Technical Information

Cross Reference Instructions & DrawingsTutorials & White Papers
Adapter Cross Reference Assembly & Mounting Guide Case Study
Cable Groups Instructions Adapter Kit FAQ
Cable to Connectors Instructions Connector Glossary of Terms
Connector to Connector Instructions Tool Tutorials and Tips
Military/UG to Connector & Adapter Interface Drawings White Papers
WiFi and Broad Band RF Connectors at a Glance  
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Glossary of Terms

10BASE-FL

An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on 62.5/125-µm fiber optic cable, a baseband medium of 10 Mbps.

10BASE-T

An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on 24-AWG, unshielded, twisted-pair wiring, a baseband medium of 10 Mbps.

10BASE2

An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on thin coaxial cable, a baseband medium of 10 Mbps. The maximum segment length is just under 200m (656ft).

10BASE5

An implementation of the Institute of Electrical and Electronic Engineers (IEEE) Ethernet standard on twin axial cable, a baseband medium of 10 Mbps. The maximum segment length is 500m (1,640ft).

100BASE-T

Official project name for 100 Mb/s Fast Ethernet.

100BASE-T4

100 Mb/s Fast Ethernet using 4-pair Category 3 cable.

100BASE-TX

100 Mb/s Fast Ethernet using 2-pair Category 5 cable.

100VG-ANY LAN

100 Mb/s LAN using Demand Priority Protocol originally developed by Hewlett Packard and AT&T for Category 3 cable.

1000BASE-T

A specification for Gigabit Ethernet over copper wire (IEEE Standard 802.3ab). The standard defines 1 Gb/s data transfer over distances of up to 100 meters using four pairs of Category 5e balanced copper cabling and a 5-level coding scheme.

1000BASE-TX

A specification for Gigabit Ethernet over copper wire (TIA/EIA). The standard defines 1 Gb/s data transfer over distances of up to 100 meters using four pairs of Category 6 balanced copper cabling.

1000Base-LX

A specification for Gigabit Ethernet over Fiber Optic cable (IEEE Standard 802.3z) at 1300nm wavelength.

1000Base-SX

A specification for Gigabit Ethernet over Fiber Optic cable (IEEE Standard 802.3z) at 850nm wavelength.

10 Gigabit Ethernet

The IEEE has initiated work on the specification of 10 Gigabit Ethernet over optical fiber cabling. The standard is planned for completion in 2001 or early 2002, with specifications for multimode and singlemode fiber.

802.3

Defined by the Institute of Electrical and Electronic Engineers (IEEE), these standards govern the use of the Carrier Sense Multiple Access/Collision Detection (CSMA/CD) network access method used by Ethernet networks.

802.5

Defined by the Institute of Electrical and Electronics Engineers (IEEE), these standards govern the use of the token ring network access method.

802.11

Defined by the Institute of Electrical and Electronics Engineers (IEEE), these standards govern the use of wireless LANs.

A

See Ampere (A).

A-Block Carrier

30-MHz personal-communications-services provider serving a major trading area in the frequency block of 1850 to 1865 MHz paired with 1930 to 1945 MHz.

A Carrier

The non-wireline cellular company which operates in radio frequencies from 824 to 849 MHz.

Abrasion Resistance

Ability of a wire, cable or material to resist surface wear by mechanical means.

Accelerated Aging

A test in which voltage, temperature, etc. are increased above normal operating values to obtain observable deterioration in a relatively short period of time.

Access Method

In a data processing system, any of the techniques available to end users for movement of data between main storage and an input/output device or channel. These techniques are most commonly a part of the operating system.

Accessories

Mechanical devices such as back-shells, cable clamps or strain reliefs which are attached to connectors to make up the total connector assembly.

Active Tag

An RF identification transponder that requires batteries for operation.

Adapter

A device that  (1) enables different sizes or types of plugs to mate with one another or to fit into an information outlet,  (2) provides for the rearrangement of leads,  (3) allows large cables with numerous wires to fan out into smaller groups of wires, or (4) makes interconnections between cables.

Adhesive

An RF identification transponder that requires batteries for operation.

Adhesive Bonded

Cables bonded by adding an adhesive coating to the surface of the cable components and hoining and curing the adhesive to form a cable.

Adhesive Liner

Lining the melts and flows inside a sleeve filling any voids in between the substrate and the sleeve

Ad Hoc Cabling

Cabling scheme where different types of cabling components from different vendors are linked together to form a cabling system.

Adjacent Conductor

Any conductor next to another conductor, either in the same multi-conductor cable layer or in adjacent layers.

Administration Point

A location at which communications circuits are administered; that is, rearranged or rerouted by means of cross connections, interconnection, or information outlets.

Administration Subsystem

The part of a premises distribution system that includes the distribution hardware components where you can add or rearrange circuits. These components include cross connects, interconnects, information outlets, and their associated patch cords and plugs. Also called "administration points". See also Cross Connect and Information Outlets (IO).

Admittance

The measure of the ease with which an alternating current flows in a circuit. The reciprocal of impedance.

Advanced Intelligent Networks (AIN)

Systems that allow a wireless user to make and receive phone calls while roaming in areas outside the user’s “home” network.

Advanced Mobile Phone Service (AMPS)

The US standard for analog cellular telephones.

Aerial Cable

A cable suspended in the air on poles or other overhead structure.

Aging

The change in properties of a material with time under specific conditions.

Aging Stability Test

The test used to determine the flexibility of a cable after temperature cycling.

Airborne

Denotes applications peculiar to aircraft and missiles or other systems designed for operation primarily within the earth's atmosphere. (MIL-STD)

Air Core Cable

A cable in which the interstices in the cable core are not filled with a moisture barrier.

Air Spaced Coaxial Cable

One in which air is the essential dielectric material. A spirally wound synthetic filament or spacer may be used to center the conductor within the dielectric.

Airtime

Time spent talking on a cellular phone. This is usually billed to the subscriber on a per-minute basis.

Alligator Clip

A mechanical device, shaped like alligator jaws used as a temporary connection on the end of interconnections wire.

Allocation

The designation of a band of frequencies for a specific radio service or services. The Federal Communications Commission and the National Telecommunications and Information Administration are responsible for frequency allocations in the US.

Alloy

1)A metal formed by combining two or more different metals to obtain desirable properties such as a lower melting point or greater strength that the individual metals do not possess. 2)A combination of two or more elements of which at least one is a metal.

Alphanumeric

A message on a digital output display containing letters, “alphas”, and numbers, “numerics”.

ALS

A type of cable consisting of insulated conductors enclosed in a continuous, closely fitting aluminum tube.

Alternate Position

Mechanical arrangement of keyways, inserts or grooves in a connector shell or insert that allows connectors of the same configuration to be used without the danger of interconnection to the wrong mating connector. Also called Keying.

Alternating Current (AC or a.c.)

Current in which the charge-flow periodically reverses.

Ambient

The atmospheric conditions surrounding a given item. Normally expressed in terms of factors which influence or modify, such as temperature, humidity, etc.

Ambient Temperature

1)The temperature of the environment, usually air, surrounding a connector. (MIL-STD) 2)The temperature of a surrounding cooling medium, such as gas or liquid, which comes into contact with heated parts of an apparatus.

A

merican National Standards Institute (ANSI)

Formerly the United States of America Standards Institute (USASI). The coordinating organization for voluntary standards in the US. Organization responsible for the definition and maintenance of the Fiber Distributed Data Interface (FDDI) standard. ANSI is the principal group in the United States for defining standards. ANSI represents the U.S. in the International Standards Organization (ISO).

American Wire Gauge (AWG)

A standard system for designating wire diameters; gauge for measuring the diameter of copper, aluminum, and other conductors. Also referred to as the Brown and Sharpe (B & S) wire gauge. Primarily used in the United States

Ampacity

The maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations. Same as Current Carrying Capacity.

Ampere (A)

The unit of current. One ampere is the current flowing through one ohm of resistance at one volt potential.

Ampere's Law

The magnetic intensity at any point near a current carrying conductor can be compute on the assumption that each infinitesimal length of the conductor produces at the point of an infinitesimal magnetic density. The resulting magnetic intensity at the point is the vector sum of the contributions of all the elements of the conductor.

Amplitude

The magnitude of variation in a changing quantity from its zero value. The work requires modification—as with adjectives such as peak, maximum, rms, etc.—to designate the specific amplitude in question.

Analog

The traditional method of transmitting voice signals where the radio wave is based on electrical impulses which occur when speaking into the phone. Today most cellular companies transmit in analog signals, but digital signal output is increasing.  1)Representation of data by continuously variable quantities.  2)A continuously variable audio or video signal.

Analogue Signal

A signal that represents information in a continuously variable and directly measurable physical quantity, such as voltage. Shaped like a wave, analogue signals, such as those transmitted over a telephone channel, vary in both frequency and amplitude proportionate to the voice or other signals initiating them. See also Digital Signal.

Analogue Transmission

Transmission of a continuously variable signal as opposed to a digital signal. A method of signal transmission in which the shape of the signal is a continuously variable and directly measurable physical quantity such as voltage.

Anechoic Chamber

A room which simulates a free-space environment by lining all surfaces, including the floor, with absorbing material to reduce reflections of sound or electromagnetic waves. A semi-anechoic chamber has absorbing materials on walls and ceiling. The floor is then reflective to create a ground-plane effect.

Angle of Advance

The angle between a line perpendicular to the axis of the cable and the axis of any one member or strand of the braid.

Anneal

Relief of mechanical stress through heat and gradual cooling. Annealing copper renders it less brittle.

Annealed Wire

1) Wire, which after final draw down, has been heated and slowly cooled to remove the effects of cold working.  2) Wire which has been softened by heating. Sometimes referred to as soft drawn wire.

Annular Conductor

A number of wires stranded in three reversed concentric layers around a core.

Anodize

Formation of a protective insulating oxide layer on a metal by electrolytic action.

ANSI

See American National Standards Institute (ANSI)

Anti-Oxidant

A substance which prevents or slows down oxidation of material exposed to heat.

Anti-Rotation Connector

A cylindrical connector design which provides keying or locking provisions to maintain positive orientation for accessory hardware.

Anvil

The part of the crimping die normally stationary, which positions and supports the contact during crimping. Sometimes called "Nest".

Application

A system, with its associated transmission method which is supported by telecommunications cabling.

Application Layer

The uppermost layer (layer 7) of the open systems interconnection (OSI) model. This layer is concerned with support to the user application and is responsible for managing the communication between applications, e.g. Email, File transfer, etc.

Arc Resistance

The time require for an arc to establish a conductive path in a material.

Armored Cable

A braid or wrapping of metal, usually steel or aluminum, used for mechanical protection. 1)A cable provided with a wrapping of metal, usually steel wires or tapes, primarily for the purpose of mechanical protection.  2)A cable covered with a heavy outer braid of metal or spiral steel tapes for the purpose of mechanical protection.

ASA

Abbreviation for American Standards Association. Former name of ANSI.

ASCII

American Standard Code for Information Interchange. The standard code, using a coded character set consisting of 7-bit coded characters (8-bits including parity check), used for information interchange among data processing systems, data communication systems and associated equipment. The ASCII set consists of control characters and graphic characters.

ASME

Abbreviation for American Society of Mechanical Engineers.

ASTM

American Society for Testing and Materials. This non-profit industry-wide organization publishes standards, methods of testing, recommended practices, definitions and other related materials.

Asynchronous

Two or more signals sourced from independent clocks, therefore having different frequency and phase relations.

Asynchronous Data Transfer

A method of data transfer in which each alphabetic or numeric character (represented by 7 or 8 bits) is preceded by 'start' and 'stop' bits to delineate the 7/8 bit pattern from the ideal pattern which otherwise occupies the (digital) transmission medium.

Asynchronous Transfer Mode (ATM)

A high speed cell-based switching and multiplexing technology based on segmentation of voice, data and video into fixed packets (cells). These cells are transferred along switched paths and are not received on a regular basis (hence the term asynchronous).

Asynchronous Transmission

A data transmission technique controlled by start and stop bits at each end of a character and characterized by an undetermined time interval between characters.

ATM

See Asynchronous Transfer Mode.

Attenuation

Power loss in an electrical system—a reduction in energy. In transmission lines the loss is expressed in decibels per unit length of transmission line. The decrease of a signal with the distance in the direction of propagation. Attenuation may be expressed as the scalar ratio of the input power to the output power, or as the ratio of the input signal voltage to the output signal voltage.

Attenuation Stability

The change in attenuation of a coaxial cable after being subjected to specified temperature cycles and mechanical deformations.

Audio Frequency

The range of frequencies audible to the human ear. Usually 2- - 20,000 Hz.

Authentication

The process used by the wireless carriers to verify the identity of a mobile station.

Automatic Vehicle Identification (AVI)

AVI is the automatic identification of vehicles through the use of readers installed in toll booths or gates and RF transponders attached to or stored inside vehicles.

Automatic Vehicle Location (AVL)

A feature AVI that allows users to immediately locate commercial vehicles and fleets to reduce off-time and vehicle misuse. See Radiomobile division for more information on AVL.

AWG

See American Wire Gauge (AWG).American Wire Gauge. The standard for copper wire sizes. The diameters of successive sizes vary in geometrical progression.

AWM

Designation for Appliance Wiring Material.

Axial Displacement

The incremental difference between an initial position and a final position resulting from a force applied along the axis of a component.

B

B-Block Carrier

A 30-MHz personal-communications services carrier serving a major trading area in the 1870-to-1885 MHz frequency range paired with the 1954-to-1965-MHz range.

B Carrier

The wireline cellular carrier, usually the local telephone company, which operates on the frequencies of 869 to 894 MHz.

B.C.

Abbreviation for Bare Copper.

BCF

Abbreviation for billion conductor feet. A quantity derived by multiplying the number of conductors in a cable by the amount of cable. Usually used to indicate plant capacity or an annual requirement.

B & S Gauge

Brown and Sharpe wire gauge where the conductor sizes rise in geometrical progression. Adopted as the American Wire Gauge standard.

Backbone/Riser Subsystem

See Riser Backbone Subsystem.

Backbone(s)

The part of a premises distribution system that includes a main cable route and facilities for supporting the cable from the equipment room to the upper floors, or along the same floor to the wiring closets.

Backend Network

A local area network that connects computers’ input/output systems to shared storage devices. They may also be used for high data rate inter-computer data transfer.

Back-Mounted (Rear Mounting)

A connector mounted from the inside of a panel or box with its mounting flange inside the equipment. (MIL-STD

Backplane Panels

An interconnection panel into which PC cards or other panels can be plugged. These panels come in a variety of designs ranging from a PC motherboard to individual connectors mounted in a metal frame. Panels lend themselves to automated wiring.

Backshell

Any device added to the rear (wiring side) of a connector to enhance the connector's operational characteristics.

Backshell Mold

A mold used to form a covering over the backshell of a connector after it is connected to a cable.

Balanced Circuit

A circuit so arranged that the impressed voltages on each conductor of the pair are equal in magnitude but opposite in polarity with respect to ground. The better the balance of a circuit, the lesser is its emissions and the greater is its noise immunity (hence the better is its EMC performance).

Balanced Twisted Pair Cable

A cable consisting of one or more metallic symmetrical cable elements (twisted pairs or quads).

Balun

A device for matching impedance between a balanced to unbalanced line, usually twisted-pair and coaxial cable.

Band Marking

A continuous circumferential band applied to a conductor at regular intervals for identification.

Banded Cable

Two or more cables banded together by stainless steel strapping.

Bandwidth

The total range of frequencies required to transmit a radio signal without undue distortion. The required bandwidth of a radio signal is determined by the amount of information in the signal being sent.  1) The difference between the upper and lower limits of a given band of frequencies. Expressed in hertz (Hz).  2) The information capacity of a channel.

Barrel Chamfer

Bevel at the end of the conductor barrel for easier entry of the conductor. (MIL-STD)

Barrel Conductor

The section of the terminal, splice or contact that accommodates the stripped conductor. (MIL-STD)

Barrel Insulation

The section of the terminal, splice or contact that accommodates the conductor insulation. (MIL-STD)

Barrier

A partition of electrically non conductive material which increases the electrical path between adjacent electrical circuits or an electrical circuit from ground.

Barrier Seal

The seal preventing the passage of moisture or gases through the insulator and the gap between insulator and center conductor or outer conductor of a connector or adapter.

Baseband

A network in which the entire bandwidth of the transmission medium is used as a single digital signal. Unlike broadband, no modulation techniques are used.

Base Material

The metal from which the connector, contact, or other piece part accessory is made and on which one or more metals or coatings may be deposited.

Base Metal

Metal from which the connector components are made and on which one or more metals or coatings may be deposited. Also called Basic Metal.

Base Station

The fixed transmitter/receiver device that a mobile radio transceiver establishes a communication link with in order to gain access to the public-switched telephone network.

Baseband

The system in local area networks whereby digitally encoded information is directly connected to the transmission medium without being modulated. See Broadband.

Basic Rate Interface (BRI)

The simplest form of network access available on the ISDN (integrated services digital network). The BRI comprises 2B + D channels for carriage of signaling and user information.

Basic Trading Area (BTA)

A service area designed by Rand McNally and adopted by the Federal Communications Commission to promote the rapid deployment and ubiquitous coverage of personal communications services. BTA’s generally cover a city and its surrounding area. They are a component of a major trading area. There are 493 BTA’s in the US.

Basis Metal

Metal from which the connector components are made and on which one or more metals or coatings may be deposited.

Baud

1)Unit of data transmission speed representing bits per second, 9600 baud = 9600 bits per second.  2)A unit of modulation rate or signaling speed used to designate the number or bits per second that can be transmitted in a given computer system.

Bayonet Coupling, Rotary

A quick-coupling device for mating connectors utilizing pins on a connector and ramps on the mating connector. Mating and unmating is accomplished by rotating the coupling ring. (MIL-STD)

Beaded Coax

Coaxial cable with a dielectric consisting of beads made of various materials.

Belled Mouth (Bellmouth)

The flared or wide entrance of a terminal splice or contact barrel to permit easier insertion of the conductor. (MIL-STD)

Belt

Number of layers of insulation on a conductor, or number of layers of jacket on a cable.

Belted Type Cable

Multiple conductor cable having a layer of insulation over the assembled insulated conductors.

Bend Radius

The radius of curvature that fiber or copper can bend without breaking or causing excessive loss.

Bending Radius, Minimum Dynamic

The minimum permissible radium for flexible applications of the cable.

Bending Radius, Minimum Static

The minimum permissible radius for fixed installation of the cable. This radius is mainly used in climatic tests.

Beryllium Copper

A relatively expensive contact material with properties superior to brass or phosphor bronze. It is used for contact applications requiring repeated extraction and reinsertion because of its resistance to fatigue at high operating temperatures.

Beta Format

A video recording format generally used in home recording.

Beta cam Format

A video recording format used in ENG (Electronic News Gathering) and some commercial broadcasting areas.

Biconical Antenna

A broadband dipole antenna used to measure and produce electric fields from approximately 30 MHz to 300 MHz.

Bifilar

A winding made non-inductive by winding together (as one wire) two wires carrying current in opposite directions.

Bifurcated Contact

A flat spring contact with lengthwise slotting which is used in a printed circuit edge connector. (MIL-STD)

Bilog Antenna

A combination of biconical and log periodic antenna with an automatic crossover network with a frequency range from 26MHz to 2 GHz.

Bimetallic Wire

A wire formed of two different metals joined together (not alloyed). It can include wire with a steel core clad wire, or plated or coated wire.

Binder

A spirally served tape or thread used for holding assembled cable components in place awaiting subsequent manufacturing operations.

Binding Post

A device for clamping or lolding electrical conductors in a rigid possition.

BIT

Contraction of binary digit, the smallest unit of information in the binary number system. Either of the digits 0 or 1. The basic unit in digital data communications.

Bit Error Rate (BER)

A measure of quality of a digital transmission line, either quoted as a percentage, or more usually as a ratio, typically 1 error in 10E8 or 10E9 bits carried. The lower the number or errors, the better quality the line.

Black, Black Burst

A composite color video signal consisting of Composite Sync, Color Burst and 7.5 IRE units of Blanking Signal.

Blown Jacket

Outer cable covering applied by controlled inflation of the cured jacket tube then pulling the cable through it.

BNC Connector

A concentric coaxial connector with a bayonet locking device. Developed in the late 1940’s, BNC stands for Bayonet-Neill-Concelman. Neill and Concelman were inventors of the N and C connector interfaces. The BNC is a miniature version of the C connector which is a bayonet version of an N connector. The frequency range is DC-4 GHz for 50ohm and DC-1 GHz for 75ohm connectors.

Body Connector

The main portion of a connector to which contacts and other components are attached. This term is not used with connectors incorporating non-integral shells in their construction. (MIL-STD)

Bond Strength

Amount of adhesion between bonded surfaces.

Bondable Wire

An insulated wire treated to facilitate adherence to materials such as potting compounds. Also, magnet wires used in making coils when bonding the turns together is desired.

Bonded Assembly

A connector assembly in which the components are bonded together using an electrically appropriate adhesive in a sandwich-like structure to provide sealing against moisture and other environment which weaken electrical insulating properties.

Bonded Cable

Cable consisting of pro-insulated conductors or multiconductor components lain-in parallel and bonded into a flat cable.

Bonded Construction

An insulation construction in which the glass braid and nylon jacket are bonded together.

Bonding

The connecting together of all building and equipment electrical grounds to eliminate differences in electrical ground potentials.

Booster

A device inserted into a line or cable to increase the voltage.

Boot

A form placed around the wire terminations of a multiple contact connector as a protective housing or as a container for potting compound. (MIL-STD)

Braid

1)A fibrous or metallic group of filaments interwoven in cylindrical form to form a covering over one or more wires.   2)Flexible conductor made of a woven or braided assembly of fine wires. (MIL-STD)  3)A woven protective outer covering over a conductor or cable. It may be composed of any filamentary materials such as cotton, glass, nylon, tinned copper, silver, or asbestos fibers.

Braid Angle

1)The smaller of the two angles formed by the shielding strand and the axis of the cable being shielded.  2)The angle between the axis of the cable and the axis of any one member or strand of the braid. (Also known as the angle of advance)

Braid Carrier

A spool or bobbin on a braider which holds one group of strands or filaments consisting of a specific number of ends. This carrier revolves during braiding operations.

Braid Ends

The number of strands used to make up one carrier. The strands are wound side by side on the carrier bobbin and lie parallel in the finished braid.

Brass

A low cost connector material which is an excellent electric conductor. Brass reaches its yield point at low deflection force, thus it deforms easily and fatigues slowly. Used in connector bodies and male contacts.

Breakdown (Puncture)

A disruptive discharge through insulation.

Breakdown Voltage

The voltage at which an insulator or dielectric between two conductors breaks down or ruptures.

Breakout

1)The point at which a conductor or group of conductors is separated from a multiconductor cable to complete circuits at various points along the main cable.  2)A breakout is the common name given to the exit point of a conductor or number of conductors from a cable of which they are a part. This point is usually harnessed or sealed with some synthetic rubber compound.

BRI

See Basic Rate Interface (BRI).

Bridge(s)

A LAN active device which provides a communication path between logically or physically separate networks. See Gateway

Bridging

A high impedance parallel connection.

British Standard Wire Gauge

A modification of the Birmingham Wire Gauge and the legal standard of Great Britain for all wires. Also known as Standard Wire Gauge, New British Standard, English Legal Standard and Imperial Wire Guide.

Brittle Temperature

The temperature below which a material becomes brittle, often measured by a cold impact test.

Broadband

A communications channel with a bandwidth greater than 64 kb/s that can provide highspeed data communications via standard telephone circuits. A LAN frequency-division multiplexing scheme which commonly employs CATV technology to provide digital and analog signals (e.g. video) on the same distribution medium. Compare with Baseband.

Broadband PCS

Personal-communications-services systems offered in 30-MHz blocks at 1.9-GHz; voice-capable versus narrowband personal communications services, which is paging oriented.

Broadcast Transmission

Message transmission which may be read by a large number of destinations rather than just one. Satellite is an example.

Buffer

A routine or storage used to compensate for a difference in flow rate of data, or time of occurrence of events, used when transferring data from one device to another.

Buffing Stripper

A motorized device for removing flat cable insulation by means of buffing wheels that metl the insulation and brush it away from the conductors. Also called Abrasion Stripper.

Building Backbone Cable

A cable that connects the building distributor to a floor distributor. Building backbone cables may also connect floor distributors in the same building.

Building Distributor

A distributor in which the building backbone cable(s) terminate(s) and at which connections to the campus backbone cable(s) may be made.

Building Entrance Facility

A facility that provides all necessary mechanical and electrical services, that complies with all relevant regulations, for the entry of telecommunications cables into a building.

Bulkead

Type of connector designed for insertion into a panel cutout from the component side if it is a rear mount style and from the front of the panel if the style is front mount.

Bunch Stranded Conductor

All strands having a random position within the conductor. No distinct layers are formed.

Bunch Stranding

A group of wires of the same diameter twisted together without a predetermined pattern.

Bundle

A group of wires fastened or held together by an auxiliary means such as straps, ties, clamps or flexible wrappings (jackets) or sheaths. Also called "Cable".

Buried Cable

A cable installed directly in the earth without use of underground conduit. Also called "direct burial cable".

BUS

Wire used to connect two terminals insode of an electrical unit. Consists of a common transmission path with a number of nodes attached to it. Sometimes referred to as linear network topology.

BUS Interface Unit (BUI)

The data-circuit terminating equipment which provides access to a LAN. It may also provide packet assembly/disassembly functions. May be an add-on card or a separate box.

Bus Topology

A local area network (LAN) topology in which endpoints connect to a single wire or fiber, or set of wires or fibers, at any point. The Ethernet LAN is one example.

Business PCS

A communication system that adds wireless capability to an in-building or campus communications network. Also known as Wireless PBX or Enterprise PCS.

Busing

The joining of two or more circuits. (MIL-STD)

Butt

Joining of two conductors end-to-end, with no overlap and with the axes in line.

Butt Slice

A splice where two wires from opposite ends butt against each other, or against a stop, in the center of a splice.

