Fiber Optics Illustrated Dictionary - Part 14 pps

Fiber Optics Illustrated Dictionary BITNET, BITNET-NJE Because It's Time Net- work. An international, cooperative, academic network 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 ffiM mainframes and Digital VAXes communicating through EBCDIC formats. From there, it spread across the U.s. and became international when it was joined by the European Aca- demic and Research Network (EARN) in 1982. A grant from ffiM in 1984 helped establish support services 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 academic network. Participation declined thereafter due to the rapid growth of the 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 ofother network systems, primarily the Internet. BITNET is based on an ffiM communications protocol called Network Job Entry (NJE), which made it practical to connect mainframe computers through telephone circuits. It uses a store-and-forward system of transmitting information through nodes on the system. See Network Job Entry, RELAY, UUCP. BITNIC BITNET Network Information Center. A support center for administering BITNET computer networks initially established with the aid of funding from ffiM in 1984. After 1987, funding was member-based and volunteer-supported. See BITNET. BITS See Base Information Transport System. bits per second bps. A very common means of de- scribing data transmission per second unit of time. 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. T 1, fiber lines, and other higher speed protocols and media can transmit at much higher rates. BIU See basic information unit. BL 1. bilateral. Having two sides. 2. See bit line. black In politics, a designation for secret and/or clas- sified information or activities. The designation has significant impact on telecommunications in a number of ways. 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 special 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 122 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 of power of the light beams could be detected beyond the point of the tap) or (2) to insert aclandestine 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 body Atheoretical body which absorbs all incident light with no reflection and consequently appears black (without light) at all wavelengths. Black Box Aregistered trademark of The B lack Box Corporation of Pittsburgh, PAl black box 1. 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 device that is used by a lay person without technical knowledge of its construction or functioning. 3. A type ofclandestine 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 design A design model for inputs and out- puts which function independently of the various ways the internal components might be configured. F or 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 way to implement and build the hardware itself. black hole 1. A theorized invisible (thus perceived as dark) region in space with a small diameter in relation to its intense gravitational field. Ablack hole could perhaps result from the collapse ofa 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 apparently didn't come out. Black hole also refers to a metaphorical repository for lost data. Disappearing into a black hole may also be jargonistically described as disappearing into the ether, into the bit- stream, or into the bit bucket. black level Areference level on a display device cor- responding to the lowest possible luminance setting, which typically appears as black (the absence ofil- lumination), or nearly black, depending upon the characteristics of the display device. black matrixtubeA cathode-ray tube in which black fills the spaces between color phosphors on the inside 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. © 2003 by CRC Press LLC black recording In recording systems using amplitude modulation, black recording is the correlation between the maximum power of the transmission and the maximum density of the recording device. In recording systems employing frequency modulation, black recording is the correlation of the lowest frequency received and the maximum density of the recording medium. The phrase applies to various wired and wireless facsimile machines, printers, electronic photocopiers, etc. See black transmission. blacktransmission, AM In an 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 represents 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, photocopiers, etc. See black recording blackjack When Samuel Morse won acontract from the u.S. Congress in the 1800s to build a telegraph line from Washington, DC to Baltimore, MD, he initially 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 of miles of communications 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) An American inventor, physicist, and photographer who became ap- pointed to the u.S. Coast Survey in 1866, Blake was talented in mathematics and became skilled in telegraphy, astronomy, and hydrography. Upon leaving the Coast Survey in 1878, he pursued his creative ideas and invented abetter telephone transmitter. He subsequently patented numerous other inventions. Emile Berliner was later to make practical improvements to some of the microphone technology developed by Blake. A number ofBlake's papers are ar- chived by the Massachusetts Historical Society, Bos- ton. See Berliner, Emil; Blake telephone; Blake transmitter; telephone history. Blake telephone A 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 magneto generator, which was cranked to ring the central switching office, and a better quality transmitter invented by Francis Blake, Jr. A wet 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 transmitterA pioneering telephone transmitter designed by Francis Blake, Jr., in 1878 so the diaphragm could vary the strength of an already established current from a battery, rather than generating energy by means of electromagnetic induction, as in earlier models, thus producing astronger sound. He received three related patents for carbon transmitting technologies in 1881. blank 1. A transmissions gap, one in which no signal or data is coming through. 