Fiber Optics Illustrated Dictionary - Part 48 ppt

Fiber Optics Illustrated Dictionary 1.410 1~88: 1.610 1995 1.620 1996 1.120 1993 1.130 1988 462 Basic user~network interface Basic user-network interface -layer 1specification Prirnary.rateuser-Il~twork interface PriJnary rate user network interface Itlyer.l specification 1.241.8 1995· Teleaction stage one service description 1.320 1993 ISDN protocol reference model 1.321 1993 B I~DN>prot()colreference Ulodel and its application © 2003 by CRC Press LLC ISDN - various 1.3251993 Reference configurations for ISDN connection types 1.327 •• 1993 B-ISDN functional architecture 1.328· 1992 Intelligent Network - Service plane architecture (also Q.1202) l329 .1992 Intelligent Network - Global functional plane architecture (also Q.1203) l331 1997 Internationalpublic telecommunication numbering plan 1.333 1993 Terminal selection inISDN 1.340 ·.·1988 ISDN connection types 1.350.1993 General aspects of quality of service and network performance in digital networks,including ISDNs 1.3511997 Relationships among ISDN performance recommendations 1.352 1993 Network perfonnance objectivesfor connectioJl processing delays in an ISDN 1.353 · 1996 Reference events fordefining ISDN and B-ISDN perfonnance parameters 1.354.1993 Network perfonnanceobjectivesfor packet mode communication in an ISDN 1.355 1995 ISDN 64kbpsconnection type availability performance 1.3571996 B-ISDN semi-penn anent connection availability 1.364<1995 Support of the broadband cOttJlectionless data bearer service by theB-ISDN 1.3 70 1991C~:n~estion m~agenlent for ISDN Frame Relaying bearerservice 1.371 · ·1996 Traffic control and congestion control inB~ISDN 1.372J993 Frante Relayingbearer sendee network-w-nenvork interface requirements 1.373.····.1993 Network capabilities. to support Universal Personal Telecommunication (UPT) L374 1993 Framework recommendation on "N'etworkcapabilities to support multimedia services" 1.376 1995 ISDN network capabilities for the support of the teleaction service 1.4111993 ISDN user-netw'orkinterfaces·"" references configurations 1.412. 1988 ISDN user-network interfaces - interface structures and access capabilities 1.413 ·1993 B-ISDN user-network interface 1.4141997 Overview of recommendations on layer 1 for ISDN andB-ISDN customer accesses B-ISON - Physical. Layer Specification 1.432>1993 B-ISDN user-network interface- physical layer specification 1.432.1 1996 B-ISDN user-network interface~ physicallay;er specification: general characteristics 1.432.2 1996 B-ISDN user-networkinterface - physical layer specification: .1S5,S20 ~bpsand~t2,080kb~~llperati()n 1.432.3·1996 B-ISDN USer-netWork interface - physical layer specification:lS44 kbps and2048 kbpsoperation 1.432.4 1996 B-ISDN~er-networkinterface- physical layer specification: S 1,840 kbpsoperation 1.432.5 . 1997B~ISDN tiSer-networkinterface- physical layer specification: 25,600 kbps operation Multiplexing 1.460 1988 Multiplexing, rate adaption, and sttpp(lrt°f~~s~~ it,t~~aces 1.464 199t Multiplexing, rate adiiption,and support of existing interfaces for restricted~4 kbitls transfer capability ATM-related 1.326 1995Functjonalarchitec~ of transport networkstiased onATM 1.356 1996 B-ISDNATM layer cell transfer perfonnance 1.361 1995 B-ISDNATM layerspecificatioll 1.363 1993 B-ISDN ATM adaptation layer (AAL) .specification 1.363.1 1.996 ~~ . .A;1JvI ~~9J1: typeI 1.363.3 1996B-ISDNATM adaptation layer specification: type 3/4AAL 1.363.5 1996B-ISI>N~ at1ap~(ln layer specification: type S·AAL 1.365.1 1993 Frame Relayingservi~e specific convergencesublayer(FR-SSCS) 1.365.2 1995 B-ISDNATM adaptation layer sublayers:· service-specific coor~~~n. fU11C1ion~opI'(jvi~~he connection-orientednetworlcservice 1.365.31995 B-ISDNATM adaptation layer sublayers:service-specjfic c()ordinatieJ:lfu~cti0tt~O provide~he connection-oriented transport.service 1.365.4 1996B-ISDN ATMatiaptation layer sublayers:service-specific convergence sublayerforHDLG applications L 731 1996 Types and~eneral. characteristics of ATM equipment I. 732 1996 Functional characteristics ofATM equipment I.75 1 1996.<A.synchro~~ustransf~rmode management of network element view 463 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary monitors are used for both input and output. Key- boards are typically input devices, except for those that have small LED displays to send configuration, status, or numeric keypad calculator information to the user. See input device, output device. I1Pinput. i.LINK See FireWire. IA 1. See implementation agreement. 2. See intelli- gent agent. lAB See InternetArchitecture Board. lAC 1. See Industry Advisory Council. 2. See Infor- mation Access Company. 3. See Infonnation Analy- sis Center. 4. See Institute for Advanced Commerce. 5. See interactive asynchronous communications. 6. See interapplication communications. 7. See Inter- net Access Coalition. lAD See Integrated Access Device. IAHC See Internet International Ad Hoc Commit- tee. lAM 1. incoming address message. 2. See initial ad- dress message. 