Butt Wrap

Tape wrapped around an object or conductor in an edge-to-edge condition.

Butted Contact

The contact achieved when two conductors come together end-to-end, but do not overlap, with their axis in line.

Butting Dies

Crimping dies so designed that the nest and indentor touch at the end of the crimping cycle. Also called "Bottoming Dies" (MIL-STD)

BYTE

A binary string operated as a unit. The byte is usually shorter than a computer word and often is used to represent a character. Byte is used colloquially to refer to eight bits or binary digits.

C

C Format

A video recording format commonly used in commercial recording.

C.S.A.

Canadian Standards Association, a non-profit, independent organization which operates a listing service for electrical and electronic materials and equipment.

C.V.

Abbreviation for continuous vulcanization.

C-Block Area

A 30-MHz personal-communications-services carrier serving a basic trading area in the 1895-to-1910-MHz range paired with 1975 to 1990 MHz.

Cable

1)Either a stranded conductor with or without insulation and other coverings (single-conductor cable), or a combination of conductors insulated from one another (multiple-conductor cable).  2)A group of individually insulated conductors in twisted or parallel configuration under a common sheath.  3) One or more conductors within a protective sheath. See also coaxial cable, twisted pairs cable

Cable Assembly

A cable with plugs and/or receptacles on each end. A combination of cable and connectors with specified performance and used as a single unit.

Cable Clamp

A mechanical clamp attached to the cable side of the connector to support the cable or wire bundle, provide strain relief and absorb vibration and shock otherwise transmitted by the cable to the contact/wire connection. (MIL-STD)

Cable Clamp Adapter

A mechanical adapter that attaches to the rear of a plug or receptacle to allow the attachment of a cable clamp.

Cable Core

The portion of an insulated cable lying under a protective covering.

Cable Fill

The ratio of cable installed into a conduit/trunking against the theoretical maximum capacity of the conduit/trunking.

Cable Filler

The material used in multiple-conductor cables to occupy the interstices formed by the assembly of the insulated conductors, thus forming a cable core.

Cable Rack

The vertical or horizontal supports, usually made of aluminum or steel, that are attached to a ceiling or wall. Cables are laid in and fastened to the rack. Sometimes called trays.

Cable Routing Diagram

A detailed drawing showing the layout of the cable routes.

Cable Sheath

The protective covering applied to cables.

Cable Sealing Clamp

A device consisting of a gland nut and sealing member designed to seal around a single jacket cable. (MIL-STD)

Cable Sheilding Clamp

A device consisting of a sealing member and cable support designed to terminate the screen (shield) of an electrical cable. (MIL-STD)

Cable Vulcanizer

Compression molding machine used to repair cable jacketing that has had apart removed for splicing, for adding connectors or other devices, or for replacing damaged sections.

Cabling

A system of telecommunications cables, cords and connecting hardware that can support the connection of information technology equipment. The twisting together of two or more insulated conductors to form an element.

Cabling Factor

Used in the formula for calculating the diameter of an unshielded, unjacketed cable.

CAD/CAM

Computer-Aided Design/Computer-Aided manufacturing. See Radiomobile division for more information on AVL.

Campus

A premises containing more than one building adjacent or near to one another.

Campus Backbone Cable

The communications cable that is part of the Campus Backbone Subsystem and runs between building. There are four methods of installing campus backbone cable: in-conduit (in underground conduit), direct-buried (in trenches), aerial (on poles), and in-tunnel (in stream tunnels).

A cable that connects the campus distributor to the building backbone distributor(s). Campus backbone cables may also connect building cabling distributors directly.

Campus Cable Entrance

The point at which Campus Backbone Subsystem cabling (aerial, direct-buried, or underground) enters a building.

Capacitance

1)Storage of electrically separated charges between two plates having different potentials. The value depends largely on the surface area of the plates and the distance between them.  2)That property of a system of conductors and dielectrics which permits the storage of electricity when potential differences exist between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference, in farads (microfarads). A capacitance value is always positive.

Capacitance Direct

The capacitance measured directly from conductor to conductor through a single insulating layer.

Capacitance Mutual

The capacitance between two conductors with all other conductors, including shield, short circuited to ground.

Capacitance Coupling

Electrical interaction between two conductors caused by the potential difference between them.

Capillary Action

The effect of surface tension that draws a liquid into a small opening.

Carrier

A continuous frequency capable of being modulated by an information carrying signal.

Carrier Sense Multiple

Network access method using contention similar to Carrier Sense Multiple.

Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

Access/Collision Detection (CSMA/CD) used by LocalTalk networks. Unlike CSMA/CD, in this method the sending node requests permission to send from communications. It defines protocols for user or applications programs.

Carrier Sense Multiple Access/Collision Detection (CSMA/CD)

Network access method in which nodes contend for the right to send data. If two or more nodes attempt to transmit at the same time, they abort their transmission until a random time period of microseconds has transpired and then attempt to resend.

Category 3

For cable and connecting hardware products with transmission characteristics specified to 16 MHz, typically used to support digital transmission of 10 Mb/s.

Category 5

For cable and connecting hardware products with transmission characteristics specified to 100 MHz, typically used to support digital transmission of 100 Mb/s and above.

Category 5e

This is an enhanced version of Category 5, with additional parameters specified to enable parallel transmission with full duplex across the four pairs. Enhanced Category 5 specifications for cable and connecting hardware products with transmission characteristics specified to 100 MHz, intended to support digital transmission of 1000 Mb/s.

Category 6

For cable and connecting hardware products with transmission characteristics specified to 250 MHz, used to support digital transmission of 1 Gbp/s and above.

Category 7

For cable and connecting hardware products with transmission characteristics specified to 600 MHz. Category 7 is a cable standard only and will require a new connector standard to fully exploit transmission at the above frequencies.

CATV

Cable television (previously Community Antenna Television) technology, commonly employed by broadband LSNs for signal distribution.

CAV

Component Analog Video, a three circuit video format where the signal is transmitted in their component form, Luminance (Y) and Color Difference (R-Y and B-Y).

CCITT

Consultative Committee on International Telegraph and Telephone. A component division of the International Telecommunications Union (ITU) that attempts to establish international telecommunications standards by issuing recommendations which expresses, as closely as possible, an international consensus.

Ceiling Distribution

Distribution system that uses the space between the false or suspended ceiling and the structural ceiling for housing horizontal cable routes.

Cell

The geographic area served by a single low-power transmitter/receiver. A cellular system’s service area is divided into multiple "cells". Cells can vary in size depending on terrain, capacity demands, etc. By controlling the transmission power, the radio frequencies assigned to one cell can be limited to the boundaries of that cell.

Cell Relay

A fast packet switching technique which uses fixed-length cells. Generic name for ATM, SMDS and BISDN.

Cell Site

The location where communications equipment is located for each cell. A cell site usually includes antennas, a support structure for those antennas, and communications equipment to connect the site to the rest of the wireless system.

Cell Splitting

A method of increasing the capacity of a wireless system by subdividing or splitting cells into two or more smaller cells.

Cellular Digital Packet Data (CDPD)

Introduced in 1992 by McCaw Cellular, IBM and a group of eight other major cellular companies, CDPD uses the idle time in the analog cellular-telephone system to transmit packetized data at rates up to 19.2 kb/s.

Cellular Polyethylene

Expanded or "foam" polyethylene consisting of individual closed cells suspended in a polyethylene medium. Often found as dielectric material in coaxial cable.

Cenelec

European committee for electrotechnical standardization.

Cenelec EN 50173

The European standard for generic cabling for customer premises.

Cenelec EN 50174

A proposed European cabling systems planning & installation standard developed by CENELEC.

Central Processing Unit (CPU)

A personal computer's (PC's) primary microprocessor chip.

Centrex

The switching system of a local telephone operator.

Certificate of Compliance (C of C)

A certificate which is normally generated by a Quality Control Department, which shows that the product being shipped meets customer’s specifications.

Certified Test Report (CTR)

A report providing actual test data on a cable. Tests are normally run by a Quality Control Department, which shows that the product being shipped conforms to test specifications.

Channel

A single path of the spectrum ban taken up by a radio signal, usually measured in kilohertz (kHz). Most analog cellular phones use 30-kHz channels. Motorola’s Narrow AMPS uses a 10-kHz channel.

Characteristic Impedance

A frequency-dependent resistance that quantifies the complex opposition to current flow offered by a transmission line.  1)That value (in ohms) which when connected as the load to an arbitrary length of the line is reproduced as the input impedance (unchanged) at the other end. The ratio of voltage to current at every point along a transmission line on which there are no standing waves.  2)The impedance that, when connected to the output terminals of a transmission line of any length, makes the line appear infinitely long. The ratio of voltage to current at every point along a transmission line on which there are no standing waves.  3)A complex measurement of a circuit or cable that defines the ability to transmit maximum power.

Chemical Resistance

The ability of the insulation to withstand exposure to and resist damage by chemicals and substances. Exposure can range from immersion to occasional contact. Six basic types of chemicals are: Acid: can be organic or inorganic; have a tendency to dissociate in water to partially or completely ionized in solution; typical organic acids are citric acid, carbonic acid, hydrogen cyanide, lactic acid and salicylic acid; typical inorganic acids are sulfuric acid, phosphoric acid, nitric acid, hydrogen sulfide and hydrocholir acid.

Alchols: organic compounds with the general formula R-OH, in which R represents an alkyl group and -OH represents one or more hudroxl groups; typical compounds are methanol, ethanol, glycols and isopropanol; used in antiseptics, cough syrups, medications, cleaners, coating, shellac, dyes, inks, fuel additives, cosmetics, perfumes and as base materials for plasticizers synthetic lubricants.

Aliphatic hydrocarbons; organic compounds whose carbon atoms are joined in straight or branched chains instead of rings; typical compoiuns are mineral spirits, paint thinner, petroleum distillate, and cyclohexane; found in oil and alkyd based coatings, pesticides, furniture oils, cleaners and som cosmetics

Alkalis: hydroxides of an alkali metal (lithium, sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium, radium); easily soluble in water and form basic solutions, neutralizes acids, forming salts and water; typical alkalis are sodium hydroxide, sodium bicarbonate, calcium hydroxide and calcium carbonate.

Aromatic hydrocarbons: organic compounds that contain at least one ring of six carbon atoms, each joined to at least two other carbon atoms; typical compounds are toluene, xylene, phenol, benzene, and styrene; found in enamel paints, paint strippers, some lacquer coatings, in gaseoline, in engine cleaners, in styrenic plastics, phenolic resins, creosol perservatives and some pesticides.

Oils: describes a variety of greasy fluid substances that are typically viscous liquids at room temperature, less dense than water, insoluble in water but soluble in alcohol and usually flammable; the wide range of compositions make generalizations not useful, but they can be grouped; groupings would be petroleum/hydrocarbons, fats/oils, and volatile oils; petroleum/hydrocarbons are used as fuels, solvents, and lubricants; fats/oils are used in soaps, lubricants. There are other additional types not listed.

Chroma

The color information contained in a color video signal.

Chroma Keying

The process of inserting one color video signal into another color video signal.

Chromatic Dispersion

Chromatic dispersion describes the tendency for different wavelengths to travel at different speeds in a fiber. If operated at wavelengths where chromatic dispersion is high, optical pulses tend to temporally broaden, leading to intersymbol interference, which can produce an unacceptable bit error rate.

Churn

The relocation of an individual or a group of individuals within a building such that the workspace or services to the workspace require change.

Cigarette Wrap

Tape insulation wrapped longitudinally instead of spirally over a conductor.

Circuit

A complete path over which electrons can flow from the negative terminals of a voltage source through parts and wires to the positive terminals of the same voltage source.

Circuit Sizes

A popular term for building wire sizes 14 through 10 AWG.

Circuit-Switched Data

Circuit-switched data involves keeping a circuit open between users for the duration of a connection.

Circular Mil

The area of a circle one mil (.001") in diameter. Used in expressing wire cross sectional area which is equal to the square of its diameter in mils. A circular inch is equal to 1,000,000 circular mils.

Circumferential Crimp

The type of crimp where the crimping dies completely surround a barrel, resulting in symmetrical indentations in the barrel. (MIL-STD)

Cladding

A method of applying a layer of metal over another metal whereby the junction of the two metals is continuously welded.

Clocking

Mechanical arrangement of keyways, inserts or grooves in a connector shell or insert that allows connectors of the same configuration to be used without the danger of interconnection to the wrong mating connector. Also called Keying.

Client

A node that requests network services from a server.

Client-Server

A technique by which processing can be distributed between nodes requesting information (clients) and those maintaining data (servers).

Closed End Splice

An insulated splice in which two or more wires overlap and enter the splice from the same end of the barrel.

Closed Entry

A contact or contact cavity design in the insert or body of the connector which limits the size or position of the mating contact or printed circuit board to a predetermined dimension. (MIL-STD)

Closet

SYSTIMAX® SCS location for hardware, conduits, power panels, and electronics, such as multiplexers and concentrators.

Coating

A protective layer of material over the cladding of an optical fiber.

Coax

Abbreviation for coaxial cable. A single solid or stranded conductor over which is extruded a dielectric material. An overall RF Shield of wire braid, Mylar-backed foil, or metal tubing is added over the inner dielectric material with an outer sheath of dielectric material extruded over the shield to form a protective covering.

Coaxial Cable (Coax)

1)A cable consisting of two cylindrical conductors with a common axis, separated by a dielectric.  2)A wide-band cable consisting of an inner conductor a dielectric and a concentric outer shield. Coaxial cable is usually specified as to characteristic impedance, frequency response and propagation delay.  3)A cable consisting of one center conductor to carry a signal, surrounded concentrically (coaxially) by an insulating dielectric and a separate outer conductor (braid or metal jacket) which acts as a shield for the signal.

Coaxial Connector

A connector that has a coaxial construction and is used with coaxial cable.

Coaxial Contact

A contact having two conducting surfaces, a center contact and a coaxially placed sleeve.

CODE

1) A set of unambiguous symbols and rules specifying the way in which data may be represented.  2) In data communications, a system of rules and conventions according to which the signals representing data can be formed, transmitted, received and processed.

CODE-Division Multiple Access (CDMA)

CDMA is a digital technology that uses a low-power signal "spread" across a wide bandwidth. With CDMA a phone call is assigned a code rather than a certain frequency. Using the identifying code and a low-power signal, a large number of callers can use the same group of channels. Some estimates indicate CDMA’s capacity increase over analog may be as much as 20 to one. The Telecommunications Industry Association has awarded CDMA inter-standard approval (IS-95).

CODEC

Coder-decoder (analog-to-digital and digital-to-analog converter). Used to convert analog signals, such as speech, for digital transmission.

Coherent Source

A light source which emits a very narrow, unidirectional beam of light of one wavelength (monochromatic).

Coil Effect

The inductive effect exhibited by a spiral-wrapped shield, especially above audio frequencies.

Coiled Cord

Cable formed into the shape of a spring by winding cable around a mandrel, and heat set into the shape (also referred to as retractile cordset). This permits the extension of a coiled cord to a length from 3 to 5 times it's length at rest. A coiled cord will typically return , after being extended and released, to a length similar to it's original length at rest.

Cold Blend

A test conducted by rapping tubing around a mandrel or by bending it in a arc while at a low temperature

Cold Flow

1)Permanent deformation of insulation due to mechanical forces, without the aid of heat-softening of the insulating material.  2)Deformation of the insulation due to mechanical force or pressure (not due to heat softening).

Co-Location

The siting of two or more separate companies’ wireless antennas on the same support structure.

Collapsed Backbone

This architecture is a backbone topology where wiring concentrators located at floor levels are attached in a star configuration to a central high performance switching concentrator.

Color Burst

8 to 10 cycles of 3.68 MHz subcarrier that is added to the back porch of the Horizontal Sync Pulse. The Color Burst is used to synchronize the color elements of a color video signal.

Color Coding

A system of identification of terminals and related devices. (MIL-STD)

Color Phase

The timing relationship between the Luminance and chroma portions of a composite color video signal.

Color Subcarrier

The 3.58 MHz subcarrier which conveys color information.

Commercial Mobile-Radio Service

The regulatory classification that the Federal Communications Commission uses to govern all commercial wireless service providers, including personal communications services, cellular, and enhanced specialized mobile radio.

Common Axis Cabling

In multiple cable constructions, a twisting of all conductors about a "common axis" with two conductor groups then selected as pairs. This practice yields smaller diameter constructions than does a separate axis construction, but tends to yield greater susceptance to EMI and ESI.

Common Carrier

Public transmission link such as the Bell or General Telephone Systems.

Common Mode (Noise)

Caused by a difference in "ground potential". By grounding at either end rather than both ends (usually grounded at source) one can reduce this interference.

Common Mode Current

The component of the signal current that induces electric and magnetic fields that do not cancel each other. For example; in circuit with one outgoing signal conductor and one ground conductor, the common-mode current is the component of the total signal current that flows in the same direction on both conductors. This is the primary source of EMI in many electronic systems.

Common Mode Interference

Interference appearing between signal leads or the terminals of a measuring circuit and ground.

Common Mode Rejection Ratio

The ratio of the common-mode interference voltage at the input of a circuit to the corresponding interference voltage at the output. This ratio expresses the capability of the device to reject the effect of a voltage that is applied simultaneously to both input terminals. A high ratio is desirable.

Communications

The electronic transfer of information between the points of origin and reception. Includes all manual and machine interfaces necessary to complete the transfer.

Communications Common Carrier

In the U.S., a government-regulated private company that furnishes the general public with telecommunications service facilities; for example, a telephone or telegraph company.

Communications Network

A complex of data communications equipment, data links and channels that connect one or more data processing systems.

Compact Conductor

Stranded conductor rolled to deform the round wires to fill the normal interstices between the wires in a strand.

Composite Cable

A cable construction technique that combines multiple cables or media in a single overjacket. A cable containing more than one gauge size or a variety of circuit types, e.g. pairs, triples, quads, coaxials, etc

Composite Conductor

Two or more strands of different metals assembles and operated in parallel.

Composite Sync

A mixed signal consisting of Composite Sync, Color Burst and Video.

Compound P

An insulating or jacketing material made by mixing two or more ingredients.

Compression Cable

A pipe type cable in which the pressure medium is separated from the insulation by a membrane or sheath.

Compression Molding

A method of molding thermosets. Compound (usually preheated) is placed in an open mold, mold is closed, and heat and pressure applied until material is cured. This process can also be used with synthetic rubber materials.

Computer Network

A collection of computers connected by a data communications network.

Computer Telephony

The adding of computer intelligence to the making, receiving and managing of telephone calls.

Concentration

The function of routing information from a number of communications links into a smaller number of higher capacity links and providing the reverse flow from fewer to more links. A device which performs this function usually is called a concentrator. Unlike the multiplexer, the concentrator is a programmable device.

Concentrator

programmable device which routes information from a number of communications links into a smaller number of higher capacity links and provides the reverse flow from fewer to more links.

Concentric-Lay Cable

A concentric-lay conductor, or a multiple-conductor cable composed of a central core surrounded by one or more layers of helically laid insulated conductors.

Concentric Stranding

1)A central wire surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement.  2)Stranding in which the individual filaments are spiraled in layers around a central core. As a general rule, each layer after the first has six more strands than the preceding layer and is applied in a direction contra-helical to that of the layer under it.

Concentricity

In a wire or cable, the measurement of the location of the center of the conductor with respect to the geometric center of the surrounding insulation.

Condensation

A chemical reaction in which two or more molecules combine resulting in a molecule of greater density. For example, water vapor condenses to form water.

Conductance

1)The reciprocal of resistance. It is the ratio of current passing through a material to the potential difference at its ends.  2)The ability of a conductor to carry an electrical charge. The ratio of the current flow to the potential difference causing the flow. The reciprocal of resistance.

Conducted Emission

The potential EMI generated inside equipment and carried through the I/O lines, the power lines or control leads.

Conducted Susceptibility

The EMI that couples from the outside of equipment to the inside of equipment over the I/O cables, power lines or signal leads.

Conductive Elastomer

A rubber-like material containing metal powder or small particles for conducting electricity to achieve a specified shielding effectiveness.

Conductivity

The capacity of a material to carry electrical current. This is usually expressed as a percentage of copper conductivity with copper being 100% conductive.

Conductor

1)An electric current carrying material such as copper wire; the conductive element in an electrical wire or coaxial connector.  2)An insulated wire suitable for carrying electrical current.  3)A conductor is a slender rod or filament of drawn metal of circular cross section or group of such rods or filaments not insulated from one another, suitable for transmitting an electric current.

Conductor Material

A type of metal used to make wire for conductors. The most commonly used material is ETP copper (usually referred to as copper). A special grade of copper is OFHC copper, which is oxygen-free, high conductivity copper. Alloys of copper are used for applications needing higher strength or longer flex life or greater reliability. These alloys are normally Cadmium bronze (also known as Cadmium copper). Less frequently used alloys are Cadmium chromium copper, phosphor bronze, and Silicone bronze.

Conductor Stranded

Solid wires twisted together or groups of twisted solid wires which are then twisted together. The most common types of stranded conductors are 7 twisted wires (7 strand), or 16 twisted wires (16 strand), or 19 twisted wires (19 strand). Other strandings are 37 twisted wires 63 twisted wires, and 127 twisted wires. Concentric stranded conductors are twisted in progressive layers of 6 wires around 1 wire (7 strand), or 12 wires around 6 wires around 1 wire (19 strand) and 18 wires around 12 wires around 6 wires around 1 wire (37 strand). Bunch stranded conductors are twisted together at one time rather than in layers. Buch stranded conductors are typically either 16, 19, 26, 28, 37 or 40 twisted wires. The finished AWG (guage) of a conductor is determined by the number of strands (of wire) based on the AWG of the wire itself. For example, 7 strands of a 34 AWG wire will result in a 26 AWG conductor. A complete listing of the strand and AWG combinations can be found in our Stranded Conductors Chart.

Conductor Stop

A device on a terminal, splice, contact or tool used to prevent excessive extension of the conductor barrel.

Conduit

A pipe, usually metal, that runs underground from floor to floor, or along a floor or ceiling to protect cables. In the Riser backbone Subsystem when riser telecommunications closets are not aligned, conduit is used to protect cable and provide the means for pulling cable from floor to floor. In the Horizontal Subsystem, conduit may be used between a telecommunications closet and an information outlet in an office or other room. Conduit is also used for in-conduit campus distribution, where it is run underground between buildings and intermediate manholes and is made of plastic encased in concrete. Multiduct, clay-tile conduit may also be used.

Configuration

The number, spacing and arrangement of contacts in a connector. (MIL-STD). Also called Contact Arrangement.

Confined Crimp

A crimp that remains in the confines of the outer diameter of the original barrel.

Connecting Block

A flame-retardant plastic block containing metal wiring terminal (quick clips) that establishes an electrically tight connection between the cable and the cross-connect wire.

Connecting Hardware

See Cross Connect.

Connector

A device used to physically and electrically join two or more conductors. A device that allows you physically to connect and disconnect copper wires or fibers in cable to equipment or to other wires or fibers. Copper wire and fiber optic connectors must often join transmission media to equipment or cross connects.

Connector Discontinuity

An ohmic change in contact resistance.

Connector Electrical

A device, whether a plug or a receptacle, used to terminate or connect the conductors of wires (individual or in cables) and which provides a means to continue the conductors to a mating connector or printed circuit board. (MIL-STD).

Connector Insert

That part which holds the contacts in their proper arrangement and electrically insulates them from each other and from the shell.

Connector Set, Electrical

Two or more separate connectors, plug connector and receptacle connector, designed to be mated together. The set may include mixed connectors mated together, such as one connector plug and one dummy connector receptacle, or a connector receptacle and one electrical plug. (MIL-STD).

Connector Shell

The outside case of a connector into which the dielectric material and contacts are assembled. (MIL-STD)

Consolidation Point

An interconnection point in horizontal cabling, typically used to support the re-arrangement of furniture cloisters.

Contact

The conductive element in a connector which makes actual contact for the purpose of transferring electrical energy. (MIL-STD) Generally, in a male connector the contact is a pin and in a female connector it is a socket.

Contact Alignment

Defines the overall side-play which contacts have within the insert cavity that permits self-alignment of mated contacts. Sometimes referred to as "Contact Float".

Contact Area

The area in contact between two conductors, two contacts or a conductor and a contact permitting the flow of electricity. (MIL-STD)

Contact Arrangement

The number, spacing and arrangement of contacts in a connector. (MIL-STD)

Contact Cavity

A defined hole in the connector insert into which the contacts must fit.

Contact Chatter

Connector ohmic discontinuities.

Contact Durability

Endurance measured by the number of insertion and withdrawal cycles that a contact withstands while remaining within its specified performance levels. (MIL-STD)

Contact Engaging & Separating Force

1) The force needed to either engage or separate pins and socket contacts when they are in and out of connector inserts. Values are generally established for maximum and minimum forces. Performance acceptance levels vary by specification and/or customer requirements.  2) Force needed to either engage or separate mating contacts. (MIL-STD)

Contact Female

A contact having an engagement end that will accept entry of a pin contact. (MIL-STD) Also called Socket contact

Contact Float

The overall side-play and/or angular displacement of contacts within the insert cavity. (MIL-STD)

Contact Hermaphroditic

A contact design which is a combination pin and socket and which mates with other contacts of the same design. (MIL-STD) Both mating elements are precisely alike at their mating face.

Contact Inspection Hole

A hole in the cylindrical rear portion of contact used to check the depth to which a wire has been inserted.

Contact Male

A contact having an engagement end that enters the socket contact. (MIL-STD) A male type contact, usually designed to mate with a socket or female contact. It is normally connected to the “dead” side of a circuit. Also called Pin Contact

Contact Plating

Metal plating applied to the base contact metal to provide the required contact resistance and/or wear resistance.

Contact Pressure

The force which mating surfaces exert against one another.

