten-sity of the two illuminated surfaces as the thickness

or distance variables were altered and matched,

Bouguer found that the relationships between the two

could be perceived and quanitified It's not a long

stretch to realize that the intervening materials could

also be swapped and the experiment performed again

for a material of different composition (e.g.,

differ-ent translucency)

In contemporary applications of the concept, the

re-lationship is usually calculated with respect to a

spe-cific wavelength with temperature and pressure held

constant.Itprovides information on absorbancy

char-acteristics or, seen another way, transparency

Bouguer's law is also known as Beer's law or, when

the concepts ofabsorption in proportion to a

concen-trate and the thickness of the intervening materials

are combined, it is called Beer-Lambert's law See

Lambert's law

bouleIn fiber optics fabrication, a sooty, layered

coat-ing that builds up inside a supportcoat-ing tube through a

chemical deposition process The boule is then

fur-thersinteredto remove impurities and collapse the

boule into a clear cylinderpreform.The preform,

which is typically composed of silica glass, can then

be drawn out into a long fiber filament See preform,

vapor deposition

bounce1 To rebound, to come back, to deflect off

of, to echo The ionosphere is used to bounce radio

signals over long distances 2.Inelectronic

transmis-sions, if data doesn't reach its intended destination

and is routed back to the sender, it is said to have

"bounced." This may happen when email is sent to

an address that no longer exists, for example

bounce, broadcast 1 In broadcast transmissions, if

a signal hits a physical impediment, it may bounce,

sometimes causing a zone in which there is

interfer-ence in the transmission or no transmission at all In

other instances, the physical characteristics of the

ers or satellites may be used to selectively bounce a signal in order to direct it See ionosphere, Moon bounce 2 In visual media such as television broad-cast displays, bounce is an undesirable and unex-pected variation in the brightness of the image

BOURBON Broadband Urban Rural Based Open Networks An ACTS Project building on a previous RACE project which studies issues ofproviding cost-effective, scalable access to ATM-based networking services in Europe and the broader Information So-ciety The project focuses both on users and technolo-gies and involves the cooperation of Member States ofthe European Union ATM and ISDN test beds are established in several countries See BBL, BONAPARTE, BROADBANDLOOP, UPGRADE, WOTAN

Bourseul, Charles (1829-1912) A Belgian-born French researcher who described, but apparently never followed up, a means of transmitting speech electrically through wires His ideas were published

inL'Illustration de Parisin 1854 See Meucci, An-tonio; Gauthey, Dom; telephone history

Bower-BarffprocessAprocessinwhich metal (iron

or steel) is heated to red heat and then treated with superheated steam in order to reduce vulnerability to corrosion

Boyle, Robert(1627-1691) A British physicist and chemist who developed pumps that could create near vacuums Boyle subsequently observed that sound required a medium for its transmission He also did numerous experiments on atmospheric pressure and discovered an important relationship between gas and pressure in 1662 In 1675, he published a treatise on electricity and observed that the attractive properties

of amber did not require the presence of air Boyle's law is named after him See barometer; Boyle's law;

Hauksbee, Francis

Boyle's law, Marriotte's lawAt a constant tempera-ture, the volume ofa definite mass ofgas is inversely proportional to the pressure such that the product of the volume (PV) is constant

BP1.bandpass 2 base pointer 3 beam position 4

bypass

BPAD Bisynchronous Packet AssemblerIDisassem-bIer The BPAD Protocol is a transport protocol as-sociated with X.25 networking

BPDU See Bridge Protocol Data Unit

BPI See bytes per inch

BPON See Broadband Passive Optical Network

BPMSee beam position monitor

BPS See bits per second

BPSKSee binary phase-shift keying

BR1 beacon receiver 2 Bureau of Radiocommu-nications

Bragg angleInthe context ofBragg's law, the angle between the lattice plane and the incident X-ray beams (commonly expressed as theta - 8) See Bragg's law

Bragg reflectorA technology used in diode lasers that allows very fine control over the focus of the beam A Bragg reflector is also called agrating

' Yi0t

l l !

.

~,:,,',:~:f,: I

!!t~~: •

Fiber Optics Illustrated Dictionary

reflector, due to the corrugated ridges used to direct

the beam that change along their lengths Bragg

re-flectors are being researched as a means of

increas-ing throughput ofdata transmissions in existincreas-ing cable

installations By finer focusing ofthe beams and

mul-tiplexing, capacity may be improved on fiber

chan-nels See Agility Communications, Bragg grating,

diffraction, quantum cascade laser

Bragg gratingA grate-like pattern that is "written"