3. intennediate access memory. lANA See InternetAssigned Numbers Authority. Sampling of IBM Desktop Computers Type Abbrev. Description IBM Portable Computer IBM 5100 Alarger desktop-sized computer introduced to businesses and educational institutions in September 1975. The Portable Computer came in a number of configurations, with varying amounts of memory up to 64K (a lot of memory in those days) at a cost ranging from just under $9000 to almost $20,000 (nearly the price of a house). IBM Computing System IBM 5110 Asmall-scale "affordable" computer that was transitional between high-priced desktops and mainframes, and later systems known as personal computers or microcomputers. Announced in January 1978, the 5110 was aimed at a wide portion of the business market, the market successfully penetrated by Tandy!Radio Shack Computers and the later line of IBM Personal Computers. It was available in configurations of up to 64K of memory. mM Personal Computer IBM 5150 The frrst relatively low-cost personal computer introduced by mM to realize significant sales to general consumers. The IBM PC was launched in 1981 to compete mainly with Tandy Radio Shack computers making big inroads in both hobbyist and business markets. Due to its better reputation for service and its licensing agreements with third parties, mM eventually succeeded in taking the majority business market away from Tandy. Tandy did some things right: they opened a chain of computer centers to support the machines and to provide customer service. mMPCjr An Intel 8088-based microcomputer, introduced in the early 1980s. The PCjr was intended as a low-cost home alternative to the mM Personal Computer XT by IBM. mM Personal Computer XT Extended Technology. An Intel 8088-based microcomputer, introduced in 1983. The processing speeds of the various models ofXTs ranged from 4.77 to 10 MHz (turbo XTs), with 16-bit data buses. Aclock/calendar chip was not standard. Microsoft BASIC was included in ROM, and the computer could use cassettes for program reads and writes. DOS 2.1 was optional, but was needed in order to read and write floppy disk drives. mM Personal Computer AT Advanced Technology. An Intel 80286-based 16-bit microcomputer, introduced in the fall of 1984 by mM as an updated alternative to the IBM XT. The processing speed of the AT was 6 MHz, with 256 kilobytes of memory. It came configured with a 1.2-MByte floppy drive, but the 20-MByte hard disk, graphics adapter, and monitor were optional. A clock/calendar chip was built in. 464 © 2003 by CRC Press LLC lAP See Internet Access Provider. lAPP See Inter-Access Point Protocol. IARL See International Amateur Radio League. IARU See International Amateur Radio Union. IBC See Integrated Broadband Communications. IBM See International Business Machines. IBM clone See IBM-compatible. IBM smaller scale computing systems A series of desktop computers has been marketed by IBM for business, educational, and home markets since the 1970s. The frrst models were compact but expensive, costing nearly as much as a house, and accessible only to corporations or institutions with larger budgets. However, with the success of the MITS Altair per- sonal computer, in 1975, and the introduction of low- cost desktop computers by other companies, it be- came clear that the market for computers was chang- ing and IBM's ballpark price and promotional cam- paigns had to be adjusted to compete with startup companies developing new systems. The first small-scale computer system intended by IBM to significantly exploit the new competitive market was the IBM 5110, announced in 1978. This lower cost successor to the IBM 5100 was unsuccess- ful in capturing popular attention, however, as it was overshadowed by the Tandy/Radio Shack TRS-80 and Apple computers and, to some extent, the Com- modorePET. Thus, in the early 1980s, IBM was scrambling to cap- ture business and home markets, as demonstrated by their release of the IBM Personal Computer and the IBM PCjr. By the mid-1980s, they had successfully recaptured a large portion of the business market, however; the home market was still showing a pref- erence for Apple, Atari, and Commodore-Amiga computers, while the educational market was largely based on Apple computers. In the graphics industry, professionals were over- whelmingly selecting Apple Macintoshes over IBM computers due to the better graphics hardware and software available for desktop publishing and pre- press. At the time, ffiM computers were difficult to network and tended to be equipped with low-resolu- tion monitors and text-based operating systems. It was not until about 1994 that IBM PCs made signifi- cant inroads in the publishing service bureau markets and, even then, companies adding IBM computers tended to hang on to Macintosh computers for large- scale printing jobs such as posters, billboards, etc., where reliable output and good printer drivers were important. Ironically, the reason IBM and IBM-li- censed third party computers became better suited to the needs of the graphics sector was because of the market force for better games machines. Computer games require substantial computing resources, in- cluding more memory, faster processors, and better graphics and sound. With the exception of better sound, these are the same capabilities needed by the graphics industry, which they finally got in a round- about way. Over time, in business markets and, eventually, home markets, IBM computers prevailed. Part of the rea- son for the success of IBM -based computers in the mid-1980s was IBM's decision to license the tech- nology to third-party manufacturers. Thus, IBM "clones" and IBM "compatibles" became prevalent in the mid-1980s, but ffiM computers were preferred until about 1987, when it became clear to consumers that the quality of some of the clones was superior to IBM systems and, in many cases, less expensive. Once again, IBM had to adjust their marketing and manufacturing to compete with a market that was rap- idly changing and evolving. By the late 1980s, desktop computers were beginning to supersede mainframes for many types of comput- ing applications in spite of the insistence of diehard mainframe reps that mainframes were here to stay. Since the mainstay of IBM up to this time had been their medium- and large-scale computers, it was im- ~~~;~;~i:!