Fiber Optics Illustrated Dictionary - Part 92 doc

Fiber Optics Illustrated Dictionary may also be a relay and may selectively collect or relay multiple messages. A relay may alter the format ofa message, but it is generally not recommended unless it is unable to discern the proper implementation of the format, in which case it should modify it. Messages are transported over User Datagram Pro- tocol (UDP) using port 514 and are usually received over port 514. See RFC 3164. sysop system operator. The sysop, or systems admin- istrator, sometimes also called the super user, due to his or her higher access privileges and power over other accounts on a system. The system operator is a technical expert with high security privileges, man- aging a bulletin board system or computer network. On small systems, like BBSs, these tasks may be per- fonned by one person. On medium-sized systems, sometimes assisting sysops are assigned intermedi- ary privileges, between those of the super user and regular system users. Larger systems often split the installation, security, administration, file management, diagnostic, and tuning responsibilities ofa network among a number of system operators, or may even have an entire facility devoted to the administration of the network. system diskA disk that includes "boot" information, that is, low-level operating infonnation, from which a computer system can be started. This may be a floppy drive, hard disk, CD-ROM, or other disk with system files somewhat transparent to the user. With- out certain system files, a computer cannot config- ure itself to recognize peripherals, available memory, monitor types, etc. See bootstrap, operating system. system integrator A commercial vendor offering a variety of network design and implementation services according to the configuration needs of various customers. system reliability architecture SRA. Systems designed as fault tolerant and reliable, and which function even while undergoing maintenance checks and procedures. SRA implies systems which incorporate redundancy, the ability to hot swap components, fast recovery from power failures, and online upgrading of sofrware. System Services Control Point SSCP. Apoint in a network host system within the Virtual Telecommu- nicationsAccess Method (VTAM) that initiates host applications, so that they can be associated with de- pendent logical units (LUs) and connections initiated and terminated. SNA systems use the SSCP to set up terminal sessions and, more recently, to link with sessions with other systems such as Unix, for example. In SNA, one SSCP in the domain handles this type of interoperability. It consists of sofrware in the host processor for handling connections to the Network Control Program (NCP) which, in tum, manages data link protocols and routing functions. The SSCP initiates sessions by issuing an Activate Physical Unit (ACTPU) command and subsequent Activate Logical Unit (ACTLU) commands. The SSCP communicates between SLUs and the host application. lfthe necessary resources are not available, an error command to the SLU is issued to prevent 902 or abort establishment of a session. Systems Network Architecture SNA. One of the first significant layered architectures, introduced in 1974 by IBM Corporation. Layered architectures like SNA were developed when computers became smaller and less expensive, result- ing in an increase in mass production and a greater variety of hardware configurations and operating systems. Thus, interconnectivity and specialization chal- lenges were posed and new markets opened up. Lay- ered architectures helped resolve these needs. Systems Network Architecture (SNA) provides a co- hesive way for users to communicate between systems for transmitting and receiving, by specifying the operating relationships ofvarious components of the different systems. To achieve this, various communications peripherals, i.e., adapters, modems, data en- cryption devices, etc. are designed to be consistent with the implementation of the SNA specification. SNA came out of the mainframe environment and thus was designed as a star topology host environment for supporting multiple terminals. However, more recent additions make it possible to support multihost, multidomain networks with peer-to-peer distributed computing topologies, as well. SNA shares many common overall concepts with the Open Systems Interconnection (OSI) hierarchically layered network model, which evolved at about the same time. Both are seven-layer models, arranged from the physical and data link layers at the lower end to presentation and transaction (application) layers at the higher end. While the two systems are not directly compatible, there is now some SNA support for OSI protocols to improve interoperability. In brief, the layers described for SNA from high level to low level include: Layer Functions transaction services application program functions for application intercommunication presentation services content of data messages is defined data flow control traffic flow and logical data grouping between two end users transmission control retransmission and error recovery, flow control, end- to-end acknowledgments path control data routing, parallel transmission over multiple links, segmentation and reassembly of data packets data link control transmissions, retransmissions across a link physical the physical media over which data are transported See System Services Control Point, Token-Ring. © 2003 by CRC Press LLC T 1. symb. tera- 2. abbrev. tenninal. 