Contact Resistance

1) Electrical resistance of a pair of engaged contacts. Resistance may be measured in Ohms or millivolt drop at a specified current over the engaged contacts. (MIL-STD)  2) Measurement of electrical resistance of mated contacts when assembled in a connector under typical service use. Electrical resistance is determined by measuring from the rear of the electrical area of one contact to the rear of the electrical area of the mating contact (excluding both crimps) while carrying a specified test current.

Contact Retainer

A device either on the contact or in the insert to retain the contact in an insert or body. (MIL-STD)

Contact Retention

The axial load in either direction which a contact can withstand without being dislodged from its normal position within an insert or body. (MIL-STD)

Contact Separation Force

The force required to separate a pair of fully mated contacts.

Contact Shoulder

The flanged portion of the contact which limits its travel into the insert.

Contact Size

An assigned number denoting the size of the contact engaging end. (MIL-STD

Contact Spacing

The distance between the centerlines of adjacent contact areas.

Contact Wipe

The distance of travel (electrical engagement) made by one contact with another during its engagement or separation or during mating or unmating of the connector halves. (MIL-STD)

Continuity

A continuous path for the flow of current in an electrical circuit.

Continuity Check

A test to determine whether electrical current flows continuously throughout the length of a single wire in a cable or center conductor of a cable assembly.

Continuous Current Rating

The designated RMS alternating or direct current which the connector can carry continuously under specified conditions.

Continuous Operating Temperature

Maximum temperature at which a component will maintain an acceptable lifetime performance, based on accelerated aging prediction

Continuous Vulcanization

Simultaneous extrusion and curing of elastometic wire coating materials.

Contrahelical

In the wire and cable industry the term is used to mean the direction of a layer with respect to the previous layer. Thus it would mean a layer spiraling in an opposite direction than the preceding layer within a wire or cable.

Conrol Cable

A multiconductor cable made for operation in control or signal circuits.

Controlled Impedance Cable

Package of two or more insulated conductors where impedance measurements between respective conductors are kept essentially constant throughout the entire length.

Convection

A conveying, or transference of heat or electricity by moving particles of matter. The transfer of heat by movement of hot air. Often used in conjunction with infrared radiation to reduce the effect of IR shadowing.

Coplanarity

The distance between the lowest and highest lead when the connector is laying in its seating place.

Copolene

A dielectric material, composed of polyisobutylene and polystyrene developed as a substitute of polystyrene. However, polyethylene is more commonly used instead of copolene.

Copolymer

A compound resulting from the polymerization of two different monomers.

Copper and Copper Alloys

The most widely used electrical conductor in wires and cables. Copper and its alloys are used extensively for contacts and connectors. Copper has the best conductivity of the common (non-precious) metals. Copper and copper alloys offer excellent corrosion resistance, thigh thermal conductivity and ease of fabrication, joining and forming.

Copper-Clad

Steel with a coating of copper welded to it, as distinguished from copper-plated.

Copperweld

The trade name for copper covered steel wire manufactured by the Copperweld Steel Company. A drawing process enables a thick copper covering to be placed over a steel core so that the copperweld performs as one metal. Hot rolling, cold drawing, pounding, or temperature changes do not affect its properties.

Cord

A small, flexible insulated cable.

Cord Set

Portable cords fitted with a wiring device at one or both ends

Cords

A short length of copper wire or fiber optic cable with connectors on each end. Used to connect equipment to cabling, or to connect cabling segments (cross-connection).

Core

In cables, a component or assembly of components over which additional components (shield, sheath, etc.) are applied. The central transmission area of a fiber. The core always has a refractive index higher than that of the cladding.

Corona

1)A discharge resulting from a partial electrical breakdown in voltage exceeding a certain breakdown value.  2)A discharge due to ionization of air around a conductor due to a potential gradient exceeding a certain critical value.

Corona Resistance

The time that the insulation will withstand a specified level of field-intensified ionization that does not result in the immediate complete breakdown of the insulation.

Corrosion

1)The destruction of the surface of a metal by chemical reaction.  2)The deterioration of a material by chemical reaction or galvanic action.

Coupling Loss

In fiber optics, signal losses due to small differences in numerical aperature, core diameter, core concentricity and tolerances in splicing connectors when two fibers are aligned. Also known as Splicing Loss and Transfer Loss.

Coupling Nut

That portion of a plug which aids in the mating or unmating of a plug and receptacle and holds the plug to the receptacle. (MIL-STD) Also called Coupling Ring

Coupling Ring

That portion of a plug which aids in the mating or unmating of a plug and receptacle and holds the plug to the receptacle. (MIL-STD)

Coupling Self-Locking

A device on a plug connector which contains means to automatically secure the coupling to the receptacle and prevent any coupling rotation during shock and vibration. (MIL-STD)

Cover Electrical Connector

An item which is specifically designed to cover the mating end of a connector for mechanical and/or environmental protection. (MIL-STD)

Coverage

A calculated percentage which defines the completeness with which a braid or shield covers the surface of the underlying component.

Covering

Textile braid or jacket of rubber, plastics, or other materials applied over wire and cables to provide mechanical protection and identification.

Coupling Torque

The force required to rotate a coupling ring or jackscrew to fully engage a mating pair of connectors.

Coulomb (C)

A quantity of electricity transferred by a current of one ampere in one second.

CPU

See Central Processing Unit (CPU)

Crazing

The minute cracks on the surface of plastic materials.

CRC

See Cyclic Redundancy Check (CRC).

Creep

The dimensional change with time of a material under load.

Creep Distance

The shortest distance on the surface of an insulator separating two electrically conductive surfaces. (MIL-STD)

Creepage

Conduction of electricity across the surface of a dielectric.

Creepage Path

The path across the surface of a dielectric between two conductors.

Creepage Surface

An insulating surface which provides physical separation as a form of insulation between two electrical conductors of different potential.

Crimp

The physical compression (deformation) of a contact barrel around a conductor or a ferrule over a braid covered ferrule stud in order to make an electrical connection. (MIL-STD) Crimp vs Solder

Crimp Contact

A contact whose back portion is a hollow cylinder to allow it to accept a wire. After a bared wire is inserted, a swedging tool is applied to crimp the contact metal firmly against the wire.

Crimp Termination

Connection in which a metal sleeve, or ferrule, is secured to aa conductor by mechanically crimping the sleeve with pliers, presses, or automated crimping machines.

Crimper

That part of the crimping die, usually the moving part, which indents or compresses the terminal barrels. Sometimes called an indentor.

Crimping

A pressure method of mechanically securing a terminal, splice or contact to a conductor. (MIL-STD) Crimp vs Solder

Crimping Chamber

Area of a crimping tool formed by mating the anvil (nest) and crimper (indentor), in which a contact or terminal is crimped.

Crimping Dies

Portion of the crimping tool that shapes the crimp. (MIL-STD) This term is used to identify the shaping tools that when moved toward each other, produce a certain desirable shape to the barrel of the terminal or contact that has been placed between them. Crimping dies are often referred to as die sets or as die inserts.

Crimping Termination

The connection in which a metal sleeve is secured to a conductor by mechanically crimping the sleeve, or ferrule, with pliers, presses, crimping tool or crimp dies.

Crimping Tool

Mechanism used for crimping. (MIL-STD) The term commonly used to identify a handheld mechanical device or table press that is used to crimp a contact, ferrule, terminal or splice.

Cross Color

Spurious color patterns in a color picture resulting from incomplete separation of the luminance and chroma portions of the color video signal.

Cross Connect

SYSTIMAX® SCS component where communication circuits are administered (that is, added or rearranged using jumper wire or patch cords). In 110 Connector Systems, Hook-Up Wire or patch cords are used to make circuit connections. In fiber optic connector systems, fiber optic patch cords are used. The cross connect is located in an equipment room or telecommunications closet. See also Jumper Wire and Patch Cord.

Cross Connect Field

Copper wire or fiber terminations grouped to provide cross-connect capability. The groups are identified by color-coded sections of back boards mounted on the wall in equipment rooms or telecommunications closets, or by designation strips or labels placed on the wiring block or unit. The color coding identifies the type of circuit that terminates at the field.

Crosslinked

A term denoting intermolecular bonds between long chain thermoplastic polymers, effected by chemical or irradiation techniques.

Crosslinking

The generation of chemical links between the molecular chains, usually achieved by chemical reactions or high energy irradiation of the material.

Crosslinking by Irradiation

A method of crosslinking polymers that makes a nonflowing material. This generally improves the properties of the polymer.

Cross Luminance

A defect that manifests itself as a dot pattern that moves through the picture because of chroma information leaking into the luminance signal.

Cross Sectional Area of a Conductor

The summation of all cross-sectional areas of the individual strands in the conductor, expressed in square inches or more commonly in circular mils.

Crosstalk

An electromagnetic coupling between two physically isolated circuits in a system.  1) A type of interference caused by signals from one circuit being coupled into adjacent circuits.  2) A magnetic or electrostatic coupling which causes the unwanted transfer of energy from one circuit (disturbing circuit) to another circuit (disturbed circuit).

CSA

Canadian Standards Association. An agency that has developed standard specifications for products with particlular emphasis on safety in the end use.

CSMA/CA

See Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA)

CSMA/CD

See Carrier Sense Multiple Access/Collision Detection (CSMA/CD)

CT-1

Cordless Telephone-First Generation, or any variety of North American, European, and Japanese analog cordless telephone.

CT-2

Cordless Telephone-Second Generation, a digital cordless telephone standard generally used in a residential cordless phone, a Telepoint application, or in a small office wireless-public-branch-exchange system. CT-2 handsets can initiate, but cannot receive calls.

Cure

To change the physical properties of a material by chemical reaction.

Curing Cycle

The time, temperature, and pressure required for curing.

Curl

The degree to which a wire tends to form a circle after removal from a spool. This is an indication of the ability of the wire to be wrapped around posts in long runs.

Current

The rate of transfer of electricity. The practical unit is the ampere, which represents the transfer of one coulomb per second.

Current Carring Capacity

1)The current a conductor of a given size is capable of carrying without exceeding its temperature limitation.   2)The maximum current an insulted conductor can safely carry without exceeding its insulation and jacket temperature limitations. (Same as Ampacity)

Current Probe

A sensor which measures EMI and clamps onto a wire, wire pair, coaxial line or cable harness to help locate and quantify ground loops. Snap-on current probes measure the normal-mode current in a wire pair, coaxial line or wire bundle.

Customer Premises Equipment (CPE)

Customer owned equipment used to terminate or process information from the public network e.g. Multiplexed or PABX.

Cut-Down

A method of securing a wire to a wiring terminal. The insulated wire is placed in the terminal groove and pushed down with a special tool. As the wire is seated, the terminal cuts through the insulation to make an electrical connection, and the spring-loaded blade of the tool trims the wire flush with the terminal. Also called punch-down.

Cut Off Frequency

The frequency, above which other than the TEM mode may occur. The transmission characteristics of cables above their cutoff frequency may be unstable.

Cutout Connector

The hole, usually round or rectangular, cut in a metal panel for mounting a connector. May include holes for mounting screws or bolts. (MIL-STD)

Cut Through Resistance

The ability of a material to withstand mechanical pressure, (usually a sharp edge or small radius) without separation.

Cycle

One complete sequence of values of an alternating quantity, including a rise to maximum in one direction and return to zero; a rise to maximum in the opposite direction and return to zero. The number of cycles occurring in one second in called the frequency.

Cyclic Redundancy Check (CRC)

A coded sequence of information allowing error checking and correction.

D

D-1 Format

A serial digital recording format.

D-2 Format

A composite digital recording format.

D-3 Format

A composite digital recording format.

Data Communications Equipment (DCE)

General terminology for data communications equipment such as modems. A device that terminates a data communications session and provides encoding or conversion if necessary. See also Data Terminating Equipment (DTE).

Data terminating equipment (DTE)

The term used to describe any type of computer or other equipment, when connected to a data communications network.

Data Link

1) The physical means of connection one location to another for the purpose of transmitting and receiving data.  2) Synonymous with communication link.

Data Link Layer

Layer 2 of the Open Systems Interconnect (OSI) model; it defines protocols governing data packetizing and transmission into and out of each node.

Data Transmission

The conveying of data from one place for reception elsewhere by signals transmitted over a data circuit.

dB

See Decibel (dB)

dB/km

See Decibel/kilometer (dB/km).

DB9

A standardized connector with nine pins for token ring and serial connections.

DB15

A standardized connector with 15 pins for Ethernet transceivers.

DB25

A standardized connector with 25 pins for parallel or serial connections.

D-Block Carrier

A 10-MHz personal-communications-services carrier serving a basic trading area in the 1865-to-1870-MHz band paired with the 1945-to-1950-MHz band.

dBm

Absolute measure of signal power where 0 dBm is equal to one milliwatt.

DCE

Abbreviation for Data Communication Equipment such as a modem.See Data Communications Equipment (DCE).

DCS-1800

Digital Communications Service 1800 MHz is an upbanded variant of the Global System for Mobile Communications.

Dead Face

The term which describes the various methods used to protect contacts when not engaged.

Dead Front

Mating surfaces of a connector designed so that the contacts are recessed below the surface of the connector insulator body to prevent accidental short-circuiting of the contacts.

Decibel (dB)

1)A unit of measurement to express logarithmic differences of power level. It is used to express power gain in amplifiers or power loss in passive circuits or components. Expressed as dB.  2)A unit to express differences of power level. A term that expresses two power levels used to indicate gains or losses in a system.

Decibel/kilometer (dB/km)

A unit of measurement for fiber optic attenuation.

Decoder

1) A device used to separate the individual component portions of a composite signal.  2) A device the decodes scrambled television broadcast signals.

Defect

Any non-conformance with the normally accepted characteristics of a part.

Degradation

A gradual deterioration in performance.

Delay Line

A device used to delay a signal for a specified length of time.

Delay Skew

Delay Skew is the difference in propagation delay between any two pairs within the same cable sheath.

Demodulation

The process of separating the information signal from the carrier signal.

Depth of Crimp

The distance the indentor penetrates into the barrel. (MIL-STD)

Derating Factor

A factor used to reduce the current carrying capacity of a wire when used in environments other than that for which the value was established.

Detector

In fiber optics, a device that picks up light from fiber and converts the information into an electrical signal.

De-Wetting

The situation where a lead or pad was at one point in the soldering process wetted by the solder, but due to extended time or temperature, the presence of intermetalics, volatiles or other causes, has become withdrawn from the wetted surface.

Die Closure

The gap between indenter dies at full handle closure. Usually defined by Go/No-Go dimensions.

Dielectric

A nonconducting or insulating material that resists passage of electric current.  1) A material having electrical insulating properties. (MIL-STD)  2) Any insulating material between two conductors which permits electrostatic attraction and repulsion to take place across it.  3) A non-conducting material or a material having the property that the energy required to establish an electric field is recoverable, in whole or in part, as electric energy. A vacuum is a dielectric.

Dielectric Breakdown

The voltage required to cause an electrical failure or breakthrough of the insulation.

Dielectric Cable

A nonconducting cable, such as fiber optic cable, without metallic members.

Dielectric Constant (Permittivity)

1)The ratio of the capacitance using the material in question as the dielectric, to the capacitance resulting when the material is replaced by air.  2)That property of a dielectric which determines the electrostatic energy stored per unit volume for a unit potential gradient. The ratio of the capacitance using the material in question as the dielectric, to the capacitance resulting when the material is replaced by air. The dielectric constant is the most important design parameter for coaxial cables and determines dimensions, losses and propagation characteristics.

Dielectric Loss

In a coaxial cable, the losses caused by the transformation of electromagnetic energy into heat within the dielectric material.

Dielectric Loss Factor (Dielectric Loss Index)

)A measure of the loss characteristics of a dielectric material.

Dielectric Strength

1)The voltage which an insulation can withstand before breakdown occurs. Usually expressed as a voltage gradient (such as volts per mil).  2)The maximum voltage that a dielectric material can withstand, under specified conditions. without rupturing. Usually expressed as a voltage gradient such as volts per mil.

Dielectric Test

A test in which a voltage higher than the rated voltage is applied for a specified time to determine the adequacy of the insulation under normal conditions.

Dielectric withstanding Voltage

The maximum potential gradient that a dielectric material can withstand without failure.

Digital

A method of transmitting a human voice using the computer’s binary code—0’s and 1s. Digital transmission offers a cleaner signal than analog technology. Cellular systems providing digital transmission are currently in operation in several locations for trial and commercial service.

1) Pertaining to the utilization of discrete integral numbers in a given base to represent all the quantities that occur in a problem or a calculation. It is possible to express in digital form all information stored, transferred or processed by a dual-state condition; e.g. on-off, open-closed, true-false.  2)Compare with Analog.  3)Representation of data by discrete characters.

Digital Advanced Mobile Phone System (DAMPS)

Digitally-enhanced AMPS based on the ID-54 standard. Also referred to as TDMA.

Digital Cordless Telephone US (DCTU)

A version of Digital European Cordless Telecommunications proposed for the US personal-communications-services market.

Digital European Cordless Telecommunications (DECT)

DECT is a digital cordless telecommunications system initially intended for wireless-public-branch-exchange applications, but which may also be used in the consumer market. DECT supports voice and data communications

Digital Signal

A signal that represents information by a series of fixed, encoded, rectangular pulses, usually consisting of two possible voltage levels. Each voltage level indicates one of tow possible values or logic states, such as on or off, open or closed, true or false. See also Analogue Signal.

Digital transmission

A technique in which all information is converted into binary digits for transmission (string of discrete "on-off" or "high-low" pulses).

DIN 7/16

Coaxial connector interface with screw type coupling mechanism. Larger than N interface and suitable for medium to high power applications. Frequency range is DC - 7.5 GHz.

Dip Coating

An insulating coating applied to the conductor by passing the conductor through an applicator containing liquid insulating medium.

Dip Solder Terminal

The terminals on a connector which are inserted into holes in a PC board and then soldered into position.

Dipole Antenna

Antenna with the gain, pattern and impedance defined at and near resonance of one-half wavelength. This antenna is split at its electrical center for connection to a transmission line. The radiation pattern is maximum at right angles to the axis of the antenna.

Direct Burial Cable

A cable installed directly in the earth.

Direct Capacitance

The capacitance measured directly from conductor to conductor through a singly insulating layer.

Direct Current (DC)

An electric current which flows in only one direction

Direction of Lay

The lateral direction in which the strands of a conductor run over the top of the cable conductor as they recede from an observer looking along the axis of the conductor or cable. Also applies to twisted cable.

Dispersion

The tendency of a beam of light to spread out and loose its focus.

Directional Antenna

An antenna which transmits or receives in certain directions more effectively than others.

Disconnect

A reusable conductive device designed to be separated from its mated part.

Discontinuity

1) A broken connection or the loss of a specific connection characteristic.  2) The temporary interruption or variation in current or voltage.

Discrete Wiring

Wire or wires having distance identity and purpose.

Dispersion

In fiber optics, the variation of the refractive index of a material with wavelength, causing light of different wavelengths to travel at different velocities in the material.

Discruptive Discharge

A sudden, large increase in current through an insulation medium due to the complete failure of the medium under the electrostatic stress.

Dissipation

Unusable or lost energy, such as the production of unused heat in a circuit.

Dissipation Factor (Loss Tangent)

A measure of the loss characteristics of a dielectric material

Distortion

An unwanted change or addition to a signal or waveform when it is amplified. This definition excludes noise which is an extraneous signal superimposed on the desired signal.

Distributed Processing

A decentralized alternative to the large-scale computer installation whereby data processing services are provided to multiple users via the direct installation of communicating computers at various user location.

Distributor

The term used for the functions of a collection of components (for example, patch panels, patch cords) used to connect cables.

Disturbed Conductor

A conductor that receives energy generated by the field of another conductor or an external source such as a transformer.

DIW

See Network Communications Cable (NCC) and Twisted Pair

Downlink

The transmission of RF signals from a satellite to an earth station.

Drain Wire

In a cable, the uninsulated wire in intimate contact with a shield to provide for easier termination of such a shield or ground.

DTE

Abbreviation for Data Terminal Equipment such as VDTs or printers. See Data Circuit-Terminating Equipment (DTE) and also Data Terminating Equipment (DTE).

Dual-Fiber Cable

A type of fiber optic cable that has two single-fiber cables enclosed in a jacket of extruded plastic.

Dual-Mode Phone

A phone that operates on analog and digital networks.

Dual Self-Normal Jack

A jack that provides a connection between the two rear connectors, except when interrupted by the insertion of a video patch plug in either of the two front panel receptacles.

Draw Feed Stock

Rod or wire that is subsequently drawn to a smaller size.

Drawing

In wire manufacture, pulling the metal through a die or series of dies to reduce diameter to a specified size.

Dual Coaxial Cable

Two individually insulated conductors laid parallel or twisted and placed within an overall shield and sheath.

Dubbing

Electronic duplicating of recorded audio and/or video signals.

Duct

An underground or overhead tube for carrying electrical conductors.

Ducts

The main feeder channels in which communication cable is routed between buildings in a campus environment. See also Campus Backbone Cable.

Dummy Connector Assembly electrical

Two or more electrical connectors having common mounting or mounted on each other, each one capable of being independently replaced. Excludes items which are furnished as mated pairs or sets. (MIL-STD)

Dummy Connector Plug

A connector device designed to mate with a receptacle connector to perform protective, environmental and/or electrical shorting functions.

Dummy Connector Receptacle

A connector receptacle which does not have provisions for attaching conductors. It is generally used for storage of a cable assembly connector plugs. (MIL-STD)

Duplex

Two-way data transmission on a four-wire transmission line.

Duplex Cable

A cable composed of two insulated single conductor cables twisted together.

Duplex Parallel

Typically used in the thermocouple industry to denote two parallel conductors of dissimilar metals insulated in parallel without twist and jacketed. Commonly applied to thermocouple grades and extension wires

Duplex Transmission

1) Data transmission over a circuit capable of transmitting in both directions at the same time.  2) Synonymous with full duplex transmission.

Dust Cover

An item which is specifically designed to cover the mating end of a connector for mechanical and/or environmental protection. (MIL-STD)

E

Earth Station

The electronic ground equipment used with a parabolic-shaped antenna or "dish" to process RF signals to and from a satellite.

E-Block Carrier

A 10-MHz personal-communications-services carrier serving a basic trading area in the 1885-to-1890-MHz frequency range paired with 1965-to-1970-MHz

Eccentricity

A measure of a conductor’s location with respect to the circular cross section of the insulation. Expressed as a percentage of center displacement of one circle within the other.

Eddy Current

Circulating currents induced in conducting materials by varying magnetic fields.

EIA

Electronics Industries Association—A US manufacturers' group which, as one of its functions, sets some interface standards.

EIA/TIA

North American Standards organization.

EIA/TIA 568B

North American commercial building telecommunications wiring standard.

EIA/TIA 569A

North American commercial building standard for telecommunications pathways and spaces. Its purpose is to standardize specific design and construction practices within and between buildings which are in support of telecommunications media and equipment.

EIA/TIA 606

North American administration standard for the telecommunications infrastructure of commercial buildings. Its purpose is to provide guidelines for a uniform administration scheme for the cabling infrastructure.

Elastic Memory

The ability of a crosslinked polymer to be deformed to some predetermined shape, hold that shape for a period, and then return to its original shape upon application of heat.

Elastomer

A material which at room temperature stretches under stress to at least twice its length and snaps back to original length upon release of stress.

Electric Strength

The maximum potential gradient that a material can withstand without rupture.

Electrical Length

That length of a cable assembly expressed as degrees of a cycle or fraction of a wave length for the signal transmitted. In the case of a cable assembly, the electrical length equals the physical length times the square root of the dielectric constant.

Electrical Resistance Test

A measurement of the resistance from circuit to circuit through the interfacial connection, designed to insure a satisfactory connection.

Electrode

A conductor through which a current enters or leaves a nonmetallic conductor.

Electromagnetic

Pertaining to the combined electric and magnetic fields associated with movements of electrons through conductors

Electromagnetic Compatibility (EMC)

The capability of equipment or systems to be used in their intended environment within designed efficiency levels without causing or receiving degradation due to unintentional EMI.

Electromagnetic Coupling

Energy transfer by means of a varying magnetic field.

Electromagnetic Field

A rapidly moving electric field and its associated moving magnetic field.

Electromagnetic Flux

Electric and magnetic fields (commonly referred to as emissions) generated by equipment or system.

Electromagnetic Induction

The production of a voltage in a coil due to a change in the number of magnetic lines of force passing through the coil.

Electromagnetic Interference (EMI)

A natural or man-made electrical or electromagnetic event conducted or radiated and resulting in unintentional and undesirable responses. Referred to as EMI

Electromotive Force (e.m.f.)

Pressure or voltage. The force which causes current to flow in a circuit.

Electronic Wire and Cable

A length of conductive or semiconductive material used in an electronic application.

Electroplating

A method of electrically depositing metals of very precise compositions and thickness onto a base metal.

Electrostatic

Pertaining to static electricity or electricity at rest. A constant intensity electric charge

Electro-Tinned

Electrolytic process of tinning wire using pure tin.

ELFEXT

See Equal Level Far End Crosstalk

Elongation

The fractional increase in length of a material stressed in tension.

Embossing

A marker identification by means of thermal indentation leaving raised lettering on the sheath material of cable.

EMC

See Electromagnetic Compatibility.

Emergency Overload

Load which occurs when larger than normal currents are carried through a cable or wire over a certain period of time.

EMI

Abbreviation for Electromagnetic Interference.

EMI Filter

A circuit or device containing series-inductive and parallel-capacitive components that provide a low impedance path for high-frequency noise around a protected circuit.

EMI Filtering

The reduction in strength of electromagnetic fields and noise that can interfere with and alter a valid transmitted signal traveling in/on a metallic wire. This is typically accomplished by shielding; it can also include use of ferrites or toroids and/or capacitive couplers.

EN 50173

The European standard for generic cabling for customer premises.

EN 50174

A proposed European cabling systems planning and installation standard developed by CENELEC.

Encapsulation

Covering and sealing

Encoder

A device that converts discrete component signals into a composite signal.

Encryption

The conversion of plain text into an unintelligible form from which the original meaning can be recovered.

Endbell

An accessory similar to a cable clamp or strain relief which attaches to the back of a connector. It serves as an adapter for the rear of a connector.

