Fiber Optics Illustrated Dictionary - Part 13 pot

Fiber Optics Illustrated Dictionary While the invention of the telephone was not as revo- lutionary as the telegraph in technical terms, it was a highly significant, culture-changing evolutionary step that personalized distance communications and facili- tated commerce in ways not previously possible. See audiometer; Bell System; Berliner, Emil; Edison, Thomas Alva; Gray, Elisha; Meucci, Antonia; Reis, Philip; Photophone; telephone history. Bell asynchronous standards A series of full duplex standards developed by AT&T. These were widely supported by other manufacturers in the late 1970s and early-/mid-1980s. Other vendors and standards bodies began competing with the Bell standards, most notably Hayes, in the early 1980s. The V Series Recommendations by the ITU-T are now the domi- nant formats. Some Bell standards are shown in the Bell Serial Communications Standards chart. BelJ Atlantic Aholding company created as a result of the AT&T divestiture in the mid-1980s. See Bell Operating Company. Bell Canada, Bell Telephone Company ofCanada The Canadian arm of the Bell system until the 1970s, when it became separated from the U.S. Bell system. Bell Canada was a member of the Stentor Consor- tium, along with BC Tel Ltd., SaskTel, and others. As companies merged and were bought out, the Sten- tor alliance dissolved and Bell became mainly fo- cused on the provinces ofOntario and Quebec. Bell is the major telecommunications carrier and supplier of telecommunications equipment in Canada. Through mergers, BCT.TELUS Communications Inc. became the second largest telecommunications company in Canada. In 1997, Bell Canada and TELUS Cable Holdings Inc. both applied to the CRTC for broadcast distri- bution licenses to conduct trials of broadcasting ser- vices, while distributing telecommunications services over the same digital networks. In 1999, both Bell and TELUS testified on issues of promoting elec- tronic commerce by protecting personal information related to Bill C-54. Bell Canada Relay Service BCRS. A 24-hour ser- vice that allows TTY users, who may be hearing im- paired, to talk to one another or to a hearing person with the help ofspecially trained operators translat- ing through teletypewriter terminals. The TTY equip- ment can signal up to 60 words per minute. As an example of the service, the subscriber calls the BCRS operator and provides his or her name and number and the number of the person to be called. The operator requests billing information and then places the call. The operator then acts as a translator, conveying a text message by voice to the hearing callee, and a voice message by text to the hearing- impaired caller. The call is kept confidential by the operator, and no record of the conversation is retained. BCRS services are billed at the same rate as normal phone charges. Bell Communications Research Bellcore. An orga- nization established as a result of the AT&T divesti- ture to provide a variety of central administration, training, standards, documentation, and quality ser- vices to the regional Bell companies who fund Bellcore and their subsidiaries. It is roughly equiva- lent to the Central Services portion of the pre-dives- titure AT &T organization. Bell Laboratories, Bell Telephone Laboratory, Bell Labs The research arm of the Bell system responsible Bell Serial Communications Standards Standard Speed Notes Bell 103 300 Asynchronous full duplex communications standard for transmitting at speeds up to 300 bps over publicly switched telephone networks (PSTNs). This standard was commonly used with computer modems in the late 1970s, but was superseded by Bell 212 in the early 1980s. Bell 212 1200 An AT&T asynchronous full duplex communications standard for transmitting at speeds up to 1200 bps over publicly switched telephone networks (PSTNs). This standard was commonly used with computer modems in the early 1980s, but was superseded by Bell 20 I in the mid-1980s. Bell 201 2400 Asynchronous full duplex conmmnicalions standard for transmitting at speeds up to 2400 bps over publicly switched telephone networks (PSTNs). This standard was commonly used with computer modems in the mid-1980s. Many other vendors began entering the modem manufacturing/standards industry at this time. Bell 208 4800 Asynchronous full duplex communications standard for transmitting at speeds up to 4800 bps over publicly switched telephone networks (PSTNs). This standard did not particularly catch on in consumer markets. Many users leapfrogged from 2400 bps to 9600 bps as vendor participation and competition for faster speeds increased in the mid-1980s. 112 © 2003 by CRC Press LLC for many important discoveries and the development of thousands of telecommunications technologies and devices over the decades. The labs were established as a combined effort of the Western Electric Com- pany and the AT&T engineering departments in 1907. It grew to be the largest industrial research organiza- tion in the U.S., and, in 1925, the engineering depart- ment of Western Electric was incorporated as Bell Laboratories, with the head office in New York City. In 1941, headquarters were moved to Murray Hill, New Jersey and larger plants were later established in Denver and Atlanta. Smaller field stations and sat- ellite labs were regularly established over the years in many parts of the U.S. In 1934, AT&T's research division was merged into Bell Laboratories. Bell LabsMuseumAn online resource sponsored by Lucent Technologies. You can visit the images and historical references at the Bell Labs Museum Web site. http://www.lucent.com/museum/ Bell Operating Company BOC. This is defined in the Telecommunications Act of 1996 and published by the Federal Communications Commission (FCC), as " any of the following companies: Bell Telephone Company of Nevada, Illinois Bell Telephone Com- pany, Indiana Bell Telephone Company, Incorpo- rated, Michigan Bell Telephone Company, New England Telephone and Telegraph Company, New Jersey Bell Telephone Company, New York Tele- phone Company, U S West Communications Com- pany, South Central Bell Telephone Company, Southern Bell Telephone and Telegraph Company, Southwestern Bell Telephone Company, The Bell Telephone Company of Pennsylvania, The Chesa- peake and Potomac Telephone Company, The Chesapeake and Potomac Telephone Company of Maryland, The Chesapeake and Potomac Telephone Company ofVrrginia, The Chesapeake and Potomac Telephone Company of West Vrrginia, The Diamond State Telephone Company, The Ohio Bell Telephone Company, The Pacific Telephone and Telegraph Company, or Wisconsin Telephone Company; and (B) includes any successor or assign of any such company that provides wireline tele- phone exchange service; but (C) does not include an affiliate of any such company, other than an affiliate described in subparagraph (A) or (B)." See Federal Communications Commission, Telecom- munications Act of 1996. Bell speak colloq. A phrase to describe the substan- tial body of telephone jargon that grew up over