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f - Frequency
Farad - A unit of capacitance that stores one coulomb
of electrical charge when one volt of electrical pressure is
applied.
Far End Cross Talk (FEXT) - Crosstalk that is measured
on the quiet line at the opposite end as the source of energy
on the active line. FEXT is not typically measured in cabling,
with Near End Cross Talk (NEXT) being the preferred crosstalk
measurement.
Fast Ethernet - Ethernet standard supporting 100 Mbps
operation.
FCC - Federal Communications Commission.
FCS - Frame Check Sequence. Error detection field.
FDDI - Fiber Distributed Data Interface. An ANSI Standard
(ANSI X3T12) for a 100 Mbps token passing network based on fiber-optic
(FDDI) and twisted-pair (CDDI) cabling.
Feeder Cable - In a CATV system, the transmission cable
from the head end (signal pickup) to the trunk amplifier. Also
called a trunk cable.
FEP - Fluorinated ethylene propylene. A thermoplastic
with excellent dielectric properties which is often used as
insulation in fire rated cables.
FEXT - see Far End Cross Talk
Fiber Optics - The technology in which communication
signals in the form of modulated light beams are transmitted
over a glass fiber transmission medium. Fiber optic technology
offers high bandwidth, small space needs and protection from
electromagnetic interference, eavesdropping and radioactivity.
Fifty-pin Connector - Commonly referred to as a Telco,
CHAMP, or blue ribbon connector, this connector is used on Ethernet
10Base-T hubs as an alternate twisted-pair segment connection
method. The 50-pin connector connects to 25-pair cables, which
are frequently used in telephone wiring systems and which typically
meet Category 3 specifications.
Fillers - Non conducting components cabled with the insulated
conductors or optical fibers to impart roundness, flexibility,
tensile strength, or a combination of all three.
Floating - Refers to a circuit that has no connection
to ground.
FOIRL - Fiber Optic Inter-Repeater Link. An Ethernet
fiber optic connection method intended for connection of repeaters.
Frequency - The number of times a periodic action occurs
in a unit of time. Expressed in hertz (abbreviated Hz). One
hertz equals one cycle per second.
Frequency Division Multiplexing (FDM) - A technique for
combining many signals on a single circuit by dividing the available
transmission bandwidth by frequency into narrower bands, each
used for a separate communication channel.
Frequency Modulation (FM) - One of three basic methods
(see also Amplitude and Phase Modulation) of adding information
to a sine wave signal in which its frequency is varied to impose
information on it.
Frequency Response - The range of frequencies over which
a device operates as expected.
FTP - see Screened Twisted Pair (ScTP) cable
Full Duplex Transmission - Data transmission over a
circuit capable of transmitting in both directions simultaneously. |
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