~r~il~~:~~~~~~~~:r~;: • more powerful than many of the main- and miniframes sold to institutions a decade earlier for tens of thousands or millions of dollars. This remark- able trend for less expensive computers to have more and more powerful capabilities continues to this day. In chronological order, the Sampling of IBM Desk- top Computers chart includes abrief list of early ffiM computing systems. See ffiM-compatible. IBM Token-Ring See Token-Ring network. IBM-compatibleA de facto marketing term used by various companies to promote a desktop computer incorporating licensed Intel-based International Busi- ness Machines (IBM) technology to the extent that most, or virtually all software compatible with IBM personal computers would run on the third-party IBM-compatible machines. IBN Institut BeIge de Normalisation. A Belgian stan- dards body of the Minister of Economic Affairs, lo- cated in Brussels. It is also involved in certification and accreditation activities. IBN is associated with the Comite Europeen de Normalisation (CEN) and ISO. http://www.ibn.be/ IDS 1. See intelligent battery system. 2. See Intelsat Business Service. IC 1. See integrated circuit. 2. See intercom. 3. in- terexchange carrier. See Inter Exchange Carrier. 4. in- termediate cross-connect. iCalendar, iCal An Internet calendaring and sched- uling core object specification submitted as a Stan- dards Track document by Dawson and Stenerson in 1998. The iCalendar spec is intended to provide a foundation for developing and deploying interoper- able calendaring and scheduling services over the Internet. Since a number of different proprietary prod- ucts from commercial vendors were beginning to be extended for use over the Net, a need was seen for defining a common format for the exchange of cal- endar and schedule information. Group or personal information managers may exchange information through the MIME content type defined in the speci- fication. As aresult ofinterest in this most basic and common 465 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary type of application for Internet use, the Internet En- gineering Task Force (IETF) initiated a calendaring and scheduling working group (CALSCH). Other protocols with a direct relationship to iCalendar inter- operability have been defmed, most of them arising from discussions of the CALSCH. CALSCH not only described and submitted specification drafts, but also administered interoperability testing. The work of CALSCH has also come to the attention of working groups developing separate but somewhat related protocols and formats, including the IPTEL working group. The iCalendar spec is based upon an earlier vCalendar specification and has been further described in UML by Michael Arick as to its components, properties, and parameters related to the properties. In 1999, Mahoney and Taler submitted a draft of the Imple- mentors' Guide to Internet Calendaring to aid in un- derstanding the iCalendar effort and the relationships of the different protocols to facilitate the creation of conformant applications. Progress towards a final embodiment dragged some- what and the specification gained in complexity over time. Market-sensitive vendors began to be wary not only of the complexity but also of the time it was tak- ing for the effort to solidify. CALSCH members even- tually acknowledged that it might he best to simplify the project and denote some areas of iCalendar imple- mentation as optional rather than mandatory, a move that sparked some renewed interest. See RFC 2445. iCAL A Web-based commercial software calendar/ scheduling utility available in personal and profes- sional editions. Demo versions may be downloaded free from the Web. lealAn X-based calendar/scheduling program devel- oped by Sanjay Ghemawat. Version 2.0 was released in 1995. C++ Source code may be downloaded from the Web and through FTP. ICAL See Internet Community at Large (natural his- tory collections project). ICALEP International Conference on Accelerator and Large Experimental Physics. ICANN See Internet Corporation for Assigned Names and Numbers. ICAPI 1. International Call Control API. 2. See In- terface Control Application Programming Interface. ICCD See Internet Configuration Control Board. ICee See Internet Channel Commerce Connectiv- ity Protocol. ICCF 1. See Interexchange Carrier Compatibility F 0- rum. 2. International Civic Communication Forum. A nongovernmental organization (NGO) in the Ukraine, somewhat analogous to a nonprofit organi- zation' that is assisting in providing guidelines for the establishment of further NGOs as democratic insti- tutions. 