3. abbrev. tip (as in tip and ring). 4. abbrev. trunk. T connectorA generic name for many types of cable connectors shaped roughly like the letter "T." This is a common shape for splitters, Ethernet cabling, certain types oftenninators, and adaptors. The purpose ofa T connector is similar to that ofa Y connector: to join two inputs into one or to split one input into two. If it is atenninating connector, its function is to electrically indicate the end (terminating point) ofa chainable data connection. See terminator. T interface In ISDN, a number of reference points have been specified as R, S, T, and U interfaces. To establish ISDN services, the telephone company typi- cally has to install a number of devices to create the all-digital circuit connection necessary to send and receive digital voice and data transmissions. The T interface is the point between the phone company's switching device that serves the subscriber and the subscriber's building wiring. Thus, the T interface is the point between the central office switch and the user's phone connection. See ISDN interfaces for a diagram and relationships. T Series Recommendations A series ofITU-T recommended guidelines for tenninals for telematic services. These guidelines are available for purchase from the ITU-T. Since ITU-Tspecifications andrec- ommendations are widely followed by vendors in the telecommunications industry, those wanting to maxi- mize interoperability with other systems need to be aware of the infonnation disseminated by the ITU- T. A full list of general categories is listed in Appendix C and specific series topics are listed under individual entries in this dictionary, e.g., S Series Recommen- dations. See T Series Recommendations chart. Tl, T-l A communications system that can be carried over ordinary twin cable pairs, or fiber optic, that provides significant speed and bandwidth improvements over earlier technologies. The T1 time division multiplexing (TOM) pulse code modulation (PCM) system is capable of carrying multiple simultaneous conversations (24 over twin cable pairs), and began to be incorporated into central office trunk switching technologies in the 1960s with more significant, widespread implementation to subscribers in 1982. T1 digital communications represented a significant change over existing analog communications systems. Pulse code modulation (PCM) was pioneered in the 1940s and 1950s, but it was not until the early 1960s that some practical success was achieved. It was then implemented on Tl lines developed in the late 1950s by AT&T. Proponents wanted the improved transmissions technologies to be compatible with existing switching systems, potentially saving billions of dollars by using, rather than replacing, central office switching circuitry. The capacity of T1 was originally stated as 1.544 Mbps (U.S., Canada, Japan), although European ITU-T standard implementations are faster, 2.048 Mbps, and upper limits tend to change as more effi- cient techniques are incorporated to improve the throughput ofa system as a whole. It is a low loss transmissions system when delivered over fiber optic cable, but is subject to crosstalk in long metal wire installations. While high-capacity 22-gauge is preferable for Tl transmissions, the system is not limited to this and can work with a number of paper or plastic insulated cable pairs, or staggered twist cable in use in telephone systems for decades. A single cable can handle up to almost 5000 channels. Due to its cost, TI is still primarily used in large installations, phone trunks, government installations, campus backbones, and medium and large enterprise networks, but installation and usage costs are still dropping and Tl may soon be accessible to small businesses, as well. See T-carrier. T-BoneA freely distributable Java-based distributed network broadcasting system that pennits interconnection ofJ avaBeans on different systems. It can be used for remote monitoring and control, push channels on the Internet, stock ticking feeds, and online discussions. See Java, JavaBeans. T-carrier The generic tenn for T-l, T-2, etc. communications technologies standardized for high-speed data transmissions in North America. It served as the basis for the European E-carrier and the Japanese J-carrier systems, which are similar in concept, but somewhat different in implementation details. T-carrier systems are a generalized technology suitable for the transmission of voice, data, facsimile, multimedia audio and visual information over one system. See T 1. See T- Carrier Transmission Systems chart. 