into a fiber during fabrication to modify the

charac-teristics of the basic fiber filament to reflect

wave-lengths selectively The performance of the grating

may also be improved by straining the fiber medium

at the time the grating is written

Bragg gratings have provided significant

advance-ments in waveguide control in fiber optics

commu-nications circuits There are many types of grating

design (and research continues) that enable the

reduc-tion ofnoise and delay, through filtering mechanisms

that may be tunable and incorporated into optical

waveguides Gratings can facilitate channel filtering

and gain equalization

Research at the MIT NanoStructures Laboratory has

resulted in new Bragg grating designs and

fabrica-tion techniques for lithographically "etching" the

grating into the medium For example, the lab has

shown that a quarter-wave shift in the grating, to

iso-late a single wavelength channel in amultiwavelength

system, can provide optical resonating functions,

similar to that ofa Fabry-Perot cavity Thus, add/drop

channel filtering capabilities can be built right into

the fiber facilitating the development of all-optical

transmission paths Through electrical circuit

mod-eling, multiple resonators can be cascaded to enable

more complex functions See add/drop multiplexer,

Alexandrite, diffraction, fiber grating

Bragg spectrometerA form of spectrometer useful

in studying X-ray diffraction characteristics based

upon the discoveries and observations of W.H and

W.L Bragg in the early 1900s X-rays are generated,

filtered, and collimated (aligned into a fine beam) and

aimed to strike a crystal surface at a specified angle

The rays reflected from the crystal are intercepted by

a detector so that their characteristics may be

stud-ied and recorded See Bragg's law

Bragg's law, Bragg's relationA diffraction effect

expressed mathematically as nl= 2d sinq by

W Lawrence Bragg in 1913 to describe the angles of

incidence associated with X-ray reflections that

occur when parallel rays encounter crystal structures

(obstacles) Thus, the wavelength ofan incident beam

times a positive integer (sometimes expressed as an

index -m)is equal to two times the distance between

the atomic layers in the crystal sinq Depending upon

which factors are known and substituted into the

equation, diffraction angle, crystal plane separation,

or the wavelength can be algebraically calculated

The relational expression was based upon

collabora-tive research with Lawrence Bragg's father,

W.H Bragg The Braggs' observations were

signifi-cant not only for their practical applications, but for

providing evidence supporting theories about the

periodic atomic structure ofcrystals Bragg's law and the study of diffraction have since been applied to many other theoretical and practical fields of study beyond X-rays and crystals See Bragg grating, Bragg reflector, Compton scattering

Bragg, William Henry(1862-1942) ABritish physi-cist who studied X-rays and ionizing radiation and,

in collaboration with his son, X-ray diffraction and its interaction with crystalline lattice structure This latter research won the father/son team a Nobel Prize

in physics, in 1915 See Bragg spectrometer Bragg, William Lawrence(1890-1871)An Austra-lian-born British physicist who studied at Cambridge and became a lecturer there.Inthe early 1900s he col-laborated with his father, W.H Bragg, in the study

of X-ray diffraction and crystal structures, an effort that jointly won them a Nobel Prize in physics in

1915 In 1915, they publishedX-rays and Crystal

Structure.

In 1938, Lawrence Bragg became head of the Cavendish Laboratory at Cambridge From 1953 to

1961, he served as director of the London Royal In-stitution

braidA fibrous or filamentous, long, tubular intri-cately woven structure usually ofplastic or fine metal that forms a covering over a conductive or insulat-ing core in a layered cable

Brainerd, PaulBrainerd founded Aldus Corporation

in 1984, the year after the introduction of the Apple Lisa computer and the year before the release of the Apple LaserWriter printer Aldus specialized in graphics applications, particularly for vector draw-ing and desktop publishdraw-ing Macintosh computers and Aldus software quickly became favorites with print industry service bureaus The Aldus Corporation was one of the few developers that created some really good, quick, intuitive user interfaces Good interface design is a rare talent in the software development industry Aldus PageMaker and Aldus Freehand, de-veloped by the Aldus Corporation, were acquired by Adobe Systems and Macromedia

brainiac Probably originating from Edmund Berkeley's computing devices from the 1950s, this term refers to someone with good technical and/or mathematical intelligence ofthe kind that is not com-mon See Brainiac

BrainiacBrain-Imitating, Almost-Automatic Com-puter.1t is essentially the electromechanical GENIAC computer designed by Edmund C Berkeley and Ol-iver Garfield, in the 1950s There were disputes and

a lawsuit between Berkeley and Garfield subsequent

to which Garfield promoted his calculating technol-ogy under the name GENIAC, and Berkeley contin-ued to promote computing devices under the name Brainiac In writings on the GeniacIBrainiac technol-ogy, Berkeley described Brainiac computing experi-ments' in 1957 and 1958, and began discussing Brainiac's relationship to GENIACs and automatic computers, in 1958.In the late 1950s, Berkeley took steps towards exporting Brainiac abroad, as well See Berkeley, Edmund; GENIAC; Simon