2. A space or nonprinted area on paper. 3. Aspacer 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. blanking In 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 of an 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 time The period during 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 pulse A mechanism for suppressing a display, usually on a cathode-ray tube. It is sometimes accomplished by means of a positive or negative square wave. A series ofpulses can be combined to create ablanking signal that is synchronized with the sweep. blazed, blazing 1. Characterized by a somewhat periodic 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 ofa group or series, as a line of blazed trees indicating a path. 4. A fabrication with a regular, periodic "sawtooth" structure that facilitates the filtering or concentration of energy through controlled diffraction, as in a blazed grating. See blazed grating. blaze angle In ablazed grating, the incline of the individual "sawtooths" in relation to the mean grating surface. The angle is designed to reflect radiant energy ofa 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 123 • '., •. ,; •. ·.1 ·, 1, li}' , ~:~ © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary due to the sinusoidal shape of the peaks and troughs in a photographically etched grating. Consistency of the blaze angles of individual facets is usually de- sirable. See Brewster's angle, incidence angle, Littrow configuration. Blazing creates asawtooth design in agrating that selectively reflects wavelengths, thus acting as a con- centrator or filter. 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 certain frequencies. In the asymmetric sawtooth configuration, the direction of the light source input is important for efficient exploitation of the angle of refrac- tion. BLISS Broadband Lightwave Sources and System. An ACTS project to bring to maturity key aspects of photonic networks and to demonstrate their practical implementation. Specific concerns include de- tailed studies of optical 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 of types of lasers, semiconductors, and other relevant devices and technologies. Trials were planned for a universal 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 under quantum theorist Werner Heisenberg in Leipzig, Germany, where his graduate thesis, published in 1928, made an important contribution to the knowledge of electron 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 different ways to approach the problem. He then trav- eled to the Lorentz Foundation, where he studied theories of electric 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 theoretical physics and gave seminars with Robert Oppenheimer. In 1936, Bloch sought to create a neutron source for the research ofparticle physics. Together with Luis Alvarez, he began work with U.S. Berkeley) cyclotron to determine the magnetic moment of the neutron. 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 of the Stanford Linear Accelera- tor Center (SLAC). In his later years he returned to his country of birth. See Hansen, William. · Bloch's theorem of superconductivity The lowest state ofa quantum mechanical system, in the absence ofa magnetic field, can carry no current. B reflective surface 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 wavelengths 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 asymmetric. The shape of the pattern of grooves or corruga- tions is sometimes called a sawtooth. 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 efficiency). Blazed gratings can be mechanically or photographically fabricated but are generally mechanically 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 diffraction order, the wavelength for which the relationship between diffraction intensity and wavelength is at its maximum efficiency. See Maxwell's equations. BLEU Belgo-Luxembourg Economic Union. A cooperative arrangement between Belgium and Luxem- bourg, established in 1921, to support currency bases and legal tender between the two countries. blind transfer, cold transfer The transfer ofa call without seeking the identity of, or receiving information about, the caller. blind zone A zone where there are no transmission signals. A skip zone is one type of blind zone. See zone of silence. 124 © 2003 by CRC Press LLC block check character BCC. An error-checking technique developed for early teletypewriters in which a control character is appended to blocks for longitudinal checking and CRC. In packet networking, 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 acknowledged (ACK) or not acknowledged (NACK) if it 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 of implementations, including most polled protocols. block cypher A 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 of ciphertext. See Blow- fish, SKIPJACK. blockdiagramA type of visual communications aid that uses simple shapes to symbolize objects, functions, relationships, conditions, and processes. A flow 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. blocktransfer The process of moving data in a block, instead of in individual bits. Double buffering, in which a screen of information or block of data is built in the background and then instantly presented or displayed by transferring it from one area of memory to another, is a type ofblock transfer commonly used to reduce screen display delays. Various file transfer protocols make use of block transfer techniques, often 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. A circumstance in which a call cannot be completed (the exchange may be overloaded or the line busy). See grade of service, call abandons. 