903 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary T-CCS Transparent Common Channel Signaling. See Common Channel Signaling. TIR transmit/receive. TAB See tone above band. table Collection of ordered data, often stored in arrays or printed in columnar form. Routing tables are an instrinsic aspect of many network linking devices. TABS Telemetry Asynchronous Block Serial Proto- col. Amedium-fast AT&T network protocol. Tabulating Machine Company Herman Hollerith, who developed Hollerith punch cards to store census data from the 1890 U.S. census, founded the Tabu- lating Machine Company in 1896 to market his products. Eventually, the company was sold out to the Computer-Tabulating-Recording company, which, in turn, became International Business Machines (IBM) in the 1920s. TACD Telephone Area Code Directory. See North American Numbering Plan. See Appendix 1. TACS Total Access Control/Communications Sys- tem. Afirst-generation, analog cellular FM-based radio system introduced in the United Kingdom by Cellnet and Vodaphone in the early 1980s. It is similar to the U.S. AMPS system. TACS used frequency shift keying (FSK) signaling with each TACS call assigned to a different frequency through frequency division multiple access (FDMA). There are now a number of variations of the original TACS system, including Extended TACS (ETACS) which used ad- ditional frequencies, International TACS (ITACS), International Extended TACS (IETACS), Narrow- band TACS (NTACS), and Japan TACS (JTACS). Tag Distribution Protocol TDB. A Cisco network protocol for building routing databases for the handling of tagged datagrams that are accessed by tag switches and tag edge routers. The tag bindings established by routers are communicated to neighbor- ing routers through TDB. See tag switching. Tag Image File Format See TIFF. tag switching A Cisco proprietary data link layer/ network layer routing/switching architecture intended to provide performance and scalability through existing network infrastructures. Tag switching is a method ofusing tag edge routers and assigning software tags to each IP datagram in a sequence in order to identify router paths. In order to reduce the time needed for each router to send datagrams across the network, the tag edge routers append a special string of bits, called the tag, to the datagrams before they are transmitted across the backbone. The tag provides routing information to otherrouters (tag switches) so that they are freed from table lookups and processing. The tag does not stand for a specific path through the network but rather represents a general class of forwarding. Tag switching is similar to IP switching, except that nonstandard tag bits are ap- pended. See IP switching, label switching, Tag Dis- tribution Protocol. TAl See International Atomic Time. tail 1. Ashort, slenderconnecting length offiber fila- ment that may be sheathed. The tail is often associated with components intended to be connected in the field. Fiber tails are usually capped as particles and scratches can significantly impede performance. See pigtail. 2. A sheathed fiber bundle connecting an il- lumination source to a light fixture up to a practical limit of about 30 feet ifno special added links or am- plifiers are used. tail circuit A final segment in a connection between a central switching location and the subscriber. Tainter, Charles Sumner (1854-1940) An Ameri- can scientific instrument-maker and inventor. Tainter, who was largely self-taught, was a significant collabo- rator with A. Graham Bell on the invention of the Photophone, a device for wirelessly conducting sound through light as a transmissions medium. He also worked with Bell on the development of the Graphophone, an improved phonograph system. Tainter took the Graphophone idea a step further, developing it into a dictation system. He began to suf- fer ill health and lost his lab to fITe in 1897. He con- tinued working on audio technologies, inventing a means ofduplicating phonograph records. Anumber ofTainter's documents are housed in the Smithsonian National Museum of American History. See Photo- phone, selenium. T-Carrier Transmissions Systems Overview Type Signal Bandwidth Typical cable Notes DS-O 64.000 Kbps Tl DS-l 1.544 Mbps 19,22, or 24 gauge Originally developed for digital voice, also used for data communications. European EI standard is similar. TIC DS-IC 3.152 Mbps 19, 22, or 24 gauge pairs T2 DS-2 6.312 Mbps low capacitance T3 DS-3 44.736 Mbps fiber optic or microwave T4 DS-4 274.760 Mbps fiber optic or microwave High-speed, high bandwidth applications. 904 © 2003 by CRC Press LLC ii. IUHI mSeriesR.~e mbleilaitoilS ·ru 1 ··lllii.~.~,:i,i"c~.,:t.lfmW~:iii\!::i:d > <, : ··::::<:~i'···· : ::. .:. . :. telematie .serV'iees::::t/.·.:·.:. . : : :>::.;. ::.) : . General. Classifications'·'· ·j.S2. N6i1LI.latin.coae(f:"l1arac~r sets··fof :::j': . •.• /: 905 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary Enhancedhuman l'l1achineiriterface . for videotex and other retrieval services (VEMMI) 1'.120 Data protocols for>multimedia conferencing . T.Imp120 Implementors'Guide for SG 16 recommendatioIl$ Network :-specific(iata protocol stacks for multimedia conferencing G~neriC.QPnferellc~ ·.control 'text cbat~pplic.ati()nentitY User-to-reservation system transactions witbinl.120 cQ~f~ence~ . ~emotedevicec9ntrolapplication protocol 'Virtual. meeting room .management ~ ~efVices:~ndpf()tocol Protocol for multimedia applicationtext conversation 1t:1ewritjpg ~el1l1imJ.l equiptnent Framework ofthetr.170~Series recommendations PrtltoP9J~for. iI1~~~ctiv~ fl114iovisual . servic~~:·codedrf:Jlresentati()n of multimedia andbypermedia·objects MHEG-~~~upport for base-level interact~¥~applicllti()ns MHEG-3 script interchange representation Application programminginterface (API) for.MHEu-l .A.ppJicationprogramming interface. (API) forMHEG-5 .A.l'Plip~i,9PPW~~1lll1:l~~g.ijlterface. <API) for Digital Storage Media c;ommandand CODtrol(DSM-CC) liomogt,m0us ac~c.:ssmechll,11ismto communica.tiol1.