the decades within the Bell system, particularly among technicians and scientific researchers. Bell System The original holders of the Bell tele- phone patents formed by Bell, Sanders, and Hubbard in 1877, and incorporated in 1878, less than 15 years after the invention of the telephone. The company thrived and grew under the management of Theodore N. Vail. Since the term of exclusivity granted by a patent lasted only 17 years, the expiry of the Bell pat- ents resulted in the founding of thousands of new in- dependent phone companies. These gradually were merged and consolidated into the Bell System. In a 1984 court decision, divestiture of the American Telephone and Telegraph company (AT&T) removed the distinction between the Bell company and inde- pendent phone companies. Bell Telephone Company of Canada Inc. Estab- lished in 1880, Bell Canada began by providing ser- vice to the larger centers in eastern Canada, most of which were interconnected within about 10 years. Bell Canada is under the jurisdiction of the Canadian Radio Television and Telecommunications Commis- sion (CRTC). Bell Telephonic Exchange The first telephone ex- change in Ohio State. Bellcore See Bell Communications Research. BellinghamAntique RadioMuseum See American Radio Museum. BellSouth Corporation A large regional holding company created as aresult of the AT&T divestiture in the mid-1980s. It is comprised of Southern Bell Telephone and South Central Bell Telephone Com- pany and a number of other companies. BellSouth is cooperating with Nippon Telegraph and Telephone to provide large-scale integration of residential fiber multimedia telecommunications services. See Bell Operating Company, fiber to the home. benchmark 1. A specified expression of performance based on agreed-upon test criteria. 2. A criterion ex- pression, often numeric, against which other systems or processes are compared. Benchmarks are so sys- tem specific that it is hard to translate benchmark per- formance scores to real-life computing situations, and their validity is often hotly contested. See benchmark test. benchmark test A criterion test for evaluating the performance ofa system, often applied to the speed of processing. Although benchmark tests may be straightforward for simple electronic components, they are sometimes used to evaluate the system per- formance of complex systems, which is difficult to measure in objective units. For example, a computer with a 40-MHz CPU will perform more slowly on benchmark tests than a 200 MHz RISC chip CPU, yet a word processor running on one system may have the same apparent speed to the user as one running on a faster system due to many factors such as load on the system, user interaction, software optimiza- tion, address bus bottlenecks, amount and type of memory, etc. In a broad sense, benchmarks cannot be said to provide definitive performance measures, but they are nevertheless often established as abest- efforts way of comparing and contrasting systems with significantly different construction and charac- teristics. Even these are often considered "better than nothing" performance indicators. See Dhrystone, Rhealstone, Whetstone. bend loss In cabling, attenuation caused by bends and twists in the wires or fibers. At each bend there is a tendency, especially in optical fibers, for the signal to want to continue to radiate in the same direction, 113 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary resulting in slight losses through the cladding as the cable curves. See Bend Factors diagram. bend radius In cabling and cabling enclosures, a description of the bend tolerance ofa certain material at a certain radius, often under a certain pulling force. This measure is important for manufacturing, for se- lecting types and sizes of parts, and for installing pul- leys, cables, and wires. See bend loss. bend-insensitive fiber Fiber optic cable that is par- ticularly resistant to losses when the fiber is bent. Bend-insensitive fibers were first being developed and described in the late 1980s. There are various ways to reduce bend-induced loss in optical fibers. The materials, diameter and ratio of core to cladding, and the numerical aperture can all influence sensitivity to bend losses. For example, in- creasing the numerical aperture (e.g., NA = 0.16 for single-mode fiber) can confine the reflected light more tightly within the conducting core, producing a more bend-insensitive fiber. Benedicks, Manson An American researcher who investigated the electromagnetic-influencing proper- ties of germanium crystals in the early 1900s and found that they could be used to convert alternating current (AC) to direct current (DC). Benjamin Franklin Institute of Global Education A resource and Web center that supports and pro- motes affordable access to education from global re- sources through distance education, founded in the mid-1990s by John Hibbs. http://www.bfranklin.edul bent pipe A description for a communications con- duit, path, or transmissions medium that reflects an incoming signal at an angle, usually between 20 and 70 degrees, thus following a path that resembles a bent pipe. This is a very common configuration for Earth-satellite/satellite-Earth transmissions and for radio transmissions which are channeled by being bounced off the ionosphere. Benton Foundation An organization established in 1948 that has promoted diverse and equitable public use of communications technologies for its social benefits since 1981. It is named after its founder, William Benton (1900-1973), a U.S. Senator, UNESCO Ambassador, and publisher of the Ency- clopedia Britannica. The Benton Foundation provides news on communications policy and the social use of technologies; it supports a number of free online newsletters and discussion lists. The Foundation op- erates from an endowment along with additional funding from major communications industry ven- dors and philanthropical organizations. See Commu- nications Policy Project. BeDS An object-oriented, multitasking, fast, non legacy, microcomputer operating system devel- oped by Be, Inc., under the leadership ofJean-Louis Gassee. Programmers claim it is a pleasure to pro- gram and that the environment is powerful and yet easier to learn and use than many others. Bend Factors in Fiber Optic Lightguides Light is guided thlVugh a fiber optiC cable thlVugh a process called total internal reflection (TIR) in which the outer cladding. which has a different refi'active indexfi'om the inlier conducting core (in this case, a multimodefibel), reflects the light beam back into the core. This plVcess continues even if thefiber is bent to some extent, which is very useful for network cable installation alldfiber optic plVbes for scielltific or medical purposes. However, there are limits to how much a cable call be bent without bend-induced loss of signal. In the diagram above, the amount of loss ill the bend depends upon the bend radius, the relationship of the core to the claddillg in tenns of size andrefractive index, and the allgle at which the beams encounter the cladding. If a light beam (A) passes the maximum point of bend, it may continue on thlVugh the lightguide. In contrast, a beam (B) traveling at a different angle such that it hits the cladding at the bend, beyond the critical angle at which it,can be reflected backinto thefiber, wouldbepartly absorbed by the cladding and by any materials outside the cladding and would be lost as far as the fiber core is concerned. Commercial mamifacturers design certain cables to minimize bend loss, by balancing cable parameters. Thus, bend-insensitive cables often have a higher numerical aperture. 