4. Deliberate exclusion of certain parties from certain 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 condenser A device in a circuit that blocks direct current (DC) while per- mitting alternating current (AC) to pass through. blocking probability A performance measure de- scribing the likelihood of data, or ofa user, being re- jected. bloom On a cathode-ray tube (CRT) display device, the tendency ofaphosphor 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. blower 1. colloq. A device to blow a current of air or gas, e.g., for installing air-blown fiber. See blown fiber. 2. Aspeaker or blowhom. Blowfish A 64-bit (8 bytes) encryption algorithm developed by Bruce Schneier, Blowfish has become the basis for a number of encryption schemes, including Kent Briggs' Puffer, Harvey Parisien's VGP, and Philip Zimmermann's PGP. Blowfish uses a variable- length key up to 448 bits in length. There may be restrictions 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 installation system designed by British Telecommuni- cations PLC that enables faster, more flexible installation 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 agreat convenience. blown fuse A 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 appropriate voltage. A blown fuse will sometimes show a blackened area inside the glass. Circuit breakers have superseded fuses in many types ofelectrical wiring, but the phrase has remained and is often used to indicate a tripped circuit breaker. See circuit breaker, fuse. BLS The u.S. Bureau ofLabor Statistics. http://www.bls.gov/ BLSR See bidirectional line-switched ring. BLU basic link unit. A generic 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, version 1. 2. The Blue Book or CD Plus standards are a subset of the 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 ofmajor audio and computer 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 standards served another purpose in preventing CD players 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 box colloq. A small handheld device designed 125 © 2003 by CRC Press LLC 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 established 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 operator 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 halfof 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 specifically 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 government information and email addresses are now sometimes called blue page listings. blue wire Acolor designation used by mM to indicate 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 communications 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. BLV IBLI An operator call wherein the caller requests information about the busy status ofa line or requests an interruption ofa 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 A file extension standing for bitmap, often 126 expressed as athree-character file name extension to maintain backward compatibility with operating systems 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 ofraster graphics file, bitmap also has a specific meaning for a standardized 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 office. board See printed circuit board. Boardwatch A good prosumer-Ievel print and Web publication dealing specifically with the telecommunications industry, particularly the Internet. http://www.boardwatch.com/ bobtail curtain antenna A phased-array, bidirectional, vertically-polarized wire antenna, intended for high-frequency transmitting and receiving. BOC See Bell Operating Company. body The main informational portion ofa communication, 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 acharacter set (typestyle). The portion from which ascenders and descenders origi- nate. Sometimes called x-height. body area network BAN. Anetwork based upon a body-worn communications network device. It is usually wireless, to enable mobility, but may also be wired if the user is stationary (usually seated at a computer, 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, David R. Along with Robert Metcalfe, the co- developer and co-builder of the first Ethernet systems in 1973 at Xerox PARCo Metcalfe and Boggs authored a frequentlycitedarticle"Ethernet: Distrib- uted packet switching for local computer networks" in Communications of the ACM in July 1976. See Ethernet; Metcalfe, Robert. Bohr's correspondenceprinciple In an atomic system, the behavior of the electrons must increasingly approach that predicted by classical physics the higher the quantum number of the orbit. bolometerAdetection instrument for measuring the intensity ofradiant energy through a thermal-sensi- tive resistor, a type of actinometer. Bolometers may be assembled in arrays. © 2003 by CRC Press LLC Boltzmann constant (symb. - k) The ratio of the universal 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 of Maxwell 's predictions, confrrm- ing them, and published his results in 1875. 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. A phrase applied to the start ofa tape or other serial storage media. 