ENG

Electronic News Gathering

Engaging and Separating Force

The amount of force needed to engage and/or separate contact elements in mating connectors.

Enhanced Specialized Mobile Radio (ESMR)

The next generation of SMR, ESMR takes advantage of digital technology combined with cellular system architecture to provide greater capacity than existing SMR systems.

Ends

In cable braiding, the number of essentially parallel wires of threads on a carrier.

Energize

To apply rated voltage to a circuit or device in order to activate it.

Enterprise PCS

A communication system that adds wireless capability to an in-building or campus communications network.

Environment

Aggregate of all conditions which externally influence a connector's performance.

Environmentally Sealed

A device that is provided with gaskets, seals, grommets, potting or other means to keep out moisture, dirt, sir or dust which might reduce its performance. Does not include nonphysical environments such as RF and radiation. (MIL-STD)

Equal Level Far End Crosstalk (ELFEXT)

Is the same as FEXT, except that the coupled signal at the remote end is relative to the attenuated signal at the remote end on the pair the signal was applied to at the local end.

Equalizer

A device to vary frequency response to compensate for differences is a system.

Equilay

More than one layer of helically laid wires with the direction of lay reversed for successive layers, but with the length of lay the same for each layer.

Equipment Cable

A cable connecting equipment to a distributor.

Equipment Room

The room in which voice and data common equipment (for example, a Definity switch) is housed, protected, and maintained, and where circuit administration is done using the trunk and distribution cross connects.

Equipment Subsystem

The part of a premises distribution system that includes the cable and distribution components in an equipment room and that interconnects system-common equipment, other associated equipment, and cross connects.

Etched Wire

A process applied to fluoroplastic wire in which the wire is passed through a sodium bath to create a rough surface to allow epoxy resin to bond the fluoroplastic.

Ethernet

The common name for the most widely used local area network (LAN), generally conforming to the Institute of Electrical and Electronic Engineers (IEEE) 802.3 Standard.  1) In a LAN, a branching broadcast communications system for carrying digital data packets among locally distributed computing stations.  2) A low-level, baseband, local-area data communications network developed by Xerox and supported by DEC and Intel among others.  3) A de facto standard in LAN technology. An Ethernet LAN uses coaxial cables in such a way that members can share the case cable to communicate with each other.

Ethylene Propylene Rubber (EPR)

An ozone resistant rubber consisting primarily of ethylene propylene copolymer (EPM) or ethylene propylene diene terpolymer (EDPM).

European Radio Message System (ERMES)

ERMES is the public Pan-European lank-based paging system.

European Telecommunications Standards Institute (ETSI)

One of the European organizations responsible for establishing common industry-wide standards for telecommunications.

Eutetic Solder

The most common solder alloy because of its low melting point, 183°C/316°F, composed of 63% tin and 37% lead

Expanded Diameter

Diameter of shrink tubing as supplied. When heated the tubing will shrink to its extruded diameter.

Expanded ID

The specified minimum (as supplied) internal diameter of tubing.

Exit Angle

In fiber optics, the angle between the output radiation vectors and the axis of the fiber or fiber bundle.

Extended Total Access Communications System (ETACS)

An analog cellular system used mainly in Europe. It has also been implemented in some areas in Japan, the United Kingdom, China, and other regions of the world. The ETACS was developed from the US Advanced Mobile Phone Service technology.

External Interference

The effects of electrical waves or fields which cause spurious signals other than the desired intelligence, e.g. noise.

External Wiring

Electronic wiring which interconnects subsystems within the system.

Extraction Tool

A device used for removing removable contacts from a connector. A device used for removing taper pins from taper pin receptacles. (MIL-STD)

Extruded Cable

Cable with conductors which are uniformly insulated and formed by applying a homogeneous insulation material in a continuous extrusion process.

Extrusion

A method of forcing thermoplastic, rubber or elastomer material under elevated temperature through a die to apply an insulation or a jacket to a cable.

F

F-Block Carrier

A 10-MHz personal-communications-services carrier serving a basic trading area in the 1890-to-1895-MHz range paired with 1970-to-1975-MHz.

Face Seal

A sealing of mated connectors over the whole area of the interface to provide sealing around each contact. (MIL-STD) Also called Interfacial Seal

Far End Crosstalk (FEXT)

Refers to the undesired coupling of signals from the transmit pair onto the receive pair at the other (=far) end. FEXT isolation is also expressed in dB. For some applications this is an important parameter, for most applications however, the NEXT values are more important.

Farad (F)

The standard unit of capacitance whereby a charge of one coulomb produces a one volt potential difference. It indicates the charge per potential difference.

Faraday Shield

A conductive material used to contain or control an electric field. Placed between the primary and secondary windings of a transformer, it reduces coupling capacitance and common-mode noise. The shield provides electrostatic shielding while passing electromagnetic waves and requires no ground.

Fast Ethernet

A 100 Mb/s LAN Based On CSMA/CD Protocol. See 100BASET.

Fatigue Resistance

Resistance to metal crystallization which leads to conductors breaking from flexing.

FDM

Abbreviation for Frequency Division Multiplexing - a method of multiplexing or combining many voice data channels for transmission on a single RF carrier. The channels are separated by frequency and carried on sub-carriers. See Multiplexing

Federal Communications Commission (FCC)

A board of five commissioners, appointed by the President, that regulates all electronic communications systems originating in the United States, including telephone systems. This government agency is responsible for the allocation of radio spectrum for communication services in the US

FEXT

See Far End Crosstalk.

FDDI

See Fiber Distributed Data Interface.

Feed-Through

A connector or terminal block, usually having double-ended terminals which permit simple distribution and bussing of electrical circuits. Also used to describe a bushing in a wall or bulkhead separating compartments at different pressure levels, with terminations on both sides.

Feed-Through Insulators

Insulators that carry a metal conductor through the chassis while preventing the hot lead from shorting to the ground chassis.

FEP

Fluorinated Ethylene Propylene is a Teflon fluorocarbon resin and is a registered T.M. of the DuPont Company. This is a melt extrudable fluorocarbon resin.

Ferrite Material

Material made by calcining a combination of metal oxides sintered into tiles. Material only a few millimeters which absorbs low frequencies. These tiles may be used with dielectric materials or as a hybrid combination with dielectric pyramids.

Ferrule

A short tube used to make solderless connections to shielded or coaxial cables by crimping. Also used in connectors to reduce transmission of torque to grommet. (MIL-STD)

Fiber

Any filament or fiber, made of dielectric materials, that guides light. Also, single discrete element used to transmit optical (light wave) information. See also Fiber Optics.

Fiber Channel

This is an ANSI standard describing point to point and switched point to point physical interface, transmission protocol, signaling protocol, services and command set mapping of a high performance serial link for uses between mainframe computers and computer peripherals.

Fiber Dispersion

In fiber optics, pulse spreading in a fiber caused by differing transit times of various modes.

Fiber Distributed Data Interface (FDDI)

An American National Standards Institute (ANSI) standard for a fiber-based token ring physical and data link protocol that operates at a 100-Mbps data transfer rate.

Fiber Optics

A fiber optic cable in which individual optical fibers are formed into a cable for primary use in side building. The technique of conveying lights or images through glass or plastic fibers. Incoherent fiber optics will transmit light but not an image; coherent fiber optics will transmit both and should actually be called "aligned fiber optics" because the fibers are all the same length and are held in a constant spatial relationship.

Fiber Optic Building Cable (LGBC)

A fiber optic cable in which individual optical fibers are formed into a cable for primary use in side building.

Fiber Optic Cable

A transmission medium consisting of a core of glass or plastic surrounded by a protective cladding, strengthening material, and outer jacket. Signals are transmitted as light pulses, introduced into the fiber by a light transmitter (either a laser or light-emitting diode [LED]). Some of the advantages offered by fiber optic cable are low data loss, high-speed transmission, large bandwidth, small physical size, light weight, and freedom from electromagnetic interference and grounding problems.

Fiber Optic Connectors

Connectors designed to connect and disconnect either single or multiple optical fibers repeatedly. Fiber optic connectors are use to connect fiber cable to equipment and interconnect cables.

Fiber Optic Cross Connection

Fiber optic apparatus for terminating cable in couplings. Designed for high-density cross-connection fields, the apparatus can terminate up to 72 fibers on each shelf, with up to nine shelves in a bay frame. Single shelves can also be wall mounted. Cross connections are handled with fiber optic patch cords. See also Patch Cord.

Fiber Optic Cross-Connect (LGX) Distribution System

A component of fiber optic cross-connect hardware. This component accommodates 24-216 fiber terminations. Also referred to as an LGX or shelf or frame.

Fiber Optic Interconnect

An interconnection unit used for circuit administration and built from modular cabinets. It provides interconnection for individual optical fibers but, unlike the fiber optic cross-connect panel, it does not use patch cords or jumpers. The fiber optic interconnect provides some capability for routing and rerouting circuits, but is usually used where circuit rearrangements are infrequent.

Fiber Optic Interconnection Unit (LIU)

A component of fiber pitch cross-connect hardware. This component accommodates 12, 24 or 48-fiber terminations. Also referred to as an LIU.

Fiber Optic Splice

A fiber optic cable splice is used to join together 2 or 24 fiber optic cable ends, permanently.

Fiber Tubing

In fiber optics, a loose, crush-resistant cylinder applied over individual fibers to provide mechanical protection.

Fiberglass

The trademark for glass which is formed into thin fibers and twisted and plied into yarns. It is used as protective braiding for cables. Normally saturated with silicone-base varnish to seal against moisture.

Field

An area of influence around a magnet or electric charge.

Field Coil

A suitable insulated winding to be mounted on a field pole to magnetize it.

File Server

A computer that stores data centrally for network users and manages access to that data. File servers can be dedicated so that no processes other than network management can be executed while the network is available, or nondedicated so that standard user applications can be run while the network is available.

Filled Cable

A telephone cable construction in which the cable core is filled with a material that will prevent moisture from entering or passing through the cable.

Filler

Material used as dummies to achieve circular cross section

Filter

A devise which blocks the flow of EMI current while passing the desired 50/60/400-Hz current. When used in communications circuits, it suppresses unwanted frequencies and noise, or separates channels.

Filter Contact

A contact which provides R.F.I. suppression without altering its normal function.

Fine Stranded Wire

Stranded wire with component strands of 36 AWG for smaller.

Finger Stock

A beryllium copper electrical gasket used to bond metal panel members on doors, sills or covers.

FIPS

Federal Information Processing Standards. ADP standards issued by the National Bureau of Standards; mandatory for federal agencies.

Fire Walls

Walls that go from structural floor to structural ceiling and, therefore, help prevent fire from spreading from one area to another.

First Article

A sample part or assembly manufactured prior to the start of production for the purpose of assuring that the manufacturer is capable of manufacturing a product which will meet the requirements.

Fixed Contact

A contact which is permanently included in the insert material.

Flame Resistance

The ability of a material not to propagate flame once the flame source is removed.

Flame Retardant

A descriptor applied to material that has been made or treated so as to resist burning

Flammability

The measure of the material's ability to support combustion.

Flammability Rating

Test methodologies of various organizations designed to simulate exposure to flame and burning, and the results of a material when tested under a specific methodology. Frequently used tests are UL94 (for testing materials as slabs or plaques), UL VW-1 or CSA FT1 (testing cable in a verticaly orientation), NEC CL2 (testing cables for general purpose communications which are installed within buildings), CSA FT6 (testing cable for horizontal flame and smoke)

Flange Connector

A projection extending from or around the periphery of a connector with provisions to permit mounting the connector to a panel or to another mating connector half.

Flash

A thin film of material formed at the sides of a forging, casting or molded part where some of the material is forced between the faces of the dies or mold halves

Flash Plating

The application of extremely thin deposits of a plating material for environmental protection or as a base for a subsequent layer of plating.

Flashover

A disruptive discharge around or over the surface of a solid or liquid insulator.

Flat Braid

A woven braid of tinned copper strands rolled flat at time of manufacture to a specified width.

Flat Cable

A cable with two smooth or corrugated but essentially flat surfaces.

Flat Conductor

A wire having a rectangular cross section as opposed to a round or square conductor.

Flat Conductor Cable

A cable with a plurality of flat conductors.

Flex Damage

Damage, usually occurring where a cord enters the housing, which is caused by the sharp bending of the cord. A strain relief or cable clamp restricts the concentration of flexing.

Flex Life

The measurement of the ability of a conductor or cable to withstand repeated bending.

Flex Life Test Types

Testing methodologies used to evaluate the durability and reliability of a cable or assemly under repeated bending. Three methods are frequently used: Weighted Bend, Bend, or Rolling Bend. The Weighted Bend test holds a section of the cable aligned within a fixed holder and with a weight attached to the calbe below the holder (applied load). At a specific distance from the holder, the free end is bent to a 90 degree angle in one direction and then reversed to a 90 degree angle in the opposite direction. This is one flex cycle. The Bend test is the same as the Weighted Bend test without a weight (no load) attached to the cable. The Rolling Bend test holds one end of the cable in a fixed holder, the cable is formed into a U shape, and the free end of the cable is moved back and forth keeping the sides of the U at a fixed distance apart during the cycling

Flexible

That quality of a cable or cable component which allows for bendi9ng under the influence of outside force, as opposed to limpness which is bending due to the cable’s own weight.

Flexibility

That quality of a cable or cable component which allows for bending under the influence of outside force, as opposed to limpness which is bending due to the cable's own weight.

Floating

Referring to a circuit which has no connection to ground.

Flood Wiring

The concept of wiring for future growth, by providing full coverage of information outlets.

Floor Distributor

The distributor used to connect between the horizontal cable and other cabling subsystems or equipment (see telecommunications closet).

Fluoropolymer

A polymer that contains atoms of fluorine. Typical fluoropolymers are TFE, FEP, PFA, ECTFE and PVF.

Flux

1) The lines of force which make up an electrostatic field.  2) The rate of flow of energy across or through a surface.  3) A substance used to promote or facilitate fusion.

Foamed Plastic

Insulations having a cellular structure.

Foil

A thin, continuous sheet of metal.

Foil screened twisted pair cable (FTP)

A cable that use's a metallic Foil to surround the conductors in a Twisted Pair cable.

Follower

A sleeve used to compress a grommet which tightens the seal around the wire entering the connector.

Footprint

1) The area of the earth’s surface covered by a satellite signal.  2) The area of a printed circuit board covered by an electronic component such as a connector, IC, etc.

Format

In video, identifies different recording and transmission signal arrangements, i.e., Beta, VHS, NTSC, PAL.

Four-Wire Circuit

1) A two-way communications circuit using two paths, arranged such that signals may be transmitted in one direction only on one path and in the other direction on the other path. The transmission cable may or may not employ four wires, since the same ground wire may serve both directions.  2) Compare with two-wire circuit.

FR-1

A flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test. This designation has been replaced by VW-1.

Frame

A metallic structure for hanging switch hardware.

Free Connector

A connector for attachment to the free end of a wire or cable.

Frequency

The number of cycles completed by a signal in one second: measured in Hertz (Hz).

Frequency-Division Muliplexing (FDM)

Simultaneous transmission of two or more messages over the same cable medium. Also called Multiplexing.

Frequency Modulation (fm)

A scheme for modulating a carrier frequency in which the amplitude remains constant but the carrier frequency is displaced in frequency proportionally to the amplitude of the modulating signal. An fm broadcast is practically immune to atmospheric and man-made interference.

Frequency Re-Use

Because of their low power, radio frequencies assigned to one channel in a cellular system are limited to a single cell. Carriers are free, however, to re-use the frequencies again in other cells in the system without causing interference

Fretting

A condition whereby mated surfaces move slightly and continually expose fresh metal. The exposed metal oxidizes and builds up until electrical continuity of the system is broken.

Fretting Corrosion

A form of excellerated oxidation that appears at the interface of contacting materials undergoing slight cyclic relative motion. All non-noble metals (i.e. tin) are susceptible to some degree of fretting corrosion and will suffer contact resistance increases.

Front Mounted

A connector mounted on the outside of a panel or box with its mounting flange outside the equipment. (MIL-STD) A front mounted connector can only be installed or removed from the outside of the equipment.

Front Release Contacts

Connector contacts are released form the front side of the connector and then removed from the rear (wire side) of the connector. The removal tool engages the front portion of the contact and pushes it out the rear where it is removed by hand.

FTP

See Foil Screened Twisting Pair Cable.

Full Cycling Control

Controls placed on the crimping cycle of crimping tools forcing the tool to be closed to its fullest extent completing the crimping cycle before the tool can be opened. (MIL-STD)

Full Duplex

In contrast to half-duplex devices, full duplex ones allow permanent, simultaneous two-way transmission of information, without interaction or interference of receive and transmit signals.

Full Duplex Ethernet

Full Duplex Ethernet will allow nodes to transmit and receive data at the same time, bringing aggregate throughput to 20 Mb/s. The CSMA/CD protocol may have to be disabled for the full duplex mechanism to function.

Full Duplex Transmission

1) Data transmission over a circuit capable of transmitting in both directions at the same time.  2) Synonymous with full duplex transmission. Also called Duplex Transmission.

G

Galvanometer

An instrument for detecting or measuring small electrical current.

Gang Disconnect

A connector that permits the rapid and simultaneous connection and disconnection of two or more electrical circuits. (MIL-STD)

Gas Tightness

The characteristic of a contact which is impervious to ingress by corrosive gasses.

Gateway

1) A node common to two or more networks through which data flows from network to network. The gateway may reformat the data as necessary and also may participate in error and flow control protocols. Used to connect LANs employing different protocols and to connect LANs to public data networks. See also Port.  2) A function designed to facilitate electronic access by users to remote services. Gateways provide a single source where users can locate and gain access to a wide variety of services.

Gauge

A measure of a conducting wire's physical size, usually referred to as AWG (American Wire Gauge). See also American Wire Gauge (AWG).

GBR

The same signals as RGB.

GBRS

The color signal set that includes Sync.

Generic Cabling

A structured telecommunications cabling system, capable of supporting a wide range of applications. Generic cabling can be installed without prior knowledge of the required applications. Application-specific hardware is not a part of generic cabling.

Genlock

One process of timing and phasing a local television signal to a remote signal.

Geostationary Satellite

A satellite whose speed is synchronized with the speed of the earth’s rotation so that it is always in the same spot over the earth (geo-synchronous orbit). Most geo-synchronous satellites operate 22,300 miles above the equator.

Giga

A numerical prefix denoting one billion.

Gigahertz (GHz)

One billion cycles per second.

Gimmick

A short length of wire soldered onto a circuit component and used as a small adjustable capacitor.

Global Positioning System (GPS)

A network of satellites developed by the US Department of Defense that provides precise location determination to special receivers.

Global System for Mobile Communications (GSM)

The European digital cellular transmission standard which has been adopted by several other countries around the world for cellular and personal communications services. It was originally called the Groupe SpecialeMobile.

Gold

The standard coating for contacts over a base of either nickel or copper.

GPIB

Abbreviation for General Purpose Interface Bus Assembly typically used for interconnecting measurement devices. General Purpose Information BUS used to daisychain instruments. Also HPIB (Hewlett Packard version).

Graded-Index Fiber

An optical fiber with a refractive index that gets progressively lower away from the axis. This causes the light rays to be continually refocused by refraction in the core. It bends the rays inwards and allows them to travel faster in the lower index of refraction regions. This type of fiber provides high bandwidth capabilities.

Grid Spaced

When contacts in a multiple contact connector are spaced in a geometric pattern. (MIL-STD)

Grommet Connector

An elastomeric seal used on the cable side of a connector to seal the connector against moisture, dirt and air. (MIL-STD)

Ground

1)The connection between an electrical circuit and the earth or other large conducting body to serve as an earth thus making a complete electrical circuit.  2)A conducting connection between an electrical circuit and the earth or other large conducting body to serve as an earth, making a complete electrical circuit.  3) A common voltage reference point, such as chassis or earth.

Ground Insulation

The insulation used between a winding and the magnetic core or other structural parts, usually at ground potential.

Ground Loop

The generation of undesirable current flow within a ground conductor, owing to the circulation currents which originate from a second source of voltage.

Ground Plane

Expanded copper mesh which is laminated onto some flat cable constructions as a shield.

Ground Potential

Zero potential with respect to the ground or earth.

Grounding Conductor

A conductor which provides a current return path from an electrical device to ground.

Grounding Fingers

A set of spring ingers provided in the connector to allow shell to shell grounding, before contacts mate and after they separate.

Guide Pin

A pin or rod extending beyond the mating faces of a connector designed to guide the closing or mating of the connector to ensure proper engagement of contacts. (MIL-STD)

H

Half Duplex Transmission

1) Data transmission over a circuit capable of transmitting in either direction, but only one direction at a time.  2) Mode of operation between two communications devices where only one of them can send or receive at a time.

Halogen-Free

A designation for gases produced during flame and burning of materials or cables. Halogen-free materials do not release potentially toxic chlorine or fluorine gasses. Toxicity of gases under flame and burning conditions is a factor in persons' survivability. There is a test methodology for toxicity which is CTI and the test method is UTE C 20.

Halogen Rating

Identifies if a thermoplatic polymer, elastomer, or thermoset rubber has or contains halogen elements. Halogen is an electro-negative atomic element which, if combined with a metal, forms a haloid salt. Halogens are chloride, fluorine, bromine, iodine and astatine. Halogen containing compounds, if exposed to flame, produce corrosive and potentially toxic fumes. Materials can be identified as either halogen-gree or as halogenated.

Handoff

Cellular systems are designed so that a phone call can be initiated while driving in one cell and continued as more cells are driven through. The transfer to a new cell is called the handoff and is designed to be transparent to the cellular phone user. This handoff is achieved by network computers which assign the call to another tower just as the user passes from one cell to another, ensuring continuous service.

Handshaking

Exchange of predetermined signals when a connection is established between two data set devices.

Hard Conversion

The process of changing a measurement from inch-pound units to nonequivalent metric units that necessitates physical configuration changes outside those permitted by established measurement tolerances. See Soft Conversion

Hard Drawn Copper Wire

Copper wire that has not been annealed after drawing.

Hardness

A general term that correlates with strength, rigidity and resistance to abrasion or penetration. Measured on Shoer or Rockwell scales.

Harness

1)An arrangement of wires and cables, usually with many breakouts, which have been tied together or pulled into a rubber or plastic sheath, used to interconnect electric circuits.  2)A group of wires or cables routed together with attached connectors and components, secured to provide a pre-shaped electrical wire or cable assembly.

HDLC

High-Lever Data Link Control—The protocol defined by ISO in 1976 for bit-oriented, frame-delimited data communications.

Head Assembly

A positioner designed to attach to a crimping tool in place of a turret head. (MIL-STD)

headend

The point in a LAN where the inbound signals are transferred into outbound signals. The headend may be passive or contain an amplifier or frequency translation equipment. Used in broadband LANs and CATV.

Heat Endurance

The time of thermal aging that a material can withstand before failing specified tests

Heat Distortion

Distortion of a material due to the effects of heat.

Heat Seal

A method for sealing by thermal fusion

Heat Shock

A test to determine stability of a material by sudden exposure to a high temperature change for a short period of time

Heat Shrinkable

A polymeric material capable of being reduced in size when exposed to heat.

Heat Treating

A process that uses precise heating and tooling of metals after stamping and forming in order to optimize internal stresses and spring properties.

Helix

Spiral winding.

Henry (H)

The standard unit of inductance. The inductance of a current is a one Henry when a current variation of one ampere per second induces one volt.

Half Duplex

A telecommunications device allowing two-way transmission of signals or other information, but only in one direction at a time. Thus a half-duplex device cannot simultaneously transmit and receive, though interspersed bursts in each direction are possible.

Hermaphroditic Connector

A connector design which utilized pin and socket contacts in a balanced arrangement such that both mating connectors are identical. The contacts may also be hermaphroditic and may be arranged as male and female contacts as for pins and sockets. Hermaphroditic contacts may also be used in a manner such that one half of each contact mating surface protrudes beyond the connector interface and both mating connectors are identical (MIL-STD)

Hermaphroditic Contact

A contact design which is a combination pin and socket and which mates with other contacts of the same design. (MIL-STD) Both mating elements are precisely alike at their mating face

Hermetic

Airtight. Since all materials are permeable, specifications define acceptable levels of hermeticity.

Hermetic Seal

Connector contacts are bonded to the connector by glass or other materials which permit maximum leakage rate of gas through the connector of 1.0 micron ft./hr. at one atmosphere pressure for special applications.

Hermetically Sealed

A gas-tight enclosure that has been completely sealed by fusion or other comparable means.

Hertz (Hz)

A term replacing cycles-per-second as a unit of frequency. This is the international standard term for cycles-per-second and is named after the German physicist Heinrich R. Hertz.

Hi-Pot

A test designed to determine the highest voltage that can be applied to a conductor without electrically breaking down the insulation.

High-Lever Data Link Control (HDLC)

The protocol defined by ISO in 1976 for bit-oriented, frame-delimited data communications

High Voltage

Generally, a wire or cable with an opreating voltage of over 600 volts.

Higher Performance Radio Local-Area Network (HIPERLAN)

HIPERLAN is the European standard for short-range (approx. 50m) high performance radio local-area networks. HIPERLAN operates in the 5.1-to-5.3-GHz band. Another band may be available in the future operating in the 17.1-to-17.3-GHz range, but as of 8/97, specifications have not been finalized.

Holding Strength

Ability of a connector to remain assembled to a cable when under tension.

Home Location Register

The data base of customer information that makes subscriber information available to a mobile-telephone switching office. The register functions as a network element.

Hood

An enclosure attached to the back of a connector to contain and protect the wires and cable attached to the terminals of a connector.See also Backshell.

Horizontal Cable

A cable connecting the floor distributor to the telecommunications outlet(s).

Horizontal Runs

The part of the premises distribution system installed on one floor that includes the cabling and distribution components connecting the riser backbone or equipment wiring to the information outlet.

Horizontal Length (HL)

The cable distance from the information outlet to the blue field of the cross connect. In SYSTIMAX® SCS, this is referred to as the Horizontal Subsystem.

