ACR: Attenuation-to-crosstalk ratio
ACRF: Attenuation-to-crosstalk ratio far-end
ANSI: American National Standards Institute
ASTM: American Society for Testing and Materials
ATM: Asynchronous transfer mode
AWG: American Wire Gauge
BELLCORE: Bell Communications Research
BICSI: Building Industry Consulting Services International
CATV: Community antenna television
EIA: Electronic Industries Alliance
ELFEXT: Equal level far-end crosstalk
EMC: Electromagnetic compatibility
EMI: Electromagnetic interference
FCC: Federal Communications Commission
FDDI: Fiber distributed data interface
FEXT: Far-end crosstalk
FOCIS: Fiber Optic Connector Intermateability Standard
F/UTP: Foil over unshielded twisted pairs
IEC: International Electrotechnical Commission
IEEE: The Institute of Electrical and Electronics Engineers
ILD: Insertion loss deviation
LCL: Longitudinal conversion loss
LCTL: Longitudinal conversion transfer loss
ISDN: integrated services digital network ISO: International Organization for Standardization LAN: Local area network
LED: Light emitting diode
Mb/s: Megabits per second
MUTOA: Multi-user telecommunications outlet assembly
NEC®: National Electrical Code®
NEMA: National Electrical Manufacturers Association
NESC®: National Electrical Safety Code®
NEXT: Near-end crosstalk
NFPA: National Fire Protection Association
NVP: Nominal velocity of propagation
PSACR: Power sum attenuation-to-crosstalk ratio
PSACRF: Power sum attenuation-to-crosstalk ratio far-end
PSELFEXT: Power sum equal level far-end crosstalk
PSFEXT: Power sum far-end crosstalk
PSNEXT: power sum near-end crosstalk
SFTP: Braided shield over pairs in foil
STP: Shielded twisted-pair
TIA: Telecommunications Industry Association
TSB: Telecommunications System Bulletin
UL: Underwriters Laboratories
UTP: unshielded twisted-pai
adapter (copper): A device that enables any or all of the following: (1) different sizes or types of plugs to mate with one another or to fit into a telecommunications outlet, (2) the rearrangement of leads, (3) large cables with numerous wires to fan out into smaller groups of wires, and (4) interconnection between cables.
adapter (fiber optic): optical fiber duplex: A mechanical device designed to align and join two duplex optical fiber connectors (plugs) to form an optical duplex connection.
administration: The method for labeling, identification, documentation and usage needed to implement moves, additions and changes of the telecommunications infrastructure.
attenuation: (see insertion loss)
attenuation-to-crosstalk ratio: A ratio, expressed in dB, determined by subtracting the insertion loss from the near-end crosstalk loss.
attenuation-to-crosstalk ratio far-end: replaces ELFEXT. A measure of the unwanted signal coupling from a transmitter at the near-end into another pair measured at the far-end, and relative to the received signal level.
backbone cable: A cable that runs between telecommunications rooms, or floor distribution terminals, the entrance facilities, and the equipment rooms within or between buildings.
balance: Balance is the ratio of the differential signal output at either end of any pair to a common mode signal input, at either end of the same or a different pair, and vice versa, under specified termination conditions.
bonding: The permanent joining of metallic parts to form an electrically conductive path that will assure electrical continuity and the capacity to conduct safely any current
likely to be imposed on it.
bundled cable: An assembly of two or more cables continuously bound together to form a single unit.
cable: An assembly of one or more insulated conductors or optical fibers, within an enveloping sheath. cable run: A length of installed media, which may include other components along its path.
cable sheath: A covering over the optical fiber or conductor assembly that may include one
or more metallic members, strength members, or jackets.
cabling: A combination of all cables, jumpers, cords, and connecting hardware.
campus: The buildings and grounds having legal contiguous interconnection.
centralized cabling: A cabling configuration from the work area to a centralized cross-connect using pull through cables, an interconnect, or splice in the telecommunications room.