3. See International Correspondence Chess Federation. ICEA See Insulated Cable Engineers Association, Inc. ICELAN 2000 A commercial software automation control system developed by lEe. It is a graphical network management and control product to provide 466 support and control over LONWorks nodes and ap- plications. Based on Peak Components, this Win- dows-based software enables LONWorks users to install, maintain, schedule, and configure LONWorks networks. See LONWorks. Birefringent Iceland Spar Mineral Raw, transparent calcspar, calledIceland spar, prior to cleavingfor use as refracting lenses. A rendered illustration of the birefingent refractive properties of Iceland spar (right), an anisotropic ma- terial, as compared to other common translucent iso- tropic materials such as glass (left). The directional crystal-like structure of calcite causes light to be re- fracted in two directions, resulting in a double image when viewed through the appropriate plane. Iceland spar, calcspar (symb. -CaC0 3 )Acommon, semihard, soluble, somewhat brittle, crystal-like min- eral of the calcite group. Calcite is one of three min- eral phases of calcium carbonate. It is the primary constitutent of limestone. The transparent form, known as Iceland spar or calcspar, was predominantly found in Iceland until sources began to dwindle and Mexico became apredominant supplier. Depending upon impurities, calcspar may be pink- ish, amber, or bluish and semitransparent. Impurities such as manganese enhance the mineral's ability to fluoresce under ultraviolet light. Iceland spar resembles crystals when cleaved, as the faces within the material are rhomboid with blunted comers. Incrystalline form, the structures are spiked. Iceland spar was widely used in optical instruments for almost 200 years. Calcspar has the interesting property of doubling an image seen through certain planes. Combining two pieces will yield four images, depending upon the orientation of the pieces and the viewer. In 1669, Danish physicist Rasmus Bartholin received a piece of calcspar from Iceland and studied its © 2003 by CRC Press LLC birefringent (doubly refractive) properties, publish- ing his findings in 1670. In 1690, Dutch physicist Christiaan Huygens enlarged upon the study ofbire- fringence in apublished treatise and described light emanations in terms ofspherical wavelets. These ob- servatierns and later ones by W. Wollaston and L. Malus were significant in the understanding of po- larization and the wave nature of light. In 1828, Nicol bonded two pieces ofIceland spar to- gether with Canada balsam, which has a slightly dif- ferent refractive index from the spar, thus develop- ing a polarizing prism component. This became a mainstay of polarimeters and microscopes for almost 100 years. Calcspar is now used less frequently in specialized optical instruments, usually for polariz- ing light in the near-infrared and visible spectra. See birefringent, Nicol prism, refraction, Ulexite. ICI See Interexchange Carrier Interface. ICIA See Information and Communications Indus- try Association, Ltd. ICM See Integrated Call Management. ICMP See Internet Control Message Protocol. ICO See International Commission for Optics in AppendixG. ICO Galileo Galilei Award An international award given annually for outstanding contributions to the field of optics achieved under relatively unfavorable circumstances. In addition to the award, which was established in 1993 and has been awarded since 1994, the Italian Society of Optics and Photonics (Societa de Ottica e Fotonica) donates a silver medal to the recipient. See ICO Prize. ICO Global Communications A Craig McCaw company which at one time was planning a merger with Teledesic, LLC, the "Internet in the Sky" project underway by Gates and McCaw. This proposal was discontinued in late 2001. See New ICO. ICO PrizeAn international award given annually to an individual who has made a noteworthy contribu- tion to the field of optics that has been submitted for publication prior to the nominee reaching the age of 40. The award was established in 1982 and is admin- istered by the ICO Prize Committee. In addition to a cash award, the Carl Zeiss foundation donates an Ernst Abbe medal to the I CO Prize winner. See Abbe, Ernst; ICO Galileo Galilei Award. iCOMP Intel Comparative Microprocessor Perfor- mance index. A simplified means ofevaluating and expressing relative microprocessor power, introduced by Intel in 1992. Intel, as a major vendor of micro- processing chips, sought a straightforward way to convey processor information to purchasers. The iCOMP is an index rather than a benchmark in a tech- nical sense, as it narrowly describes instruction ex- ecution speed (not clock speed). Benchmarks involve sophisticated and careful evaluation of many perfor- mance factors, whereas an index is abasic indicator, in this case, a compilation based on four industry- standard benchmarks, without taking into consider- ation other aspects of the system architecture, includ- ing video display, device addressing, etc. iCOMP is expressed on a comparative scale, which uses the instruction speed of the 25 MHz 486SX pro- cessor as abaseline, assigning it a value of 100, with subsequent processors rated relative to this. icon 1. Pictorial representation, symbolic image, emblem. 2. In telecommunications documents and applications, a symbolic image, usually small and abbreviated, representing an object, program, state, or task. Visually similar iconic representations are sometimes used to show different aspects or states of the same thing, such as a ghosted icon to show something is in use or an iconized version of an ap- plication symbol to show something is loaded and available. Icons are used extensively in documenta- tion and graphical user interfaces (Gills) to represent concepts or contents. Some are specific to an appli- cation or platform, but some are common enough to be recognized across avariety of systems, e.g., folder ~~~~~er::;:'~i~;r:~=:ications network being it.if:; put into place by ICO Global Communications. See :1,:1:'· NewICO. ICONTEC Instituto Colombiano del Normas Tecnicas. A Columbian technical standards body. ICTA 1. Idaho Cable Telecommunications Associa- tion. 2. Indiana Cable TelecommunicationsAssocia- tion. 3. See Independent Cable & Telecommunica- tions Association. 