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Glossary of Terms for the Telecommunications Industry

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• AFAN

All-fiber access network. Used primarily in cable TV (CATV) market. More info...

• Absorption

The loss of energy in an optical fiber resulting from impurities in the glass.

• Acceptance Cone

A cone angled area that light must enter in order to "bounce" down the fiber and remain in the core of the fiber.

• Access Jumper

A length of fiber placed between the OTDR and the first event along a fiber that is to be measured. Allows the user to see fiber on both sides of the event so that its loss can be estimated. Length must be significantly greater than the OTDR attenuation dead zone. (Also Known as: Launch Cable)

• Acrylate

Acrylic resin

• Adapter

A mechanical termination device designed to align and join optical fiber connectors; often referred to as a coupling or interconnect sleeve. (Also Known as: Bulkhead, Coupling Sleeve, Interconnect Sleeve, Sleeve, Coupler, Bulkhead Adapter) More info...

• ADSS Cable

All-dielectric self-supporting More info... Related Terms: Aerial, OSP Cable, Figure-8, SOLO® Cable

• All-Dielectric

Non-conducting; made entirely of dielectric (insulating) materials, without any metal conductors.

• Alligator Clips

This hardware is used for bonding and grounding metallic components of fiber optic cable.

• Alligator Clip with Strength Member Strain-Relief

This hardware is used for bonding and grounding metallic components of fiber optic cable and securing the strength member for strain relief.

• ALTOS®

Outside plant (OSP) loose tube cable. More info...   Related Terms:  Loose Tube, OSP

• Anaerobic-Cured Connector

A field-installable connector that uses an adhesive with an activating agent, to secure the fiber in the connector ferrule. No oven or lamp is needed. More info...

• Analog

A format that uses continuous variables such as voltage amplitude or frequency variations to transmit information.

• APC

Angled physical contact. Connectors which have their end-face mating surface polished at an eight-degree angle to the fiber axis. Minimizes reflections; required in RF video applications. (Also known as: Green Connector, Connector) Related Terms: Connector, Green Connector



• Aramid Yarn

Strength elements that provide cable tensile strength, support, and additional protection of the optical fiber bundles. Fiberglass and Kevlar® are two common types of aramid yarn. Related Terms: Fiberglass

• Armor

Additional protective element beneath the cable jacket. It is an outer jacket used to provide protection against severe outdoor environments and gnawing rodents. Usually made of plastic-coated steel, it may be corrugated for flexibilty. Related Terms: Rodent Resistant, Crush Resistant

• Attenuation

The decrease in magnitude of signal power transmitted between points. A term used for expressing the total loss of an optical system, normally measured in decibels (dB) at a specific wavelength.

• Attenuation Coefficient

The rate of optical power loss with respect to distance along the fiber, usually measured in decibels per kilometer (dB/km) at a specific wavelength; the lower the number, the better the fiber’s attenuation. Typical multimode wavelengths are 850 and 1300 nanometers (nm); single-mode wavelengths are 1310 and 1550 nm.

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• Backbone Cabling

The portion of premises telecommunications cabling that provides connections between telecommunications closets, equipment rooms and entrance facilities. The backbone cabling consists of the transmission media (optical fiber cable or copper twisted-pair), main and intermediate cross-connects, and terminations for the horizontal cross-connect, equipment rooms and entrance facilities. The backbone cabling can further be classified as interbuilding backbone (cabling between buildings) or intrabuilding backbone (cabling within a building).

• Backscatter

The portion of light that is scattered by the internal structure of the glass and which travels back toward the source. The optical time domain reflectometer (OTDR) uses this scattered light to make measurements.

• Bandwidth

Measure of the information-carrying capacity of an optical fiber usually measured in MHz•km at a specific wavelength. The higher the bandwidth, the more information can be transmitted over that fiber. Note: This term is often used to specify the normalized modal bandwidth of a multimode fiber.

• Bandwidth Distance Product

The information-carrying capacity of a transmission medium is normally referred to in units of MHz•km. This is called the bandwidth-distance product or, more commonly, bandwidth. The amount of information that can be transmitted over any medium changes according to distance. The relationship is not linear, however. A 500 MHz•km fiber does not translate to 250 MHz for a 2 km length or 1000 MHz for a .5 km length. It is important, therefore, when comparing media, to ensure that the same units of distance are being used.

• Bend-Improved Optical Fiber

Class of optical fibers compatible with ITU G.657A recommendations and having bending performance of .75 dB per 360-degree turn at 1550 nm with a 10 mm bend radius. These fibers are required to be backward compatible with standard single-mode. (Also Known as: ClearCurve® Fiber)

• BER

Bit error rate

• BISDN

Broadband Integrated Services Digital Network.

• BPON

Broadband Passive Optical Network. System described in ITU G983 standard. Uses optical splitters to create a one-to-many relation between the CO/HE and the subscribers. Capable of delivering voice and data; usually combined with an RF overlay for video. Usually no active (powered) components between CO/HE and subscriber.

• Broadband

Typically referring to copper, it denotes transmission facilities capable of handling a wide range of frequencies simultaneously, thus permitting multiple channels in data systems rather than direct modulation.

• Brownfield

Existing neighborhoods and/or MDUs already served by at least one provider.

• Buffering

(1) A protective material extruded over or around the fiber to protect it from the environment. (2) Extruding a tube around colored fiber to allow isolation of the fiber from stresses in the cable. (Also Known as: Buffer Tubes, Tight Buffered)

• Buffer Tubes

Extruded cylindrical tubes covering optical fiber(s) used for protection and isolation. (Also Known as: Loose Tube)

• Buffer Tube Stripper

Buffer tube stripper

• Building Homerun

MDU topology in which each subscriber's fiber link runs all the way to a common point for the entire building (usually a terminal in the basement or mounted on an outside wall).

• Bundle

Many individual fibers contained within a single jacket or buffer tube. Also, a group of buffered fibers distinguished in some fashion from another group in the same cable core.