··.f:t~rvices Cooperative document handling (CDH) - framewprk and basic.services Coope~~ve dQc-umentbaIlclling (CPH) - joint s}'Ilchronous editing (point-to-point) Cooperative Document Handling - c(Jmplex.s~rvice~;~oint sypchronolls editing~djointaocumentpresentationJ viewing PrograrpmablecoIl1munic~tion interface fortennillalequipment connected to ISDN Telematic access to interpersonal messaging system TeletexreQ.uiretll~nts forinterworking with thetelex service T.SO 1 Document application profile MM for the . ·~terchtmge offc;>rmatted nUxed mode documents Documentapplication profile PM-II for the interc:hange ofsimplestrueture, charact~fcontent documents in processable and formatted forms T.66 T.70 T.6~. T.64 T.I03 T.I02 T.I06 T.lOS T.IOl T.71 T.90 T.100 T.6S 1.104 906 © 2003 by CRC Press LLC 907 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary Talbot effect In observing an image through a magnifying glass that appears through adiffraction grating, the image appears to be in focus whether the magnifier is held close to the image at the normal focusing distance or whether it is held farther away where the image would be expected to be blurred and at which the grating itself appears blurred. Talbot also observed alternating bands ofcomplementary colors, depend- ing upon the distance of the magnifying lens from the grating surface. As the magnifier was moved farther from the image surface, the sequence of observed colors repeated in a regular pattern and the diffraction grating would become alternately focused, un- focused, and focused again at particular distances. As it turns out, the Talbot effect is doubly periodic for the patterns across the grating and the viewing distance from the grating. In other words, the wave fields exhibit lateral and longitudinal periodicity and create a near-field "self-imaging" effect. W. Henry F. Talbot demonstrated his observations to scientific societies and followed up the demonstrations with an article on optical science, published in 1836. As interesting and important as his observations were to optical science, they didn't receive much at- tention until Lord Rayleight provided mathematical interpretations of the Talbot effect (sometimes called Talbot distance), in 1881. This rediscovery and mathematical description of the effect made it possible to design and fabricate different types of diffraction grat- ings through photographic film processes. Surpris- ingly, very few scientists followed up on this research and it languished until recent advancements in optics highlighted its importance. The Talbot effect is now ofinterest in theoretical and applied optics. It is exploited for testing and calibra- tion purposes and the production ofgratings for scientific instruments such as interferometers. Optical coupling in laser arrays may be based upon the Tal- bot effect. By placing a laser array in a Talbot cavity, the diffractive radiant energy may be laterally phase locked. This, in turn, has the potential to improve the efficiency and density ofphased arrays and amount of light emitted from these components. See diffraction grating, Ronchi grating. Talbot, William Henry Fox (1800-1877) An En- glish inventor who developed a salt and silver nitrate photographic paper print process in the early 1930s. Photos up to this time had been printed on ceramic and silver-plated copper. Talbot was able to produce photographic silhouettes that he called sciagraphs, by embedding light-sensitive chemicals in the paper and exposing parts of it to light. He further realized that an image created on a glass plate could be repli- cated many times in the same manner, avariation on the concept of steel engravings (an early type of manual replicating process). He also made important observations in optics related to diffraction and polarization that he demonstrated and recorded. The Fox Talbot Museum of Photography has a project underway to develop a searchable archive of the ca. 10,000 letters that make up Henry F. Talbot's corre- spondence. See Daguerre, L.J.M; Talbot effect. 