3. See Beginning of Message. BONAPARTE Broadband Optical Network using ATM PON Access Facilities in Realistic Telecommu- nications Environments. An ACTS project to demonstrate the viability of broadband ATM PON as a cost-effective communications system and to demonstrate interoperability between ATM mc island through the Pan European ATM Network. See BROADBANDLOOP, BOURBON. bond n. 1. To join, adhere, or unite into a combined unit or system. Bond usually implies a semiperma- nent or permanent 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, electrical To form an electrical connection by joining two conductive surfaces, usually metal, to provide a low-resistance path for the circuit. In electronics, wires are often bonded to a small metallic pad on a circuit board. See bonding. bonding 1. Joining two or more items with adhesive, weld or solder. In PC boards, there may be a bonding pad on the board or on a chip for the express purpose of providing sufficient space and electrical contact for a potential bond (usually solder). 2. An inverse multiplexing specification described by BOND- ING. See BONDING. BONDING Bandwidth On Demand Interoperability Group. A set of protocols, known as the BONDING specification, developed by a consortium of data communications consultants and suppliers. BONDING arose from efforts to create a standardized inverse multiplexing protocol in order to improve interoperability among multiplexers from various vendors. The BONDING specification describes a number of modes ofinteroperability for switched networks, so a sideband signal can be subdivided into multiple 56 Kbps or 64 Kbps channels, and recombined at the receiving end. bong A tone transmitted through a phone line to indicate 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) An English-born mathematician, son ofa maid and a shoemaker, Boole set up a school at the age of only 19. He taught himself mathematics and began publishing his ideas, intro- ducing Invariant Theory. His t 854 publication "The Laws of Thought" introduced mathematical concepts applicable to computing operations and earned him the sobriquet of"father of symbolic logic." Boolean logic is named after him. Boolean expressionA type of expression often used in programming to control binary relational operations 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 algebra works readily on binary computing systems. boom 1. 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 of visual obstruction. 3. The horizontal supporting rods for many common antennas from which there may be secondary protruberances to increase transmission or reception. boom pole A 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. A boom pole is sometimes called a pike pole. boom truck roller See stringing roller. boomer colloq. 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. boot abbrev., v. To start, to power up, to get a ma- chine going, to 'kick' something into operation. De- rived from bootstrap, which is further derived 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. bootROMA read-only computer memory chip usually located on the motherboard as an essential part ofa 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 operating system, device drivers, and sometimes user applications. On many Intel-based desktop computers, the information for accessing devices may be transferred to the BIOS during system startup. See BIOS. BOOTP See Bootstrap Protocol. bootstrap In 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 apower-off state, low-level hardware and software systems are brought online to the point where self tests can be performed and devices recognized. 127 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary These basic systems are then used to "pull the system up by its bootstraps" to the next level of operating system capabilities for processing input from the user, network configurations, and basic applications parameters. Bringing a system online from a power-off state is called a cold boot. A warm boot is a reset from a power-on state during which the system typically re- reads the boot ROM and restores basic operating parameters 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 operating mode. See device drivers. Bootstrap Protocol BOOTP. An Internet Protocol! User Datagram Protocol (IPfUDP) client/server protocol for storing and providing configuration information 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 ofaserver host, and the name ofa file to be loaded into memory and executed. It is accomplished in two phases: address de- termination and bootfile selection; and file transfer, typically 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. bopper A Biocomputing Office Protocol (BOP) server developed by Don Gilbert, based on popper, a Post Office Protocol server. Bopper provides biocomputing services to BOP-compatible clients. It was initially released for Solaris2 in June 1996. Border Gateway Protocol BGP. An interdomain 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. Border Gateway Protocol Version 4 BGP4. A version ofBGP which uses route aggregation to reduce the size of routing tables, and which supports Class- less Inter-Domain Routing (CIDR). border node In ATM networking, a logical node in a specified peer group that has at least one link that crosses the peer group boundary. Border Node A means for establishing connections between networks ofdistinct topologies while limiting 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- 128 tip Ie subnets. It facilitates interoperability, topology isolation, subnet partitioning, route calculation, optional security, optional 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. BORSCHT An acronym used in the telephone industry 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 - co dec (analog/digital conversions) H- hybrid (two-/four-wire conversions) T - test access. Boston Computer Society BCS. Formally, one of the largest computer user groups in the world, with a membership ofover 25,000 at its peak, the Society served users ofa variety of types ofcomputer 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. bot, 'bot A term frequently used on the Internet to 