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• Cabinet

A physical enclosure for rack-mount equipment.

• Cable

Optical fibers and other material(s) assembled to provide mechanical and environmental protection for the fibers.

• Cable Assembly

Optical fiber cable with connectors installed on one or both ends. Cable assemblies are generally used for interconnection of optical fiber cable systems and opto-electronic equipment. If connectors are attached to only one end of a cable, it is known as a pigtail. If connectors are attached to both ends of a low-fiber-count cable, it is known as a jumper or patch cord. (Also Known as: Pigtail, Jumper, Patch Cord, CCA.) More Info...

• Cable Bend Radius

Cable bend radius during installation infers that the cable is experiencing a tensile load. Free bend infers a smaller allowable bend radius since it is at a condition of no load.

• Cable Cutter

Tool used for cutting cable.

• CamSplice™  

Corning Cable Systems CamSplice™ Mechanical Splice is recommended for indoor and outdoor through or branch splicing. More info...

• Category N Cable

Copper twisted-pair data cables. CAT 3 is general telephone and low-data-rate performance level; others are data cable performance levels. The higher the number, the greater the bandwidth and/or distance performance.

• CATV

Community Antenna Television or Community Access Television Related Terms: MSO, Video

• CCH

Closet Connector Housing. CCHs provide interconnect or cross-connect capabilities between the outside plant, riser or distribution cables and the opto-electronics. (Also Known as: Rack-Mount Housing, Connector Housing) Related Terms: Patch Panel More info...

• CDF

Closet distribution frame

• CDS

Core detection system Related Terms: Splicers, Fusion Splicing More info...

• Central Member

The center component of a stranded loose tube cable. It serves as an anti-buckling element to resist temperature-induced stresses. The central member material is either steel, fiberglass, or glass-reinforced plastic (GRP). It is also used in MIC® Unitized Cable.

• Central Office (CO)

The telephone company's central location containing active (powered) equipment, from which services are provided. May contain telephone switching equipment and/or optical line terminals and RF video for BPON and GPON systems.

• Centralized Cabling

A cabling topology used with centralized electronics connecting the optical horizontal cabling with the building backbone cabling passively in the telecommunications closet.

• Chromatic Dispersion

Signal dispersion caused by light traveling at multiple wavelengths which arrive at the detector at different times. It is the sum of material dispersion and waveguide dispersion.

• Cladding

The glass layer surrounding the core of an optical fiber. The cladding must have a lower index of refraction to keep the light in the core.

• Cleaning Cassette

Corning Cable Systems Universal Connector Cleaning Cassette is designed for effective cleaning of all fiber optic connectors with an accessible ferrule including MTP®, MT-RJ and the UniCam® MT-RJ and MTP® Connectors.

• ClearCurve® Optical Fiber

Bend-insensitive fiber developed by Corning Incorporated. This fiber uses nanoStructures™ technology in the fiber to trap light, producing performance of 0.1 dB per 360-degree turn at 1550 nm with a 5 mm bend radius, while remaining backward compatible with standard single-mode fibers. ClearCurve® represents the state-of-the-art fiber for MDU deployments. More info...

• CMIC

Cabinet-mounted interconnect center

• Coating

A material applied to a fiber during the manufacturing process to protect it from the environment and handling. This is the material that comes off like shavings when stripping the fiber.

• Coax Cable

Video cable in which a central signal conductor is surrounded by a metallic shield.  Most common inside wiring types are RG59 and RG6 with the latter having better performance.

• Coaxial Cable

A central conductor surrounded by an insulator which is surrounded by a tubular outer conductor covered by more insulant. Also called coax cable.

• Coaxial Cable Stripper IDEAL Tool

Tool used in removing the protective tube that protects ribbon and loose tube fibers.

• Compact Drop Cable

These cables leverage ClearCurve® Optical Fiber to minimize or eliminate loss due to bending, but have a smaller 2.9 mm diameter to make them more aesthetically pleasing, when required, and to enable a bend-insensitive solution. For those who prefer to use microduct, compact drop cable is the ideal ClearCurve® solution. More info...

• Composite Cable

A cable containing both fiber and copper media per article 770 of the National Electrical Code® (NEC®).

• Conduit

Pipe or tubing through which cables can be pulled or housed.

• Connecting Hardware

A device used to terminate an optical fiber cable with connectors and adapters that provides an administration point for cross-connecting between cabling segments or interconnecting to electronic equipment. More info...

• Connector

A mechanical device used to align and join two fibers together to provide a means for attaching to and decoupling from a transmitter, receiver or another fiber. Commonly used connectors include the SC, ST® Compatible, or LC. (Also Known as: Termination) Related Terms: UniCam®

• Connector Module

A connector panel with a pre-installed cable assembly(s) or MTP®s on the back plane which can be spliced to backbone cable fibers (designed for use with patch panels). (Also Known as: Pigtailed Panel, Plug and Play). More info...

• Connector Panel

A panel insert designed for use with patch panel housings. Connector panels often contain pre-installed adapters. (Also Known as: Panel, Patch Panel) More info...

• Connector Removal Tool CRT-001

Corning Cable Systems Connector Removal Tool is designed to allow for easy removal and insertion of SC and small-form-factor connectors in high-density patch panels. The CRT-001 contains an integrated flashlight to make visibility in dark patch panels easier. The Connector Removal Tool is used with SC, LC, MT-RJ and MU connectors and is designed to work with cable jacket types of 3 mm, 2 mm and 1.6 mm, and with 900 µm buffered fiber.

• Consolidation

The second manufacturing step in the OVD process which removes water vapor from the preform and sinters it into a solid, dense, transparent glass blank.

• Core

The central region of an optical fiber through which light is transmitted.

• Coupling

See Adapter.

• CP

Consolidation point. Interconnect distribution point located within the horizontal pathway and space that links to the telecommunications outlet.