908 talking battery In historic telephone central offices, a 24- or 48- V battery supplying power for a phone conversation. Around 1893, these were replaced by common batteries at the central office which, in tum, provided subscribers with talking batteries. See battery. tandem Two, dual, pair. Acting together, in conjunc- tion with, partnership. Tandem Connection TC. Tandem connections, that is, paired or redundant connections, are used at the discretion ofnetwork carriers, and software with TC are mostly interoffice network applications rather than general public subscriber network applications. In SONET, the Tandem Connection layer is optional. Tandem Connection Overhead TCO. In SONET, an optional overhead layer between the Line and Path layers as defined in ANSI TUOS. The layer deals with the reliable network transport ofPath layer pay- load and its associated overhead. TANE The Telephone Association of New England. A regional association providing information, education, and support to its membership. http://www. tane. org/ tangent galvanometer An early current-detecting instrument employing a card to record the degree of deflection. This type of galvanometer is subject to interference from the Earth's magnetic field. See galvanometer. TAO Project TAO is part of the Satori project at Washington University, being developed by the Dis- tributed Object Computing group, funded partly by the DARPA Quorum program. It is a high-performance, realtime Object Requester Broker (ORB) designed to provide end-to-end network quality ofser- vice (QoS) guarantees to applications by integrating CORBA middleware with operating system input/ output subsystems, communications protocols, and network interfaces. TAO is freely distributable to re- searchers and developers. See CORBA. tap Asplitting/joining component in which each input (or output) is coupled with two or more outputs (or inputs), at least one of which is intended for "tapping in" to the system through aprobe (network ana- lyzer). Tap assemblies are generally designed to fa- cilitate network monitoring without disrupting the normal functioning of the network. tap, fiber optic Taps for coupling into and monitoring data or power in asignaling/communication system. In hybrid electrical optical networks, such as fiber-based cable TV/modem services, taps can be used to monitor energy distribution, network efficiency, quality of service, reliability, and bandwidth allocation. Some sources refer to the link between a cable TV loop and local neighborhood drops as a tap, but this is probably better described as a drop connector or distribution device, rather than a tap, unless it also includes monitoring components. Taps are commercially available for single- and mul- timode fiber optic networks and can be purchased with commonly available connectors. Some models are polarization-maintaining and may optionally include isolating components. Designs for monitoring systems in which test points are distributed throughout © 2003 by CRC Press LLC the network to isolate specific parts of the link have been proposed. Some Ethernet switches will include an RF-45 port that enables a computer to be tapped into the network for systems analysis and maintenance. Most tap assemblies are palm-sized or a little larger but innovative small-format taps that combine the tap coupler within the body of a standard fiber optic connector are being pioneered by companies such as the FONS Corporation. Taps may be used where local drops from a loop or backbone cable are connected for sharing data from a single transmission source, or may be inserted at other points in the link to monitor network transmissions (e.g., a fiber-based network running in full-du- plex mode). Fiber optic transmission taps are designed to split or join the light signal with minimum loss. Taps generally do not require electrical power unless extra monitoring or peripheral link electronics are included. Most taps with extra monitoring electronics will continue to couple the lightguide inline whether or not the monitoring electronics are active. A tap may be a permanent component in a network link or may be temporarily inserted for testing or maintenance assessments. The more demanding the application (e.g., Gigabit-speed computer networks) the more precise the coupling in the tap must be. tap loss In a tap coupler, the loss ofpower between the input power and the output power related to the physical coupling and assembly. See tap. tap port The port on a coupler that has the lower power of two unequal outputs. tap testA means oflocating an object or component by tapping around the general region of the object and feeling its location or inferring the location from changes in sound or other properties. A common tap test is locating a stud wi thin a wall by tapping across the wall in a horizontal direction until a deeper, more solid, less hollow sound indicates the presence of something denser behind the area tapped. When fiber optic sensors are embedded within components, it is sometimes difficult to locate the posi- tion of the sensor. By performing a tap test at the same time as watching sensor output, it may be possible to locate the sensor but may be difficult to determine its orientation. TAPI See Telephony Application Programming In- terface. tariff Scheduled rate or charge between acarrier and its subscribers, usually published, and sometimes regulated by government agencies. TAS Telecommunication Authority of Singapore. taut sheath splicing The process ofsplicing a wire or fiber optic joint that does not have much give in it for maneuvering. This occurs in the field where in- stalled cables are repaired and maintained after they have been secured to poles, towers, walls, floors, or within piped conduits such that there is little slack for working with the fiber. See fusion splicing. TAXI Transparent Asynchronous Transmitter/Re- ceiver Interface. Taylor, A.H. A member of the U.S. Naval Research Laboratory who