channel: The end-to-end transmission path between two points at which application-specific equipment is connected.
connecting hardware: A device providing mechanical cable terminations.
connector, small form factor: An optical fiber duplex connector with a size approximating that of an 8-position modular outlet/connector typically used for terminating 4-pair copper cable. cord (telecommunications): A cable using stranded conductors for flexibility, as in distribution cords or line cords.
cross-connect: A facility enabling the termination of cable elements and their interconnection or cross-connection.
cross-connection: A connection scheme between cabling runs, subsystems, and equipment using patch cords or jumpers that attach to connecting hardware on each end.
decibels (dB): logarithmic unit that is used to describe a wide range of differences in signal voltage or power levels.
delay skew: The difference in propagation delay between any two pairs within the same cable sheath.
demarcation point: A point where the operational control or ownership changes.
drain wire: A non-insulated conductor placed in electrical contact with a shield.
electromagnetic interference: Radiated or conducted electromagnetic energy that has an undesirable effect on electronic equipment or signal transmissions.
entrance facility (telecommunications): An entrance to a building for both public and private network service cables (including wireless) including the entrance point of the building and continuing to the entrance room or space.
entrance point (telecommunications): The point of emergence for cations cabling through an
exterior wall, a floor, or from a conduit entrance room or space (telecommunications): A space in which the joining of inter or intra building telecommunications backbone facilities takes place.
equal level far-end crosstalk: (obsolete) A measure of the unwanted signal coupling from a transmitter at the near-end into another pair measured at the far-end, and relative to the received signal level.
equipment cable, cord: A cable or cable assembly used to connect telecommunications equipment to horizontal or backbone cabling.
equipment room (telecommunications): An environmentally controlled centralized space for telecommunications equipment that usually houses a main or intermediate cross-connect.
far-end crosstalk loss: A measure of the unwanted signal coupling from a transmitter at the near end into another pair measured at the far end.
fiber optic: See optical fiber.
ground: A conducting connection, whether intentional or accidental, between an
electrical circuit (e.g., telecommunications) or equipment and the earth, or to some conducting body that serves in place of earth.
high-order mode transient losses: Losses in
power caused by the attenuation in the cladding of multimode optical fiber.
horizontal cabling: (1)The cabling between and including the telecommunications outlet/
connector and the horizontal ross-connect. (2) The cabling between and including the building automation system outlet or the first mechanical termination of the horizontal connection point and the horizontal cross-connect. horizontal cross-connect: A cross-connect of horizontal cabling to other cabling, e.g., horizontal, backbone, and equipment.
hybrid cable: An assembly of two or more cables, of the same or different types or categories, covered by one overall sheath.
hybrid optical fiber cable: An optical fiber cable containing two or more fiber types
(e.g., multimode and single mode).
infrastructure (telecommunications): A collection of those telecommunications components, excluding equipment, that together provide the basic support for the distribution of all information within a building or campus.
insertion loss: The signal loss resulting from the insertion of a component, or link, or channel, between a transmitter and receiver. insertion loss deviation: The difference between the actual insertion loss as measured on a permanent link or channel and the insertion loss as determined by adding the component losses.
interconnection: A connection scheme that employs connecting hardware for the direct connection of a cable to another cable without a patch cord or jumper.
intermediate cross-connect: A cross-connect between first level and second level backbone cabling. intrabuilding telecommunications backbone: A pathway or cable facility for interconnecting telecommunications service entrance rooms, equipment rooms, or
telecommunications rooms within a building.
jumper: An assembly of twisted-pairs without connectors, used to join telecommunications circuits/links at the cross-connect.
keying: The mechanical feature of a connector system that guarantees correct orientation of a connection, or prevents the connection to a jack, or to an optical fiber adapter of the same type intended for another purpose.
link: A transmission path between two points, not including terminal equipment, work area cables, and equipment cables. longitudinal conversion loss: A ratio, expressed in dB, of measured differential
voltage relative to the common mode voltage on a conductor pair applied at the same end.