4. See International Center for Technology Assessment. 5. International Christian Technologists' Association. 6. See International Com- mission on Technology and Accessibility. 7. Interna- tional Conference on Technology and Aging. ID 1. identification, identifier. 2. See input device. 3. See integrated dispatch. 4. intermediate device. IDA 1. See integrated data access. 2. integrated digi- tal access. Digital systems intended to facilitate ac- cess to networks and/or application or information sources. The phrase is usually used with reference to systems where a number of features have been inte- grated into one easily used unit, such as a portable scheduler with a built-in wireless modem. 3. intelli- gent drive array. See RAID. IDAI See Accessible Information on Development Activities. IDCMA Independent Data Communications Manu- facturers Association. An independent trade organi- zation representing the interests of independent com- munications manufacturers. The IDCMAhas spoken out on some of the FCC-related rulings regarding new technologies that mayor may not be considered as customer premises equipment. IDE See integrated development environment. IDE devices and controllers Integrated Drive Elec- tronics. A control mechanism and format for com- puter hard disk drive devices developed in 1986 by Compaq and Western Digital. IDE provides data transfer rates of about 1 to 3 Mbytes per second, de- pending upon other system factors, including the data bus. On common Intel-based microcomputers, the IDE uses an intenupt interface to the operating system. IDE has been highly competitive with the SCSI stan- dard, another very common drive format. To get the production costs down, and because many Intel-based 467 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary computers in the early 1980s did not come standard with controllers for extra peripherals, the IDE con- troller mechanism was incorporated into the drive. Each controller can handle two drives, a"master" and a "slave" (compared with seven, including control- ler, for SCSI). IDE is more limited than SCSI (fewer devices can be chained, smaller addressable space, IRQs neces- sary, not compatible with RAID systems, etc.), but it is also less expensive and has become widely estab- lished. In order to overcome some of its limitations, a number of enhanced IDE formats now exist. Most workstations and Motorola-based desktop com- puters (Suns, SOls, Amigas, most Apple Macin- toshes, NeXTs, and others) include SCSI controllers on the basic machine, making it unnecessary to pur- chase a separate drive controller to add SCSI periph- eral devices to the computer. Some of the newer Macintosh and PowerMac computers support both SCSI and IDE. Most Intel-based desktop computers come with IDE controllers on the basic machine and SCSI controllers can be purchased as options. See FireWire, hard disk drive, SCSI. IDEA See International Data Encryption Algorithm. iDEN integrated Digital Enhanced Network. Digital phone technology developed and marketed by Motorola for workgroups. The phones may be used like two-way radios over a cellular network, thus overcoming the distance limitations ofconventional portable two-way radios while also offering other services such as phone, messaging, and data trans- missions. Fax and Internet access capabilities are also provided on data-ready iDEN units. The system is based on the concept of multiple workgroups com- municating within a private virtual network that is part ofa larger common infrastructure. See Enhanced Specialized Mobile Radio. IDEN integrated digital electronic network. identifier ID I. In database management, a keyword used to locate information, or a category of inform a- tion. 2. In programming, avariable name, extension, prefix, suffix, or other device to provide a means to easily recognize an element, or distinguish it from others. IDF intermediate distribution frame. See distribution frame. IDL See Interface Design Language. IDLC See Integrated Digital Loop Carrier. idle In a state of readiness, but not cUrtently activated. Idle is often used as a power-saving measure, and may be a state in which only minimal power is used by the system until full power is needed, as in laptops that power-down the monitor and hard drives when they are not in active use. idle channel code A repeated signal that identifies a channel that is available, but not currently in active use. See idle. idle channel noise Noise in a communications chan- nel that can be heard or occurs when no transmissions are active. For example, low level hums can often be heard in phone lines when no one is talking, but are not noticed when talking continues. 468 idle line cutoff In computer networks, it is not un- common for Internet Services Providers (ISPs) or network administrators to set the system to log off any clients (machines or applications) that are inac- tive for longer than a specified period of time (e.g., 15 minutes). This frees up abandoned terminals or modem lines that are no longer in use. idle signal I. In networking, a channel which is open and ready, and which may be sending an idle signal, but through which no active or significant transmis- sions are occurring. 