branch1 Ajunction point from which there is more

tion in a computer program which, when evaluated,

can lead to a different destination for execution ofthe

next step, depending upon the condition 3 A

sub-station, subsidiary office, or other facility which is a

satellite of, or auxiliary to, the main operations

branch circuitIn a wiring installation, a separate

circuit that, if damaged or tripped, doesn't affect the

other branch circuits This divides the power so the

main circuit is not overloaded On a circuit breaker

panel, the branch circuit is a constellation of

appli-ances and sockets wired to a particular breaker

branch feederIn an electrical distribution system, a

cable that connects the main cable and the subscriber

distribution system, as between a phone switching

center's main cable and a business distribution closet

branch officeBO Subsidiary office (in the sense that

a tree branch is subsidiary to a tree trunk) separate

from the head office There may be multiple branch

offices In large distributed computer networks,

branch offices are often established to provide

rout-ing or switchrout-ing services, customer services

(includ-ing installation, maintenance, and repairs), and local

marketing, billing, and tax procedures

branching1 Dividing, splitting into two or more

paths or sections 2 A hierarchical structure often

used for database creation, search, and retrieval

3 Branching electrical distribution systems for

elec-trical installations and data networks

branching filter1 A device for separating or

com-bining separate frequencies when used in

conjunc-tion with a guiding structure for the wave 2.In

com-puter networking, a software utility for selectively

routing data into several paths or files based on

speci-fied characteristics

Branly detectorAdevice created in 1890 by Edouard

Branly, consisting of a small, glass, metal-filled tube

with a short wire inserted to make contact with the

metal filings When connected between a power

source and a meter, current didn't pass through the

glass unless a spark was discharged The spark caused

the filings to cohere and thus act as a conductor This

on/off quality of the Branly detector was very useful

to the dev,elopment of radio

Branly, Edouard Eugene Desire (1844-1940) A

French inventor who devised the Branly detector in

the late 1800s, a cohering device that contributed to

the development of radio or, as it was then, wireless

telegraphy His technology was subsequently adapted

by G Marconi Branly also investigated the

transmis-sion ofnerve impulses See Branly detector, coherer

BRASbroadband remote access server

Braun, Karl Ferdinand(1850-1918)AGerman

re-searcher who discovered in the 1870s that certain

minerals had a property of one-way conductivity of

radiant energy; they could function, in a sense, as

one-way gates This discovery was an important early

con-tribution to electronic circuitry that provided a

tran-sition from coherers to crystal detectors

Braun invented the cathode-ray indicator tube or

evo-lution ofelectronics Braun's attitude towards science

was a shrewd and successful businessman, he also had a strong inclination to share knowledge that he felt would benefit humankind Like Franklin, Braun published descriptions ofhis earlier discoveries rather

tuning transmitters in Britain, starting in 1899, tech-nology that may have influenced Marconi's tuning patent of 1900

Ayear after his invention ofthe CRT, Braun was hired

to provide guidance on an undetwater wireless tele-graphy project that needed improvements By rear-ranging the main components of the circuits and al-tering the coupling, Braun was able to greatly extend the range of the system His employer and backers formed the Telebraun company which evolved into the well-known Telefunken

Braun was awarded aNobel Prize in Physics in 1909, along with G Marconi, for his contributions to wire-less telegraphy See cathode-ray tube; crystal detec-tor; Murgas, Jose£

BRCSBusiness and Residence Customer Service

breadboardA board with numerous attachment points, often in agrid,that permits the prototyping ofcircuits Breadboards often resemble a nest ofcol-ored worms, as they are frequently hand-wired with

a lot of crisscrossing conductors with temporary attachments Breadboards are handy for concept de-sign, testing, teaching, temporary circuits, and con-vincing the boss that you have a good idea that will work See proof of concept

breakWillful or inadvertent interrupting or stopping ofa process, transmission, or broadcast On computer terminals, a break can be sent in many instances with Ctrl-C or Esc, depending upon the software

break in 1.v.Interrupt, or take control of, a circuit

or process This break may be from human or sys-tems intervention or through an automated system

See Barge In, buttinsky 2.lJ.Gain illegal entry to a system See back door, hacking, Trojan horse

Break keyAspecialized key included on some com-puter keyboards that permits a one-keystroke inter-ruption of the current task, assuming the software supports, and correctly interprets, the input from the keystroke Break keys are included since some ofthe common ways to interrupt tasks involve combination keystrokes, such as Ctrl-C, and hitting one key is easier, especially for less experienced computer us-ers See break

break out boxSee breakout box

breakdown potential, breakdown strength Dielec-tric strength, the maximum voltage that can be toler-ated without breakdown

breakdown voltage 1 The voltage at which an in-sulator or dielectric breaks, or at which ionization and conduction occurs in a gaseous environment 2 The voltage that needs to be applied in a device to jump a gap (in air)

breaker1 In electrical installations, a point in a circuit, usually a junction installed in series between the main electrical source and a branch circuit, in