longitudinal conversion transfer loss: A ratio, expressed in dB, of measured differential voltage at one end of a conductor pair relative to the common mode voltage applied on any pair at the opposite end or on any other pair on the same end.
main cross-connect: A cross-connect for first level backbone cables, entrance cables, and equipment cables.
main terminal space: The location of the cross-connect point of incoming cables from the telecommunications external network and the
premises cable system.
megabits per second (Mbps): An application dependent specification describing the number of discrete bits of information (i.e. a “1” or a “0”) transmitted per second. megahertz (MHz): Transmitted signal frequency described as the number of millions of sinusoidal signal cycles per second. mode: A path of light in an optical fiber.
modular jack: A female telecommunications connector that may be keyed or unkeyed and may have 6 or 8 contact positions, but not all the positions need be equipped with jack contacts.
modular plug cord: A length of cable with a modular plug on both ends. multimode optical fiber: An optical fiber that carries many paths of light.
multipair cable: A cable having more than
four pairs.
multi-user telecommunications outlet assembly: A grouping in one location
of several telecommunications outlet/connectors.
open office: A floor space division provided by furniture, moveable partitions, or other means instead of by building walls.
optical fiber: Any filament made of dielectric materials that guides light.
optical fiber cable: An assembly consisting of
one or more optical fibers.
optical fiber duplex connection: A mated assembly of two duplex connectors and a duplex adapter.
outlet/connector (telecommunications): A connecting device in the work area on which horizontal cable or outlet cable terminates. patch cord: A length of cable with a plug on one or both ends.
patch panel: A connecting hardware system that facilitates cable termination and cabling administration using patch cords.
pathway: A facility for the placement of telecommunications cable.
permanent link: A test configuration for a link excluding test cords and patch cords.
plenum: A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.
power sum attenuation to-crosstalk ratio: A ratio, expressed in dB, determined by subtracting the insertion loss from the power sum near-end crosstalk loss.
power sum attenuation to-crosstalk ratio far-end: replaces PSELFEXT. A computation of the unwanted signal coupling from multiple transmitters at the near-end into a pair measured at the far-end, and normalized to the received signal level.
power sum equal level far-end crosstalk: (obsolete) A computation of the unwanted signal coupling from multiple transmitters at the near-end into a pair measured at the far-end, and normalized to the received signal level. power sum near-end crosstalk loss: A computation of the unwanted signal coupling from multiple transmitters at the far-end into a pair measured at the near-end.
propagation delay: The time required for a signal to travel from one end of the transmission path to the other end. return loss: A ratio expressed in dB of the power of the outgoing signal to the power of the reflected signal.
room (telecommunications): An enclosed space for housing telecommunications equipment, cable terminations, and cross-connect cabling, that is the recognized location of the horizontal cross-connect.
screen: An element of a cable formed by a shield.
screened twisted-pair (ScTP): A balanced cable with an overall screen.
shield: A metallic layer placed around a conductor or group of conductors.
singlemode optical fiber: An optical fiber that carries only one path of light.
splice: A joining of conductors in a splice closure, meant to be permanent.
splice closure: A device used to protect a splice.
star topology: A topology in which telecommunications cables are distributed from a central point.
telecommunications: Any transmission, emission, and reception of signs, signals, writings, images, and sounds, that is information of any nature by cable, radio, optical, or other electromagnetic systems.
topology: The physical or logical arrangement of a telecommunications system.
transfer impedance: A measure of shielding performance determined by the ratio of the voltage on the conductors enclosed by a shield to the surface currents on the outside of the shield.
transition point: A location in the horizontal cabling where flat undercarpet cable connects to round cable.
work area (work station): A building space where the occupants interact with
telecommunications terminal
equipment.
work area cable (cord): A cable connecting the telecommunications outlet/connector to the terminal equipment.