• Cross-Connect

A fabric switch that connects only to other switches (I/O). More info...

• CWDM

Coarse wavelength time-division multiplexing. More info...

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• D4

2.0 mm ferrule threaded connector developed by NEC®. Related Terms: Obsolete Connector

• Dead Zone

Attenuation dead zone is the distance after a reflective event at which the trace line has returned to within 0.5 dB of the actual backscatter line. This is caused by the laser pulse reflecting as it passes through the connection or event. Related Terms: Event Dead Zone

• Decibel

Unit for measuring the relative strength of light signals expressed as dB. It is equal to one-tenth the common logarithm of the ratio of the two power levels; expressed in dBm when a power level is compared to 1 milliwatt. (Also Known as: dB) Related Terms: dBm, dBr

• Dielectric

Non-metallic and, therefore, nonconductive. Glass fibers are considered dielectric. A dielectric cable contains no metallic components. (Also Known as: Nonconductive).

• Digital

A data format that uses two physical levels to transmit information corresponding to 0s and 1s. A discrete or discontinuous signal.

• Dispersion

The broadening of light pulses along a length of the fiber. Two major types are: (1) modal dispersion caused by different optical path lengths in a multimode fiber and (2) chromatic dispersion which is the sum of material dispersion and waveguide dispersion in single-mode fiber. Material dispersion is pulse spread caused by different index of refraction for light of various wavelengths in a waveguide material. Waveguide dispersion is caused by light traveling at different speeds in the core and cladding of single-mode fibers. The spreading of a light pulse as it travels down a fiber. The higher the dispersion, the lower the maximum transmission frequency. (Also Known As: Spreading of Signal Pulse) Related Terms: Chromatic Dispersion, Modal Dispersion More info...

• DM

Direct modulated

• Draw

The third and final step in the OVD process which draws the glass blank into a continuous strand of glass fiber.

• DS

Digital signal

• DWDM

Dense wavelength division multiplexing

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• Eclipse®

Hardware designed for CATV market. (Also Known as: Patch Panel) Related Terms: Rack-Mount Housing, Connector Housing More info...

• EDA

Equipment distribution area. The computer room space occupied by equipment racks.

• EDC

Environmental distribution center Related Terms: NEMA, Weatherproof More info...

• EDFA

Erbium doped fiber amplifier. Fiber amplifier in which the signal to be boosted travels through a special fiber containing, as an additive, the element erbium. Laser light pumped into this special section of fiber excites the valence electrons in the erbium. When the transmitted signal passes through the fiber, the excited electrons give up their extra energy in sync with the transmitted signal, adding to its strength. The output is identical to the input, but now has a much higher power level. EDFAs amplify the optical signal without the need to convert it to an electrical signal and back to optical.

• EIA

Electronic Industry Alliance Related Terms: Standard, TIA

• EM

Externally modulated

• EMI

Electromagnetic interference. Electromagnetic interference is a disturbance that affects an electrical circuit due to either electromagnetic conduction or electromagnetic radiation emitted from an external source.

• Encircled Flux

Encircled Flux (EF) is the percentage of power within a given radius when light is launched by a transmitter into a multimode fiber. More info...

• End-to-End Test

Measurement of optical power loss using a source and meter which transmits into one end of the fiber and receives at the other end; typically from one patch panel to another.

• Entrance Facility

An entrance to a building for both public and private network service cables including the entrance point at the building wall and continuing to the equipment room or space.

• EP2P

Ethernet Point to Point

• EPON

Ethernet Passive Optic Network

• ER

Equipment room. A centralized space for telecommunications equipment that serves the occupants of a building. An equipment room is considered distinct from a telecommunications room because of the nature or complexity of the equipment.

• ESCON

Enterprise system connector Related Terms: Obsolete Connector

• Ethernet

An IEEE network protocol standard for a 10 Mbit/s local area network. The IEEE 802.3 standard defines the various requirements and speeds of Ethernet that include 100 Mb/s, 1000 Mb/s and 10 Gb/s, Ethernet. Related Terms: Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet.

• Event

Any components, such as connectors, splices, faults, etc, that are displayed on an OTDR trace. Related Terms: End-to-End Test, OTDR, Trace, Event Table

• Extrinsic

External; outside the fiber.

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• Fan-Out

Corning Cable Systems tight-buffered breakout-style multi-fiber cable designed for ease of connectorization and rugged applications for intra- or interbuilding requirements. (Also Known as: Furcation, Buffer Tube Fan-Out) More information on: Buffer Tube Fan-Out Kits and Spider Fan-Out Kits

• Fast Ethernet

Ethernet at 100 Mb/s transmission rate. This is defined by the IEEE 802.3 standard.

• FC

Fiber connector More info...

• FCC

Federal Communications Commission

• FDC® 

Fiber distribution center (Also Known as: Patch Panel) Related Terms: CCH More info...

• FDDI

Fiber distributed data interface

• Ferrule

A mechanical component, generally a rigid tube, used to protect and align a fiber in a connector.

• Fiber

An optical waveguide consisting of a core and a cladding that is capable of carrying information in the form of light. Optical fibers are typically made of glass. Plastic optical fibers are also available.

• Fiber Bend Radius

Radius a fiber can bend before the risk of breakage or increase in attenuation.

• Fiber Identifier

A device that can detect the presence of traffic and its direction, as well as recognize the presence of a test tone (usually 2 kHz), by causing a slight bend in the fiber and causing light to leak out. Related Terms: Putting Tone on Fiber, Testing Fiber, Locating Fiber

• Fiber Optics

Fiber optic lines are strands of optically pure glass as thin as a human hair that can carry transmitted information via light pulses over long distances. They are also used in medical imaging and mechanical engineering inspection. They are composed of three main components: core, cladding and coating. More info...

• Field Installable

An optical connector that can be assembled in the field (at the job site) and installed by hand. (Also Known as: Connector) Related Terms: UniCam® More Info...

