It consists of sofrware in the host processor for handling connections to the Network Control Program NCP which, intum,manages data link protocols and routing functions.. In brief, the l
Trang 1Fiber Optics Illustrated Dictionary
may also be a relay and may selectively collect or
relay multiple messages A relay may alter the
for-mat ofa message, but it is generally not recommended
unless it is unable to discern the proper
implementa-tion 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 thesuper 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
manage-ment, diagnostic, and tuning responsibilities of a
net-work among a number of system operators, or may
even have an entire facility devoted to the
adminis-tration of the network
system disk Adisk 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 itselfto recognize peripherals, available memory,
monitor types, etc See bootstrap, operating system
system integrator A commercial vendor offering a
variety of network design and implementation
ser-vices according to the configuration needs of
vari-ous customers
system reliability architecture SRA Systems
de-signed as fault tolerant and reliable, and which
func-tion even while undergoing maintenance checks and
procedures SRA implies systems which incorporate
redundancy, the ability tohot swapcomponents, fast
recovery from power failures, and online upgrading
of sofrware
System Services Control Point SSCP A point 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
ses-sions with other systems such as Unix, for example
InSNA, 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, intum,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
avail-able, an error command to the SLU is issued to prevent
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 ofhardware configurations and operating sys-tems 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 sys-tems for transmitting and receiving, by specifying the operating relationships ofvarious components of the different systems To achieve this, various commu-nications 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 environ-ment 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) lay-ers 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:
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
Trang 2in tip and ring) 4.abbrev.trunk.
T connectorAgeneric name for many types ofcable
connectors shaped roughly like the letter "T." This is
a common shape for splitters, Ethernet cabling,
cer-tain types of tenninators, and adaptors The purpose
of a T connector is similar to that of a Y connector:
to join two inputs into one or to split one input into
two If it is a tenninating connector, its function is to
electrically indicate the end (terminating point) of a
chainable data connection See terminator
T interfaceIn 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
in-terface is the point between the central office switch
and the user's phone connection See ISDN interfaces
for a diagram and relationships
T Series RecommendationsA series ofITU-T
rec-ommended guidelines for tenninals for telematic
ser-vices 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 ofthe infonnation disseminated by the ITU-T
A full list of general categories is listed in Appendix
Cand specific series topics are listed under individual
entries in this dictionary, e.g., S Series
Recommen-dations See T Series Recommendations chart
Tl, T-lA communications system that can be
car-ried over ordinary twin cable pairs, or fiber optic, that
provides significant speed and bandwidth
improve-ments over earlier technologies
The T1time 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
cen-tral office trunk switching technologies in the 1960s
with more significant, widespread implementation to
subscribers in 1982
tems 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 im-proved transmissions technologies to be compatible with existing switching systems, potentially saving billions ofdollars by using, rather than replacing, cen-tral 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 of a system as a whole It is a low loss transmissions system when delivered over fiber op-tic 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 ofpaper or plastic insulated cable pairs, or staggered twist cable in use in tele-phone systems for decades Asingle cable can handle
up to almost 5000 channels
Due to its cost, TI is still primarily used in large in-stallations, phone trunks, government inin-stallations, 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-BoneAfreely distributable Java-based distributed network broadcasting system that pennits intercon-nection of JavaBeans on different systems.Itcan be used for remote monitoring and control, push chan-nels on the Internet, stock ticking feeds, and online discussions See Java, JavaBeans
T-carrierThe generic tenn for T-l, T-2, etc commu-nications 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-car-rier systems are a generalized technology suitable for the transmission ofvoice, data, facsimile, multimedia audio and visual information over one system See
Trang 3Fiber 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
ar-rays or printed in columnar form Routing tables are
an instrinsic aspect ofmany network linking devices
TABS Telemetry Asynchronous Block Serial
Proto-col A medium-fast AT&T network protoProto-col
Tabulating Machine Company Herman Hollerith,
who developed Hollerith punch cards to store
cen-sus data from the 1890 U.S cencen-sus, founded the
Tabu-lating Machine Company in 1896 to market his