114 © 2003 by CRC Press LLC Gassee is well known for his previous contributions to R&D at Apple Computer, when the Apple II line was being developed. BeDS is aimed at multimedia audio and visual applications. BeDS was introduced to developers late in 1995 along with the Be computer. About a year later, Be, Inc. dis- continued the hardware, to concentrate on software development, as their operating system software is able to run on several hardware platforms by various vendors. See Be, Inc. BEP 1. See back end processor. 2. Bureau Economique de la Province de Namur. 3. Bureau of Engraving and Printing (Federal) 4. Business Enterprise Program (for minorities and handicapped workers). BER 1. See Basic Encoding Rules. 2. See bit error rate. Berkeley, Edmund Callis (1909-1988) An Ameri- can educator and pioneer computer developer who worked on the Mark II construction project in 1942 and developed a lifelong interest in computer appli- cations. Berkeley founded the Eastern Association for Computing Machinery in 1947, which became the respected Association for Computing Machinery (ACM) the following year. In 1948, Berkeley started his own company, Berke- ley Associates, to market his inventions. He authored many books foreshadowing computer and telecom- munications history. In 1949, Great Brains, Or, Ma- chines That Think was released with instructions on how to design computing devices. In 1950, Berke- ley published Computers and Automation, a historic computing magazine. In 1956, he coauthored Com- puters, Their Operation and Applications with L. Wainwright. And, in 1959, he authored Symbolic Logic and Intelligent Machines. Following up on the ideas in Great Brains, Berkeley described and constructed one of the first desktop mi- crocomputers that became generally known through popular publications. The Simon (named after "Simple Simon") was made public in an electronics magazine in 1950 (as construction plans). Berkeley was also actively interested in the design and con- struction of small robots (quite prolific, in fact), which he marketed through Berkeley Enterprises, Inc. (originally Berkeley Associates). Berkeley sought to bring computing concepts to hob- byists through the GENIAC computing device. Un- fortunately, after disputes with his business partners, Berkeley lost the legal right to use the name, so he gave the name Brainiac to essentially the same tech- nology and his former business partner used the Geniac name to market tube-shaped calculators. The archival legacy of Edmund Berkeley from 1923 to 1988 has been donated to the Charles Babbage in- stitute by Berkeley Enterprises, Inc. and the Berke- ley family. See Brainiac, Charles Babbage Institute, GENIAC, Simon. Berkeley Internet Name Domain BIND. A popu- lar implementation of the Internet domain name ser- vice (DNS) originally developed and distributed by the University of California in Berkeley. There have been numerous commercial implementations of BIND. As of2001, BIND 4.9.8 (for older systems), BIND 8.2.3, and BIND 9.1.2 were in widespread use on the Internet as free software. However, the pur- chase of support contracts aids in the continued de- velopment of the Internet Software Consortium's ~~~:r~~!~:~=~:~~~~~~~Fty~ef:~a r:. 1974, adapted to the Digital VAX and PDP-II, and now widely ported to many systems. BSD was fur- ther developed by Bill Joy and others at the Univer- sity of California in Berkeley, who released it in 1978. Joy subsequently wrote the well-known vi editor, and co-founded Sun Microsystems. BSD flourished with the development of the ARPA- NET, the forerunner to the Internet, and the Computer Systems Research Group (CSRG) enhanced BSD with 32-bit addressing, virtual memory, and a fast file system supporting long filenames. They further in- troduced BSD Lite which was BSD without the li- censed AT &T code, which could be freely distributed. The CSRG disbanded in 1992, and the community at large adopted BSD and developed FreeBSD. See FreeBSD, Unix, UNIX. Berliner, EmU (later Emile) (1851-1929) A German- born American/Canadian inventor and musician who was keenly interested in acoustics, electricity, and physics as telephone technology began to emerge. Berliner is best known for music technologies, but also made some significant contributions to historic telephone technology. In April 1877, he filed a ca- veat for a patent on a telephone transmitter and six months later is reported to have demonstrated sev- eral telephone devices at the Smithsonian Institution. In 1878, he received apatent for a transfonner. Ber- liner joined the Bell Company and later founded Deutsche Grammophon and Gramophone Co., Ltd. F. Barraud's painting of a dog listening to a gramophone (trademarked "His Master's Voice") became the popular "Nipper and the Gramophone" trademark registered May 1900 by Berliner. RCA adopted the popular symbol, which is still recognized more than 100 years later. Berliner also founded the Esther Berliner fellowship to support women pursu- ing scientific research. See Gramophone. Berners-Lee, Tim (1955- )A British physicist and programmer, Berners- Lee gained a spot in the his- tory books with his Web project proposal introduced in March 1989, and his demonstration of World Wide Web software in the winter of 1989. The rapid accep- tance and growth of the Web is a tribute to the viabil- ity of this concept. Prior to that, Berners-Lee devel- oped Enquire, while at CERN in 1980, a hypertext system that no doubt formed the seed for his Web project. In 1994, he joined the Laboratory for Com- puter Science at MIT. He has won many awards of distinction for his work, including the 1998 MacArthur Fellowship. He is the coauthor, with Mark Fischetti, of Weaving the Web, a book about the ori- gins and development of the World Wide Web. See World Wide Web. Bernoulli, Daniel (1700-1782) Bernoulli was a Swiss mathematician born in the Netherlands, who 115 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary pioneered the principles of fluid dynamics, now used broadly in aeronautics, electronics, and other fields. The Bernoulli principle is derived from his writings in Hydrodynamica which described basic properties of fluid pressure, density, and flow. Bernoulli box An electronic, high-speed data mass storage and retrieval device based upon technology pioneered by Daniel Bernoulli. In general, the Ber- noulli effect occurs as pressure acts upon a fluid me- dium in relation to the volume