FIBER OPTIC CENTER GLOSSARY
There are currently 76 names in this directory beginning with the letter N.
Coaxial connector with screw type coupling mechanism. Available in 50 ohm and 75 ohm version. Frequency range DC - 18 GHz (50 ohm) and DC-1 GHz (75 ohm), respectively.
National Electrical Code® (NEC)
A U.S. consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations. (The Canadian Counterpart is the CE Code.)
National Electrical Code® Article 725
The NEC Article which covers remote control signal and communication power limited circuits that are not an integral part of the device or appliance.
National Electrical Code® Article 760
The NEC Article which covers the fire and burglar alarms installation of wire and equipment operating at 600 Volts or less.
National Electrical Code® Article 800
The NEC Article which covers telephone, telegraph as well as outside wiring for fireand burglar alarms.
National Electrical Safety Code (NESC)
This outside plant code contains basic safety provisions that cover supply, communication lines, equipment, and work practices of personnel employed by utilities.
National Institute of Standards and Technology (NIST)
A U.S. government organization that develops standards in support of industry, commerce, scientific institutions, and all branches of government. The calibration of test equipment is traceable to NIST equipment.
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.
National Television Standards Committee (NTSC)
Committee that defines specifications and methods for displaying video information on a standard television.
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.
The part of the infrared electromagnetic spectrum near visible wavelengths, in the range of 700 to 1500/2000 nm.
NEAR-END CROSSTALK (NEXT)
The coupling of power from the transmitted signal pair to an adjacent pair at the same transmitting end of the LAN cable.
NEC Type CL2
A Class 2 power-limited type cable for general use applications within a building under NEC Article 725, this type design is "Listed" by UL. These cables meet a 70,000 BTU flame test.
NEC Type CL2P
A Class 2 power-limited cable which is suitable for use in plenums in accordance with NEC Article 725. The cable meets the requirements of UL 910 the Steiner Tunnel test which classifies fire and smoke characteristics. The cable is "Listed" by UL.
NEC Type CL2R
A Class 2 power-limited cable which is suitable for use in riser shafts in accordance with NEC Article 725. These cables meet the UL 1666 flame test and are "Listed" by UL.
NEC Type CL2X
A Class 2 power-limited cable which is suitable for restricted applications (Iess than 0.25" in diameter in residences, exposed lengths less than 10f t.) or else in raceways under NEC Article 725. These cables meet a VW-1 flame test and a re Listed by UL.
NEC Type CM
A general application communications cable, Listed by UL, for use within buildings under NEC Article 800. It meets the requirements of the 70,000 BTU flame test.
NEC Type FPL
A general application fire p rotection cable for use within buildings in accordance with NEC Article 760. These cables are Listed by UL and meet the 70,000 BTU flame test.
NEC Type MP
A general use, multipurpose cable which may be employed interchangeably in either a communications (Article 800), power-limited (Article 725) or fire protective (Article 760) application.
Necking or narrowing produces a high loss splice. Also caused by bad cleaves which leave a void between the fiber ends resulting in a narrow section during fusion.
A synthetic rubber with good resistance to oil, chemicals and flame. Also called polychloroprene.
An electrical unit similar to decibel, used to express the ratio between two amount of power existing at two distinct points. 1 Neper = 8.686 decibels.
1) Series of points connected by communications channels; 2) Network of telephone lines normally used for dialed telephone calls; 3) Network of communications channels connected to the use of one customer. For purposes of data communications applications
Network access point (NAP)
A major Internet connection point that allows organizations to interconnect and exchange information and traffic to flow from freely from ISP to ISP.
A device such as an Ethernet card that enables a computer to be attached to a network.
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 equipment building system (NEBS)
A requirement for central office equipment in the North American Public Switched Telephone Network. Originally developed by Bell Labs (now Telcordia) in the 1970s and released as a public document in 1985.
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.
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.
Network Operating System
NOS. The software component of a network. The NOS contains all instructions pertinent to data transfer, file manipulation and services and interfacing routines.
Network Operations Center (NOC)
The group responsible for the day-to-day care and feeding of a network. Also called a network control center (NCC).
New Bedford, MA
City in Massachusetts in North America that is home to Fiber Optic Center's headquarters. New Bedford was known in the 19th Century as “the city that lit the world”, because as the active seaport which was home to the worldwide whaling industry, its products were used to light the lamps and later lighthouses throughout the U.S. and elsewhere. Whaleships were at sea for 3 or more years at a time in every direction, including both poles and everywhere in between. On returning back to the home port, goods gathered overseas were shared with others, as were stories of people, customs and cultures. Immigrants came from far places to man the ships, and many stayed and settled when their sailing days ended.
The property of a liquid in which its viscosity is constant over a stated range of strain rates.
A pressure system designed to apply a large amount of pressure for an instant. This system is frequently used for hot melt, fast-set adhesives, or contact cements.
A connection point into a network. The node may perform several functions (i.e., file server, workstation, print server, bridge, etc.).
In a cable or circuit, any extraneous signal which tends to interfere with the signal normally present in or passing through the system.
A descriptor applied to a dimension representing the center of the range of tolerance or a value if no tolerance is applied.
The stress at a point calculated on the net cross section by simple elastic theory without taking into account the effect on the stress produced by discontinuities such as holes, grooves, fillets, or any combination of them.
Nominal Velocity of Propagation
"NVP" is the relative speed a signal travels on a conductor that is proportionate to the speed of light in a vacuum. Length measurements are determined by sending a signal down a line and measuring the reflected signal that comes back and factoring in the amount of time that it took to make the return trip. (also see c and LENGTH)
Type of PVC jacket material whose plasticizer will not migrate into the dielectric of a coaxial cable and thus avoids contaminating and destroying the dielectric.
An adjective describing a chain macromolecule that behaves in a hydrodynamic field as though the solvent within the domain of the macromolecule were virtually immobilized with respect to the macromolecule. (IUPAC)
The property of a liquid in which its viscosity is not constant over a stated range of strain rates.
A chassis mounted device that provides a connection between a rear mounted receptacle and a front mounted receptacle.
Non-Rotating Wire Ropes
18x7 wire rope consisting of a 6x7 left lay Lang lay inner rope covered by twelve 7-wire strands right lay regular lay - also 19x7’s
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.
The portion of a material that remains after volatile matter has been evaporated under specified ambient or accelerated conditions.
Nonzero dispersion-shifted fiber (NZDS)
Single-mode fiber designed for DWDM and optical amplifier applications. Specified in the ITU-T G.655 standard.
Norid Mobile Telecommunication System (NMT)
A European analog cellular standard operating at 450 and 900-MHz
The same as a Non-Normal Jack, except that there is also an interruptible connection between the two rear mounted receptacles.
A dual male connector that can be inserted into two vertical jacks to provide a continuous connection. Sometimes called a "looping" plug.
A phenolic resin containing less than a 1:1 ratio of formaldehyde to phenol so that normally it remains thermoplastic until heated with an appropriate amount of a compound (for example, formaldehyde or hexamethylenetetramine) capable of giving additional linkages, thereby producing an infusible material.
Numerical Aperture (NA)
Measure of the range of angles of incident light transmitted through a fiber. Depends on the differences in index of refraction between the core and the cladding. (The number that expresses the light gathering ability of a fiber.)