observed in 1922 that a radio echo from a steamer could potentially be used to locate a vessel. This observation was not put into practical use unti 1 some years later. See radar, sonar. THOP See Transparent Bit Oriented Protocol. Tc See Committed Rate Measurement Interval. TCAP See Transaction CapabilityApplication Part. TCI Telecommunications, Inc. TCIF Telecommunications Industry Forum. TCM trellis code modulation. See trellis coding. TCO See Tandem Connection Overhead. TCPIIP Transmission Control ProtocollIntemet Pro- tocol. An intemetworking transmissions protocol combination developed in the 1970s on the ARPA- NET to enable the intercommunication of various types of computers across wide area networks (WANs). It was widely adapted by educational insti- tutions by the 1980s and by corporations by the 1990s. Although it appeared for a time that Open Sys- tems Interconnection might overtake TCP/IP, it has now become an international standard which has been implemented on most microcomputers since the mid- 1 990s. TDC See time-to-digital converter. TDM See time division multiplexing. TDMA See time division multiple access. TDRSS Tracking and Data Relay Satellite System. TDS See Terrestrial Digital Service. TDU 1. tape drive unit. 2. See Topology Database Update. te wave transverse electric wave. Team OS/2 A strong, independent, international support and advocacy group for IBM's OS/2 (Operating System/2). It provides education, demonstrations, resources, Web links, and other services for OS/2 users and the general community. See OS/2. http://www.teamos2.org/ Technical and Office Protocols TOP. A protocol development effort to support the needs of engineer- ing and office environments. TOP was initiated by Boeing, and is now part of the Manufacturing Auto- mation Protocol/Technical and Office Protocols (MAP/TOP) users' group. TOP was designed to con- form to the Open Systems Interconnection (OSI) model. Technical Reference Model TRM. A common framework and vocabulary for creating and commu- nicating digital information services infrastructures, components, and their relationships in order to facili- tate the development of systems that can intercom- municate. Various prominent bodies, including the American National Standards Institute (ANSI), the International Telecommunication Unions (ITU), the Institute of Electrical and Electronics Engineers (IEEE), the International Organization for Standard- ization (ISO), and others have made efforts to provide basic frameworks for the development of consistent, interoperable, multiplatform environments, thus providing flexibility in the choice of platform while still maintaining a means to exchange data. The TRM essentially consists ofthree main entities, the Application Programming entity, the Application 909 © 2003 by CRC Press LLC Fiber Optics Illustrated Dictionary Platfonn entity, and the External Environment. Further, there are two interfaces, thus comprising five basic aspects. Providing a data link between the Applica- tion Programming and Application Platform entities is the Applications Programming Interface. Between the Application Platform entity and the External En- vironment is the External Environment Interface. See Applications Programming Interface, External Envi- ronment Interface. Technical Specification TS. In the Internet Standards Process, a TS is any formal description ofa conven- tion, format, procedure, protocol, or service. The description may be complete in itself, or may contain references to other specifications. Certain conventions guide the general format of a TS, and a statement of scope and intent for use is required, but a TS does not specify its application within the context of the Internet; this is defined in an Applicability State- ment. See Applicability Statement. Technology Policy Working Group TPWG. A working group within the Committee on Applications and Technology founded in the mid-1990s. The TPWG addresses broadbased, overlapping technology issues related to interoperability and scalability of new telecommunications and information services. The group fosters partnership and cooperation between industry and government agencies. tee connector/coupler See T connector. TEl See Terminal Endpoint Identifier. telautograph A historic telegraph machine invented in the late 1800s, which could transmit handwriting over short distances. The earliest models used a pen writing a continuous line, and did not leave breaks between letters or words. Subsequent improvements were made by E. Gray, F. Ritchie, and others, which allowed the pen to be lifted off the paper when de- sired. These devices were used for several decades. Modem versions of the telautograph, using electronics, are known as telewriters, and were superseded by facsimile machines. See facsimile machine. Telco, TelCo Abbreviation for telephone company, a local or regional telephone carrier. telebusiness The British counterpart of telemarket- ing, teleresearch, and telesales. Telecom Developers A telephony industry trade show, the forerunner to the Computer Telephony Con- ference and Exposition, held regularly in the spring. Telecom Information Exchange Services TIES. A service of the International Telecommunication Union (lTD) which provides member resources and access to the ITU Terminology database (TERMITE). See TERMITE. Telecom Services Association of Japan TELESA. A nonprofit group of member companies providing Internet-related services. The group has established a consortium to conduct field trials of electronic commerce systems in cross-border contexts and is responsible for initiating the Integrated Next Generation of Electronic Commerce Environment Project (INGECEP) which is carried out in cooperation with APEC. See Integrated Next Generation of Electronic Commerce Environment Project. 