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 frequently been given personalities by their respective programmers and thus take on anthropomorphic characteristics not usually attributed to applications programs, hence the term bot instead ofapplication. See avatar, robot. bottleneck Apoint in a system, device, or transmission link that slows the rate of communication below the expected efficiency or below the capabilities of other links in the system. For example, acomputer with a CPU capable of64-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 aconstant limitation ofa system or may be a limitation occurring only during times ofpeak traffic. Bouguer, Pierre (1698-1758) A French mathematician, 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 © 2003 by CRC Press LLC known as Bouguer's law. Traite d'Optique sur La Gradation de La Lumiere, his treatise on photometry, was posthumously published as a first edition in 1760. In addition to his observations of absorption properties of radiant energy in atmospheric optics, it describes a number oftypes ofphotometers, including a method ofgoniophotometry. See Bouguer's law. Bouguer's lawAdescription of the relationship between an absorbing medium and the radiant energy absorbed in terms 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 of the same kind. One was set at a fixed distance from the illuminated surface but had an absorptive 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 of the illumination on the first surface would vary depending upon the thickness of the intervening materials and the intensity of the illumination on the second would vary ac- cording to distance. By visually assessing the intensity 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 ofdifferent composition (e.g., different translucency). In contemporary applications of the concept, the relationship is usually calculated with respect to a specific wavelength with temperature and pressure held constant. It provides information on absorbancy characteristics or, seen another way, transparency. Bouguer's law is also known as Beer's law or, when the concepts ofabsorption in proportion to aconcen- trate and the thickness of the intervening materials are combined, it is called Beer-Lambert's law. See Lambert's law. boule In fiber optics fabrication, a sooty, layered coating that builds up inside a supporting tube through a chemical deposition process. The boule is then further sintered to remove impurities and collapse the boule into a clear cylinder preform. The preform, which is typically composed of silica glass, can then be drawn out into a long fiber filament. See preform, vapor deposition. bounce 1. To rebound, to come back, to deflect off of, to echo. The ionosphere is used to bounce radio signals over long distances. 2. Inelectronic transmissions, 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 interference in the transmission or no transmission at all. In other instances, the physical characteristics of the Earth and the ionosphere and the position ofrepeat- 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 broadcast 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 aprevious RACE project which studies issues of providing cost- effective, scalable access to ATM -based networking services in Europe and the broader Information So- ciety. The project focuses both on users and technologies and involves the cooperation of Member States of the 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 in L'Illustration de Paris in 1854. See Meucci, An- tonio; Gauthey, Dom; telephone history. Bower-BarffprocessAprocess in which 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) ABritish 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 law At aconstant temperature, the volume ofa definite mass of gas is inversely proportional to the pressure such that the product of the volume (PV) is constant. BP 1. bandpass. 2. base pointer. 3. beam position. 4. bypass. BPAD Bisynchronous Packet AssemblerIDisassem- bIer. The BPAD Protocol is a transport protocol associated with X.25 networking. BPDU See Bridge Protocol Data Unit. BPI See bytes per inch. BPON See Broadband Passive Optical Network. BPM See beam position monitor. BPS See bits per second. BPSK See binary phase-shift keying. BR 1. beacon receiver. 2. Bureau of Radiocommu- nications. Bragg angle In the context of Bragg's law, the angle between the lattice plane and the incident X-ray beams (commonly expressed as theta - 8). See Bragg's law. Bragg reflector A technology used in diode lasers that allows very fine control over the focus of the beam. A Bragg reflector is also called a grating 129 ' Yi0t ll! . ~,:,,',:~:f,: I !!t~~: • © 2003 by CRC Press LLC 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 of data transmissions in existing cable installations. By finer focusing of the beams and multiplexing, capacity may be improved on fiber channels. See Agility Communications, Bragg grating, diffraction, quantum cascade laser. Bragg grating A grate-like pattern that is "written" into a fiber during fabrication to modify the characteristics of the basic fiber filament to reflect wavelengths 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 communications circuits. There are many types of grating design (and research continues) that enable the reduc- tion of noise 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 N anoStructures Laboratory has resulted in new Bragg grating designs and fabrication 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 a multi wavelength 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 studied and recorded. See Bragg's law. Bragg's law, Bragg's relation A 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 of an 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 significant not only for their practical applications, but for providing evidence supporting theories about the 130 periodic atomic structure of crystals. 