• FOC

Fiber optic cable

• FOTP

Fiber optic test procedure. A fiber optical standard. (Also Known as: TIA/EIA) Related Terms: Standard

• FREEDM®

Indoor/outdoor loose tube cable. Corning Cable Systems tight-buffered breakout-style multi-fiber cable designed for ease of connectorization and rugged applications for intra- or interbuilding requirements. (Also Known as: Furcation, Buffer Tube Fan-Out) Related Terms: Loose Tube, Indoor/Outdoor, Riser, Plenum More information on: FREEDM® One - Dielectric, OFNR Flame Rating and FREEDM One - Dielectric, OFNP Flame Rating

• FREEDM® LST™

Corning Cable Systems indoor/outdoor loose tube cable. Related Terms: Low-Fiber-Count Indoor/Outdoor, Riser, Plenum More info...

• Frequency

The number of pulses or cycles per second; measured in units of Hertz (Hz) where 1 Hertz equals 1 pulse/cycle per second.

• Fresnel Reflection Losses

Reflection losses that are incurred at the input and output of optical fibers due to the differences in refraction index between the core glass and immersion medium.

• FT-6

Flame test 6. A test used for cables which must pass a Horizontal Flame and Smoke Test in accordance with ANSI/NFPA standard 262-1985 (UL-910).

• FTTx

Fiber to the x. Refers to a host of acronyms based on taking fiber to the home (FTTH), fiber to the node (FTTN), fiber to the curb (FTTC), fiber to the desk (FTTD), fiber to the antenna (FTTA), fiber to the premises (FTTP) and fiber to the tower (FTTT).

• Fusing

The actual operation of joining fibers together by fusion or by melting. (Also Known as: Splicing) Related Terms: Arc, CDS, LID, LPAS, PAS, Splicer, VIDEO

• Fusion Splice

A permanent joint produced by the application of localized heat sufficient to fuse the ends of two optical fibers, forming a continuous single light path. Related Terms: Arc, CDS, LID, LPAS, PAS, Splicer, VIDEO

• Future-Proofing

Design decision process in which elements that may not be required today, but which are very likely to be needed in the future, are either built into the design up front or are planned as simple upgrades.

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• Gainer

A splice loss measurement in which the trace appears to go up (more power) and there appears to be a gain, instead of a loss; typical in cases where fibers of differing manufacturers are spliced together. Testing from the opposite direction usually produces a corresponding loss equal to the power gain measured from the other direction.

• GbE

Gigabit Ethernet (Also Known as Gig).

• GFCI

Ground fault circuit interpreter. Type of electrical power supply circuit protection that detects faults to ground and immediately shuts off the flow of electricity. Required for most outdoor, basement and garage, kitchen and bathroom outlets.

• Ghost

An “echo” caused by highly reflective components (connectors) in which light is reflected back from the connection, strikes another connection, which reflects it back out into the fiber, only to be reflected back to the OTDR again. (Also Known as: Non-loss Event). Related Terms: Event, Event Table, OTDR, Trace

• GIC

Glass insert connector. Corning Cable Systems has obsoleted this connector. We offer a standard anaerobic as a replacement. Related Terms: Obsolete Connector

• Gigahertz (GHz)

A unit of frequency that is equal to one billion cycles per second, 10^6 Hertz.

• GPON

Similar to BPON but based on higher Gigabit speeds. Like BPON, these systems may use an RF overlay for video, but because of their increased bandwidth per subscriber, are also being used for IPTV deployment, in which all services (voice, video and data) are placed on the GPON and the RF video overlay is not required.

• Graded-Index

Fiber design in which the refractive index of the core is lower toward the outside of the fiber core and higher toward the center of the core; thus providing higher bandwidth capabilities for multimode fiber transmission by reducing the amount of modal dispersion.

• Greenfield

New construction of MDUs and neighborhoods. In this case, no service provider and no network exists. Fiber can be planned and placed efficiently while walls, ceilings, basements and attics are openly accessible to create pathways.

• G.652 and G.655

International Organization for Standardization that describes types of single-mode fiber.

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• HC

Horizontal cross-connect Related Terms: Patch Panel

• HDC

Hybrid distribution center

• HE

Headend. Cable TV term analogous to the telephone company's central office.

• Hertz (Hz)

The frequency in pulses/cycles per second where 1 Hertz equals 1 pulse/cycle per second.

• HomePNA

The HomePNA Alliance. (Also Known as Home Phoneline Networking Alliance) HPNAv3 - technology that can use existing copper phone lines or coax lines to deliver broadband services.

• Homerun

Installation in which cables are pulled from each outlet or device back to one common location, such as the optical network terminal (ONT) in a living unit or from each living unit to a common location for the multidwelling unit (MDU) building.

• Homes Connected

Number of residential and business premises to which an operator is supplying fiber-to-the-home (FTTH) access under a commercial contract.

• Homes Passed

Number of residential and business premises to which an operator can currently deliver fiber-to-the-home (FTTH) access within the operator's standard service activation period (for example 30 days) should the owners/occupiers sign a contract for an access service.

• Horizontal Cabling

That portion of the telecommunications cabling that provides connectivity between the horizontal cross-connect and the work-area telecommunications outlet. The horizontal cabling consists of transmission media, the outlet, the terminations of the horizontal cables and horizontal cross-connect.

• Horizontal Cross-Connect (HC)

A cross-connect of horizontal cabling to other cabling, e.g., horizontal, backbone, equipment.

• Housing

An enclosure for splicing or termination that protects optical components. Related Terms: Splice Housing, Connector Housing

• Hybrid Cable

A fiber optic cable containing two or more different types of fiber, such as 62.5 µm multimode and single-mode.

• Heat-Cure Connector

A field-installable connector that uses a heat-cured epoxy to secure the fiber in the connector ferrule. Typically a hot oven is required. (Also Known as: Connector) More Info...

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• IBS

Inter-bay storage.