Horizontal Subsystem

The part of a premises distribution system installed on one floor that includes the cabling and distribution components connecting the Riser backbone Subsystem to the information outlet via cross-connect components of the Administration Subsystem.

Horn Antenna

A microwave antenna made by flaring out the end of a circular or rectangular waveguide in the shape of a horn. It is used for radiating radio waves into space.

Host Computer

1) A computer attached to a network providing primarily services such as computation, database access or special programs or programming languages.  2) An information processor which provides supporting services and/or guidance to users and/or satellite processors, terminals and other subsidiary devices. A host processor generally is assumed to be self-sufficient and to require no supervision from other processors.  3) Compare with communications computer.

Housing Connector

Connectorless insert but with insert retaining and positioning hardware required by standard construction. (MIL-STD)

Hub(S)

A concentrator or repeater in a star topology at which node connections meet.

Hum

A term used to describe 60 or 120 cycle sound present in the sound of some communication equipment, usually the result of either undesired coupling to 60 cycle source or defective filtering of 120 cycle rectifier output.

Hybrid

Cable which contains both optical fiber(s) and metallic conductor(s).

Hybrid Cable

An assembly of two or more different types of cable units, cables or categories covered by an overall sheath. It may be covered by an overall shield.

Hygroscopic

Capable of absorbing moisture from the air.

Hz

See Hertz (Hz).

I

IBM

International Business Machines Corporation.

ICEA

Insulated Cable Engineers Association (ICEA).

ID

The internal diameter of a tubing.

IEC

International Electro-technical Commission.

IEC 331

Horizontal flame test.

IEC 332-1,2,3

Vertical flame tests.

IEC 60332

The international standard covering fire performance of cables.

IEEE

Institute of Electrical and Electronic Engineers in the USA. This organization is also involved in producing Local Area Network standards such as 10Base-T and Token Ring. such as Ethernet.

IEEE 802.11

Designation for the IEEE subcommittee which is developing the wireless local-area network standard. This standard is being formulated to provide interoperability of wireless local-area-network products.

IEEE Project 802

An IEEE standards development project concerned with LANs.

IM /PIM (Passive Intermodulation)

The generation of new, and in the case of cable assemblies, undesirable signals called intermodulation products, at the non-linear characteristics of transmission elements

Impact Strength

A test for determining the mechanical punishment a cable can withstand without physical or electrical breakdown by impacting with a given weight, dropped a given distance, in a controlled environment.

Impedance

The total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency. It is a combination of resistance R and reactance X, measured in ohms

Impedance Matching

Connecting cables and devices together which have the same impedance value in ohms.

Impulse

A surge of unidirectional polarity

Impulse Strength

The voltage breakdown of insulation under voltage surges on the order of microseconds in duration.

Impulse Test

An insulation test in which the voltage applied is an impulse voltage of specified wave shape.

Indentor

The part of a crimping die, usually the moving part, which indents or compresses the contact barrel. (MIL-STD)

Individual Pair Screened

Where each twisted pair in one overall cable has its own screen.

Inductance

The property of a circuit or circuit element that opposes a change in current flow, thus causing current changes to lag behind voltage changes. It is measured in henrys.

Inductive Coupling

Crosstalk resulting from the action of the electromagnetic field of one conductor on the other.

InfiniBand Architecture

A high bandwidth switched network topology currently being developed for Storage Area Networks (SANS).

Industrial Scientific Medical

The unlicensed radio band in North America and some European countries. Also referred to as Part 15.247, this FCC regulation defines the parameters for use of the ISM bands in the US, including power output, spread spectrum, and non-interference. The commonly used ISM bands include 902-to-928-MHz, 2400-to-2483-MHz and 5725-to-5850-MHz.

Infrastructure Equipment

The fixed transmitting and receiving equipment in a communications system. This usually consists of base station, base station controllers, antennas, switches, management information systems and any other equipment that makes up a system which sends and receives signals from mobile or handheld subscriber equipment and/or the public-switched telephone network.

Input/Output (I/O)

The machine or device used to insert information, data or instructions into a computing system or the medium or device used to transfer information or data, usually processed data, from a computing system to the outside world. Input/output also can refer to the act of entering or retrieving information.

Insert

That part which holds the contacts in their proper arrangement and electrically insulates them from each other and from the shell.

Insert Arrangement

The number, spacing and arrangement of contacts in a connector.

Insert Cavity

A defined hole in the connector insert into which the contacts are inserted.

Insert Retention Force

The maximum allowable force which, if applied to the mating face of a connector insert, does not displace the insert permanently from its normal position in the connector housing or jeopardize or damage the insert or connector housing retention provision.

Insert Electrical Connector

An insulating element with or without contacts designed to position and support contacts in a connector. (MIL-STD

Insertion Force

The effort, usually measured in ounces, required to engage mating components.

Insertion Loss

The ratio between the power received at a specified load before and after the insertion of a filter at a given frequency. It is an indication of the attenuation provided by a filter.

Insertion Tool

A device used to insert contacts into a connector A device used to insert taper pins into taper pin receptacles. (MIL-STD)

Inspection Gage

A device which conforms to the gaging limits specified on the applicable tool specification sheet.

Inspection Hole

A hole placed at one end of a crimp contact barrel to insure proper insertion of the conductor prior to crimping. (MIL-STD)

Installation Tool

A device used to install contacts into a connector. A device used to install taper pins into taper pin receptacles.

Insulated Wire

A conductor of electricity covered with a non-conducting materials.

Insulated Terminal

A solderless terminal with an insulated sleeve over the barrel to prevent a short circuit in certain installations.

Insulation

1)A material which offers high electrical resistance making it suitable for covering components, terminals and wires to prevent the possible future contact of the adjacent conductors resulting in a short circuit. This is often called a dielectric.  2)A material having high resistance to the flow of electric current.

Insulation Adhesive

The degree of tightness of the insulation over the base conductor, measured in terms of force required to remove a specified length of insulation from the wire.

Insulation Conductor

A non-metallic covering applied around a metallic conductor or optical fiber to provide electrical isolation and/or moisture protection.

Insulation Crimp

The area of a terminal, splice, or contact that has been formed around the insulation of the wire.

Insulation Crip

An extended cylinder at the rear of a contact designed to accept the bared wire and a small length of its insulation. When crimped, both the wire and insulation are held firmly in place.

Insulation Displacement

The type of wire terminals that require no wire stripping; when the wire is correctly attached, its insulation is displaced (pierced) to form a connection.

Insulation Displacement Connector (IDC)

An assembly process wherein an insulation piercing edge of the contact is pushed through the insulation and into contact with the wire by the assembly press. Most commonly used in mass termination applications.

Insulation Piercing

A method of crimping whereby lances cut the insulation of the wires and enter into the strands to make electrical contact.

Insulation Resistance (I.R.)

The measure of the ability of an insulation material to resist the flow of current through it; usually measured in Megohm-feet (Mµ-ft).  1)That resistance offered by an insulation to an expressed dc voltage, tending to produce a leakage current through the insulation.  2)Electrical resistance of insulating material between any pair of contacts, conductors or grounding devices in various combinations.

Insulation Support

The portion of a barrel similar to an insulation grip except that it is not compressed around the conductor insulation. (MIL-STD)

Insulation System

All of the insulation materials used to insulate a particular electrical or electronic product.

Integrated Services Digital Network (ISDN)

Integrated voice and data network based on digital communications technology and standards interfaces.

Insulation Thickness

The wall thickness of the applied insulation.

Insulator

A material of low electrical conductivity that the flow of current through it can usually be neglected.

Integral Belt

A layer of insulation or semi-conductive material applied by extrusion over two or more insulated, twisted or parallel conductors, to form a round smooth diameter.

Integrated Services Digital Network (ISDN)

): An integrated digital network in which the same digital switches and digital paths are used to establish connections for different service; for example, telephony, data, etc.

Integrated Services Digital Network (ISDN)

A switched network providing end-to-end digital connectivity for simultaneous transmission of voice and data over multiplexed communications channels.

Intelligent Buildings

Buildings that maximize the efficiency of its occupants and allow effective management of resources with minimum life-time costs (Source: European Intelligent Building Group).

Intelligent Peripheral Interface (IPI)

Links peripheral (subordinate) devices to host or master.

Intelligent Terminals

A terminal which contains an integral microprocessor with some logical capability.

Interaxial Spacing

1)Center to center conductor spacing is paired wire or  2) center to center spacing between conductors in a flat cable.

Interchangeable

Characteristic of connectors in which one manufacturer's connector can be replaced by one of another manufacturer and provide the same function in the same panel space as the connector it replaced.

Intercloset Cables

Cables that connect telecommunications closets.

Interconnect

A circuit administration point, other than a cross connect or information outlet, that provides capability for routing and rerouting circuits. It does not use patch cords or jumpers. Typically it is a jack-and-plug device used in smaller distribution arrangements or to connect circuits in large cables to those in smaller cables.

Interconnecting Cable

The wiring between nodules, between units, or the larger portions of a system

Interconnection

Mechanically joining assemblies together to complete electrical circuits

Interface

1) Shared boundary defined by common physical interconnection characteristics (often including a connector), signal characteristics and meanings of interchanged signals.  2) A device or equipment making inter-operation of two systems possible; for example, a hardware component or common storage register.  3)The two surfaces on the contact side of a mating connector or plug-in component (e.g. relay) and receptacle, which face each other when mated. (MIL-STD)

Interface Cards

See Network Interface Cards.

Interfacial Compression

The compression of the resilient material which faces the mating inserts and provides positive sealing and insulation when plug and receptacle are fully engaged or mated.

Interfacial Gap

Any space between the faces of mated connectors.

Interfacial Seal

A sealing of mated connectors over the whole area of the interface to provide sealing around each contact. (MIL-STD)

Interference

A signal impairment caused by the interaction of another unwanted signal. Electrical or electromagnetic disturbances which introduce undesirable responses into other electronic equipment.

Inter-Mateable

Characteristic of connectors in which a connector half of one manufacturer will mate directly with a connector half manufactured by a different company.

Intermetallic

Chemical compounds formed between the metals present in the solder, base metal and protective platings. Intermetallic formation is necessary for good solder joints, but excessive intermetalics can cause brittleness.

Internal Wiring

Electronic wiring which interconnects components, usually within a sealed subsystem.

International Standards Organization (ISO)

The organization responsible for the Open Systems Interconnect (OSI) standards. International Standards Organization.

International Telegraphy and Telephone Consultative Committee (CCITT)

A standards organization that, among numerous other activities, specializes in the electrical and functional characteristics of switching equipment. The CCITT sets standards for interfaces to ensure compatibility between data communications equipment (DCE) and date terminating equipment (DTE).

Interoperability

The ability to operate and exchange information in a heterogeneous network.

Interstices

Voids or valleys between individual strands in a conductor or between insulated conductors in a multiconductor cable during extreme flexing.

IO

Information Outlets (IO).

Ionization Voltage (Corona Level)

The minimum value of falling rms voltage which sustains electrical discharge within the vacuous or gas-filled spaces in the cable construction or insulation.

IPCEA

Insulated Power Cable Engineers Association

IR Shadowing

When connector bodies or other components prevent the infrared energy from directly striking some solder joints, causing non-uniform heading.

IR Reflow

A soldering process that uses infrared (IR) light with a wavelength between visible light and microwave radiation as its energy source.

IrDA

Infrared Data Association established in 1992. They set and support hardware and software standards which enable IR-featured products to work together.

IRE or IEEE Units

An industry measurement of 100 IRE or IEEE units equals one volt of video.

Irradiation

In insulations, the exposure of the material to high energy emissions to alter the molecular structure by cross-linking. This leads to improved mechanical stability with temperature.

IS

Interim Standard

IS-41

The protocol for roaming within the US as designated by the Telecommunications Industry Association.

IS-54

The dual-mode (analog and digital) cellular standard for North America. In the analog mode, IS-54 conforms to the Advanced Mobile Phone Service standard.

IS-95

The code-division-multiple-access standard for US digital cellular as designated by the TIA.

IS-136

The time-division-multiple-access standard designated by the Telecommunications Industry Association (TIA).

IS-661

A technology which combines elements of code-division multiple access and time-division multiple access. It was developed by Omnipoint, a personal-communications-services licensee in the New York metro area.

ISA

Instrument Society of America

ISDN

Integrated Services Digital Network.

ISO

See International Standards Organization (ISO). International Standards Organization.

ISO Seven Layer Model

A 7 layer hierarchical reference structure developed by the ISO for defining, specifying and relating communications protocol.

ISO/IEC IS 11801

An international standard for generic cabling for customer premises.

ISO/IEC 14763-1

The international standard for basic administration of generic cabling.

Isochronous Ethernet

This is part of the IEEE 802.9 integrated services LAN standard. It is an extension of 10Base-T which provides for the inclusion of a 6.144 Mbps isochronous (real time and delay sensitive) data service in addition to the 10 Mb/s 10BaseT packet service. It will provide multimedia capability.

ISDN

Integrated Services Digital Network (ISDN).

J

Jack

A receptacle used with a plug to make electrical contact between communications circuits. Jacks and their associated plugs are used in a variety of connecting hardware applications including adapter, information outlets, and equipment connections.

Jacket

1)An outer covering, usually non-metallic, mainly used for protection against the environment.  2)The outermost layer of insulating material of a cable or wire. (MIL-STD)

Jackscrew (Screwlock)

A screw attached to one half of a two-piece multiple contact connector used to draw and hold both halves together and to separate them. (MIL-STD)

Japan Digital Cellular (JDC)

A digital cellular standard developed by NTT of Japan, operating in Japan at 800 and 1500 MHz.

J-Lead

A surface mount lead configuration where leads are bent into curves. Infrequently used on interconnects.

Joule (J)

A unit of work or energy equal to 0.7375 foot-pounds.

JTAC

The Japanese variant of the Total Access Communications System analog standard. It was developed by Motorola for Japan.

Jumper

A cable unit or cable element without connectors used to make a connection on a cross-connect.

Jumper Cable

1)A short flat cable interconnecting two wiring boards or devices.  2)A coaxial cable terminated at each end with a coaxial connector and used to interconnect two electronic devices.

Jumper Wire

A short length of Connectorized copper wire used to route a circuit by linking two cross-connect termination points.

Junction

A point in a circuit where two or more wires are connected.

K

Key

A short pin or other projection which slides in a mating slit, hole , groove, or keyway to guide two parts being assembled. Generally used in shell-enclosed connectors to obtain polarization. (MIL-STD)

Keying

Mechanical arrangement of keyways, inserts or grooves in a connector shell or insert that allows connectors of the same configuration to be used without the danger of interconnection to the wrong mating connector.

Keying Signal

The video signal that is used to delete that portion of the background signal that is to be replaced with another video signal.

Keyway

A slot or groove in which a key slides. (MIL-STD)

Kilohertz (Khz)

One thousand cycles per second.

Kynar™

Pennwalt trade name for polyvinylidene fluoride, a fluorocarbon material typically used as insulation for wire wrap wire.

L

Lacing Cord or Twine

Used for tying cable forms, hook-up wires, cable ends, cable bundles and wire harness assemblies.

Lacquer

A liquid resin or compound applied to textile braid to prevent fraying, moisture absorption, etc.

LAN

Abbreviation for Local Area Network, a data communications network confined to a limited geographic area.

LAND

The metal portion of a printed circuit board where the pads on a surface mount component are mated. Also called a footprint or a pad.

Lanyard

A device attached to certain connectors which permits uncoupling and separation of connector halves buy a pull on a wire or cable.

Lanyard Release

A plug connector which may be separated from a counterpart receptacle by axial pull of an attached lanyard. (MIL-STD)

Lays

The twists in twisted-pair cable. Two single wires are twisted together to form a pair; by varying the length of the twists, or lays, the potential for signal interference between pairs is reduced.

LC Connector

A high density connector for fiber optic applications used in both public and private networks. This high performance connector is available in both singlemode and multimode.

Leaching

The movement of metal atoms from the lead base metal into liquid solder. This is prevented by nickel plating. May also refer to alloying of a gold protective plating into the solder.

Lead

A wire, with or without terminals, that connects two points in a circuit.

Lead Cured

A cable that is cured or vulcanized in a metallic lead mold.

Lead Dress

The placement or routing of wire and component leads in an electrical circuit.

Lead-In

The conductor or conductors that connect the antenna proper to electronic equipment.

Leakage Current

The undesirable flow of current through or over the surface of an insulation.

Life Cycle

A test that indicates the time span before failure; the test occurs in a controlled, usually accelerated environment.

Lightpack Cable

A cable core design that allows bundles of optical fibers in a cable core without central strength members.

Light Source

In fiber optics, an object capable of emitting light. The light source is normally an LED or a laser.

Limits of Error

The maximum deviation (in degrees or percent) of a thermocouple or thermocouple extension wire from standard emf-temperature to be measured.

Limpness

The ability of a cable to lay flat or conform to a surface.

Line

The portion of a data circuit external to the data circuit-terminating equipment (DCE) that connects it to an exchange, other DCEs, or connects two exchanges.

Line Balance

The degree to which the conductors of a cable are alike in their electrical characteristics with respect to each other, to other conductors and to ground.

Line Drop

A voltage loss occurring between any two points in a transmission line, due to the resonance, reactance or leakage of the line.

Line Impedance

Impedance as measured across the terminals of a transmission line; frequently the characteristic impedance of the line.

Line Voltage

Voltage existing in a cable or circuit.

Link

The interconnection of two nodes in a network. A link may consist of a data communications circuit or a direct channel (cable) connection. It excludes equipment cables and work area cables.

Link Budget

Optical loss budget that determines the maximum distance allowable between station. Loss and dispersion factors are included.

LIU

See Fiber Optic Interconnection Unit (LIU).

LOCA

Loss of Coolant Accident. A system malfunction associated with nuclear generating stations.

Local Area Network (LAN)

A data communications network consisting of host computers or other equipment interconnected to terminal devices, such as personal computers, often via twisted-pair or coaxial cables. LAN's allow users to share information and computer resources. Typically, a network is limited to a single premises.  1)A baseband or broadband interactive bi-directional communication system for video or data use on a common cable medium.  2)A communications system whose dimensions typically are less than five kilometers. Transmissions within a local area network generally are digital, carrying data among units.

Local Exchange Carrier

The local wired phone company.

Local Multipoint Distribution System (LMDS)

A “wireless cable” service operating in the 28-GHz band. LMDS uses low-power transmitters, configured in a cellular-like arrangement to transmit video to receivers in homes and businesses.

Locator

Device for positioning terminals, splices or contacts into crimping dies, positioner, or turret heads. See STOP PLATE. (MIL-STD)

Locking Spring

A device either on the contact or in the insert to retain the contact in an insert or body. (MIL-STD). Also called Contact Retainer

Log Periodic Antenna

A broadband antenna where the electrical lengths and element spacings are chosen so the bi-directional radiation pattern, impedance and other antenna properties are repeated for several frequencies. The bandwidth is approximately the ratio of the longest dipole element to the shortest.

Longitudinal Change (Shrink Tubing)

The change in length of tubing when recovered. Expressed in the percent change from the original length.

Longitudinal Shield

A tape shield, flat or corrugated, applied parallel to the axis of the core being shielded.

Longitudinal Shrinkage

A term generally applied to shrink products denoting the discrete axial length lost through heating in order to obtain the recovered diameter.

Longitudinal Wrap

Tape applied longitudinally with the axis of the core being covered.

Loop Antenna

An antenna consisting of one or more complete turns of a conductor; usually tuned to resonance by a variable capacitor connected to the terminals of the loop. It measures magnetic-field strengths at frequencies <30 kHz.

Loop Resistance

The total resistance of two conductors measured round trip from one end.

Loop Thru

A high impedance parallel connection. Also called Bridging

Looping-In

Wiring method which avoids tee joints by carrying the conductor or cable to and from the point to be supplied.

Loss

1) Energy dissipated without performing useful work.  2) A decrease in power suffered by a signal as it is transmitted from one point to another (transmission loss).

Loss Factor

The product of the dissipation and dielectric constant of an insulating material.

Lossy Line

A cable having large attenuation per unit of length.

Lot Number

The number that identifies one production run of material.

Low Loss Dielectric

An insulating material that has a relatively low dielectric loss, such as polyethylene or Teflon.

Low Noise Cable

Cable specially constructed to avoid spurious electrical disturbances caused by mechanical movements.

Low Tension

Low voltage, as applied to ignition cable.

Lug

Termination, usually crimped or soldered to the conductor, with provision for screwing on to the terminal. Sometimes referred to as Solder Lug.

M

MAC

Multiplexed Analog Component, the same as CAV.

Magnet Wire

Insulated wire intended for use in windings on motor, transformer, and other coils for electromagnetic devices

Magnetic Field

The region within which a body or current experiences magnetic forces.

Magnetic Flux

The rate of flow of magnetic energy across or through a surface (real or imaginary).

Magnetic Noise

Caused by change in current level, e.g. ac powerline (creates magnetic field around that cable) this magnetic field causes the magnetic noise.

Major Trading Area (MTA)

A personal-communications-service area designated by Rand McNally and adopted by the Federal Communications Commission to determine the 51 MTAs in the US.

Marking

A printed identification number or symbol applied to the surface of tubing or cable jackets.

Mate

The joining of two connectors. (MIL-STD)

Material Scattering Loss

In fiber optics, the loss due to fluctuations in the refractive index and to inhomogeneities in material composition and temperature.

Mating Face

1) Shared boundary defined by common physical interconnection characteristics (often including a connector), signal characteristics and meanings of interchanged signals.  2) A device or equipment making inter-operation of two systems possible; for example, a hardware component or common storage register.  3) The two surfaces on the contact side of a mating connector or plug-in component (e.g. relay) and receptacle, which face each other when mated. (MIL-STD)Also called Interface.

Mating Face Seal

A seal which prevents the passage of moisture or gases into or out of the connecting interface of two connectors in mated condition.

MATV

Acronym for Master Antenna Television System—a combination of components providing multiple television receiver operations from one antenna or group of antennas; normally on a single building.

MCM

One thousand circular mils.

MCX

Micro-miniature coaxial connector with snap-on coupling mechanism. Frequency range is DC - 3 GHz.

Megahertz (MHz)

One million cycles per second.

Megarad

A unit for measuring radiation dosage. Equal to one million rads.

Melting Point

The temperature at which crystallinity disappears when crystalline material is heated.

Messenger

The linear supporting member, usually a high strength steel wire, used as the supporting element of a suspended aerial cable. The messenger may be an integral part of the cable, or exterior to it.

Metal To Metal Bottoming

In cylindrical connectors, the situation in which the shell surface of the receptacle bottoms (contacts) the inside rear portion of the mating plug.

Method of Moments

Equations for numerically computing electromagnetic fields.

Metropolitan Statistical Area (MSA)

An MSA denotes one of the 306 largest urban population markets as defined by Rand McNally and designated by the Federal Communications Commission as a guide to determine coverage areas for cellular networks. Two cellular operators are licensed in each MSA.

Mft

A popular abbreviation for 1000 feet.

Mho

The unit of conductivity. The reciprocal of an ohm.

Mhz

Megahertz, or one million cycles per second. Formerly Mc

Micro

Prefix for one-millionth.

Microbending Loss

In fiber optics, the loss due to small geometrical irregularities along the coreclad interface of the fiber.

Microcell

A small cell site in a personal-communications-services network. Personal-communications-services networks use many microcells.

Microfarad

One-millionth of a farad.

Micromicrofarad

One millionth of a microfarad.

Microphonics

Noise in a system caused by mechanical vibration of components within the system.

Microstrip

A type of transmission line configuration which consists of a conductor over a parallel ground plane and separated by a dielectric.

Microwave

A short (usually less than 30 cm.) electrical wave. RF signals between 890-MHz and 20-GHz. Point-to-point microwave transmission is commonly used as a substitute for copper or fiber cable.

Microwave Frequency

The frequency of a microwave, usually above 1 gigahertz.

Migration

The movement of some metals, notably silver, from one location to another.

MII Format

A video recording format used by broadcasters.

Mil

A unit used in measuring diameter of a wire or thickness of insulation over a conductor. One one-thousandth of an inch (.001).

Millivolt Drop Test

A test designed to determine the voltage loss due to resistance of a crimped joint.

MIL-SPEC

Abbreviation for Military Specification, which is a document that the U.S. Government issues to define a product that will be used in military end-use applications.

Miniature Wire

Insulated conductors of approximately 20-34 AWG.

Minimum Dynamic Bending Radius

The minimum permissible radius for flexible applications of the cable.

Minimum Static Bending Radius

The minimum permissible radium for fixed installation of the cable. This radium is used I climatic tests.

Mismatch (Connector Impedance or Line Impedance)

1) The condition in which the impedance of a source does not match or equal the impedance of the connected load. This reduces power transfer by causing reflection.  2) A termination having a different impedance than that for which a circuit or cable is designed.

MMCX

Micro-miniature connector, even smaller than an MCX connector, which has a snap-on coupling mechanism. They are used at frequencies from DC-6 GHz and are available in 50ohm and 75ohm versions.

Mobile Telephone Switching Office (MTSO)

The central computer that connects a cellular-phone call to the public telephone network. The MTSO controls the entire system’s operations, including monitoring calls, billing, and handoffs.

Mode

One of the components of a general configuration of a propagating wave front.

Modem

DCE which places and receives data signals over a common carriers' communication facility.

Modulation

In fiber optics, the manner in which information is coded into light for transmission through a fiber.

Modulus of Elasticity

The ratio of stress to strain in an elastic material.

Moisture Absorption

The amount of moisture, in percentage, that a material will absorb under specified conditions.

Moisture Resistance

The ability of a material to resist absorbing moisture from the air or when immersed in water.

Mold, Potting, Electrical, Connector

An item, solid or split, designed to be used as a hollow form into which potting compound is injected and allowed to cure or set to seal the back of an electrical connector. The potting may eliminate the need for a backshell on the connector. The form may or may not be removable after potting.

Molded Plug

A connector molded on wither end of a cord or cable.

Monochrome Signal

A television signal that does not contain any color information, a "black and white" signal.