of the fluid. These forces will equal changes in kinetic energy associ- ated with the fluid (whether liquid or gaseous). In general, as fluid flow slows, pressure increases, and vice versa. As applied to storage technology, in- creased rotational speed in a magnetic disk creates a cushion of air that controls the distance of the read! write head from the storage medium. Daniel Bernoulli One of the earlier removable computer storage media, called Bernoulli drives, were named after Daniel Bernoulli, a mathematician. Bernoulli-Euler law In a homogenous bar, the cur- vature of its central fiber is proportional to the bend- ing movement. It is a general concept, applicable to many fields including elastic theory and mechanical engineering. Bernoulli's Theorem in a Field of Flow At every point in a steadily flowing fluid, the sum of the pres- sure head, the velocity head, and the height is con- stant. Berry,Clifford Edward (1918-1963) An intelligent and mechanically gifted American who collaborated with J. V. Atanasoff in the development of one of the world's first digital computers. Atanasoff and Berry began working together on the project soon after Berry completed his Bachelor's degree in electrical engineering. The completion ofa prototype computer led to a small grant to build a working version, in December 1939, while Berry continued his graduate studies. Berry then subsequently worked in corporate positions and applied for more than 40 patents in the 116 areas of spectrometry and electronics, 30 of which had been granted before his untimely death. See Atanasoff-Berry computer. BERT bit error rate test/tester; block error rate test! tester. A diagnostic device that is used to test data in- tegrity by transmitting a known pattern of bits and evaluating the subsequent bit error rate (BER), usu- ally on a cable segment. See bit error rate. BERTS See Basic Exchange Radio Telecommuni- cations Service. bespoken, bespoke Custom-made, made to order, made by engagement, requested item. Bessel beamA nondiffracting optical beam, a recent technology that began showing some exciting prac- tical results by the end of the 1990s. The potential for infinitely propagating beams for manipulating particles or transmitting information are exciting new fields of experimentation. By 2001, U.K. researchers had demonstrated Bessel beam "tweezers" for manipulating, stacking, and aligning a variety of silica and biological structures. The linear momentum of light and its interaction with matter were exploited to trap particles. They also demonstrated the use ofa laser beam as an optical particle guide, moving 1 Ilm spheres upward within the microscope slide medium within which the par- ticles were held. In addition to applications in biol- ogy and medical imaging, this technology may have significant practical applications in optical fiber- based telecommunications. Bessel beams can be generated with a glass element called an axicon. See acousto-optic deflector, axicon, laser. Best Current Practice BCP. A process similar to the Internet Standards process, in that specifications are submitted to the IESG for review, but streamlined to provide industry leaders with a more flexible, and often quicker, consensual alternative to the Standards Track specifications for resolving individual policy and operations issues. See Internet Standards process. Best Effort See available bit rate. Best EffortCapabilityA capability offered on some ATM networks that tries to provide transmission but provides no guarantees of throughput. Might be used between two routers, for example. See ATM traffic descriptor, RFC 1633. beta 1. In electronics, the current gain ofa bipolar transistor in a grounded-emitter amplifier. 2. A ver- sion of software that is mostly complete, has been in- house tested, but requires wider input and trials from testers and users outside the company. See beta test. 3. (symb. - B) quartz. 4. (symb. -~) The second let- ter in the Greek alphabet, sometimes used to denote a specific angle in a geometric diagram. BETA Business Equipment Trade Association. A rep- resentative for many of the large hardware manufac- turers in the computing industry. beta site A location or group of people designated to test and use a piece of nearly completed, internally tested software in working conditions more nearly like those in which the software will eventually be used. © 2003 by CRC Press LLC beta testing The in-house process of testing and us- ing a nearly complete software or hardware product to try to detennine if there are still bugs or problems of usability, consistency, continuity, and ergonomics. Beta testing can take months or years, depending upon the state of readiness and the complexity of the software. Some developers use automated monkeys, programs that systematically climb through the soft- ware, to identify bugs or flow problems. It is a good process to use in conjunction with human testing. In the author's experience, as much as 85% of soft- ware may be commercially introduced without suf- ficient beta testing. Because computing is confusing to the average user, users are hesitant to complain, thinking the fault is in their use of the product rather than the product itself, and sometimes this is true. But, upper managers often insist the product has to ship (whether it's ready or not) in order to generate rev- enues to stay in business even though, in most cases, it's bad economy. The cost of testing and correcting bugs before the product ships is almost always lower than the cost of repeated patches, upgrades, techni- cal support, and loss of business due to consumer dis- satisfaction when firefighting and corrections are done after the product ships. If cars were sold with the same number of defects as many software products, consumer rights organiza- tions would boycott the manufacturers. The author of this dictionary has contributed many hundreds of hours to beta testing and once found more than 300 bugs in two days of testing in a software product that the manufacturer insisted was "complete, ready to ship, and absolutely bug-free." There are responsible software houses that engage in extensive testing and quality control, and their efforts should be recognized and rewarded. For those that don't, caveat emptor or get your money back. See alpha testing, gamma test- ing, upgrade, user acceptance testing. BETRS See Basic Exchange Telecommunications Radio Service. beyond visual range BVR. Something that is out- side human sight, or in some contexts, out of sight of human vision with binoculars. In a very general sense, it can mean something distant or obstructed. In tele- communications contexts it is more often used to in- dicate objects, communications means, or antennas that require 'line of sight' distances or unimpeded pathways to be effective. See line of sight. bezel The rim or edge ofa tool or piece of equipment, often angled or sloped. On a computer monitor, the housing edge around the cathode-ray tube. BFA See Brocade Fabric Aware program. BFI 1. See Bad Frame Indicator. 