• IBU

Inter-bay unit

• IC

Intermediate cross-connect. A secondary cross-connect in the backbone cabling used to mechanically terminate and administer backbone cabling between the main cross-connect and horizontal cross-connect.

• ICEA

Insulated Cable Engineers Association

• ICH

Industrial connector housing Related Terms: NEMA Box, Patch Panel (Same as EDC)

• IEC

International Electrotechnical Commission

• IEEE

Institute of Electrical and Electronics Engineers Related Terms: Standard

• Index of Refraction

The ratio of light velocity in a vacuum to its velocity in a given transmission medium.  Also Known as: Refractive Index or IOR.

• Index-Matching Gel

A gel with an index of refraction close to that of the optical fiber. It is used to reduce reflections caused by refractive-index differences between glass and air. Related Terms: UniCam®, Connector, CamSplice™ More info...

• Interbuilding Backbone

The portion of the backbone cabling between buildings. See Backbone Cabling.

• Intermediate Terminals

Topology in which multi-fiber cables are run (usually in a riser) to serve terminals (MDU terminals) placed on multiple floors. This approach is used in larger MDUs to consolidate individual drops into larger cables that can be easily connected in a central point in the building.

• Internet

Refers to use of the public Internet for exchanging e-mail, Web-browsing, etc.

• Intrabuilding Backbone

The portion of the backbone cabling within a building. See Backbone Cabling.

• Intrinsic

Inherent; within; inside the fiber.

• IO

Information outlet

• IPTV

Internet Protocol Television. Use of Internet protocol to handle transmission of television signals over a data network (instead of doing so over a radio frequency (RF) network such as cable TV). Allows the television signals to be sent over the same "pipe" as data and voice.

• ISO

International Organization for Standardization

• ITS

Intelligent transportation systems Related Terms: Traffic

• ITU

International Telecommunications Union. Industry organization that makes recommendations for product specifications. ITU G.652 defines standard single-mode fibers and ITU G.657 defines bend-improved and bend-tolerant fibers.

• IW

Inside wiring. The communications wiring inside a home or living unit. Includes phone, data and CATV (coax) wiring.

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• Jumper

Optical fiber cable that has connectors installed on both ends. See Cable Assembly.

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• Kevlar® 

See Aramid Yarn.

• Kilometer (km)

One thousand meters, approximately 3,281 feet or 0.62 miles. The kilometer is a standard unit of length measurement in fiber optics. Conversion is 1 ft. = 0.3048 m.

• kpsi

A unit of force per area expressed in thousands of pounds per square inch; usually used as the specification for fiber proof test, e.g., 100 kpsi.

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• LAN

Local area network. Local area network is a computer network covering a small physical area, like a home, office, or small group of buildings, such as a school or an airport. The defining characteristics of LANs, in contrast to wide-area networks (WANs), include their usually higher data-transfer rates, smaller geographic area, and lack of a need for leased telecommunication lines. Related Terms: Campus

• LASER

Light Amplification by Stimulated Emission of Radiation. Used as a transmitter in optical systems.

• Laydown

The first step of fiber manufacturing using the OVD process; deposition of ultrapure vapors around a rotating target rod to form a glass preform.

• LC

Lucent Connector. High-density connector. (Also Known as: Little Connector, 1.25 mm) Related Terms: Connector, UniCam® More Info...

• LCP

Local convergence point. The point in the network, usually a cabinet or closure, that marks the breakout from the feeder cable (from the CO/HE) to the distribution cables that go through a neighborhood or MDU. The LCP usually contains optical splitters.

• LEAF® 

Large effective area fiber. Optical fiber used for long-haul applications.

• LED

Light emitting diodes. Used as a transmitter in lower speed optical systems. Related Terms: Connector, UniCam®

• LID

Local injection and detection device. Splicer LID-SystemTM Technology Unit provides the accuracy of power through splice loss measurement. Related Terms: Splicer More Info...

• Link

A telecommunications circuit between any two telecommunications devices, excluding the equipment connectors.

• Loose Tube Cable

Type of cable design whereby coated fibers are encased in buffer tubes offering excellent fiber protection and segregation.

• Loss

Reduction in optical power due to absorption, scattering and/or reflection.

• LPAS

Lens profile alignment system. Splice loss estimator. Related Terms: Splicer More info...

• LSZH

Horizontal intrabuilding backbones where limited-smoke, zero-halogen requirements exist. Related Terms: Cable, General Rated More info. ..

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• Macrobend

A large cable bend that can be seen with the unaided eye; often reversible.

• Mandrels

TIA/EIA-568-B-1 recommends mandrel wrapping to strip out high-order modes. A 50 µm mandrel should be of 22 mm diameter and a 62.5 µm mandrel should be of 17 mm diameter.

• MC

Main cross-connect. The centralized portion of the backbone cabling used to mechanically terminate and administer the backbone cabling, providing connectivity between equipment rooms, entrance facilities, horizontal cross-connects and intermediate cross connects.

• MDA

Main distribution area. The space in a computer room where the main cross-connect is located.

• MDPE

Medium-density polyethylene Related Terms: Outside Plant Cable, Sheath, Jacket

• MDU

Multidwelling unit. A building structure that has two or more residential dwelling units occupied by separate entities. The living units may be owned individually or the entire building may be owned as one property with units rented to tenants.

• MDU Terminal

The Multidwelling Unit (MDU) terminal serves as an interconnection between a distribution cable (with many fibers) and individual drops going to subscriber living units. This is usually a small cabinet or enclosure. In some cases, it may contain splitters. It can be located inside or on the exterior of an MDU.

• Mechanical Splicing

Joining two fibers together by permanent or temporary mechanical means (vs. fusion splicing or connectors) to enable a continuous signal. (Also Known as: CamSplice™) More Info...

• Megahertz (MHz)

A unit of frequency that is equal to one million cycles per second.

• Meter/Foot Marks

The distance markings stamped on the cable jacket by the factory in either meters or feet.