910 Telecommunication Standardization Advisory Group TSAG. A division of the International Tele- communications Union which interprets global standardization concepts and goals into practical implementations. telecommunications 1. Meaningful wired/cabled or wireless transmission and receipt of signals over distance. 2. Broadcast, telegraph, phone, and computer network communications, frequently with a give-and- take quality or by choice of the receiving party, carried through a variety of media, including wires, fi- bers, air, etc. 3. The term is sometimes used to indicate a broader scope of communications telephony, to include video, for example (although telephony's meaning is not quite as narrow as thought by some). 4. This is defined in the Telecommunications Act of 1996, and published by the Federal Communications Commission (FCC), as follows: " the transmission, between or among points specified by the user, of information of the user's choosing, without change in the form or content of the information as sent and received." See Federal Communications Commission, Post Roads Act, Telecommunications Act of 1996. Telecommunications Act of 1996 This is the first substantial overhaul of telecommunications regula- tions since 1934, signed into law by President Clinton on 8 February 1996. The goal and intent of the law is to enable open access to the communications business and to permit any business to compete with any other telecommunications business. The chief impact of this act is on phone and broadcast services. Regu- latory responsibility is largely shifted away from state courts and regulatory agencies to the Federal Com- munications Commission (FCC), but much of the administrative workload remains with the state au- thorities. Some of the changes include the lifting of some long- standing restrictions, with the Regional Bell Operat- ing Companies (RBOCs) now permitted to provide interstate long distance services. Telephone companies can now provide cable television services and cable companies can now provide local telephone services. The FCC and individual states are responsible for implementing the terms, and the FCC has published an implementation schedule for this important act regarding the various issues of interconnection, uni- versal service, access, assignment of broadcast li- censes, etc. See Above 890 decision, Commercial Space Launch Act of 1984, Communications Act of 1934, Federal Communications Commission. Telecommunications and Customer Service Foun- dation TCSF. A Canadian-based association formed to promote excellence in customer service in the telecommunications industry. Telecommunications and Information Infrastruc- ture Assistance A U.S. Department of Commerce grant program established in 1994 to assist local government and nonprofit organizations in funding projects which contribute to the design and development of the national information infrastructure (NIl). © 2003 by CRC Press LLC Telecommunications and IP Harmonization Over Networks TIPHON. An ETSI working group result- ing from the result of the shift from traditional analog telephony to digital telephony and the desire of vendors to offer voice services over digital networks such as the Internet. Project TIPHON addresses market demand and service compatibility and transmission over network boundaries. The ETSI-trade- marked TIPHON group works jointly with the Inter- national Multimedia Teleconferencing Consortium (IMTC) to organize interoperability plugtests so vendors can test their Internet Protocol (IP) products with other developers' telephony systems. See Voice over IP. Telecommunications Association, LatviaA Latvian trade organization fostering the development of telecommunications technologies and products, the lib- eralization of the telecommunications business sphere, and the adjustment ofregulations in Latvia to further growth and development in the field. In February 2001, the association admitted the IF Tele- phony Association with the view of improving progress in the standardization and regulation of the Latvian communications sector. telecommunications bonding backbone TBB. See telecommunications main grounding busbar. telecommunications broker An entity (person or business) that assists in negotiating contracts for communications services on the part ofa user, or who pur- chases specialized or bulk telecommunications services with the intent of reselling these services to con- sumers, sometimes at discount rates. telecommunications carrier This is defined in the Telecommunications Act of 1996 and published by the Federal Communications Commission (FCC), as: " any provider of telecommunications