prod-ucts 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
ra-dio system introduced in the United Kingdom by
Cellnet and Vodaphone in the early 1980s.Itis
simi-lar 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
han-dling of tagged datagrams that are accessed by tag
switches and tag edge routers The tag bindings
es-tablished by routers are communicated to
neighbor-ing routers through TDB See tag switchneighbor-ing
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 of usingtag edge routers
and assigning softwaretags to each IP datagramina sequence in order to identify router paths In order to reduce the time needed for each router to send data-grams across the network, the tag edge routers append
a special string ofbits, called thetag, to the datagrams
before they are transmitted across the backbone The tag provides routing information to other routers (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 gen-eral 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, slender connecting length offiber fila-ment that may be sheathed The tail is often associ-ated 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, de-veloping 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 of duplicating phonograph records A number ofTainter's documents are housed in the Smithsonian National Museum of American History See Photo-phone, selenium
T-Carrier Transmissions Systems Overview
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 E I 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
Trang 4> <, : ··::::<:~i'···· : :: .: :.telematie.serV'iees::::t/.·.:·.: .: : :>::.; ::.) :
General Classifications'·'· ·j.S2 N6i1LI.latin.coae(f:"l1arac~r sets··fof:::j': •.•/:
Trang 5Fiber Optics Illustrated Dictionary
Enhancedhuman l'l1achineiriterface for videotex andother retrieval services (VEMMI)
1'.120 Dataprotocols for>multimedia conferencing
T.Imp120 Implementors'Guide for SG 16 recommendatioIl$
Network.-:-specific(iata protocolstacksfor multimedia conferencing
User-to-reservation system transactions witbinl.120cQ~f~ence~
.~emotedevicec9ntrolapplication
protocol 'Virtual meeting room management~
~efVices:~ndpf()tocol
Protocol for multimedia applicationtext conversation
1t:1ewritjpg~el1l1imJ.lequiptnent Frameworkofthetr.170~Series recommendations
PrtltoP9J~for iI1~~~ctiv~fl114iovisual
.servic~~:·codedrf:Jlresentati()nof
multimedia andbypermedia·objects
MHEG-~~~upportfor 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;ommand and CODtrol(DSM-CC)
liomogt,m0usac~c.:ssmechll,11ismto
communica.tiol1.··.f:t~rvices Cooperative document handling (CDH) -framewprk and basic.services
-joint s}'Ilchronous editing (point-to-point) Cooperative Document Handling
-c(Jmplex.s~rvice~;~ointsypchronolls editing~djointaocumentpresentationJ viewing
PrograrpmablecoIl1munic~tion interface fortennillalequipment connectedtoISDN Telematic accessto interpersonal
messaging system
TeletexreQ.uiretll~nts forinterworking with the telex service
T.SO1 Document application profile MM for the
documents Document application profile PM-II for theinterc:hange ofsimplestrueture,
charact~fcontentdocumentsin 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
Trang 7Fiber Optics Illustrated Dictionary
Talbot effectInobserving an image through a
magni-fying glass that appears through a diffraction grating,
the image appears to be in focus whether the
magni-fier 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 itselfappears blurred Talbot also observed
alternating bands of complementary colors,
depend-ing upon the distance ofthe magnifydepend-ing 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
diffrac-tion 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
dis-tance from the grating.Inother words, the wave fields
exhibit lateral and longitudinal periodicity and
cre-ate a near-field "self-imaging" effect
W HenryF.Talbot demonstrated his observations to
scientific societies and followed up the
demonstra-tions 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
math-ematical description of the effect made it possible to
design and fabricate different types ofdiffraction
grat-ings through photographic film processes
Surpris-ingly, very few scientists followed up on this research
and it languished until recent advancements in
op-tics highlighted its importance
The Talbot effect is now of interest in theoretical and
applied optics It is exploited for testing and
calibra-tion purposes and the produccalibra-tion of gratings for
sci-entific instruments such as interferometers Optical
coupling in laser arrays may be based upon the
Tal-bot effect By placing a laser array in a TalTal-bot cavity,
the diffractive radiant energy may be laterally phase
locked This, in turn, has the potential to improve the
efficiency and density of phased arrays and amount
of light emitted from these components See
diffrac-tion 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, a variation on
the concept of steel engravings (an early type of
manual replicating process) He also made important
observations in optics related to diffraction and
po-larization that he demonstrated and recorded
The Fox Talbot Museum ofPhotography has a project
underway to develop a searchable archive of the ca
10,000 letters that make up HenryF.Talbot's
corre-spondence See Daguerre, L.J.M; Talbot effect
talking batteryInhistoric telephone central offices,
a 24- or 48-V battery supplying power for a phone conversation Around 1893, these were replaced by
common batteriesat the central office which, in tum,
provided subscribers with talking batteries See battery.