2. See British Film Institute. 3. Buckminster Fuller Institute. BFO See beat frequency oscillator. BFOC, bayonet FOC bayonet fiber optic connec- tor. A quick-connect device without a screw thread. BFT See binary file transfer. BG, BGND background. BGP 1. See Border Gateway Protocol. 2. See Byz- antine Generals problem. BHLI See Broadband High Layer Information. bias 1. Expected or consistent deviation, inclination of outlook. 2. Deviation from expected value, sys- tematic error. 3. In an electron tube, the fixed volt- age that is applied between the control grid and the cathode. bias distortion Inconsistencies or aberrations in the linearity ofa signal. In finely tuned equipment, bias distortion is usually an undesirable property. bias stabilizationA means of controlling the bias in a circuit so that it does not fluctuate. Heat or signal variations can throw offbias, resulting in damage to components. See bias, bias distortion. biasing To apply a small amount of positive or nega- tive stimulus to a circuit, as in an electron tube, to shift it in one direction or the other. BIB See backward indicator bit. BIBO bounded input, bounded output. Input and/or output falling between specified values or other boundaries. A concept used in linear mathematics theory and calculations and in data networking analy- sis of traffic flow. While many models for network traffic are based on unlimited or scalable queues, for the purposes of modeling, testing, or design, it is of- ten practical to establish bounds for input and output. BICEP See bit-interleaved parity. biconical antenna A balanced broadband antenna which resembles a bowtie in the sense that it has two metal cones mounted in the same axis, that meet at the narrow ends where the feed line is attached. The orientation of the assembly affects its polarity. It is suitable for transmissions in the VHF range. BICSIA not- for-profit international telecommunica- tions association headquartered in Tampa, Florida. There are regional offices in Australia, Brazil, and the U.K. BICSI provides educational resources, technical pub- lications, and support for cabling distribution design and installation. It was originally established in the early 1970s as the Building Industry Consulting Ser- vices, International, but is now formally known as BleSI: A Telecommunications Association. http://www.bicsi.org/ BID bridge identification code. See bridge. BIDDS See Base Information Digital Distribution System. BiDi bidirectional. 1. Capable of communicating in two directions either alternately or simultaneously. 2. Oriented or pointing in two directions, as direc- tional antenna components with two main receiving or transmitting elements. bidirectional reflectance distribution func- tion BRDF. A function describing light reflectance from a surface at a given orientation from a source of illumination incident from a given direction. See Lambert's law. bidirectional line-switched ring BLSR. A fault-tol- erant topology for SONET that overcomes some of the problems associated with breaks in basic point- to-point ring topologies. In most ring topologies a secondary ring is in place, in case ofa failure in the primary ring. In local area networks, this is a practi- cal solution, but on long-haul phone networks, for 117 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary example, it involves the costly installation ofa sec- ondary cable that is rarely used. In BLSR, ifa failure occurs, the bidirectional portion of the link is en- gaged, and the traffic is routed in the opposite direc- tion around the section that has failed. In fiber optic cables, this is a very fast transition and wouldn't be noticed by endusers under most conditions. BIDS Broadband Infrastructures for Digital TV and Multimedia Services. An ACTS project to provide a comprehensive analysis of future broadband digital television and interactive multimedia services for European users. BIDS has established a database of information gathered from interactive digital TV tri- als and has analyzed a number ofcase studies. See BBL, BLISS, BONAPARTE, BOURBON, BROAD- BANDLOOP, BTl, UPGRADE, WOTAN. bifurcated routing A routing technique that splits data traffic so that it continues through multiple routes (technically it would be two routes, as bifurcated means split into two branches). BIG See broadband integrated gateway. big-endian Stored or transmitted data in that the most significant bit or byte precedes the least significant bit or byte. Many file incompatibilities between com- puter systems, in which the file formats are otherwise almost identical, are due to platform conventions about whether the data is stored in big-endian or little- endian form. BIGA Bus Interface Gate Array. Technology built into Cisco Catalyst systems to receive and transmit frames from packet-switching memory to its MAC local buffer memory external to the host processor. Bll base information infrastructure. The communi- cations foundation for military establishments. bilateral antenna An antenna whose maximum transmitting or receiving poles are diametrically op- posite, that is 180 0 apart in a plane. Bildshirmtext [trans!. picture screen text] A German interactive videotext system from the German Bundespost. It is similar to the French Telecom Minitel service, except that the German Bundespost did not provide the terminal free. See Minitel. billboard array antenna An antenna array that re- sembles a billboard in that it uses a large sheet metal reflector behind the stacked bipole arrays. Billing Account Number BAN. An identifier that enables telephone carriers to bill individual custom- ers or each of multiple accounts belonging to the same customer. Billing Telephone Number, Billed Telephone Num- ber BTN. In some situations, the telephone number billed may be one ofseveral associated numbers but, for simplicity, all the calls are billed to one. This sys- tem is sometimes done with extension numbers. In other situations, the main number used may be dif- ferent from the number to which the calls are billed, again, usually to simplify accounting or billing state- ments. billion In North America and France, one thousand million (10 9 - 1,000,000,000). In the U.K. and parts of Europe, one million million (10 12 - 1,000,000,000,000). (It used to be a huge number.) 