• MFD

Mode field diameter. The functional parameter for defining the diameter of the light-guiding region (i.e., the core and cladding) of a single-mode fiber.

• MIC®

Indoor cable that is designed for use in plenum, riser and general purpose environments for intrabuilding backbone and horizontal installations. Related Terms: Tight Buffered, Premise Cable, Riser/Plenum, Distribution, 900 m More info...

• Microbend

A small, microscopic bend which may be caused by the cabling process; mechanical stress due to water in the cable during repeated freeze and thaw cycles, packaging or installation.

• Micrometer (µm)

One millionth of a meter; 10 ^ -6 meter; typically used to express the geometric dimension of fibers, e.g., 62.5 µm.

• Migration

The process of moving from one cabling system or technology to another, such as migrating from a copper to optical network.

• Miller Stripper

Tool used for removing the 250 µm or 900 µm coating from fiber.

• Minimum Bend-Radius

The amount of bend a fiber (or cable) can withstand before experiencing problems in performance.

• MoCA ®

Multimedia over Coax Alliance. A technology that can deliver broadband services to subscribers using existing coax within a building or living unit.

• Mode

A term used to describe an independent light path through a fiber, as in multimode or single-mode.

• Mode Field Diameter

The diameter of one mode of light propagating in a single-mode fiber. The mode field diameter replaces core diameter as the practical parameter in single-mode fiber.

• Modulation

Coding of information onto the carrier frequency. This includes amplitude, frequency or phase modulation techniques.

• MSO

Multiple-system operator. An operator of multiple cable television networks.

• MT

Mechanical transfer. The connector technology used with OptiTip® Connector (FlexNAP™, OptiFit®, etc.). Multi-fiber molded connector ferrule technology.

• MTP®

Multiple terminations push-pull (MTP) is a type of connector. (Also Known as: MPO) Related Terms: Connector More Info...

• MT-RJ

Mechanical transfer registered jack (MT-RJ) latch is a type of connector. Related Terms: Connector

• MU

Miniature unit. (Also Known as: Connector, 1.25 mm) Related Terms: Obsolete Connector

• Multi-Fiber Cable

An optical fiber cable that contains two or more fibers.

• Multimode Fiber (MM)

A type of optical fiber mostly used for communication over shorter distances, such as within a building or on a campus. Typical multimode links have data rates of 10 Mb/s to 10 Gbps over link lengths of up to 600 meters. (Also Known as: 50 µm, 62.5 µm, OM1, OM2, OM3 and OM4.)

• Multiplex

Combining two or more signals into a single bit stream that can be individually recovered.

• Multiport Mounting Bracket

Bracket used for mounting multiport terminals.

• Multi-Trunking

Increasing available bandwidth by connecting more than one switched port to a single device.

• Multi-User Outlet

A telecommunications outlet used to serve more than one work area, typically in open-systems furniture applications.

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• NA

Numerical aperture. The numerical aperture of a fiber is the measure of the maximum angle of the light entering the end of the fiber that will propagate with the core of the fiber.

• NEC®

National Electric Code® Related Terms: Demarc, Demarcation Box

• NEMA

National Electrical Manufacturers Association Related Terms: Flame Rating, NEC, Indoor Cable

• NESC® 

National Electrical Safety Code

• Network

A means of providing connection to many potential devices/users, where a dedicated path does not exist but is established and released as necessary to send/receive data. It is typically very software dependent, with more overhead than channels.

• NID

Network interface device More info...

• Nm

Nanometers. 10^9.

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• OFCP

Optical Fiber Conductive - Plenum. A conductive cable (armored) that is suitable for installation in a plenum space. (Also Known as: Plenum). Related Terms: Flame Rating, NEC, Indoor Cable

• OFCR

Optical Fiber Conductive - Riser. A conductive cable (armored) that is suitable for installation in a riser space. (Also Known as: Riser). Related Terms: Fiber Type, IEC 11801

• OFL

Over filled Launch

• OFNP

Optical Fiber Nonconductive - Plenum. Cable installed in ducts, plenums, and other spaces used for environmental air must be listed as having adequate fire-resistant and low-smoke producing characteristics. Related Terms: Fiber Type, IEC 11801

• OFNR

Optical Fiber Nonconductive - Riser. Cable used in riser areas which are building vertical shafts or runs from one floor to another floor. (Also Known as: Riser) Related Terms: Fiber Type, IEC 11801

• OLT

Optical Line Terminal. For BPON and GPON systems, this is the electronics that reside in the CO/HE and which control the ONTs served at each subscriber's location. Typically, OLTs service 16, 32 or 64 ONTs.

• OM1

Optical Multimode 1 (62.5/125 mm - 200/500 MHz•km BW) (Also Known as: 62.5 µm Fiber) Related Terms: Fiber Type, IEC 11801

• OM2

Optical Multimode 2 (50/125 µm - 500/500 MHz•km BW) (Also Known as: 50 µm Fiber) Related Terms: Fiber Type, IEC 11801

• OM3

Optical Multimode 3 (50/125 µm 1500/500 - MHz•km BW) (Also Known as: 50 µm Laser-Optimized Fiber) Related Terms: Fiber Type, IEC 11801

• OM4

Optical Multimode 4 (50/125 µm 3500/500 - MHz•km BW) (Also Known as: 50 µm Laser-Optimized Fiber) Related Terms: Fiber Type, IEC 11801

• ONT

Optical Network Terminal. For BPON and GPON systems, this is the electronics located at the subscriber's premises.The ONT converts the optical signal to copper and coax-based signals for connection to phones, computers and televisions in the residence.

• On-the-Reel Test

OTDR test of a new reel of cable prior to installation to verify length and condition of the fiber. Related Terms: Fiber Testing, OTDR, Continuity Testing

• Open Access (Duct)

Refers to the situation where multiple retail or wholesale service providers may share the use of a duct network covering a substantial region by drawing or blowing their fiber cables through the shared ducts and compete to offer their services.