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,WilliamHenry (1862-1942) A British physicist 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,WilliamLawrence(1890-1871) An Austra- lian-born British physicist who studied at Cambridge and became a lecturer there. In the 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 published X-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. braid A fibrous or filamentous, long, tubular intri- cately woven structure usually of plastic or fine metal that forms a covering over a conductive or insulat- ing core in a layered cable. Brainerd, Paul Brainerd 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 publishing. 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, developed 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 of the kind that is not common. See Brainiac. Brainiac Brain-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 technology under the name GENIAC, and Berkeley contin- ued to promote computing devices under the name Brainiac. In writings on the GeniacIBrainiac technology, Berkeley described Brainiac computing experiments' 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. branch 1. Ajunction point from which there is more © 2003 by CRC Press LLC than one path along which to continue. 2. An instruc- tion in a computer program which, when evaluated, can lead to a different destination for execution of the 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 circuit In 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 feeder In 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 office BO. 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 routing or switching services, customer services (including installation, maintenance, and repairs), and local marketing, billing, and tax procedures. branching 1. 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 electrical installations and data networks. branching filter 1. A device for separating or com- bining separate frequencies when used in conjunc- tion with a guiding structure for the wave. 2. In computer networking, a software utility for selectively routing data into several paths or files based on specified characteristics. BranlydetectorA device created in 1890 by Edouard Branly, consisting ofa 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 transmission of nerve impulses. See Branly detector, coherer. BRAS broadband remote access server. Braun,KarlFerdinand (1850-1918)A German researcher 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 contribution to electronic circuitry that provided a tran- sition from coherers to crystal detectors. Braun invented the cathode-ray indicator tube or Braun tube in 1897, a significant device in the evo- lution of electronics. Braun's attitude towards science was similar to Benjamin Franklin's. While Franklin 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 of his earlier discoveries rather ~~~ek~;h~~~:e~:~~~~t~~~::~~~~r;;~~:n~r:J~r; iB tuning transmitters in Britain, starting in 1899, technology that may have influenced Marconi's tuning patent of 1900. Ayear after his invention of the CRT, Braun was hired to provide guidance on an undetwater wireless telegraphy 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 aN obel Prize in Physics in 1909, along with G. Marconi, for his contributions to wireless telegraphy. See cathode-ray tube; crystal detector; Murgas, Jose£ BRCS Business and Residence Customer Service. breadboard A board with numerous attachment points, often in a grid, that permits the prototyping of circuits. Breadboards often resemble a nest of col- ored worms, as they are frequently hand-wired with a lot of crisscrossing conductors with temporary attachments. Breadboards are handy for concept design, testing, teaching, temporary circuits, and con- vincing the boss that you have a good idea that will work. See proofof concept. break Willful 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 systems 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 computer keyboards that permits a one-keystroke interruption of the current task, assuming the software supports, and correctly interprets, the input from the keystroke. Break keys are included since some of the common ways to interrupt tasks involve combination keystrokes, such as Ctrl-C, and hitting one key is easier, especially for less experienced computer users. See break. break out box See 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). breaker 1. In electrical installations, a point in a circuit, usually ajunction installed in series between the main electrical source and a branch circuit, in 131 © 2003 by CRC Press LLC . Fiber Optics Illustrated Dictionary BITNET, BITNET-NJE Because It's Time Net- work. An international, cooperative, academic network established in 1981 by Ira H. Fuchs (City Uni- versity. algorithm developed by Bruce Schneier, Blowfish has become the basis for a number of encryption schemes, including Kent Briggs' Puffer, Harvey Parisien's VGP, and Philip Zimmermann's PGP. Blowfish uses a variable- length key up to 448 bits in length. There may be restrictions 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 installation system designed by British Telecommuni- cations PLC that enables faster, more flexible installation 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. 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary These basic systems are then used to "pull the system up by its bootstraps" to the next level of operating system capabilities for processing input from the user, network configurations, and basic applications parameters. Bringing