118 BINAC Binary Automatic Computer. Ajoint project of 1. Mauchly and 1. P. Eckert who founded the Eckert-Mauchly Computer Corporation. The BINAC was developed under contract with the Northrop Air- craft Corporation, unveiled in 1949, and was histori- cally significant not only as a successor to ENIAC but for its ability to store data programmed using C-l 0 code on magnetic tapes rather than on paper tape or punch cards. See ENIAC; Hopper, Grace Murray; UNIVAC. binaries, binary files Files that have been compiled or assembled into machine-readable codes, usually 32-bit executable files, that are inscrutable to most human beings. Source code is higher level code (as in BASIC, C, or Perl) that can more easily be read and modified by a programmer. Binary files can be edited directly with a hexadecimal (base 16) editor. See attachment. binary, base 2 A system of numeric concepts and numerals representing quantities in terms of ones and zeros with the smaller units on the right. Thus, two in the base 10 decimal system is written as "2." The same quantity expressed in binary is "10" or "00000010" with the one in the 'twos' position, sec- ond from the right. The columns from right to left are thought of as the "ones column," "twos column," "fours column," "eights column," etc. so that a digit in aspecific column indicates the presence or absence of that amount. Thus, the following numeral in bi- nary: 00 II 0I0 can be transposed to decimal by add- ing its values: 0+0+ 16+8+0+2+0 = 26. In electronics, binary values can be variously repre- sented by pulses ofunequal length, by amplitudes of specified magnitudes, by power on or offconditions, or by different tones. Because most computers are two-state systems, the binary number system is used for programming and storage of data. Thus, zero and one can represent states such as on or off, yes or no, etc. binary asymmetric channel BAC. A concept used in information theory related to Markov channels. As an example, images can be modeled as binary asym- metric Markov sources for transmission over com- munication channels. In mathematical descriptions of the capacity of physical or theoretic structures, the concept of BAC is useful for surface area calcula- tions. binary coded decimal BCD. I. A system wherein each decimal digit is coded into afour-bit word. 2. A system wherein each octet within an ATM cell has each bit set to one of two allowable states, i.e., one or zero. 3. A system of coding high and low power transmissions. For example, BCD is used by the Na- tional Institute of Standards and Technology (NIST) to represent decimal numbers in order to dissemi- nate time code information. At the start ofeach sec- ond of the 60-kHz broadcast, the carrier power is re- duced 10 dB, putting the leading edge of each nega- tive-going pulse on time. To create a binary zero (0), full power is restored 0.2 seconds later. Alternately, to create a binary one (I), full power is restored 0.5 seconds later. Position markers are signaled © 2003 by CRC Press LLC Binary Phase-Shift Keying A "" if'i" iA A 1 , , r", r, : : : : : __ cyfl!.~*l:"~~l!.~ ,Cl~f+- ercl~ : : '.& '~ A wave can be altered in a variety of ways to repre- sent information. By using two wavephases, with one of the phases shifted by halfcompared to the preced- ing reference wave, it is possiblefor the linear modu- lation of a wave to represent two values, zero (0) and one (1) which, in turn, can be transmitted in sequences of patterns to represent data values (e.g., ASCII char- acters). Note that the length of theperiodand the am- plitude remain the same, only the phase is changed. Biocomputing Office Protocol BOP. An Internet transaction protocol for transmitting command line and file data, somewhat analogous to SMTP-POP, but designed specifically to send command-line plus data input file block from the client to the server where it is analyzed and passed back to the client upon request. BOP was developed as an easier way for nontechnical professionals to access biocomputing resources. The server designed to implement BOP requests is called hopper, with SeqPup used as the initial client. BOP can be used with anonymous or password access and provides both deferred and interactive processing modes. See bopper. biometricAn objective measure or representation of a biological attribute, which may be a physical char- acteristic or the output of certain physical character- istics (e.g., handwriting). In technology applications, biometrics that are specific to an individual, such as fingerprints, iris or retina patterns, brain waves, and voice prints, are of interest for developing access, login, and authentication systems. Fiber optic faceplates are being developed for use as biometric light-guiding surfaces in conjunction with BinHexA very useful software archiving/translation tool that can be used to convert an 8-bit binary file into a 7 -bit ASCII file through run-length encoding, so that it can be handled by 7 -bit systems that may use different protocols but understand ASCII. Many email clients use BinHex internally to handle binary attachments to text messages. At the receiving end, the file must be converted back to its original fonn before it can be executed or otherwise used as origi- nally intended. BinHex is a very widely used appli- cation on many platfonns but is especially prevalent in Unix and Macintosh environments. by restoring full power 0.8 seconds later. binary file transfer BFT. Binary files are those that have been translated into a base 2 system to be more readily used by a computer. Binary files cannot be readily transported over 7 -bit systems that typically use ASCII (or EBCDIC on some older systems) en- coding unless they are encoded. Due to the encod- ing, binary files cannot be directly read by (most) humans or directly edited by most text editors, al- though a hexadecimal editor is sometimes used to make limited changes to binary files. Binary file transfers are usually accomplished by (1) encoding the file into ASCII with a utility such as BinHex, (2) transmitting the file, and (3) re-encod- ing it at the destination. Most email clients now au- tomatically convert binary file attachments. Multipur- pose Internet Mail Extension (MIME) is one of the protocols used with mail clients to handle transpar- ently the encoding and decoding of attached files. binary phase-shift keying BPSK. A type of linear modulation in which the phase ofa constant ampli- tude carrier signal represents two values through 180 0 shift reversals. When there is no phase change, a value of zero (0) is represented, while a phase change rela- tive to the preceding wave period represents a value of one (1). This basic modulation scheme is effective for ama- teur high-frequency radio transmissions and LowFER- and MedFER-band operations. BPSK is used in the SLOWBPSK program developed by Pawel Jalocha. The system was updated as PSK31 (phase-shift keying 31 baud) by Peter Martinez to function over a narrow 160-Hz phase-shift mode. binary signaling Signaling based upon two states, whether it be digital or analog. Binary signaling is a common fonn of modulation with a variety of imple- mentations, including arbitrary binary signaling, syn- chronous binary signaling, antipodal binary signal- ing (spread spectrum, Manchester), binary noncoher- ent signaling, binary orthogonal signaling (codewords placed at orthogonal axes). See binary phase shift keying. binaural Related to two sound sources or two sound receiving sources, as human ears. Since humans are accustomed to using two sound sources to distinguish the quality and directionality of sound, monaural music tends to sound somewhat flat. Thus, stereo (binaural) sound systems have evolved to provide a more natural representation of sound. BIND See Berkeley Internet Name Domain. bind triangle In an International Business Machines (ffiM) SNA implementation, a session setup message sequence. binding post In electrical installations, a screw ter- minal with a corresponding nut around which U-shaped lugs or wrapped wires can be wound and secured with the nut. Sometimes there are two nuts, close together so the wire can be secured between the two screws. Binding posts tend to be used in tempo- rary circuits, or in small installations. In medium- and large-scale telephone installations, mounting blocks and punchdown tools are much faster. 