2. Any signal in a circuit intended to signify that no significant transmission is cUrtently in progress. An administrative tool to allow poten- tial users, operators, or operating software to detect available lines and put them into use, or to compile and record usage statistics for further evaluation and tuning ofa system. See idle channel code. IDML See International Development Markup Lan- guage. IDMLInitiativeAcollaborative initiative to improve global information exchange using XML in an inter- national context through use ofa standardized Inter- national Development Markup Language (IDML). http://www.idmlinitiative.org/ IDN See Integrated Digital Network. IDSCP See Initial Defense Communications Satel- lite Program. IDIV See Improved Definition Television. IDU See Interface Data Unit. IEC I. See Inter Exchange Carrier. 2. See Interna- tional Electrotechnical Commission. 3. See Interna- tional Engineering Consortium. IEEE Institute of Electrical and Electronic Engineers, Inc. The world's largest electrical, electronics, and computer engineering/computer science technical professional society, founded in 1963 from a merger of the American Institute of Electrical Engineers (AlEE) and the Institute of Radio Engineers (IRE). IEEE is a respected and influential organization that serves about a quarter ofa million professionals and students in almost 200 countries. IEEE's activities are broad-reaching, including standards-setting, publica- tions, conferences, historical preservation and study, and much more. See American Institute ofElectrical Engineers, IEEE Standards Association, Institute of Radio Engineers, Organizationally Unique Identifier. http://www.ieee.org/ IEEE Canada Institute ofElectrical and Electronic Engineers of Canada. The Canadian arm of the well- known IEEE, organized across the country into groups based on geographic regions. http://www.ieee.ca/ IEEE History Center The historical archive of the IEEE, including about 300 artifacts and a number of oral histories. The IEEE includes among its early members some of the pioneer inventors in the tele- communications field, including Thomas Edison and Nikola Tesla. It works in cooperation with the IEEE library in which IEEE publications are stored. See IEEE IEEE Standards Association IEEE-SA. An interna- tional organization serving individual and corporate © 2003 by CRC Press LLC members with a portfolio of standards programs. IEEE-SA focuses on full consensus standards pro- cesses as well as innovative policies for standards development. It is affiliated with the IEEE and is empowered to formulate and promote international engineering standards to further globally beneficial applications of technology. Membership in IEEE-SA is not necessarily a requirement to participate in a standards working group. See IEEE. IEEE 802.11 Standard for wireless local area net- works (LANs) adopted in June 1997. lEN See Internet Experimental Note. IES, IESNA See Illuminating Engineering Society of North America. IETF See Internet Engineering Task Force. IF intermediate frequency. IFax device An Internet-interfaced device capable of sending and/or receiving Internet facsimiles through existing Internet mail mechanisms as defined in RFC 822 and RFC 1123. In general, IFax formats must be MIME compliant. IF ax devices can also be used as gateways between the Internet and G3Fax (traditional) phone-based fac- simile machines, with the IFax configured to handle the connection and dialup and any authentication nec- essary to prevent undue cost or unauthorized use. An IFax device can serve as a mail transfer agent (MTA) for one or more G3Fax devices. In general, Simple Mail Transfer Protocol (SMTP) should be used for such applications, although dedicated servers may use POP or IMAP. The IFax specification was developed by the IETF Fax Working Group and described as a Standards Track comment in 1998. See facsimile for- mats, G3Fax, TIFF-FX, RFC 2305. IFCM See independent flow control message. IFD See image file directory. IFIP See International Federation for Information Processing. IFRB See International Frequency Registration Board. IFTL See Fiber in the Loop, Integrated. IFWP See International Forum on the White Paper. IGC intelligent graphics controller. IGMP See Internet Group Multicast Protocol. ignition Lighting, kindling, applying a spark so as to inflame or provide sufficient heat or current to set offa chain of events. IGP See Interior Gateway Protocol. IGRP See Interior Gateway Routing Protocol. IGT Ispettorato Generale delle Telcomunicazioni. General Inspectorate of Telecommunications in Italy. IGY International Geophysical Year. IIA 1. See Information Industry Association. 2. See Irish Internet Association. DCA See International Intellectual Capital Codes Association. llIA 1. See Integrated Internet Information Architec- ture. 2. See International Internet Industrial Associa- tion. 3. See Internet Information Infrastructure Archi- tecture. IIR Interactive Information Response. HOP Internet Inter-ORB Protocol. Awire-level com- munications protocol. See CORBA, Object Request Broker. IISP 1. See Information Infrastructure Standards Panel. 