tandemTwo, dual, pair Acting together, in conjunc-tion with, partnership
Tandem ConnectionTC Tandem connections, that
is, paired or redundant connections, are used at the discretion of network 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 OverheadTCO 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, edu-cation, and support to its membership
http://www tane.org/
tangent galvanometerAnearly 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 gal-vanometer
TAO ProjectTAO 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-perfor-mance, realtime Object Requester Broker (ORB) de-signed to provide end-to-end network quality of ser-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 in-put (or outin-put) is coupled with two or more outin-puts (or inputs), at least one ofwhich is intended for "tap-ping in" to the system through a probe (network ana-lyzer) Tap assemblies are generally designed to fa-cilitate network monitoring without disrupting the normal functioning of the network
tap, fiber opticTaps for coupling into and monitor-ing data or power in a signalmonitor-ing/communication sys-tem In hybrid electrical optical networks, such as fi-ber-based cable TV/modem services, taps can be used
to monitor energy distribution, network efficiency, quality ofservice, 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 in-clude isolating components Designs for monitoring systems in which test points are distributed throughout
Trang 8been proposed Some Ethernet switches will include
an RF-45 port that enables a computer to be tapped
into the network for systems analysis and
mainte-nance 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
transmis-sions (e.g., a fiber-based network running in
full-du-plex mode) Fiber optic transmission taps are
de-signed 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
electron-ics 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 lossIn a tap coupler, the loss of power between
the input power and the output power related to the
physical coupling and assembly See tap
tap portThe port on a coupler that has the lower
power of two unequal outputs
tap testA means of locating an object or component
by tapping around the general region ofthe object and
feeling its location or inferring the location from
changes in sound or other properties A common tap
test is locating a stud within 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
com-ponents, it is sometimes difficult to locate the
posi-tion ofthe 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
TAPISee Telephony Application Programming
In-terface
tariffScheduled rate or charge between a carrier and
its subscribers, usually published, and sometimes
regulated by government agencies
TASTelecommunication Authority of Singapore
taut sheath splicingThe process of splicing 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
TAXITransparent Asynchronous
Transmitter/Re-ceiver Interface
Taylor, A.H.A member of the U.S Naval Research
from a steamer could potentially be used to locate a vessel This observation was not put into practical use unti1some years later See radar, sonar
THOPSee Transparent Bit Oriented Protocol
TcSee Committed Rate Measurement Interval TCAPSee Transaction Capability Application Part TCITelecommunications, Inc
TCIFTelecommunications Industry Forum TCMtrellis code modulation See trellis coding TCOSee Tandem Connection Overhead
TCPIIPTransmission 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-1990s
TDCSee time-to-digital converter
TDMSee time division multiplexing
TDMASee 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 wavetransverse electric wave
Team OS/2Astrong, independent, international sup-port and advocacy group for IBM's OS/2 (Operating System/2) It provides education, demonstrations, resources, Web links, and other services for OS/2 us-ers and the general community See OS/2
http://www.teamos2.org/
Technical and Office ProtocolsTOP A protocol development effort to support the needs ofengineer-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 pro-vide basic frameworks for the development of con-sistent, interoperable, multiplatform environments, thus providing flexibility in the choice of platform while still maintaining a means to exchange data The TRM essentially consists of three main entities, the Application Programming entity, the Application
Trang 9Fiber 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 ApplicaApplica-tion Platform entities
is the Applications Programming Interface Between
the Application Platform entity and the External
En-vironment is the External EnEn-vironment Interface See
Applications Programming Interface, External
Envi-ronment Interface
Technical Specification TS.Inthe Internet Standards
Process, a TS is any formal description of a
conven-tion, format, procedure, protocol, or service The
de-scription may be complete in itself, or may contain
references to other specifications Certain
conven-tions guide the general format of a TS, and a
state-ment ofscope 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 StateState-ment
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
technol-ogy issues related to interoperability and scalability
ofnew telecommunications and information services