119 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary detectors/sensors. This has good potential for 3D bio- metric imaging, remote biometric sensing, and larger sensing/scanning areas. See faceplate. BIOS basic input/output system. A system in read only memory (ROM) on some Intel-based desktop computers, that supports the central processing unit (CPU) by supplying access to a variety of input/out- put devices, such as serial ports, joysticks, monitors, keyboards, etc. As these peripherals are basic to the functioning of the computer, they are frequently used and loaded from ROM into RAM for fast access as a system comes online during the powerup sequence. Biot, Jean-Baptiste (1774-1862) A French profes- sor of mathematics and astronomy, Biot collaborated with Arago in studying the refractive properties of gases, and discovered, in collaboration with Felix Savart, fundamental relationships in electromagnetic theory. The Royal Society awarded him the Rumford Medal for his work in the chemical polarization of light. A crater on the moon is named after Biot. See Biot-Savart law. Biot-Savart law In electromagnetics, the magnetic field produced by a current flowing through a con- ductor may be described as a vector product inversely related to the distance ofa point in the magnetic field to the source current. It is similar to Coulomb's law for electrical relationships. Using integrals, the com- putation may be applied to various arrangements of conducting sources by breaking the system down into smaller components. See Ampere's law, Coulomb's law, Gauss's law, right-hand rule. BIP See bit interleaved parity. biphase codingA networking bipolar coding scheme in which clocking information is carried in the syn- chronous data stream without separate clocking leads. biphase-shift keying BPSK. A simple type of modu- lation scheme used in digital satellite transmissions. In BPSK, each phase of the carrier wave is shifted once with each complete cycle, with a shift indicat- ing the change of the value (from one to zero or zero to one). See binary phase-shift keying. bipolar 1. Having two mutually opposing or repel- ling forces, characteristics, or viewpoints. 2. Having two poles. 3. Acircuit with both positive and nega- tive polarity or alternating between positive and nega- tive polarity. 4. In electronics, a structure prevalent in integrated circuits (ICs). 5. A device having both majority and minority carriers. 6. Having electromag- netic characteristics alternating between two poles. 7. A type of signaling in digital transmissions in which a binary value represents a signal amplitude of either polarity, and no value represents zero amplitude. bipolar receiver A type of telephone receiver used extensively in the Bell System. It improved on ear- lier technology by using new magnetic alloys and employing a different acoustical system for the dia- phragm. See ring-armature receiver. bipolarsignalA signal with two nonzero polarities; it can represent two states or three states in a binary coding scheme. See bipolar. bipolartransistorA semiconductor commonly used in oscillators, switches, and amplifiers. 120 birdie 1. Twittering, squealing, or whistling noise, often high-pitched. Birdie is a descriptive term for auditory interference associated with electrical cir- cuits. In older analog phone circuits, overloading sometimes caused crosstalk (conversations bleeding into one another) or, more commonly, birdies. In amateur radio systems, birdies may result from ra- dio frequency (RF) leakage from nearby devices. In studios with both amateur radio and computer equip- ment close together, it may be necessary to power down everything to a skeleton system and gradually add them back in to locate sources of birdies. Moni- tors, cables, and unshielded devices are common cul- prits; even a computer keyboard can cause birdies. In circuit boards, birdies may result from improper grounding. Homemade or commercial radio fre- quency (RF) sniffers or more sophisticated spectrum analyzers can help locate sources of radio frequency leakage. Proper shielding and grounding, line filters, and toroids can help reduce birdies. If the birdies can- not be easily eliminated, it may be necessary to note the frequencies at which they occur and work around them. 2. Alightweight cable or wire installation ac- cessory device. Once the conduit has been installed for awiring/cabling installation, a birdie, attached to the wire by a long lead, can be blown with a com- pressed air tool so that it "flies" through the conduit, with the wire subsequently pulled through using the birdie as a lead. See pulling eye, snake. birefringent A material with a molecular structure patterned the same along two axes but differently along the third. In a light-admitting material, this anisotropic structure will influence properties such as the index of refraction, which will vary depend- ing upon the angle of incidence of any light that en- counters the substance. Observe a pebble in a bowl ofwater and one pebble will be visible, a little offset from its actual location. The offset is due to the index of refraction of the wa- ter compared to the adjacent air. If you look at a pebb Ie through a translucent birefringent material, de- pending upon the angle, you may see two pebbles be- cause birefringent materials are doubly refractive. Calcium carbonate (CaC0 3 ) is an example ofa com- mon natural substance with birefringent properties. See anisotropic, Iceland spar, index of refraction, re- fraction. birefringent filter A mechanism for filtering wave- lengths using intrinsic birefringent properties of ma- terials used in the filtering component. Birmington Wire Gauge A gauge standard for de- scribing the diameter of iron wires (nonferrous wires are described with American Wire Gauge). The thin- ner the wire, the higher the number from 1 to 20, ex- clusive of the coating. See American Wire Gauge. bis Second, update, revision, encore. In the V Series Recommendations of the ITU-T related to telecom- munications, his indicates a second version or update to a previously numbered standard. This was prob- ably substituted for a revision number to prevent con- fusion between the series number and revision level. Similarly, ter designates three, or third. © 2003 by CRC Press LLC BIS 1. See Bank for International Settlements. 