2. Interim Interswitch Signaling Protocol. A basic call routing scheme which does not automati- cally handle link failures; routing tables established by the network administrator are used instead. IITC Information Infrastructure Task Force. IJCAI International Joint Conferences on Artificial Intelligence. An international biennial forum (in odd- numbered years) held since 1969. http://ijcai.org/ ILD injection laser diode. See laser diode. ILEC See Incumbent Local Exchange Carrier. ILLIAC I Ahistoric large-scale computer introduced in 1952 by the University of Illinois. It consisted of vacuum-tube technology and performed 11,000 ar- ithmetical operations per second. See ENIAC, MA- NIAC. ILLIAC II The successor to the ILLIAC I, the ILLIAC IT was introduced in 1963. It was based upon transistor and diode technology and could perform up to 500,000 operations per second. ILLIAC In The ILL lAC ill was introduced in 1966. It was designed to process nonarithmetical data, and so was adeparture from ILLIAC II, a special purpose machine. ILLIAC IV Based on the new semiconductor tech- nology, the ILLIAC IV was introduced in the early 1970s. It was logically designed after the Westing- house Electric Corporation's SOLOMON computers developed in the early 1960s. The ILL lAC IV con- sisted ofa battery of 64 processors which could ex- ecute from 100 million to 200 million instructions per second. It was significant not only for its speed, but also for the ability of its multiple processors to per- form simultaneous computations. The services of the ILLIAC IV were made available to other institutions through high-speed phone line timesharing. illuminator A radiant energy source that provides light which may be used directly or channeled through fiber optic filaments to another location. Il- luminators commonly light buildings, microscopic stages, projectors, lighthouses, signal systems, cali- bration and aiming systems, and, when modulated, provide communications signals that can be sent over long distances through alightguiding channel. Com- mon sources of illumination for fiber optic systems are lasers and light-emitting diodes (LEDs). Illuminating Engineering Society of North America IES, IESNA. Aleading technical authority on illumination. For almost a century, the IESNA has been providing expertise on lighting practices through programs, publications, and services. Members in- clude engineers, educators, scientists, manufacturers, and utility services personnel. http://www.iesna.org/ ILMI See Interim Link Management Interface. IMA Interactive Multimedia Association of Malay- sia. Information about this standards-setting organi- zation is available on the Web. http://wwwl.jaring.my/cornerstone/ima/about.htm 469 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary IMAC See Isochronous Media Access Control. image antenna A hypothetical antenna, used for mathematical modeling, defined as a mirror-image of an above-ground antenna, located below the ground symmetric to the surface, at the same distance as the actual antenna is above the surface. image dissector A vacuum tube-based image scan- ning mechanism about the size and shape ofa long flashlight, developed by television pioneer Philo T. Farnsworth in the early 1920s. It was a type ofpho- tomultiplier component enabling the transmission of straight line images by sweeping the image past an aperture at about thirty times per second. When F arns- worth applied for a patent for an electronic television system, in January 1927 (U.S. #1,773,980), the de- sign included the "image dissector tube." By the 1930s, Farnsworth had improved the technol- ogy so that it could transmit 300 lines per frame, leap- frogging over his competitor, John Logie Baird, in the U.K. At this point, Farnsworth began demonstrat- ing and promoting his device in Europe. Gaumon British licensed the technology, with Baird in charge of incorporating the tube into a new television sys- tem. Baird took an unexpected path and hybridized Farnsworth's electronic system with a mechanical system and produced a 700-line image by 1935. The technology caught the attention of other scien- tists. As RCA was working to simplify and improve upon photomultipliers, J. Pierce and W. Schockley (coinventor of the transistor) at Bell Laboratories were working on the concept as well, in the late 1930s. R. Winans joined Pierce in the effort and they published their results in the early 1940s. The mecha- nisms developed at that time are similar to those in use today. The invention and its evolutionary descendents was an important component in image display/reading products and some military guidance systems for sev- eral decades until solidstate components began re- placing vacuum tubes. Working as a television pickup it made it possible to broadcast film programs for tele- vision broadcasting. It differed from Zworykin's Iconoscope in light sensitivity and storage capabil- ity and thus was not as well-suited as the Iconoscope for broadcasting live performances. Over the years, image dissectors became more com- pact than Farnsworth's original tube, measuring about 2-in. diameter by the 1940s and half that by the 1960s, while retaining the same general structure. By the 1950s, the basic flashlight-shaped image dissector had been integrated with a bulbous camera tube for commercial television sets. Vacuum-tube-based image dissectors have been in- corporated into optical readers, electronically scanned spectrometers, industrial defect detectors, and elec- tronic astronomical star trackers. Modem versions have been used to image synchrotron radiation emis- sions in conjunction with phase-locked radio fre- quency signals, similar to the functioning ofa stro- boscope. The image can be scanned and viewed on an oscilloscope. Image dissectors have applications in current optical systems. Goldstein et a1. have developed an acousto- optical laser-scanning confocal microscope incorpor- Fiber Optic Illumination Source and Beam Conditioning 2 