Monomer

The basic chemical unit used in building a polymer.

Motherboard

A printed circuit board used for interconnecting arrays of plug-in electronic modules or sub-assemblies.

MTW

An acronym for thermoplastic insulated machine tool wire.

Multiconductor

More than one conductor within a single cable complex.

Multimedia

A means of conveying information with components in different media such as voice, music, text, graphics, image and video.

Multimode

Many light rays (modes) propagating through the fiber core.

Multimode fiber

In fiber optics, a fiber which transmits many modes. Optical fibers that have a large core and that permit nonaxial rays or modes to propagate through the core. 62.5 micron is the common standard core size for premises cabling systems.

Multiple Conductor Cable

A combination of two or more conductors cabled together and insulated from one another and from sheath or armor where used.

Multiple Conductor Concentric Cable

An insulated central conductor with one or more tubular stranded conductors laid over it concentrically and insulated from one another.

Multiplexing

Simultaneous transmission of two or more messages over the same cable medium. See FDM and TDM.

Mutual Capacitance

1)Capacitance between two conductors when all other conductors are connected together to shield and ground.  2) Capacitance between two conductors when all other conductors including ground are connected together and then regarded as an ignored ground.

MUX

Multiplexer

MYLAR™

DuPont trade name for a polyester material.

N

Nanometer (nm)

A unit of length in the metric system denoting one-billionth of a meter (10µm).

Nanosecond

One thousandth of one millionth of a second.

Narrowband

Mobile or portable radio services, usually paging and data services.

National Electrical Code (NEC)

A consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations. Safety standard for the design, construction, and maintenance of electrical circuits. The NEC, sponsored by the National Fire protection Association (NFPA), generally covers electrical power wiring within buildings.

National Telecommunications and Information Administration (NTIA)

An agency of the US Commerce Department, it is the President’s adviser on communications policy and is responsible for administering all federal government use of the radio spectrum, including military communications.

NBS

National Bureau of Standards

NCC

See Network Communications Cable (NCC)

Near End Crosstalk (NEXT)

Refers to the undesired coupling of signals from the transmit pair onto the receive pair on the same (=near) end. NEXT isolation is expressed in dB and is a measure of how well the pairs in a cable are isolated from each other.

NEC

See National Electrical Code (NEC)

NEMA

National Electrical Manufacturers Association.

Nest

The portion of a crimping die which supports the barrel during crimping. See Anvil. (MIL-STD)

Network

The local and long-distance telecommunications capability provided by common carriers for switch and private line telecommunications services. A system of software and hardware connected in a manner to support data transmission.

Network Architecture

Network topology and design.

Network Communications Cable (NCC)

Network Communications Cable, often called NCC, is generally used in the Riser Backbone Subsystem in locations not involving plenums. The cable consists of 24-AWG, annealed-copper conductors insulted with color-coded polyvinyl chloride (PVC) in twisted pairs, encased in an outer PVC jacket whose frictional properties permit it to be pulled in conduit without the aid of lubricants. This type of cabling used to be referred to as Direct Inside Wire (DIW).

Network Interface

The point of interconnection between building communications wiring and outside communications lines (telephone company facilities).

Network Interface Cards (NICs)

The piece of equipment that is installed into the expansion port of a personal computer and allows communication between the PC and the network.

Network Layer

The network layer is layer 3 of the OSI model. This layer sets up an end-to-end connection across a network determining which permutation of individual links to be used. Thus the network layer performs overall routing functions.

NEXT

See Near-end cross talk.

NFPA

National Fire Protection Association. That association responsible as the Administrative Sponsor of the National Electrical Code. Also identified as "ANSI Standards Committee CI".

Nick (Notch)

A cut or notch in conductor strands or insulation. (MIL-STD)

nm

See Nanometer (nm).

Node(S)

A piece of communications equipment on the network.

Noise

The term used for spurious signals produced in a conductor by sources other than the transmitter to which it is connected. Noise can affect a legitimate signal to the extent that it is inaccurate or indecipherable when it reaches the receiver. The higher the speed of data transmission, the worse the effects of noise become. Unwanted and/or unintelligible signals picked up on a cable circuit. Random electrical signals that are generated by circuit components or by natural disturbances.

Nominal

A descriptor applied to a dimension representing the center of the range of tolerance or a value if no tolerance is applied.

Non-Contaminating PVC

A polyvinylchloride formulation, which does not produce electrical contamination.

Non-Normal Jack

A chassis mounted device that provides a connection between a rear mounted receptacle and a front mounted receptacle.

Non-Wireline Cellular Company

The Federal Communications Commission licensed two cellular systems in each market—one for the local telephone company and the second, the “A” carrier, for other applicants. The distinction between A and B (the wireline cellular carrier) was meaningful only during the Federal Communications Commission’s licensing process. Once a system is constructed, it can be sold to anyone. Thus, in some markets today, the A and B systems are owned by telephone companies. One happens to be the local phone company for the area and the other is a phone company that decided to buy a cellular system outside its home territory.

Norid Mobile Telecommunication System (NMT)

A European analog cellular standard operating at 450 and 900-MHz

Normal Jack

The same as a Non-Normal Jack, except that there is also an interruptible connection between the two rear mounted receptacles.

Normal Plug

A dual male connector that can be inserted into two vertical jacks to provide a continuous connection. Sometimes called a "looping" plug.

NTSC

National Television Standards Committee. NTSC refers to the color standard that was adopted by this committee.

Nylon

A group of polyamide polymers which are used for wire and cable jacketings.

Numerical Aperture

The size of the vertex angle of the largest core of rays that can enter or leave a multimode fiber optic system, multiplied by the refractive index of the medium in which the vertex of the core is located.

O

O Ring

A doughnut-shaped ring of rubber used as a seal around the periphery of the mating insulator interface of cylindrical connectors.

Off Center

Conductor displaced within the cross-section of its insulation, no longer concentric.

Offgasing

Percentage of a specified gas released during the combustion of insulation or jacketing material.

OFHC

Abbreviation for oxygen-free, high conductivity copper. It has no residual deoxidant, 99.95% minimum copper content and an average annealed conductivity of 101%.

OFT (Optional Flame Test)

Canadian Standards Association's test for flame retardance. Tubing with an OFT rating is highly flame-retardant.

Ohm (W)

The standard unit of electrical resistance. One volt will cause one ampere of current to flow through on ohm of resistance.

Oil Aging

Cable aged in an accelerated manner by placement in an oil bath and heated to a pre-set temperature for a stated time.

Open Cell

Foamed or cellular material with cells which are generally interconnected.

Open Entry Contact

A female-opening contact unprotected from possible damage or distortion from a test probe or other wedging device.

Open system interconnection (OSI)

A conceptual model specified by CCITT recommendations in the X200 series. The model describes the 7-layer process of communication between 'co-operating' computers. The model provides a standard for the development of communication protocols allowing for computers of different manufacturers to be interconnected.

Operating Frequency

The maximum frequency at which a connector will function and yield satisfactory electrical performance.

Operating Temperature

The maximum internal temperature resistant capabilities of a connector in continuous operation. (MIL-STD)

Operating Voltage

The maximum voltage at which a connector is rated to operate.

Optical Communication Cable

In fiber optics, fiber with a protective jacket around it.

Optical Conductors

In fiber optics, materials which offer a low optical attenuation to transmission of light energy.

Optical Connectors

See Fiber Optic Connectors.

Optical Cross Connection

See Fiber Optic Cross Connection.

Optical Fiber

A transmission medium consisting of a core of glass or plastic surrounded by a protective cladding. Signals are transmitted as light pulses, introduced into the fiber by a light transmitter i.e. Laser or an LED.

Optical Interconnect

See Fiber Optic Interconnect.

Optical Splice

See Fiber Optic Splice.

Optical Time-Domain Reflectometer (OTDR)

An instrument that characterizes cable loss by measuring the backscatter and reflecting of injected light as a function of time. It is useful for estimating attenuation and for locating splices, connections, and breaks.

Optical Waveguide

In fiber optics, a fiber used for optical communications. Analogous to a waveguide used for microwave communications.

Oscillatory Surge

A surge which includes both positive and negative polarity values.

OSHA

Abbreviation for Occupational Safety and Health Act. Specifically the Williams-Steiger law passed in 1970 covering all factors relating to safety in places of employment.

OSI

See Open Systems Interconnect (OSI).

OTDR

See Optical Time-Domain Reflectometer (OTDR)

Outgassing

1)De-aeration or other gaseous emission from a connector when exposed to heat, reduced pressure or both.  2)Percentage of a gas released during the combustion of insulation or jacketing material

Outlets

A term used to describe the sockets provided in the work location of a Structured Cabling System. These are usually 8-pin modular sockets which can support a variety of services e.g. voice, video and data.

Overall Diameter

Finished diameter over wire or cable.

Overcoat Conductor

A stranded conductor made from individual strands of tin coated wire stranded together, and then given an overall tin coat.

Oxidation

1) The addition of oxygen to a metal.  2) Any process where a metal loses electrons and is converted from a metal of zero electrical charge to a metallic ion with a positive charge.

Ozone

Reactive form of oxygen, typically found around electrical discharges and present in the atmosphere in small quantities.

P

PABX

Private Automatic Branch Exchange. A private switching system that switches calls both internally within a building or premises and outside to the telephone network.

Packet-Switching

A type of exchange or network which conveys a string of information from origin to destination by cutting it up into a number of packets and carrying each independently. A packet-switched effect could be achieved by sending individual pages of a book through the post separately. The receiving device reassembles the message. Thus a direct connection between origin and destination does not exist at any point.

PAD

The metal portion of a printed circuit board where the leads on a surface mount component are mated. Also called a footprint or a land.

Pair

Two wires grouped (usually twisted) together and marked with reciprocal color coding. See also Twisted Pair.

Pairing

The union of two insulated single conductors through twisting.

PAL

Phase Alternate Line, a composite color standard used in many parts of the world.

Panel

The side or front of a piece of equipment, usually metal, on which connectors are mounted.(MIL-STD)

Panel Mount

A connector designed to be fixed to a panel by means of screws or mounting nuts.

Panel Seal

A seal preventing the passage of moisture or gases through the gap between the mounting hole of the panel and the connector body of the fixed connector.

Parallel Digital

The processing and transmission of digital information in parallel information sets.

Parallel Pair

A duplex construction of two insulated conductors laid parallel and then covered overall with a braid or jacket.

Parasitic Capacitance

The capacititive leakage across a component such as a resistor inductor, filter, isolation transformer or optical isolator that adversely affects high-frequency performance.

Part 15

A Federal Communications Commission ruling which defines the parameters for use of the industrial-scientific-medical bands in the US (such as low-power output, spread spectrum, non-interference, etc.)

Passive Tag

An RF identification transponder that does not have an internal power source. Their energy source is the power emitted from an antenna.

Patch Cable

A cable with plugs or terminals on each end of the conductors to temporarily connect circuits of equipment together. Braid covered with plugs or terminals on each end to connect jacks or blocks in switchboards or programming systems.

Patch Cord(s)

A short length of copper wire or fiber optic cable with connectors on each end used to join communications circuits as a cross connect.

Patch Panel(s)

A cross-connect designed to accommodate the use of patch cords. It facilitates administration for moves and changes.

Pathway(s)

Designated cable routes and/or support structures in a false floor or ceiling.

Pay-Off

The process of feeding a cable or wire from a bobbin, reel, or other package.

PBX

See Private Branch Exchange (PBX)

PCS-1900

One of the emerging US personal-communications-services standards, which operate at 1.9 GHz.

PDS

See Premises Distribution System (PDS).

Percent Plating

Quantity of plating on a conductor expressed as a percentage by weight.

Percentage Conductivity

Conductivity of a material expressed as a percentage of that of copper.

Periodicity

The uniformly spaced variations in the insulation diameter of a transmission cable that result in reflections of a signal, when its wavelength or a multiple thereof is equal to the distance between two diameter variations.

Peripheral(s)

Additions to a system, a resource e.g. printer, scanner, etc.

Peripheral Seal

A seal provided around the periphery of connector inserts to prevent the ingress of fluids or contaminants at the perimeter of mated connectors.

Permanent link

The transmission path between two mated interfaces of generic cabling, excluding equipment cables, work area cables and cross-connections.

Permeability

The extent to which a material can be magnetized; often expressed as the parameter relating the magnetic-flux density induced by an applied magnetic-field intensity.

Permittivity Relative

Synonym term for relative dielectric constant.

Personal Communications Services (PCS)

Federal Communications Commission terminology for two-way, personal, digital wireless communications systems.

Personal Digital Assistant (PDA)

A portable computing device that is capable of transmitting data. PDAs can be used for paging, data messaging, electronic mail, receiving stock quotations, personal computing, facsimile, and as a personal electronic organizer.

Personal Handyphone System (PHS)

Japan’s designation for its digital cordless telephony standard.

pF

See Picofarad (pF)

Phase

A particular stage or point of advancement in an electrical cycle. The fractional part of the period through which the time has advanced, measured from some arbitrary point. Usually expressed in electrical degrees where 360 degrees represent one cycle.

Phase Shift

Change in phase of a voltage or current after passing through a circuit or cable.

Phase Stability

The variation of the electrical length of a cable as a function of, for example, the temperature or mechanical stressing such as bending or torsion.

PHY

Physical layer of the Fiber Distributed Date Interface (FDDI) standard. Also used to refer to the actual hardware used to implement the physical layer (PHY entity).

Physical Layer

Layer 1 of the open systems interconnection (OSI) model. The physical layer protocol is the hardware and software in the line terminating device which converts the databits needed by the datalink layer into the electrical pulses, modem tones, optical signals or other means which will transmit the data.

Physical Topology

Physical cabling layout i.e. ring, bus, star wired etc.

Pick

The distance between two adjacent crossover points of braid filaments. The measurement in picks per inch indicates the degree of coverage.

PICO

Prefix meaning one millionth of one millionth.

Picocell

A cell site for a personal-communications-services network that is somewhat smaller than a microcell and often used to provide service within large buildings and malls.

Picofarad (pF)

A unit of capacitance used to designate capacitance unbalance between pairs of capacitance unbalance of the two wires of a pair to ground. One picofarad equals one trillionth of a farad.

Pigtail

A short wire extending from an electric or electronic device to serve as a jumper or ground connection. (MIL-STD)

Pigtail Orientation

A pigtail may be approximately perpendicular to the axis through the center of the coil of a cordset, and this is referred to as a dropped pigtail or perpendicular pigtail. A pigtail may be approximately parallel to the axis through the center of the coil and this is referred to as a turned out pigtail or an axial pigtail.

Pin

A conductor on a plug or connector.

Pin Contact

A contact having an engagement end that enters the socket contact. (MIL-STD) A male type contact, usually designed to mate with a socket or female contact. It is normally connected to the “dead” side of a circuit.

Pitch

In flat cable, the nominal distance between the index edges of two adjacent conductors.

Pitch Diameter

Diameter of a circle passing through the center of the conductors in any layer of a multiconductor cable.

Plain Conductor

A conductor consisting of only one metal.

Plain Weave

A weave used on woven cables. Threads between the wires act as binders and give the cable lateral stiffness and linear flexibility. Also called Standard and Square weave.

Plastic Deformation

Change in dimensions under load that is not recovered when the load is removed.

Plasticizer

A chemical agent added to plastics to make them softer and more pliable.

Plated Through Hole

A hole through a Printed Circuit Board that has been electroplated and into which a lead is placed and soldered for electrical and mechanical connection.

Plating

The overlaying of a thin coating of metal on metallic components to improve conductivity, provide for easy soldering or prevent rusting or corrosion. (MIL-STD)

Plenum

The air return path of a central air handling system, either ductwork or open space over a dropped ceiling.

Plenum Cable

Cable approved by Underwriters Laboratories for installation in plenums without the need for conduit. This cable has adequate fire resistance and low smoke producing characteristics. It is installed without conduit in ducts, plenums and other spaces used for environmental air, as permitted by NEC Articles 725-2(b) and 800-3(b). The space above a suspended ceiling use to circulate air back to the heating or cooling system in a building. Plenum cable has insulated conductors often jacketed with Teflon or Halar on copper and low smoke PVC on fiber optics to give them low flame-producing and low smoke-producing properties.

Plug

A device used for connecting wires to a jack. It is typically used on one or both ends of equipment cords or on wiring for interconnects or cross connects.

Plug Connector

An electrical fitting with pin, socket or pin and socket contacts, constructed to be affixed to the end of a cable, conduit, coaxial line cord or wire for convenience in joining with another electrical connector and not designed to be mounted on a bulkhead, chassis or panel. (MIL-STD)

PLY

The number of individual strands or filaments twisted together to form a single thread.

PMD

Physical Medium Dependent part of the Fiber Distributed Data Interface (FDDI) standard. Determines the specifications for the fiber optic transmitters and receivers, fiber optic cable, fiber optic connectors, and fiber optic bypass switch.

Point to Point Wiring

An interconnecting technique wherein the connections between components are made by wires routed between connecting points.

Poke Home Contact

Term applied to a male or female contact to which a wire has been permanently affixed prior to the assembly of the contact into the insert. A registered trade name of Amphenol.

Polarization

Mechanical arrangement of keyways, inserts or grooves in a connector shell or insert that allows connectors of the same configuration to be used without the danger of interconnection to the wrong mating connector. Also called Keying

Polarize

The arrangement of mating connectors such that the connector can be mated in only one way. (MIL-STD)

Polarizing Pin, Key or Keyway

A device incorporated in a connector to accomplish polarization. (MIL-STD)

Polyamide

A polymer formed by the reaction of a diamine and a diacid. Nylons are commercial polyamides characterized by toughness, solvent resistance and sharp melting point.

Polyethylene

A family of insulations derived from the polymerization of ethylene gas and characterized by outstanding electrical properties, including high I.R. low dielectric constant, and low dielectric loss across the frequency spectrum. Mechanically rugged, it resists abrasion and cold flow.

Polyester

Polyethylene terephthalate which is used extensively in the production of a high strength moisture resistant film used as a cable core wrap.

Polymer

A material of high molecular weight formed by the chemical union of monomers.

Polyolefin

A family of thermoplastics based upon the unsaturated hydrocarbons known as olefins. When combined with butylene or styrene polymers they form compounds such as polyethylene and polypropylene.

Polypropylene

A thermoplastic similar to polyethylene but stiffer and having higher softening point temperature with excellent electrical properties.

Polyurethane

A family of flexible, abrasion resistant jackets used for harsh environment cables.

PolyvinylChloride (PVC)

A flame-retardant thermoplastic insulation material that is commonly used in jacks or building cables. Both plenum are riser. A general purpose family of insulations whose basic constituent is polyvinylchloride or its copolymer with vinyl acetate. Plasticizers, stabilizers, pigments and fillers are added in lesser quantity to improve mechanical and/or electrical properties of this material.

POPS

A cellular industry term for population. If the coverage area of a cellular carrier includes a population base of one million people, it is said to have one million POPS. The financial community uses the number of potential users as a measuring stick to value cellular carriers.

Porosity

Multiple air voids in an insulation or jacket wall.

Port

The cable terminations in the equipment system at which various types of communications devices, switching equipment, and other devices are connected to the transmission network.  1) A functional unit of a node through which data can enter or leave a data network.  2) In data communications, that part of a data processor which is dedicated to a single data channel for the purpose of receiving data from or transmitting data to one or more external, remote devices.  3) An access point for data entry or exit.

Ports

A computer interface capable of transmitting and or receiving information.

Positioner

A device that is attached to a crimping tool and locates the contact in the correct location for crimping. It is usually interchangeable with other positioners. (MIL-STD)

Post Insulate

To insulate a connection after assembly.(MIL-STD)

Potting

1)The permanent sealing of the cable end of a connector with a compound or material to exclude moisture and/or provide a strain relief.(MIL-STD)   2)The sealing of a cable termination or other component with a liquid which thermosets into an elastomer.

Potting Cup

An accessory which, when attached to the rear of a plug or receptacle, provides a pouring form for potting the wires at the wire entry end of the connector.

Potting Form

Not preferred. See Mold, Potting, Electrical Connector.

Power Contact

Type of contact used in multi-contact connectors to support the flow of rated current.

Power Factor

The ratio of resistance to impedance.The ratio of the actual power of an alternating current to apparent power. Mathematically, the cosine of the angle between the voltage applied and the current resulting.

Power Handling Capacity

The average power which a cable can handle without exceeding its maximum operating temperature.

Power Sum

A method of testing and measuring crosstalk in multi-pair cables that accounts for the sum of crosstalk affecting a pair when all other pairs are active. This is the only method of specifying crosstalk performance that is suited to cables with more than four pairs.

PP (Polypropylene)

A polymer similar to polyethylene (PE), but stiffer and harder.

Precious Metal

One of the relatively scarce and valuable metals; gold, silver and the platinum group metals.

Pre-Insulate

The insulation of a connector prior to assembly of the contact or termination of the conductor.(MIL-STD)

Premises Distribution System (PDS)

The transmission network inside a building or group of buildings that connects various types of voice and data communication devices, switching equipment, and information management system together, as well as to outside communications networks. It includes the cabling and distribution hardware components and facilities between the point where building wiring connects to the outside network lines, back to the voice and data terminals in to office or other work locations. The system consists of all the transmissions media and electronics, administration points, connectors, adapters, plugs, and support hardware between the building's side of the network interface and the terminal equipment required to make the system operational.

Presentation Layer

Layer 6 of the OSI model. Responsible for identifying the syntax of the data being transmitted.

Press Fit Contact

An electrical contact which can be pressed into a hole in an insulator, printed board, with or without plated through-holes, or a metal plate.

Pre-Tinned

Solder applied to either or both the contact and conductor prior to soldering. (MIL-STD)

PRI

See Primary Rate Interface (PRI)

Primary Insulation

The first layer of non-conductive material applied over a conductor, whose prime function is to act as electrical barrier (sic…insulation).

Primary Rate Interface (PRI)

ISDN standard interface comprising 23 B + 1 D channel for North America, and 30 B + 1 D Channel for Europe. See Basic Rate Interface (BRI) and Integrated Services Digital Network (ISDN).

The North American 1.544 Mb/s T1 (23B+D) or European 2.048 interface (PRI) Mb/s E1 (30B+D) ISDN interface typically used to connect ISDN PBXs to the public ISDN.

Printed Circuit Board (PCB)

An epoxy glass and metal composite on which circuits are etched and to which active, passive and hardware components are attached. Also called a PCB or PC board.

Private Branch Exchange (PBX)

A private switching system usually serving an organization, such as a business or government agency, and located on the customer's premises. It switches calls both inside a building or premises and outside to the telephone network, and can sometimes also provide access to a computer from a data terminal.

Propagation

Delay time required for an electrical wave to travel between two points on a transmission line.

Propagation Delay

A signal traveling from end to end of a simplex link is delayed in time by an amount equal to the length of cable divided by the velocity of propagation for that transmission medium. This delay is called Propagation Delay.

Proprietary Networks

Networks that are not designed, installed to any standard based guidelines and do not relate specifically to any relevant standard.

Proprietary Systems

Systems that are not Standards specific and therefore inoperable with standards based equipment.

Protocol(s)

A rule of procedure by which computer devices intercommunicate. Thus a protocol is the equivalent of a human language, with punctuation and grammatical rules.

Prototype

A model suitable for use in the complete evaluation of form, design and performance of a new component or assembly.

Proximity Effect

Non-uniform current distribution over the cross-section of a conductor caused by the variation of the current in a neighboring conductor.

PTFE

Polytetrafluoroethylene. The thermally most stable and chemically most resistant carbonaceous compound. It is unaffected by sunlight, moisture, and virtually all chemicals. The temperature range is -200°C to +260°C Its electrical properties are very constant over temperature and a wide range of frequencies.

PTT

The European government organizations responsible for postal and telecommunications services within their respective countries are called PTTs. This stands for Post, Telephone, and Telecommunications.

Public Branch Exchange (PBX)

A telephone switching system designed to serve as a control and to route calls in large multi-phone environments, such as offices. Most PBXs can handle custom features for users’ specific telecom requirements.

Public Network Interface

A point of demarcation between public and private network. In many cases the public network interface is the point of connection between the network provider's facilities and the customer premises cabling.

Public Switched Telphone Network (PSTN)

A landbased telecommunications system where cellular calls are routed.

Pulling Eye

A device fastened to a cable to which a hook may be attached in order to pull the cable into or from a duct.

Pulling Tension

The amount of pull, measured in pounds, placed on a cable during installation.

Pull-Out Force

Force necessary to separate a conductor from a contact or terminal, or a contact from a connector by exerting a tensile pull. (MIL-STD)

Pulse

A change in the level, over a relatively short period of time, of a signal whose value is normally constant.

Pulse Cable

A type of coaxial cable constructed to transmit repeated high voltage pulses without degradation.

Pulse Width

The length of time that the pulse voltage is at the transient level. Electronic pulse widths are usually in the millisecond, microsecond or nanosecond range.

Punch-Down

A method of securing a wire to a wiring terminal. The insulated wire is placed in the terminal groove and pushed down with a special tool. As the wire is seated, the terminal cuts through the insulation to make an electrical connection, and the spring-loaded blade of the tool trims the wire flush with the terminal. Also called Cut-Down.

PUR (Polyurethane)

Thermoplastic polymer used for cables as an extruded jacket. Exhibits extreme toughness and abrasion resistance. It is flexible to below -50°C.

PVC

See Polyvinyl Chloride (PVC)Plasticized vinyl resin used as an insulation or jacket material which exhibits the property of high electrical resistivity, good dielectric strength, excellent mechanical toughness, superior resistance against oxygen, ozone, most common acids, alkalis and chemicals. It is flame-resistant, and oil-resistance and the temperature range (-55° to 105°C) are dependent upon the compound composition.

PVC-2

A type of PVC which meets MIL-C-17F and performs with low migration of plasticizer.

PVDF

Polyvinylidene fluoride

Q

Quad

A four conductor cable.

Quad Fiber Cable

A type of fiber optic cable that has four single cables enclosed in an extruded jacket of polyvinyl chloride (PVC), with a rip cord for pulling back the jacket to access the fibers.