The group fosters partnership and cooperation
be-tween industry and government agencies
tee connector/coupler See T connector
TEl See Terminal Endpoint Identifier
telautograph Ahistoric 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 ofthe telautograph, using
electron-ics, are known astelewriters, 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 theITUTerminology 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 ofelectronic
com-merce systems in cross-border contexts and is
respon-sible for initiating the Integrated Next Generation of
Electronic Commerce Environment Project
(INGECEP) which is carried out in cooperation with
APEC See Integrated Next Generation ofElectronic
Commerce Environment Project
Telecommunication Standardization Advisory Group TSAG A division of the International Tele-communications Union which interprets global stan-dardization concepts and goals into practical imple-mentations
telecommunications 1 Meaningful wired/cabled or wireless transmission and receipt ofsignals over dis-tance 2 Broadcast, telegraph, phone, and computer network communications, frequently with a give-and-take quality or by choice of the receiving party, car-ried through a variety of media, including wires, fi-bers, air, etc 3 The term is sometimes used to indi-cate a broader scope of communicationstelephony,
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 busi-ness and to permit any busibusi-ness to compete with any other telecommunications business The chiefimpact
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 ofthe changes include the lifting ofsome long-standing restrictions, with the Regional Bell Operat-ing Companies (RBOCs) now permitted to provide interstate long distance services Telephone compa-nies 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 ACanadian-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 gov-ernment and nonprofit organizations in funding projects which contribute to the design and develop-ment ofthe national information infrastructure(NIl)
Trang 10Networks TIPHON.AnETSI working group
result-ing from the result of the shift from traditional
ana-log telephony to digital telephony and the desire of
vendors to offer voice services over digital networks
such as the Internet Project TIPHON addresses
mar-ket demand and service compatibility and
transmis-sion over network boundaries The
ETSI-trade-marked TIPHON group works jointly with the
Inter-national Multimedia Teleconferencing Consortium
(IMTC) to organize interoperability plugtests so
ven-dors can test their Internet Protocol(IP)products with
other developers' telephony systems See Voice over IP
Telecommunications Association, Latvia ALatvian
trade organization fostering the development
oftele-communications technologies and products, the
lib-eralization of the telecommunications business
sphere, and the adjustment of regulations 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
com-munications services on the part ofauser, or who
pur-chases specialized or bulk telecommunications
ser-vices with the intent ofreselling these serser-vices 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
oftelecommunications services (as defined in
sec-tion 226) A telecommunicasec-tions carrier shall be
treated as a common carrier under this Act only to
the extent that it is engaged in providing
telecom-munications services, except that the Commission
shall determine whether the provision offixed and
mobile satellite service shall be treated as common
carriage."
See Federal Communications Commission,
Telecom-munications Act of 1996, telecomTelecom-munications 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
telecom-munications 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-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 telecommu-nications in third-world countries France is the lo-cation for many regulatory and standardization bod-ies BDT activities began in 1990
Telecommunications Electric Service Priority TESP Agovernmental restoration initiative that pro-motes 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 of Priority Tele-communications (OPT) at the National Communica-tions System (NCS) in cooperation with the U.S Department ofEnergy (DoE), state governments, and utility services
TESP promotes the voluntary modification of exist-ing electric utility emergency priority power resto-ration systems to include telecommunications facili-ties 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 telecom-munications 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 se-cure 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 communica-tions suppliers Later, it became a committee of the U.S Independent Telephone Association (USTSA) This group split from the USTSA in1979to become
a separate, affiliated association, and TIAwas formed
in 1988 through a merger ofUSTSA and the EIA In-formation and Telecommunications Technologies Group
Anational trade organization representing about 1000 member companies which provide communications and infoqnation technology products, materials, and services, TIA provides a forum for discussing
indus-tryinformation and issues, organizes industry trade conventions, and serves as a voice for manufacturers