8 l' 10 5" This example of apatented illumination sourceforfiber optic systems illustrates many of the basic concepts and components related to fiber light sources. The initial light source is provided by an array of light-emitting diodes (3, 3') from which the light beams propagate outwards (like flashlight beams). The light beams encounter an array of lenses matched to the LEDs. The lenses align the beams so they travel in congruent rather than varyingpaths (colli- mation). The collimated beams then pass through a transparent Fresnel lens (8), with facets angled relative to the center to amplify and "concentrate" the beam (like a lighthouse assembly). This conditioned beam propagates to- ward the connectorfor the lightpipe (9) where afiberorfiber bundle can be coupled to the light source. [Maas et al., U.S. patent#6,402,347, awarded June 2002.J 470 © 2003 by CRC Press LLC 12, Image Intensifier - Basic Parts ating an image dissector tube for measuring head motion inside MRI and PET medical imaging scan- ners and image dissectors are used for certain photo- nic space-based star sensors. See Baird, John; Farnsworth, Philo; iconoscope; pho- tomultiplier; television history; Zworykin, Vladimir. Farnsworth Dissecting Target Tube Farnsworth continued to make adaptations to the dissecting tube technology hefirst conceivedin 1922. In July 1930, he described a more sensitive dissector target tube, with amplification bysecondaryemissions through a II targe t" or auxiliary electrode, in hispatent application for an electron discharge apparatus for the electricalscanning and transmission of television images. lM'ENI'OIt, , 1( Excerpts adaptedfrom the patent show the dissec- tor tube (left) and a detailed view of the target com- ponent (right) housed at the top of the dissector tube. The image to be transmitted isfocused through a win- dow (11) just in front of the target and falls upon a photosensitive surface on the face of a front-silvered mirror (12). [U.S. patent #1,941,344.] image file directory IFD. A data file structure pro- viding location information for image data in the form of image information and data pointers. In a TIFF raster image file, for example, the IFD is an ordered sequence of tagged fields that begins on a word boundary somewhere after the header data. As more than one raster image may be in a TIFF file (as in a multi-page document or document with different ver- sions of the same image), there can be more than one IFD. Multiple IFDs can be organized as tree struc- tures or as linked lists. See TIFF. image intensifier In the optical spectrum, a device that increases the luminance of an image. The tech- nology was first pioneered by French researchers in the 1930s and significantly developed two decades later by U.S. Army Corps engineer John Johnson un- der the direction of Robert Wiseman. Image intensification in the optical spectrum is ac- complished by means ofa photocathode in a photo- multiplier electron tube that amplifies the signal and turns it back into an image with increased luminance. Outside the optical spectrum (e.g., X-rays), the radi- ant energy is first passed through a scintillator, that converts the high-energy rays to frequencies in the optical spectrum, from which a photocathode can sense the signals. For imaging over a larger area than ~~~:l~~~i~~~~t;i;et~~l~~~~~~;~~~~1~ • sometimes also used to take the image out of the de- vice and feed it into a computer or remote viewing device. The contrast or sharpness of the image may be processed with computer algorithms in conjunc- tion with image intensification, prior to reconstruc- tion of the intensified image. The range of frequencies and the particular part of the spectrum that are intensified depend upon the sys- tem and the application. The system may be config- ured to intensify only certain parts of an image within stated bounds. 1 2 The three basic components of an image intensifier include a photocathode (1) which emits electrons in proportion to the light falling upon the cathode, a microchannel plate (2), which is afinely fused array of glass channels coated with a resistive layer, and a phosphor screen (3). The phosphor screen typically emits light into a light-guiding component such as a fiber optic taper (4) which maybecoupledto a charge coupled device (5). The microchannel plate (MCP) provides a cascad- ingamplifying effect to the electronsprovided to it by the photocathode. The phosphor screen converts the amplified electron signal back into photons. The fiber optic taper may be substituted with a fi- ber opticfaceplate (a fiber optic a"ay similarinform to the microchannelplate) and mayfurther include a 180 0 twist in the fiber filaments to invert the image. Image intensifiers are typically used with weak light 471 © 2003 by CRC Press LLC . 1 for ISDN andB-ISDN customer accesses B-ISON - Physical. Layer Specification 1.432>1993 B-ISDN user-network interface- physical layer specification 1.432.1 1996 B-ISDN user-network interface~ physicallay;er. specification: general characteristics 1.432.2 1996 B-ISDN user-networkinterface - physical layer specification: .1S5,S20 ~bpsand~t2,080kb~~llperati()n 1.432.3·1996 B-ISDN USer-netWork interface - physical layer specification:lS44 kbps and2 048. Association of Malay- sia. Information about this standards-setting organi- zation is available on the Web. http://wwwl.jaring.my/cornerstone/ima/about.htm 469 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary IMAC See Isochronous Media Access Control. image antenna A