Quick Disconnect

A type of connector or splice which permits rapid locking and unlocking of mating parts.(MIL-STD)

R

Raceway

Any distribution method designed for holding cables, e.g. conduit, metal or plastic trunking, cable trays, etc.

Rack

A type of structure used to house electronic components which permits convenient removal of portions of equipment. (MIL-STD)

Rack and Panel

The type of connector that is attached to a panel or side of equipment so that when these members are brought together, the connector is engaged.

RAD

The unit of radiation dose which is absorbed, equal to 100 ergs/gram.

Radiated Emission

The potential EMI that emits from paths including cables, leaky apertures, or inadequately shielded housings.

Radiated Susceptibility

Undesirable EMI radiated into equipment from outside electromagnetic sources.

Radio Frequency

A frequency at which coherent electromagnetic radiation of energy is useful for communications. Radio frequencies are designated as very low: <30 kHz; low: 30 to 300 kHz; high: 3 to 30 MHz; very high ; 30 to 300 MHz; ultrahigh: 300 to 3000 MHz; superhigh: 3 to 30 GHz; and extremely high: 30 to 300 GHz.

In terms of cellular applications, RF is the part of the electromagnetic spectrum between the audio- and light-range frequencies, between 500 kHz and 300 GHz. Cellular transmission frequencies are found in two distinct locations in the microwave segment of the spectrum, between 824-to-849-MHz and 869-to-894-MHz.

Radio Frequency Contact (RF Contact)

An impedence matched shielded contact.

RAM

The moving portion in the head of a crimping tool. (MIL-STD)

RAMP

The sloped channel that accepts the detent pin in a bayonet connector

Range Wire

The sizes of conductors accommodated by a particular barrel. Also the diameters of wires accommodated by a sealing grommet. (MIL-STD)

Ratchet Control

A device to ensure the full crimping cycle of a crimping tool. (MIL-STD)

Rated Temperature

The maximum temperature at which a connector can operate for extended periods without loss of its basic properties.

Rated Voltage

The maximum voltage at which a connector can operate for extended periods without undue degradation or safety hazard.

RCR

Research and Development Center for Radio Systems, the Japanese organization which provides industry-wide telecommunications standards.

REA

Rural Electrification Administration. A branch of the U.S. Department of Agriculture responsible for the standardization of the independent telephone companies throughout the U.S.

Reactance

The opposition offered to the flow of alternating current by inductance or capacitance of a component or circuit.

Rear Release Contacts

Connector contacts are released and removed from the rear (wire side) of the connector. The removal tool engages the contact from the rear and pulls the contact out of the connector contact retainer.

Rear Seal

An elastomeric seal used on the cable side of a connector to seal the connector against moisture, dirt and air. (MIL-STD). Also called Grommet

Receptacle

A chassis mounted male or female connector.

Receptacle Connector

An electrical fitting with contacts constructed to be electrically connected to a cable, coaxial line, cord or wire to join with another electrical connector and is designed to be mounted on a bulkhead, wall, chassis or panel. (MIL-STD)

Recovered Diameter

Diameter of shrinkable products after heating has caused it to return to its extruded diameter.

Recovered ID

In heat-shrink tubing the guaranteed maximum internal diameter of tubing after being freely recovered.

Red Plaque

A powdery, brown-red growth found on silver-coated copper conductors and shield braids.

Redraw

The consecutive drawing of wire through a series of dies to reach a desired wire size.

Reducing Joint

A joint between two lengths of cable where the conductors are not the same size.

Redundancy Risers

A fail-safe method of splitting and routing riser/ backbone cables via two or more riser cores. Also known as diverse routing.

Reference Junction

The junction of a thermocouple which is at a known reference temperature. Also known as the "cold" junction, it is usually located at the emf measuring device.

Reflection

In fiber optics, the change in direction of a light wave or ray.

Reflection Loss

The part of a signal which is lost due to reflection of power at a line discontinuity.

Reflow Soldering

The process of connecting two solder-coated conductive surfaces by remelting of the solder to cause fusion.

Refraction

In fiber optics, the bending of light waves or rays as they go from one material to another due to the difference in velocities in the materials.

Removable Contact

A contact that can be mechanically joined to or removed from an insert. Usually, special tools are required to lock the contact in place or to remove it for repair or replacement.

Removal Tool

A device used to remove removable contacts from a connector.

Reseller

In telephony, a middle-person who buys blocks of time from a cellular carrier at discounted wholesale rates and then resells them at retail prices.

Resin

A synthetic organic material formed by the union (polymerization) or one or more monomers with one or more acids.

Resistance

1)Property of a conductor that determines the current produced by a given difference of potential.  2)A measure of the difficulty in moving electrical current through a medium when voltage is applied. The Ohm is the practical unit of resistance and the symbol ( Ω )designates resistance in Ohms.  3)A measure of the difficulty in moving electrical current through a medium when voltage is applied. It is measured in ohms.

Resistive Conductor

A conductor with high electric resistance.

Resistivity

The ability of a material to resist passage of electrical current either through its bulk or on a surface.

Retractile Cable

A cable that returns by its own stored energy from an extended condition to its original contracted form.

Retractile Cordset

Cable formed into the shape of a spring by winding cable around a mandrel and heat set into that shape (also referred to as coiled cord or cordset). this permits the extension of a cordset to a length from 3 to 5 times it's length at rest. A cordset will typically return, after being extended and released, to a length similar to it's original length at rest.

Retractile Springback

The rate of the coiled portion of a cordset, when released from being held in an extended position, to return to it's approximate original length. Springback, in simplest terms, can be specified as rapid, medium or controlled.

Return Loss

The Channel Return Loss (RL) is a measure of the consistency of the impedance down the length of not just the cable, but also the connections and the patch cables.

Return Wire

A ground wire or the negative wire in a direct-current circuit.

RF Fingerprinting

RF fingerprinting technology is based on the fact that no two handsets have the same signature. Once a call is places, the signature is compared to the RF fingerprint in the carrier’s database. The user’s mobile identification number and electronic serial number are then compared. If the MIN and ESN do not match the fingerprint, the call does not go through.

RFI

Abbreviation for Radio Frequency Interface.

RG/U

Abbreviation for Radio Government, Universal. RG (Radio Government) is the military designation for coaxial cable in MIL-C-17 and U stands for "universal specification".

RGB

(Red, Green and Blue), the basic parallel component set, in which a signal is used for each primary color.

RGB Format

The television format that uses the basic component set of Red, Green and Blue.

Ribbon Fiber Cable

A cable that accommodates 1 to 12 ribbons, each ribbon having 12 fibers for a cable size range of 12 to 216 fibers. Ribbon cables are designed for use in large distribution systems where small cable size and high pulling strength are important.

Ribbon Riser Cable

An optical fiber, nonconductive, riser (OFNR)-rated premises cable containing optical fibers in ribbons.

Ridge Marker

One or more ridges running laterally along the outer surface of an insulated wire for purposes of identification.

Rigid Coaxial Cable

Nonflexible coaxial cable, usually a metal tube armored coaxial cable.

Ripple

The AC component of the output of a DC signal. This term typically refers to the residual line-frequency-related AC part in the output of a DC power supply that arises as a result of incomplete or inadequate filtering. The amount of filtering depends on the ripple frequency and the load resistance. More filtering is required as load resistance decreases.

Ring

A closed loop network topology.

Ring In (RI)

Port for connecting multistation access units (MAUs) together.

Ring Out (RO)

Port for connecting multistation access units (MAUs) together.

Rise Time

The time required for a component or logic circuit to change from the quiescent to the transient state when an input is applied, (e.g. elapsed time between application of input and attainment of full output level).

Riser(s)

The term used to describe a space utilized by backbone cabling to house communications cabling and other building services. This space should preferably be specified, or allowed for, at the time of the building design.

Riser Backbone Subsystem

The part of a premises distribution system that includes a main cable route and structure for supporting the cable from an equipment room (often in the building basement) to the upper floors, or along the same floor, where it is terminated on a cross connect in a riser telecommunications closet, at the network interface, or at distribution components of the Campus Backbone Subsystem. The Riser Backbone Subsystem usually extends from an equipment room (often in a building's basement) to the upper floors in a multistory building, or along the same floor in a low-wide building. It is terminated on a cross connect in a riser telecommunications closet, at the network interface, or on the distribution components of the Campus Backbone Subsystem.

RO

See Ring Out (RO)

Roaming

Using a cellular phone outside one’s usual service area. For example, in a city other than where one lives.

Root Mean Square (RMS)

The effective value of an alternating current or voltage.

Rope Lay Conductor

A conductor composed of a central core surrounded by one or more layers of helically laid groups of wires.

Round Wire Shields

Shields constructed from bare, tinned, or silver plated copper wire that include braided, spiral, and reverse spiral.

Router(s)

A router can be used to connect networks with similar protocols (802.5 token ring local area networks [LANs]) or dissimilar Open Systems Interconnection (OSI) model protocols (802.5 token ring LANs and X.25 packet-switching networks). Routers are more sophisticated than bridges and can be used to prevent some of the speed mismatch, security, and reliability problems that occur in large networks.

An intermediate system between two or more networks capable of forwarding data packets at the network layer (layer 3).

RS-170A

The EIA technical standard for NTSC color television.

Rupture

In the breaking strength or tensile strength tests, the point at which the material physically comes apart, as opposed to elongation yield strength, etc.

Rural Statistical Area (RSA)

The Federal Communications Commission divided the less-populated areas of the country into 428 RSAs and licensed two service providers per RSA.

S

S-MAC Serial Multiplexed Analog Component

A proposed standard for television transmission. The signal uses time compression and time domain multiplexing to transmit luminance and color difference signals as a single channel signal.

S/N (Signal to Noise Ratio)

The ratio of total signal to noise level, usually expressed in decibels.

SAE

Society of Automotive Engineers

SAE J551-2

The Society of Automotive Engineers standard for measuring RFI in cars, boats and other vehicles.

SAE J1113

The Society of Automotive Engineers standard for determining EMC for vehicles. It includes Part 27 for measuring immunity to radiated fields.

Safety Wire

A means of safety wiring a plug and/or receptacle to prevent the loosening or vibrating free of the plug from the receptacle.

Safe-Tying

That feature of a connector design which permits safety wiring of plug and/or receptacle to prevent the loosening or vibrating free of the plug from the receptacle.

Satellite Cabinet

Surface-mounted or flush-type wall cabinets for housing circuit administration hardware. Satellite cabinets, like satellite telecommunications closets, supplement riser telecommunications closets by providing additional facilities for connecting horizontal cables from information outlets in user work areas. Sometimes referred to as a "satellite location".

Satellite Telecommunications Closet

A walk-in or shallow wall closet that supplements a riser telecommunications closet by providing additional facilities for connecting riser backbone cables to horizontal cables from information outlets. Also referred to as a "satellite location". See also Riser Telecommunications Closet.

Scaleable

The ability to adapt to different bit rates.

Scoop-Proof

Connectors with long shell design to insure proper alignment during mating, thus avoiding damaged pins or electrically shorted contacts. (MIL-STD)

Screened Cable

See Foil Screened Twisted Pair Cable.

Screening Effectiveness

The ratio of the power fed into a coaxial cable to the power transmitted by the cable through the outer conductor.

Screw Machine Contact

A contact made by screw-machine operations from bar or rod material.

Screwlock

A screw attached to one half of a two-piece multiple contact connector used to draw and hold both halves together and to separate them. (MIL-STD) Also called Jackscrew

Sealant

Solft, tacky, pliable material that seals where mechanical strength is not required.

Sealing Plug

An accessory used to fill open, non-wired cavities in a connector grommet to prevent the entry of moisture or fluids or foreign particulate contaminants into the connector.

Seamless Terminal or Splice

Terminal or splice conductor barrel made without an open seam. (MIL-STD)

SECAM

Sequential Couleur Avec Memoire, a color television in use in France and USSR.

Secondary Insulation

A nonconductive material that protects the conductor against abrasion and provides a second electrical barrier.

Segmental Conductor

A stranded conductor consisting of three or more stranded conducting elements, each element having approximately the shape of the sector of a circle, assembled to give a substantially circular cross-section.

Selective Plating

The application of plating material to a limited portion of a connector contact, especially those areas susceptible to wear.

Self Align

Two mating parts designed so that they will engage in the proper relative position.

Self Alignment

The tendency of leads to center themselves on solder pads due to the surface tension of the liquid solder.

Self Extinguishing

The characteristic of a material whose flame is extinguished after the igniting flame is removed.

Self Normal Jack

A jack that provides a connection between the two rear connectors, except when interrupted by the insertion of a video patch plug into the front panel receptacle.

Self Terminating Jack

A jack that automatically provides a 75 ohm termination on the circuit that is connected to the rear connector, except when a plug is inserted into the receptacle on the front panel.

Semiconductor

A material that has a resistance characteristic between that of insulators and conductors.

Semi-Conduction Jacket

A jacket having a sufficiently low resistance so that its outer surface can be kept at substantially ground potential.

Semi-Conducting Tape

A tape of such resistance that when applied between two elements of a cable, the adjacent surfaces of the two elements will maintain substantially the same potential. Such tapes are commonly used for conductor shielding and in conjunction with metallic shielding over the insulation.

Semi-Rigid Cable

Cable containing a flexible inner core and a relatively inflexible sheathing.

Semi-Rigid PVC

A hard semi-flexible polyvinylchloride compound with low plasticizer content.

Separator

A layer of insulating material such as textile, paper, polyester, etc. Used to improve stripping qualities, flexibility, mechanical or electrical protection to the components.

Serial Communications

See Serial Data Transmission.

Serial Data Transmission

Data transmission between computer devices using only a single circuit path. Whole bytes of information (8 bits) are sent in sequential pattern. Compares with parallel transmission. Parallel transmission is often used internally within computing devices because of the higher processing speeds which are possible, but for long-distance telecommunication, serial transmission is more economic in terms of line plant.

Serial Digital Video Transmission

Transmission of a video signal by a series of discrete "on-off" or "high-low" pulses.

Serial Port(S)/Transmission

Normally a DB 9 pin connector located on the mother board of a PC. A technique in which each Bit of information is sent sequentially on a single channel.

Serrations

Deformation of the inside surface of a conductor barrel to provide better gripping of the conductor or on the outside of the connector body to provide better gripping of the connector. (MIL-STD)

Server(S)

Host Computer(s). A filament or group of filaments such as fibers or wires, wound around a central core.

Served Wire Armor

Spiral wrap of soft galvanized steel wires wrapped around a cable to afford mechanical protection and increase the cable pulling tension characteristics.

Service Entrance

See Campus Cable Entrance.

Serving Closet

See Satellite Telecommunications Closet

Service Life

A period of time during which a device is expected to perform satisfactorily. (MIL-STD)

Service Rating

The maximum voltage or current which a connector is designed to carry continuously. (MIL-STD)

Session Layer

Layer 5 of the OSI model. Responsible for establishment and control of dialogues between users on different machines. Synchronization for reliable data transfer and token management to control use of the connection are services provided by this layer.

Sexless Connection

An interconnecting device in which the mating parts are exactly alike at their mating surfaces. Also called "Hermaphroditic Connector".

Sheath

A common term for the collection of twisted pairs of multipair cables. The outer covering or jacket of a multiconductor cable.

Sheet Metal Contacts

Contacts made by stamping and bending sheet metal rather than by the machining of metal stock.

Shelf Life

Generally, the length of time a product or material may be stored without deterioration. Specifically, the length of time during which shrink tubing will retain its expanded ID and return to its recovered ID

Shell Electrical Connector

The outside case of a connector into which the dielectric material and contacts are assembled. (MIL-STD)

Shield

In cables, a metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields.

Shield Coverage

The physical area of a cable that is actually covered by the shielding material and is expressed in percent.

Shield Dual

A set of two shields in which one shield is adjacent to and surrounds another shield. Dual shields provide higher shield effectiveness over a broader range of frequencies. They typically consist of a foil shield, surrounded by either a spiral strand or braid shield.

Shield Effectiveness

The relative ability of a shield to screen out undesirable signals.

Shield Electrical Connector

An item especially designed to be placed around that portion of a connector which contains facilities for attaching wires or cables. It is used for shielding against electrical interference or mechanical injury and usually has provisions for passage of the wire. (MIL-STD)

Shielded Cable

A cable or group of wires enclosed within a conductive shield to minimize the interference effects of internal or external circuits.

Shielded Contact

A contact which carries alternating current and is shielded from unwanted signals (RFI and EMI). Generally, these contacts are not impedance matched.

Shielded Line

A transmission line whose elements confine propagated radio waves to an essentially finite space inside a tabular conducting surface called the sheath, thus preventing the line from radiating radio waves.

Shielded Room

A room made free from EMI by applying shielding to floor, walls and ceiling surfaces and by suppressing any interference entering through the power lines

Shielded Twisted Pair Cable (STP)

An electrically conducting cable comprising one or more elements each of which is individually shielded. There may be an overall shield in which case the cable is referred to as a shielded twisted pair cable with an overall shield.

Shielding

Strands or tapes of conductive material, which can be formed into a braid, or spiral wrap, or longitudinal cover, around insulated conductors or cable to reduce signal interference. Typical shielding materials are copper, tin or silver plated copper and aluminum.

Shielding Effectiveness

The relative capability of a shield to screen out undesirable electric and magnetic fields and plane waves. The measurement is the ratio of the signal received without the shield to the signal received inside the shield.

Shielding Gasket

A material used to maintain shielding effectiveness across a seam or gap in an electronic enclosure. It may be made from a variety of materials including fabric-wrapped foam, wire mesh, stamped metal and elastomer compounds.

Shock (Mechanical)

1) An abrupt impact applied to a stationary object.  2) An abrupt or non-periodic change in position, characterized by suddenness, and by the development of substantial internal forces

Shore

A scale for comparing hardness. Higher shore values represent harder materials.

Shorting Plug

A connector device designed to mate with a receptacle connector to perform protective, environmental and/or electrical shorting functions. Also called Dummy Connector Plug

Shrink Ratio

An expression of how much the inside diameter of shrink tubing will reduce in size when recovered. The inverse of the expansion ratio.

Shrink Temperature

That temperature which effects complete recovery of a shrinkable product from the expanded state.

Shrink Tubing

Tubing which has been extruded, cross-linked, and mechanically expanded which when reheated will return to its original diameter.

Shrinkage Ratio

The ratio between the expanded diameter and recovered diameter of shrinkable products.

Shroud Insulation

The portion of a barrel similar to an insulation grip except that it is not compressed around the conductor insulation. (MIL-STD). Also called Insulation Support.

Signal

1)An electrical impulse of a predetermined voltage, current, polarity and pulse width. Used to convey information, either digital, analog, audio or video.  2)A current used to convey information, either digital, analog, audio or video.

Signal Cable

A cable designed to carry current of usually less than one ampere per conductor.

Signal To Noise Ratio (SNR)

The ratio of the signal magnitude to the noise magnitude and is usually expressed in dB. The higher the SNR of a system, the better is its performance.

Signaling System 7 (SS7)

An out-of-band signaling system that provides basic routing information, call setup and other cell termination functions. Signaling is removed from the voice channel and put on a separate data network.

Silver (Ag)

A highly conductive metal with atomic number 47. When applied as terminal plating, it provides a hard-oxide soft-base finish that requires only moderate pressure for a metal-to-metal contact. Silver plating is normally used on metals that are relatively good conductors such as copper and brass.

Simplex

A transmission means allowing only one direction of transmission. Usually on a two-wire facility (For example public broadcast radio).

Single-Fiber Cable

A plastic-coated fiber surrounded by an extruded layer of plastic encased in a synthetic strengthening material, and enclosed in a plastic sheath.

Singlemode

Optical fiber with a small core diameter in which only single mode is capable of propagation. 8.3 micron is the common standard core size.

Sintering

Fusion of a spirally applied tape wrap jacket by the use of high heat to a homogeneous continuum. Usually employed for fluorocarbon, non-extrudable materials.

Skeleton Braid

Widely separated braid of fiber, copper, or steel used to hold core together, for reinforcing jacket or for shielding.

Skin Effect

1) The phenomenon in which the depth of penetration of electric currents into a conductor decreases as the frequency increases.  2) The tendency of alternating current, as its frequency increases, to travel only on the surface of a conductor.

Sleeve

Covering over the terminal barrel. It can be insulated or metallic.

Sleeves

Short lengths of rigid metal pipe, approximately 4 in. (10.1 cm) in diameter, located in riser telecommunications closet, that allows cables to pass from floor to floor when closets are vertically aligned. Sleeves also provide for easy pulling of cable.

Sleeving

A braided, extruded or woven tube.

Slots

Openings in the floor of riser telecommunications closets that allow cables to pass thorough from floor to floor when closets are vertically aligned. A slot accommodates more cables than an individual sleeve.

Slotted tongue

A slotted tongue for sliding onto the screw or stud so that neither screw nor unit needs removing. (MIL-STD)

SMA Subminiature A)

A subminiature coaxial connector with screw type coupling mechanism and has a frequency range of DC - 18 GHz.

SMB

A subminiature coaxial connector with snap-on coupling mechanism. Its frequency range is DC - 4 GHz.

SMC

A subminiature coaxial connector with screw type coupling mechanism which has a frequency range of DC - 10 GHz.

Smoke Density Rating

Test methodologies of various organizations designed to simulate smoke density generated during flame and burning and the results of a material when tested under a specific methodology. Several tests are typically used: NBS Smoke Density per ASTM E662, OSU per FAR 25, NBS Smoke Density per ISO 5659, IF index per NFF 16 or Smoke Density per NFX 10. Smoke density is designing to evaluate the visibility for escape from a burning area.

SMPTE

Society of Motion Picture Television Engineers

SMPTE

A three circuit connector that meets the proposed SMPTE, Standard for GBR interconnects.

SMPTE Recommended Practice

Advisory operating information issued by the SMPTE, as differentiated from a Standard.

SNR

See Signal to Noise Ratio.

Socket Connection

A connector containing socket contacts into which a plug connector having male contacts is inserted.

Socket Contact

A contact having an engagement end that will accept entry of a pin contact. (MIL-STD)

Socket Contact Sleeve

A sleeve that holds the contact spring in the correct position within the socket contact.

Sockets

For plug-in devices, for use on panel boards, printed circuit boards and microelectronic components. (MIL-STD)

Soft Conversion

The process of changing a measurement from inch-pound units to equivalent metric units within acceptable measurement tolerances without changing the physical configuration of the items.

Solder Contact

A contact having a cup, hollow cylinder, eyelet or hook to accept wire for soldered termination.

Solder Cup

The end of a terminal or contact in which the conductor is inserted prior to being soldered. (MIL-STD)

Solder Eye

A solder type contact provided with a hole at its end through which a wire can be inserted prior to being soldered. (MIL-STD)

Solder Pot

The end of a terminal or contact in which the conductor is inserted prior to being soldered. (MIL-STD) Also called Solder Cup

Solder Sleeve

A heat-shrinkable tubing device containing a predetermined amount of solder and flux used for environmental resistant solder connections and shield termination.

Solder Type Connector

A connector in which the contact between the conductor and the connector is made by a soldered joint.

Soldering

A process of joining metallic surfaces with solder without the melting of the base metals. Soldering is an economical, versatile and fast termination method. A soldered connection has metallic continuity and, therefore, excellent long term reliability.

Soldering Sleeves

Shrinkable tubing with a solder preform used for high-test reliability soldering connections or shield grounding.

Solderless Connection

The joining of two metals by pressure means without the use of solder, braze or nay method requiring heat. (MIL-STD)

Solderless Wrap

A technique of connecting stripped solid wire to a terminal post containing a series of sharp edges by winding the wire around the terminal. (MIL-STD)

Solid Conductor

A conductor consisting of a single wire.

Solvent Resistance

The ability of a material to retain physical and electrical properties after being immersed in specific solvents.

Sonet

Synchronous Optical Network; provides broadband connectivity for existing networks on a global scale.

Source Coupling Loss

In fiber optics, the loss of light intensity as light from source passes into fiber.

Source Routing

A bridge uses source routing when the route to be followed is carried within each frame by the source stations. The source station acquires and maintains information by a search process, allowing parallel bridges to exist and to share traffic between the same two rings.

Space

Denotes applications peculiar to spacecraft and systems designed for operation near or beyond the upper reaches of the earth's atmosphere. (MIL-STD)

Span

In flat cables, the distance from the reference edge of the first conductor to the reference edge of the last conductor (in cables having flat conductors), or the distance between the centers of the first and last conductors (in cables having round conductors), expressed in inches or centimeters.

Spade Tongue Terminal

Slotted tongue terminal designed to slip around a screw or stud without removing the nut. (MIL-STD

Spark Test

A test designed to locate imperfections (usually pin-holes) in the insulation of a wire or cable by application of a voltage for a very short period of time while the sore is being drawn through the electrode field.

Specialized Mobile Radio (SMR)

A private, mobile dispatch radio service that is usually used by businesses, such as taxi services.

Specific Gravity

The ratio of the density (mass per unit volume) of a material to that of water.

Specific Inductive Capacity (S.I.C.)

1)The ratio of the capacitance using the material in question as the dielectric, to the capacitance resulting when the material is replaced by air.   2)That property of a dielectric which determines the electrostatic energy stored per unit volume for a unit potential gradient. The ratio of the capacitance using the material in question as the dielectric, to the capacitance resulting when the material is replaced by air. The dielectric constant is the most important design parameter for coaxial cables and determines dimensions, losses and propagation characteristics. Also called Dielectric Constant

Specification

A document prepared specifically to support acquisition which clearly and accurately describes essential technical requirements for purchased material.

Spectrum

The complete range of electromagnetic waves which can be transmitted by natural sources such as the sun and manmade devices, including cellular phones. Electromagnetic waves vary in length and have different characteristics. Longer waves in the low-frequency range can be used for communications, while shorter waves of high trequency show up as light. Spectrum with even shorter wavelengths and higher frequencies is used in X-rays.

Spiral Wrap

The helical wrap of a material over a core.