services, except that such term does not include aggregators of telecommunications services (as defined in section 226). A telecommunications carrier shall be treated as a common carrier under this Act only to the extent that it is engaged in providing telecommunications services, except that the Commission shall determine whether the provision of fixed and mobile satellite service shall be treated as common carriage." See Federal Communications Commission, Telecom- munications Act of 1996, telecommunications carrier duties. telecommunications carrier duties The Federal Communications Commission (FCC) stipulates a number of duties in the Telecommunications Act of 1996 as follows: "Each telecommunications carrier has the duty- (1) to interconnect directly or indirectly with the facilities and equipment of other telecommunications carriers; and (2) not to install network features, functions, or capabilities that do not comply with the guidelines and standards established pursu- ant to section 255 or 256." telecommunications closet A wiring panel or room or other centralized, secured or separated adminis- trations center for equipment junctions and/or demar- cation points. Larger systems may have a series of panels, punchdown blocks, racks, or other furnish- ings to secure and organize the wiring system. See telecommunications main grounding busbar, wiring closet. Telecommunications Development Bureau BDT. An agency established as a result of the Plenipoten- tiary Conference in Nice, France in 1989 to set up technical assistance in developing countries for co- ordinating, standardizing, and regulating telecommunications in third-world countries. France is the location for many regulatory and standardization bodies. BDT activities began in 1990. Telecommunications Electric Service Priority TESP. A governmental restoration initiative that promotes voluntary inclusion of telecommunications facilities considered critical to national security and emergency preparedness (NS/EP) in existing electric utility emergency priority restoration systems. TESP is administered by the U.S. Office ofPriority Tele- communications (OPT) at the National Communica- tions System (NCS) in cooperation with the U.S. Department of Energy (DoE), state governments, and utility services. TESP promotes the voluntary modification of existing electric utility emergency priority power restoration systems to include telecommunications facilities that may be critical to NS/EP. See National Com- munications System. telecommunications equipment This is defined in the Telecommunications Act of 1996, and published by the Federal Communications Commission (FCC), as: " equipment, other than customer premises equipment, used by a carrier to provide telecommunications services, and includes software inte- gral to such equipment (including upgrades)." See Federal Communications Commission, Telecom- munications Act of 1996. telecommunications facilities The integrated struc- tures and equipment that enable telecommunications to be conducted and managed. This may include secure rooms for servers or patch bays, consoles, PBX systems, satellites, telephones, facsimile machines, modems, wires and cable, video cameras, radio trans- ceivers, etc. telecommunications grounding busbar TGB. See telecommunications main grounding busbar. Telecommunications Industry Association TIA. TIA began in 1924 as a small group of communications suppliers. Later, it became a committee of the U.S. Independent Telephone Association (USTSA). This group split from the USTSA in 1979 to become a separate, affiliated association, and TIA was formed in 1988 through a merger ofUSTSA and the EIA In- formation and Telecommunications Technologies Group. A national trade organization representing about 1000 member companies which provide communications and infoqnation technology products, materials, and services, TIA provides a forum for discussing industry information and issues, organizes industry trade conventions, and serves as a voice for manufacturers 911 © 2003 by CRC Press LLC . document handling (CDH) - framewprk and basic.services Coope~~ve dQc-umentbaIlclling (CPH) - joint s}'Ilchronous editing (point-to-point) Cooperative Document Handling - c(Jmplex.s~rvice~;~oint sypchronolls editing~djointaocumentpresentationJ viewing PrograrpmablecoIl1munic~tion interface fortennillalequipment. pioneered by companies such as the FONS Corporation. Taps may be used where local drops from a loop or backbone cable are connected for sharing data from a single transmission source, or may be inserted at other points in the link to monitor network transmissions (e.g., a fiber- based network running in full-du- plex mode). Fiber optic transmission taps are designed to split or join the light signal with minimum loss. Taps generally do not require. Tl DS-l 1.544 Mbps 19,22, or 24 gauge Originally developed for digital voice, also used for data communications. European EI standard is similar. TIC DS-IC 3.152 Mbps 19, 22, or 24 gauge pairs T2 DS-2 6.312 Mbps low capacitance T3 DS-3 44.736 Mbps fiber optic or microwave T4 DS-4 274.760 Mbps fiber optic or microwave High-speed, high bandwidth applications. 904 ©

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