• Open Access (Fiber)

Refers to the situation where multiple retail or wholesale service providers may use the FTTH network by connecting at a physical layer ("dark" fiber) interface and compete to offer their services.

• Open Access (Packet)

Refers to the situation where multiple retail service providers may use the FTTH network by connecting at a packet layer interface and compete to offer their services to end users.

• Open Access (Wavelength)

Refers to the situation where multiple retail or wholesale service providers may use the FTTH network by connecting at a wavelength layer interface and compete to offer their services.

• Optical Fiber

See Fiber. An optical waveguide consisting of a core and a cladding that is capable of carrying information in the form of light. Optical fibers are typically made of glass.

• Optical Test Set

Test set having a calibrated light source and meter, used to measure the power loss in an optical link or network. (Also Known as: Test Set, OTS) More Info...

• OptiTap® 

Single-fiber drop cable assembly with factory-terminated hardened connector. More Info...

• OptiTip® 

Multi-fiber drop cable assembly with factory-terminated hardened connector. More Info...

• OptiTip®  Cleaning Tool

Tool used to clean OptiTip®  Connectors. More info...

• OS1

Optical Single-Mode Fiber. Corning Cable Systems currently manufactures cable to meet OS2 requirements. (Also Known as: Single-Mode Fiber) Related Terms: Fiber Type, IEC

• OS2

Optical Single-Mode Fiber. (Also Known as: Single-Mode Fiber) Related Terms: Fiber Type, IEC

• OSE

Optical splice enclosure. It is designed to manage the transition between outside plant cables and fire-retardant indoor riser cables in fiber optic networks.

• OSI

Open systems interconnection. Refers to a seven-layered model that serves as a guideline for creating and implementing network standards, devices, and internetworking schemes to allow communication between multiple network devices.

• OSP

Outside plant. Cabling outside of buildings, including aerial and buried installations.

• OTDR

Optical time domain reflectometer. Corning Cable Systems OV-1000 Optical Time Domain Reflectometer (OTDR) provides testing flexibility by combining a rugged platform with field-interchangeable multimode, single-mode and advanced testing modules. More Info...

• Outside Vapor Deposition (OVD)

An optical fiber manufacturing method developed and used by Corning; manufacturing method using three steps: laydown, consolidation and draw.

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• P2MP

Point-to-multipoint

• P2P

Point-to-point

• PAS

Profile alignment system

• Patch Panel

Hardware which holds adapters in a housing. More Info...

• PE

Polyethylene

• Physical Ring

A cable layout in which each node is connected to two adjacent nodes. There is not a central point of cable termination.

• Physical Star 

A cable layout in which all cables route back to a central location, directly or through other consolidation points.

• Pigtail

Optical fiber cable that has a connector installed on one end. See Cable Assembly.

• Pigtailed Panel

Stubbed panel for fusion termination.

• PIN Diode 

PIN diode is a diode with a wide, lightly doped 'near' intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor regions. The p-type and n-type regions are typically heavily doped because they are used for ohmic contacts. The wide intrinsic region is in contrast to an ordinary PN diode. The wide intrinsic region makes the PIN diode an inferior rectifier (the normal function of a diode), but it makes the PIN diode suitable for attenuators, fast switches, photodetectors and high-voltage power electronics applications.

• Plenum

An air-handling space such as that found above drop-ceiling tiles or in raised floors; also, a fire-code rating for indoor cable suitable for use in plenum spaces.

• PMD

Polarization mode dispersion

• Point-to-Point

A connection established between two specific locations as between two buildings.

• Preconnectorized

Cables having optical connectors pre-installed and tested at a factory before being shipped to the field for installation as an assembly.

• Prefusing

A low current electric arc used to clean the fiber end prior to fusion splicing.

• Pre-Stubbed

Hardware (rack, wall, LCP cabinet ) that has a factory-connectorized or factory-prepared cable (stub) built into it. In the field, the hardware is placed and the stub cable is spliced into the system. The work of connectorizing each fiber or preparing the cable inside the cabinet is already complete, saving field time and labor. More Info...

• Pulling Grip

A device used to couple the strength members of the cable and the actual pulling apparatus.

• PVC

Polyvinylchloride is a type of plastic material used for cable jacketing. Typically used in flame-retardant cables.

• PVDF

Polyvinyldefluoride is a type of material used for cable jacketing. Often used in plenum-rated cables.

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• Rack

Vertical support for equipment typically with 1.75 inches of space between mounting holes. Standard rack sizes are 19 inches and 23 inches wide.

• Rack Space

A unit of measure of 1.75 inches for equipment space in a rack. Many housings are measured in rack space.

• Receiver

An electronic package that converts optical signals to electrical signals.

• Reference

The power level of the source as measured through a test jumper that will be connected to a fiber for testing. Measurements through the system fiber are compared to this value and the difference is the system loss.

• Reflectance

The ratio of reflected power to incident power at a connector junction or other component or device, usually measured in decibels and typically stated as a negative value, e.g., -30 dB. The terms return loss, back reflection and reflectivity are also used synonymously to describe device reflections but are stated as positive values.

• Reflection

Light which is reflected whenever there is a difference in media and the index of refraction, such as a connector interface, where air (different index) is present, or the end of a fiber, where glass meets air.

• Repeater

An active device used to regenerate an optical signal to allow an increase in the system length.

• Residential

Refers to private users in their homes. Residential users may live in "MDU" (multi-dwelling units such as apartments/condominiums) or "SFU" (single-family dwelling units such as stand-alone houses/villas/landed property).

• Return Loss

See Reflectance.

• RF

Radio frequency

• RF Video Overlay

Use of a radio frequency (RF) video signal, usually at a separate wavelength from the data/voice transmission, to provide television/video services. The transmission technique is similar to that used for CATV.

• RFI

Radio frequency interference

• RH

Relative humidity

• Riser

Pathway for indoor cables that passes between floors, normally a vertical shaft or space; also a fire code rating for indoor cable suitable for use in riser spaces.