Splice

The physical joining of two or more copper wires or optical fibers to form a common connection. Device used to join two or more conductors to each other. (MIL-STD) A connection of two or more conductors or cables to provide good mechanical strength as well as good conductivity.

Spread Spectrum

Originally developed by the military because it offered secure communications, spread-spectrum radio transmissions essentially "spread" a radio signal over a very-wide frequency band in order to make it difficult to intercept and jam.

SSMA (Sub-Subminiature A)

A sub-subminiature coaxial connector with screw type coupling mechanism and operates within a frequency range of DC - 40 GHz.

Stamped Contacts

Contacts made by stamping and bending sheet metal rather than by the machining of metal stock. Also called Sheet Metal Contacts

Standard

A document that establishes engineering and technical requirements for items, equipment, processes, procedures, practices and methods that have been adopted as standard. Standards may also establish requirements for selection, application and design criteria for material.

Standardization Documents

Specifications, standards, handbooks, QPL's and such other engineering records, drawings, purchase descriptions, etc., as are or may be utilized for comparable purposes

Standby Time

The amount of time a fully-charged wireless phone can be left on before its battery runs down.

Star

A physical point to point network topology.

Star Physical Topology

See Star.

Star Quad

A cable element which comprises four insulated conductors twisted together. Two diametrically facing conductors from a transmission pair.

Star Topology

A physical point to point network topology.

Static Condition

Used to denote the environmental conditions of an installed cable rather than the conditions existing during cable installation.

Static Noise

Signal distortion due to the electrical field radiated by a voltage source which has coupled into the signal-bearing circuit.

ST Connector

See Straight-Tip (ST) Connector.

Steel

A material usually specified for applications requiring unusually high mechanical strength. Steel is used as a base metal and protected by a suitable plating.

Stop Plate

A device attached to a crimping tool to properly locate a terminal, splice or contact in the tool prior to crimping. See locator. (MIL-STD)

Storage Area Network (SAN)

A high speed network or subnetwork of shared storage devices.

Straight Connector

A connector which joins two lengths of conductor end-to-end in a straight line.

Straight-Tip (ST) Connector

A fiber optic connector used to join single fibers together at interconnects or to connect them to fiber optic cross connects.

Strain Damage

The disconnection of conductors from their termination points due to excessive axial stress.

Strain Relief

A technique involving devices or methods of termination or installation which reduce mechanical stresses from being transmitted to the conductor termination.

Strain Relief Clamp

A mechanical clamp attached to the cable side of the connector to support the cable or wire bundle, provide strain relief and absorb vibration and shock otherwise transmitted by the cable to the contact/wire connection. (MIL-STD) Also called Cable Clamp

Strand

One of the wires of any stranded conductor.

Stranded Cable

A strong woven-copper-wire cable used to support cable in aerial distribution systems. The cable is lashed to the stranded cable during installation.

Stranded Conductor

A conductor composed of single solid wires twisted together, either singly or groups.

Strip

To remove insulation from a conductor. (MIL-STD)

Strip Force

The force required to remove a small section of insulating material from the conductor it covers.

Stripline

A type of transmission line configuration which consists of a single narrow conductor parallel and equidistant to two parallel ground planes.

Stripper

A tool or chemical used to remove insulation material from wire or cable.

STP

See Shielded Twisted Pair Cable.

Structured Cabling

Flexible cabling scheme which allows rapid reconfiguration for office moves through patching.

Structural Return Loss

Backward reflected energies from uneven parts of the cable structure are termed structural return loss.

Stud Cable

A short cable (usually 25 ft [7.6 m] or less) that extends from a cable terminal, protector, or block and is used to make connections to such devices.

Subscriber Identify Module

The "SIM card" is an integrated-circuit chip housed in a plastic card which enables a cellular subscriber to use any (usually Global System for Mobile Communications) handset. The card identifies and bills the caller, no matter whose phone is being used.

Suggested Working Voltage

A.C. voltage that can be applied between adjacent conductors.

Support Hardware

The racks, clamps, cabinets, brackets, trays, tools, and other equipment that provide the physical means to attach the transmission media and connecting hardware to walls or ceilings.

Surface Mount Device (SMD)

An active or passive device designed to be soldered to the surface of the printed circuit board.

Surface Mount Technology (SMT)

The process of assembling printed circuit boards with components soldered to the surface rather than to plated through-holes.

Surface Resistivity

The resistance of a material between two opposite sides of a unit square of its surface. It is usually expressed in ohms.

Surge

A temporary large increase in the voltage or current in an electric circuit or cable.

Switching

A function carried out by a switching hub, alleviating traffic by making virtual connections between transmitting and receiving nodes.

Sweep Test

A method to determine the frequency response of a cable by generating an RF voltage whose frequency is varied at a rapid constant rate over a given range.

System-Common Equipment

The equipment on a premises that provides functions common to terminal devices such as telephones, data terminals, integrated workstations terminals, and personal computers. Typically, the system-common equipment is the private branch exchange (PBX) switch, data packet switch, or central host computer. Often called common equipment.

Sync

A mixed signal consisting of Composite Sync, Color Burst and Video.

Sync Burst

A signal consisting of Composite Sync and Color Burst.

Synchronization

The method by which the bit patterns appearing on digital line systems may be properly "clocked" and interpreted—allowing the beginning of particular patterns and frame formats to be correctly identified.

Synchronous

Signals that are sourced from the same timing reference and hence are identical in frequency.

Synchronous Data Transfer

Data transfer employing a strictly regular pattern, rather than using start and stop bits to distinguish character patterns from idle line operation.

SYSTIMAX SCS

Brand name of Avaya's Structured Cabling System.

T

Tank Test

A voltage dielectric test in which the test sample is submerged in water and voltage is applied between the conductor and water as ground.

Take Up

The process of accumulating wire or cable onto a reel, bobbin, or some other type of pack. Also, the device for pulling wire or cable through a piece of equipment or machine.

Tape Wrap

A spirally applied tape over an insulated or uninsulated wire.

Taper Pin

A pin type contact having a tapered end designed to be impacted into a taper hole.

TCP/IP

TCP/IP See Transport Control Protocol/Internet Protocol (TCP/IP).

T

DM

Time Division Multiplexing.

Tear Strength

The force required to initiate or continue a tear in a material under specified conditions.

Teflon

A DuPont Company trade mark for polytetrafluoroethylene.

Tefzel

A DuPont trade name for a fluorocarbon material typically used as the insulation on wire wrap wire.

Telecommunications

A branch of technology concerned with the transmission, emission and reception of signs, signals, writing, images and sounds; that is, information of any nature by cable, radio, optical or other electromagnetic systems.

Telecommunications Closet

A room where cables are terminated on cross-connect fields, where circuit administration takes place. There are two kinds of telecommunications closets: riser telecommunications closets and satellite telecommunications closets. See also Riser Telecommunications Closet and Satellite Telecommunications Closet.

An enclosed space for housing telecommunications equipment, cable terminations, and cross-connect cabling. The telecommunications closet is a recognized cross-connect point between the backbone and horizontal cabling subsystems.

Telecommunications Outlet

A socket where the horizontal cable terminates. The telecommunications outlet provides the interface to the work area cabling.

Telemetry Cable

Cable used for transmission of information from instruments to the peripheral recording equipment.

Telepoint

A cordless-telephone system is which a subscriber can make but not receive phone calls in public areas which have been equipped with Telepoint base stations. If the system is not mobile; the user must remain essentially in a fixed location throughout the duration of the call. Service and equipment are less expensive than cellular.

Telecommunications Industry Association (TIA)

The US-based organization established to provide industry-wide standards for telecommunications equipment used in North America.

TEM Cell

Transverse electromagnetic cell; a chamber that maintains its characteristic impedance throughout its volume. Cable, connector assemblies, and electronic devices are placed inside the cell. The cell also can be used as a detector to measure radiation emitted by devices inside the cell.

Temperature Rating

The maximum and minimum temperature at which an insulating material may be used in continuous operation without loss of its basic properties.

Temperature Rise

Temperature change of contact from a no-load condition to full current load. Also referred to as "T" rise.

Tempest

A complex measurement of the combined reduction of all electromagnetic emissions from specified equipment used in high data security areas.

Tensile Strength

1)Greatest longitudinal stress that a substance can bear.  2)The pull stress required to break a given specimen.  3) The breaking strength per square inch of cross-sectional area of the material tested.

Tensile Testing

A controlled pull test on the crimp joint to determine its mechanical strength.

Terminal Block

A protected or unprotected unit of wiring blocks, connecting blocks, and troughs that serves as a transition point between cable conductors.

Terminals

Metal wire termination devices designed to handle one or more conductors, and to be attached to a board, bus, or block with mechanical fasteners or clipped on.

Terrestrial Communications

A system where all transmitters and receivers are on the ground.

TFE

Teflon (tetrafluoroethylene).

Thermal Aging

Exposure to a thermal condition or programmed series of conditions for predescribed periods of time.

Thermal Shock

1) The effect of heat or cold applied at such a rate that non-uniform thermal expansion or contraction occurs within a given material or combination of materials.  2) A test to determine the ability of a material to withstand heat and cold by subjecting it to rapid and wide changes in temperature.

Thermocouple

A device consisting of two dissimilar metals in physical contact, which when heated will develop an emf output.

Thermocouple Contact

Contact made of special material used in connectors employed in thermocouple applications. Materials often used are iron, constantan, copper, chromel and alumel.

Thermocouple Element

A thermocouple designed to be used as part of an assembly, but without associated parts such as the terminal block, connecting head, or protecting tube.

Thermocouple Extension Cable

A cable comprised of one or more twisted thermocouple extension wires under a common sheath.

Thermocouple Extension Wire

A pair of wires of dissimilar alloys having such emf-temperature characteristics complimenting the thermocouple which is intended to be used, such that when properly connected allows the emf to be faithfully transmitted to the reference junction.

Thermocouple Wire (Grade)

A pair of wires of dissimilar alloys having emf-temperature characteristics calibrated to higher temperature levels than the extension type of thermocouple wire. Unlike the thermocouple extension wire, this wire may be employed as the thermocouple hot junction in addition to serving as the entire wire connection between hot and cold reference junctions.

Thermoplastic

A material which softens when heated or reheated and becomes firm on cooling. This process can be repeated.

Thermoset

A material which hardens or sets by heat, chemical or radiation cross-linking techniques and which, once set, cannot be re-softened by heating.

Thread Coupling

A means of coupling mating connectors by engaging threads in a coupling ring with threads on a receptacle shell. (MIL-STD)

Thread Self-Locking Coupling

A coupling mechanism utilizing matching screw threads for mating and un-mating of cylindrical connectors incorporating an automatically actuated locking mechanism to prevent the coupling ring from becoming loose under vibration

Thick Coax

The transmission medium used for Ethernet or IEEE 802.3 10Base5 LANs. It is a 50 ohm thick coax cable (commonly referred to as the thick yellow cable).

Thin Coax

The transmission medium used for IEEE 802.3 10Base2 LANs (sometimes referred to as CheaperNet). It is a 50 ohm thin coax cable.

Thermoset

A plastic material that is crosslinked by a heating process known as curing. Once cured, thermosets cannot be reshaped.

TIA/EIA

North American Standards Organization.

TIA/EIA 568A or B

North American Commercial Building Telecommunications Wiring Standard.

TIA/EIA 569

North American commercial building standard for telecommunications pathways and spaces. Its purpose is to standardize specific design and construction practices within and between buildings which are in support of telecommunications media and equipment.

TIA/EIA 606

North American administration standard for the telecommunications infrastructure of commercial buildings. Its purpose is to provide guidelines for a uniform administration scheme for the cabling infrastructure.

Time-Division Multiple Access (TDMA)

The cellular industry established a TDMA digital standard in 1989. TDMA increases the channel capacity by chopping the signal into pieces and assigning each one to a different time slot. Current technology divides the channel into three time slots, each lasting a fraction of a second. Therefore, a single channel can be used to handle three simultaneous calls.

Tin (Sn)

A metallic element with atomic number 50. A common terminal plating material used on brass, copper and (over a layer of copper flash) on steel. It provides high conductivity at low cost and is often used on terminal components that will be in contact with aluminum to reduce galvanic corrosion.

Tin-Lead

An alloy used for the majority of soldering operations in the electronics industry. Usually an alloy close to the eutectic composition (62% Sn, 38% Pb) is chosen to permit usage of the lowest possible soldering temperature thereby reducing risk of damage to temperature-sensitive components.

Tinned Copper

Tin coating added to copper to aid in soldering and inhibit corrosion.

TNC (Threaded Neill-Concelman)

Coaxial connector with screw type coupling mechanism. Available in 50 ohm with frequency range of DC - 11 GHz and 75 ohm with range of DC - 1 GHz versions.

TP-PMD

Twisted Pair Physical Medium Dependent. A twisted pair version of the FDDI standard that allows 100Mb/s transmission over Category 5 copper cable.

Token

A special data sequence that is continuously sent around the ring. The term "token" represents permission to transmit from one station to its downstream neighbor.

Token Ring

A data link protocol type which implements media access control (MAC) by the circulation of a token around a complete ring network. Each station in the ring sequentially receives the opportunity to send data on the network as the token is passed around the network.

Token Ring LAN

A 4 or 16 Mb/s LAN standard based on token passing access protocol originally developed by IBM. Sometimes referred to as IEEE 802.5 or ISO 8802-5 standard.

Tolerance

The total amount by which a quantity is allowed to vary from nominal; thus, the tolerance is half the algebraic difference between the maximum and minimum limits.

Topology

The physical or electrical configuration of a local communications network (that is, the shape or arrangement of the system). The most common distribution system topologies are the bus, ring, and star.

TP-PMD

Twisted Pair Physical Medium Dependent. A twisted pair version of the FDDI standard that allows 100 Mb/s transmission over Category 5 copper cable.

Transcoder

A device used to convert one television format to another.

Transducer

A sensing device that converts a signal from one form to another e.g. mechanical to electrical.

Trans-European Trunked Radio Access

The European digital cellular land mobile-radio system.

Transmission

Transfer of electric energy from one location to another through conductors or by radiation or induction fields.

Transmission Cable

Two or more transmission lines.

Transmission Distance

The actual length of the path from the transmitter of one node to the receiver of the next downstream node. The maximum transmission distance is determined by the maximum signal loss (attenuation limit) that can be withstood between any transmitter and receiver.

Transmission Line

A signal-carrying circuit with controlled electrical characteristics used to transmit high-frequency or narrow-pulse signals.

Transmission Loss

The decrease or loss in power during transmission of energy from one point to another, Usually expressed in decibels.

Transmission Media

The various types of copper wire and fiber optic cable used for transmitting voice, data, or video signals.

Transponder

A device which includes a traveling-wave tube or solid-state amplifier, used to transmit and receive radio signals on command at different frequencies. Modern communications satellites may have up to 90 transponders.

Transport Control Protocol/Internet Protocol (TCP/IP)

A common network layer and transport layer data networking protocol.

Transition Point

A location in the horizontal cabling where a change of cable form takes place.

Transport Layer

Layer 4 of the OSI model. The transport layer provides for end-to-end data relaying service across any type of data network and is responsible for end-to-end reliability.

Tray

A cable tray system is a unit or assembly of units or sections, and associated fittings made of non-combustible materials forming a rigid structural system used to support cables. Cable tray systems (previously termed continuous rigid cable supports) include ladders, troughs, channels, solid bottom trays, and similar structures.

Triaxial

A connector or cable construction having 3 coincident axes such as conductor, first shield and second shield, each isolated from one another.

Triaxial Cable

A cable construction having three coincident axes, such as conductor, first shield and second shield all insulated from one another.

Triaxial Cable Connector

Connector composed of three concentric conductors, an inner conductor, intermediate conductor and outer conductor, separated by dielectrics.

Triboelectric Noise

Noise generated in a shielded cable due to variations in capacitance between shielding and conductor as the cable is flexed.

Triple (Triad)

A cable consisting of three insulated single conductors twisted together.

True Concentric Cable

A cable in which each successive layer has a reversed direction of lay from the preceding layer.

Trunk

A communication link between two switching systems. The term switching typically includes equipment in a central office (or the telephone company) and PBXs. A tie trunk connects PBXs. Central office trunks connect a PBX to the switching system at the central office. See also Private Branch Exchange (PBX)

Tubing

A tube of extruded non-supported plastic or metallic material.

Turret Head

A device that is attached to a crimping tool which contains more than one locator and allows the locators to be rotated to hold a contact in the correct position for crimping. It is usually interchangeable with other turret heads and head assemblies. (MIL-STD)

Twin Coaxial

Coaxial cable with two conductors that are insulated from one another, twisted together and surrounded by a common shield.

Twinaxial Cable (TWINAX)

Two insulated conductors inside a common insulator, covered by a metallic shield and enclosed in a cable sheath.

Twisted Pair(s)

A cable composed of two small insulated conductors twisted together without a common covering. The twists, or lays, are varied in length to reduce the potential for signal interference between pairs. In cables greater than 25 pairs, the twisted pairs are grouped and bound together in a common sheath. Twisted pair is the most common type of transmission media.

U

UL

See Underwriters Laboratories (UL)

U-Matic Format

A format commonly used in ENG (Electronic News Gathering) and industrial television.

UF

Thermoplastic underground feeder and branch circuit cable.

UHF

Abbreviation for ultra high frequency, 300 to 3,000 MHz.

UHF Connector

A concentric coaxial connector with a screw type locking arrangement. Large impedance discontinuities limit their range to about 500 Mhz. Used extensively in commercial communications applications.

UL

Abbreviation for Underwriters Laboratories, a non-profit independent organization, which operates a listing service for electrical and electronic materials and equipment.

UL Style

A numeric code, usually four digits, used to describe a type of construction of cable which typically specifies a range of conductor AWGs, an insulation material or materials, jacket material and thickness, a temperature rating and other parameters.

Ultraviolet Degradation

The degradation caused by long-time exposure of a material to sunlight or other ultraviolet radiation.

Umbilical Connector

A connector used to connect cables to a rocket or missile prior to launching and which is unmated from the missile at time of launch. (MIL-STD)

Unbalanced Circuit

A transmission line in which voltages on the two conductors are unequal with respect to ground; e.g. a coaxial cable.

Underwriters Laboratories (UL)

A private testing laboratory concerned with electrical and fire hazards of equipment. With SYSTIMAX® SCS components, several abbreviations are used to designate the approved use.

Unidirectional Concentric Stranding

A cable stranding where each successive layer has a different lay length, thereby retaining a circular form without migration of strands from one layer to another.

Unidirectional Stranding (Unilay)

A term denoting tat in a stranded conductor all layers have the same direction of lay.

Unilay Strand

A cable conductor constructed with a central core surrounded by more than one layer of helically-laid wires, with all layers having a common length and direction of lay.

Universal Digital PCS (UD)PCS)

An alternative system proposed by Bell Communications Research (Bellcore) for in-building cordless-phone service.

Unshielded Twisted Pair Cable

Normal copper building cable, capable of high-speed data transmission. Techniques exist to address the signal impairments due to the transmission characteristics of copper media and to limit the radiated emission of UTP media.

Uplink

The transmission of an RF signal from an earth station to a satellite.

USASI

: United States of America Standards Institute—now called ANSI (American National Standards Institute)

UTP

See Unshielded Twisted pair (UTP)

V

Vapor Phase Soldering

A soldering process that uses the latent heat of vaporization of a liquid as its energy source.

VDA

Video Distribution Amplifier.

Video Conferencing

Real time communications via video between two or more users at separate locations.

Vectorscope

An instrument used to display the vector relationships of color signals.

Vector-Sum Excitation Linear Predictor (VSELP)

VSELP refers to a technique that digitally codes and significantly compresses voice signals, increasing radio channel capacity by reducing the amount of information that needs to be transmitted.

Velocity of Propagation

The speed of an electrical signal down a length of cable compared to speed in free space expressed as a percent. It is the reciprocal of the square root of the dielectric constant of the cable insulation.

VHF

Abbreviation for very high frequency, 30 to 300 MHz.

Video

The picture signals in a television system.

Video Jack

A rack mountable connector with a recessed female receptacle and an outer concentric female receptacle.

Video Jackfield

A rack mounted device used to manually route video signal. Usually consists of a panel containing several video jacks of normal or non-normal configurations.

Video Pair Cable

A transmission cable containing low-loss pairs with an impedance of 125 ohms. Used for TV pick ups, closed circuit TV, telephone carrier circuits, etc.

Video Patch Cord

A flexible coaxial cable with Video Plugs on both ends, used to connect two Video Jacks.

Video Plug

A cable mounted connector with a recessed make plug and an outer concentric housing, The Video Plug is designed to mate with a Video Jack.

VITS

A test signal, transmitted on lines 17 and 18 of the vertical interval of the video signal, for the purpose of evaluating technical performance.

Vocoder

A speech-compression device used to convert speech into digital signals. Vocoders are usually characterized by the bandwidth required, such as 8 or 13 kb/s.

Volt (V)

The standard unit of electromotive force or electrical pressure. One volt is the amount of pressure that will cause one ampere of current to flow through one ohm of resistance.

Voltage

The term most often used in place of electromotive force, potential, potential difference, or voltage drop to designate the electric pressure that exists between two points and is capable of producing a current when a closed circuit is connected between two points.

Voltage Drop

The voltage developed across a component or conductor by the current in the resistance or impedance of the component or conductor.

Voltage Rating

The highest voltage that may be continuously applied to a wire or connector in conformance with standards or specifications.

Voltage Standing Wave Ratio (VSWR)

1)The ratio of the maximum effective voltage to the minimum effective voltage measured along the length of a mismatched radio frequency transmission line.  2)The ratio of the maximum effective voltage to the minimum effective voltage measured along the length of a mis-matched radio frequency transmission line.

Volume Resistivity

The electrical resistance between opposite faces of a one cm. cube of insulating material, commonly expressed in ohms-centimeter.

VTR

Video Tape Recorder, an electro-mechanical device that records, stores and reproduces an electronic signal that contains audio, video and control information.

VW-1

A flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test, formerly designated FR-1.

W

W

See Watt (W)

Wall Thickness

The thickness of the applied insulation or jacket.

WAN

See Wide Area Network (WAN)

Water Absorption

Water by percent weight absorbed by a material after a given immersion period.

Water Blocked Cable

A cable constructed with no internal voids in order to allow no longitudinal water passage under a given pressure.

Watt (W)

A unit of power equal to one joule per second. The power of 1 ampere of current pushed by 1 volt of electromotive force. The power required to do work at the rate of one joule per second.

Wavelength

The physical distance of one electromagnetic wave cycle. In a periodic wave, the distance between points of corresponding phase of two consecutive cycles The distance, measured in the direction of propagation, of a repetitive electrical pulse or waveform between two successive points.

Wave Soldering

The most widely used mass soldering process, used primarily for through-hole circuit boards. The board is passed over a wave of solder which laps against the bottom of the board to wet the metal surfaces to be joined.

Wetting

The ability of liquid solder to attach itself to the surfaces being joined through the formation of inter-metallic bonds.

Wicking

The longitudinal flow of a liquid in a wire or cable due to capillary action.

Wide Area Network (WAN)

Any physical network technology that spans large geographic distances. WANs usually operate at slower speeds and have higher delays than local area networks (LANs).

Windows

Graphics based operating system developed by Microsoft.

Wiping Action

Action of two electrical contacts which come in contact by sliding against each other See Contact Wipe. (MIL-STD) Wiping has the effect of removing small amounts of contamination from the contact surfaces, thereby achieving better conductivity.

Wire

A slender rod or filament of drawn metal.

Wire Size

A numerical designation for a conductor, usually expressed in terms of American Wire Gage (AWG) based on the approximate circular mil area of the conductor.

Wire Wrapped Connection

A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool. Also called "Solderless Wrapped Connection" or "Wrap Post Connection".

Wireless Local-Area Network (WLAN)

A network which supports the transfer of data and has the ability to share resources, such as printers, without the need to physically connect each node or computer with wires.

Wireless Local Loop (WLL)

Wireless systems that can be used to replace copper to connect telephones and other communications devices with the public-switched telephone network.

Wireless PBX

A communication system that adds wireless capability to an in-building or campus communications network.

Wiring Block

A molded plastic block that is designed in various pair configurations to terminate cable pairs and establish pair location on 110 Connector Systems.

Wiring Closet

See Telecommunication Closet.

Wireless LANs

Local area network that communicates using radio technology.

Withdrawal Force

1) The force needed to either engage or separate pins and socket contacts when they are in and out of connector inserts. Values are generally established for maximum and minimum forces. Performance acceptance levels vary by specification and/or customer requirements.  2) Force needed to either engage or separate mating contacts. (MIL-STD) Also called Contact Engaging and Separating Force

Work Area

A building space where the occupants interact with telecommunications terminal equipment. A user's work area which is typically 9 sq. meter or 100 sq. ft.

Work Area Cable

A cable connecting the telecommunications outlet to the terminal equipment.

Work Area Subsystem

The part of a distribution system that includes the equipment and extension cords from the information outlet to the terminal device.

Work Curve

A graph which plots the pull-out force, indent force and relative conductivity of a crimp joint as a function of various depths of crimping. (MIL-STD)

Working Voltage

Maximum voltage at which a connector is rated to operate. See Service Rating. (MIL-STD)

Wrap Post

A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool. Also called "Solderless Wrapped Connection" or "Wire Wrapped Connection".

Wrap Type

A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool. Also called "Solderless Wrapped Connection" or "Wire Wrapped Connection".

Wrapped Connection

A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool. Also called "Solderless Wrapped Connection" or "Wire Wrapped Connection".

X

X.25

A communication architecture developed by the International Telegraph and Telephone Consultative Committee (CCITT).

Y

Yield Strength

The minimum stress at which a material will start to physically deform.

Z

Zero Force Connector

A connector in which the contact surfaces do not mechanically touch until it is completely mated thus requiring no insertion force. After mating the contacts are actuated in some fashion to make intimate electrical contact.

Zone Method

A ceiling distribution method in which ceiling space is divided into sections or zones. Cable is then run to the center of each zone to serve the information outlets nearby.