2. bor- der immediate system. BISDN See B-ISDN. BISSI Broadband Inter-Switching System Interface. BIST built-in self-test. Testing capabilities included with a system. Many consumer laser printers have test modes that will create a printout detailing the oper- ating parameters, settings, status, and problems, if there are any that can be reported on paper. Some of the newer printers also have LED screens or Ether- net links so test results can be reported on a built-in monitor or connected computer system. Bisync (pron. bye-sink) Binary Synchronous Com- munication Protocol. Acharacter-oriented serial net- work protocol that was developed in the 1960s, at a time when IBM dominated the network market. It is now mainly supported as a legacy protocol. bisynchronoustransmissionA transmission that can flow in two directions on the same line or channel, usually at the same time. Traditional wire line tele- phones are bisynchronous, whereas some types of radios or intercoms transmit only in one direction, or in one direction at a time. bit binary digit. A basic unit of digital information with two (bi-) states. Many schemes for signaling binary states have been developed: on/off (early tele- graphs), high/low, one or zero (mark or space, data bits), black/white, dot/dash, etc. bit-interleaved parity BICEP. InATM networks, an error-monitoring method implemented at the physi- cal (PHY) layer. The link overhead contains a check bit or word for the previous frame to flag errors. bit-oriented Data communications that can encode control information in single-bit data units. bit-oriented protocol BOP. In general, a network control protocol functioning at the data link layer. There are variations on bit-oriented protocols typi- cally used for synchronous transmissions, including Synchronous Data Link Control (SDLC), Advanced Data Communication Control Procedures (ADCCP), and High Level Data Link Control (HDLC). See Transparent Bit-Oriented Protocol. bit bucket slang A mythical container into which unwanted or unused code, email, chad from punch cards, or other computer information is discarded or lost. Infonnation may also be deliberately discarded by sending it to the null device (dev/null) bit bucket. See chad, leaky bucket. bit error A fault condition in which the value of an individual bit is changed by transmission or data in- terpretation errors. bit error rate BER. Ameasure oftransmission qual- ity, usually expressed as a ratio oferror bits to total bits received. A high bit error rate does not necessar- ily result in a faulty transmission. Error-detecting and correcting algorithms are incorporated into most cur- rent transmissions protocols. However, a high BER may result in slower transmissions, smaller packets, a higher percentage ofretries, and perhaps even the necessity to connect several times to complete a file transfer, for example. bit interleaved parity BIP. In ArM networking, a method used at the physical layer to monitor the er- ror performance of the link. Acheckbit or check word is sent in the link overhead covering the previous block or frame. Bit errors in the payload will be de- tected and may be reported as maintenance informa- ~~~~~~:;~~ ~::~~e~~~~s.f~7~~ :'J~:~r ]1_ In ATM trunking, when the BFrame is created on in- gress, a BIP is generated and remains until the cell is extracted on egress ofa switch. Cells may be dropped ifa BFrame parity error is detected. Payload data may be BIP-checked separately and does not necessarily result in dropped cells. In SONET implementations, distinctions are made between section (BIP-B 1), line (BIP-B2), and path (BIP-B3) overhead, depending upon which part of the path is specified. Layers are hierarchical in SONET such that if section parity is correct, the layers beneath it should also be correct. BIP is described more fully in Bellcore documents and in ANSI Tl.105. See coding violation. bit line BL. Aconcept in array-based memory tech- nologies to designate the location ofa specific bit, often in conjunction with a word line (WL). The word and bit information may be combined into a binary address to indicate the row and column of an array element, especially in a 20 array. bit pipe 1. A generic descriptor for the physical or data transmission line ofa digital circuit. A wider pipe is considered to have more capacity than a narrow pipe or pipeline. A bit pipe need not connect sepa- rate devices or systems; a pipe may be established between two processes on one device. 2. A telephone circuit used to transmit digital data packets. bit robbing A process of commandeering bits in a transmission for something other than their usual purpose. Extra bits may be robbed to convey signal- ing information, especially if the signals are only oc- casionally needed. See robbed-bit signaling. bit stuffing See zero bit insertion. bitmap 1. A point-by-point digital encoding of graph- ics data for transmission, storage, or display. The dis- played image does not necessarily reflect the format of the image file. For example, a vector file may be represented as a bitmap or pixmap image on aprinter or computer monitor, or a pixmap file may be con- verted to a continuous tone image when printed to a dye sublimation printer. 2. A pixelated image. An image (picture or font) represented by discrete dots on a monochrome display, which is typically white, green, or amber (technically a multicolor image is called apixmap rather than a bitmap). Grayscale im- ages, with varying degrees of intensity on amonitor or varying sizes of monochromatic dots on aprinted page, are often referred to as bitmap images, although they may be closer to pixmaps. Abit in computer data does not map directly to apoint on the output device (in fact, several bits are usually needed to encode one image point). In the context ofa bitmap, the term bit is used in its lay meaning to indicate a small amount, a section, or an individual point of the displayed im- age. See raster, pixels, vector. 121 © 2003 by CRC Press LLC . a description of the bend tolerance ofa certain material at a certain radius, often under a certain pulling force. This measure is important for manufacturing, for se- lecting types and sizes of parts, and for installing pul- leys, cables, and wires. See bend loss. bend-insensitive fiber Fiber optic cable that is par- ticularly resistant to losses when the fiber is bent. Bend-insensitive fibers were first. ring BLSR. A fault-tol- erant topology for SONET that overcomes some of the problems associated with breaks in basic point- to-point ring topologies. In most ring topologies a secondary ring is in place, in case ofa failure in the primary ring. In local area networks, this is a practi- cal solution, but on long-haul phone networks, for 117 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary example, it involves the costly installation ofa sec- ondary cable that is rarely used. In BLSR, ifa. Fiber Optics Illustrated Dictionary While the invention of the telephone was not as revo- lutionary as the telegraph in technical terms, it was a highly significant, culture-changing evolutionary step that personalized distance communications and facili- tated commerce in ways not previously