• RoHS

Restriction of hazardous substances. RoHS, also known as Directive 2002/95/EC, restricts the use of specific hazardous materials found in electrical and electronic products.The restricted materials are hazardous to the environment, pollute landfills and are dangerous in terms of occupational exposure during manufacturing and recycling.

• Rough-In

Phase of construction when walls and ceilings are framed, but not yet covered with finishing materials. At this point, the hidden elements of electrical and communications, plumbing, HVAC and other systems can be installed. Once wall and ceiling finishing materials are installed, these systems also receive their finishing work in the form of outlet plates, fixtures, grates and so on. It is during rough-in that microduct, cabling and wiring boxes can be installed to make service connections easy to complete after the building is finished.

• Route Diagram

A schematic diagram showing the physical location/layout of the fiber run and the location of splices and termination points.

• Router

Provides connection over the OSI network layer (Layer 3).

• Rugged Drop Cable

MDU drop cables designed to provide inherent bend-radius control (self-limiting), ensuring low optical loss and robust mechanical performance when installed, bent and stapled like copper and coax cabling. Rugged drop cables typically use bend-insensitive fibers, such as ClearCurve® Optical Fiber, to minimize or eliminate loss due to bending.

• Rural Utilities Services (RUS)

An agency within the U.S. Department of Agriculture which provides public utilities to rural areas in the U.S. using public and private partnerships.

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• SBS

Stimulated Brillouin scattering

• SC

Subscriber or square connector. Type of connector.

• Scattering

The loss of signal power (light) from the fiber core caused by impurities or changes in the index of refraction of the fiber.

• Seam Ripper

Tool used while accessing cables to remove stranded dielectric strength members.

• Self-Contained Distribution

An MDU topology element in which splitters are placed in the same building as the subscribers they serve. Therefore the entire distribution portion of the network is contained within the building.

• Self-Limiting Cable Sheath

Cable sheath designed to limit bending of the enclosed optical fiber(s) to ensure both low attenuation and mechanical reliability.

• Shared Distribution

An MDU topology element in which splitters are external to the building and the subscribers they serve. Usually, two or more buildings share a common splitter location (LCP).

• Single-Mode (SM)

Single-mode fiber

• SONET

Synchronous optical network

• Splice Closure

A container used to house cable splice points and organize and protect splice trays; typically used in outside plant environments. More info see  EVO-931-EN  or  EVO-433-EN

• Splice Tray

A container used to secure, organize and protect spliced fibers. More info...

• Splicing

Joining of bare fiber ends to one another.

• SRP

Standard recommended procedure (Also Known as: Installation Guide)

• ST

Straight tip. Developed by AT&T. Type of connector.

• STP

Shielded twisted-pair

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• Take Rate

Calculated by the simple division of "Home/Premises Connected" by "Home/Premises Passed" and is expressed as a percentage.

• TELCO

Telecommunications companies

• Telcordia

Provides international accepted industry standards and specifications for communication practices.

• Telecommunications Closet (TC)

An enclosed space for housing telecommunications equipment, cable terminations and cross-connects. The closet is the recognized cross-connect between the backbone and horizontal cabling.

• Tensile

Pulling (strength or stress).

• Termination

A connection.

• Test Fiber Box (TFB)

Launch cable used in conjunction with an Optical Time Domain Reflectometer (OTDR) which allows the loss of the first system connector to be measured or observed.

• TIA

Telecommunications Industry Association

• Tight-Buffered Cable

Type of cable construction whereby each glass fiber is tightly buffered by a protective thermoplastic coating to a diameter of 900 micrometers. Increased buffering provides ease of handling and connectorization.

• Topology

The physical layout of the network that describes how the system components are actually placed and connected to each other. While the architecture is the logical view, the topology is a physical view of the network.

• Total Internal Reflection

Reflection that occurs when a light ray traveling in one material hits another material and reflects back into the original material without any loss of light.

• Triple Play Services

The offering by carriers of voice, video and data services over one medium (one network). Usually this reduces network complexity and cost for the carrier and offers preferred pricing for subscribers.

• Tx

Transmitter

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• UL

Underwriters Laboratories® develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing with product safety. UL also evaluates and certifies the efficiency of a company’s business processes through its management system registration programs.

• Ultraviolet Cure Connector

A field-installable connector with a polymer epoxy that hardens when exposed to ultraviolet light. Corning Cable Systems has obsoleted this connector. The anaerobic connector is a replacement.

• UniCam® 

Corning Cable Systems field-installable connector that requires no-epoxy/no-polish. More info...

• UPC Connector

Ultra physical contact connector More info...

• UTP

Unshielded twisted-pair

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• VCSEL

Vertical cavity surface emitting laser

• VFL

Visual fault locator

• Video

Refers to the exchange of visual material by use of "IP", "RF" (carried via a separate optical wavelength) or "other" encoding and transport protocols.

• Visible Spectrum

The portion of the electromagnetic spectrum that can be seen by the unaided human eye.

• Voice

Telephone services

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• Wavelength

The distance between two successive points of an electromagnetic waveform, usually measured in nanometers (nm).

• WCH

Wall-mountable closet housing. Wall-mountable closet housing provides interconnect or cross-connect capabilities between the outside plant, riser or distribution cables and the opto-electronics. More info...

• WDC

Wall-mountable distribution center More info...

• WIC

Wall-mountable interconnect centers More Info...

• Window

A range of wavelengths within which a fiber best operates.

• Work-Area Telecommunications Outlet

A connecting device located in a work area at which the horizontal cabling terminates and provides connectivity for work area patch cords.

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• ZDA

Zone distribution area. A space in a computer room where a zone outlet or a consolidation point is located.

• Zero-Dispersion Wavelength

Wavelength at which the chromatic dispersion of an optical fiber is zero; the wavelength at which waveguide dispersion cancels out material dispersion in an optical fiber.