Components

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GLOSSARY
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Glossary
Copper Glossary of Terms
DSL (Digital Subscriber Line): Modems on either end
of a single twisted pair wire that delivers ISDN Basic
Rate Access.
DSLAM (Digital Subscriber Line Access
Multiplexer): Specifically, a device which takes a
number of ADSL subscriber lines and concentrates
these to a single ATM line.
Duct: Conduit for the installation and protection
of cables in congested areas.
EF&I: (Engineer Furnish and Install)
Electromagnetic Coupling: The transfer of energy by
means of a varying magnetic field.
ELFEXT (Equal Level Far-end Crosstalk): The ratio
of the unwanted crosstalk at the far-end of the
disturbed pair, used to quantify the noise seen at a
receiver due to a far-end transmitter on another pair.
Usually expressed in decibels (dB). Similar to ACR
but is measured at the far end of the cable.
It is an indication of the quality of the signal sensed
by the receiver.
EMI (Electromagnetic Interference): “Noise”
generated in copper conductors when
electromagnetic fields induce currents. EMI may
be caused by other copper cables and is caused by
proximity to motors and machinery. The all-dielectric
fiber optic cable design makes them immune to EMI.
Equipment Room: A centralized space for
telecommunications equipment that serves the
occupants of a building. An equipment room is
considered distinct from a telecommunications
closet because of the nature or complexity of the
equipment.
Eye, Pulling: A strong metal ring usually installed at
the factory, for use in pulling a cable into a duct.
Farad: A unit of capacitance that will store one
coulomb of electrical charge when one volt of
electrical pressure is applied.
FEP (Fluorinated Ethylene-Propylene): A
thermoplastic material with good electrical
properties insulating
FEXT (Far-End Crosstalk): Refers to crosstalk that
is measured at the opposite end of the cable from
which it is being disturbed.
F (Frequency): The number of times a periodic action
occurs in a unit of time. The number of cycles that an
electric current completes in one second, expressed
in Hertz.
Flooding: The act of applying a liquid material over
a cable or any of its components, usually for the
purpose of adhesion, corrosion deterrent, or to fill
voids to accomplish a specific purpose.
Frequency, Voice: Although frequencies from
32 to 16 kHz are audible to some persons the band
normally used for telephone communications is
limited to about 3500 Hz. Test frequency most
commonly used is 1kHz.
Gas Pressurization: A method of preventing water
from entering small cracks in cable splices or sheath
and for alerting personnel to larger leaks by
keeping cables under pressure with dry gas.
Gigabit Ethernet: This standard was written by the
IEEE 802.3 committee and adopted as a new
standard for Gigabit transmission of LANs.
Group Binder: A binder applied over a number
of units giving group identification.
Headroom: The amount of margin in ACR. A good rule
of thumb for adequate cable headroom is 10dB ACR.
Hertz: The unit of frequency, one cycle per second.
Hybrid Cable (Copper): An assembly of two or more
cables, of the same or different types or categories,
continuously bound with an overall sheath to form a
single unit.
Hygroscopic: Readily absorbing and retaining
moisture.
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.
ILEC (Incumbent Local Exchange Carrier):
A local telephone company service consistant with
the services provided by a previous carrier. ILECs
compete with upstart Competitive Local Exchange
Carriers (CLEC).
Laminate: A sheet material made by bonding
together two or more layers of the same or different
material.
LAN (Local Area Network): A network connecting
several nodes within a limited geographic area,
usually within a building or campus
Lay: The longitudinal distance that a pair or unit
advances in one spiral turn about the cable axis.
LCL (Longitudinal Conversion Loss): Ratio of the
common-mode (longitudinal) signal applied to a
cable or transmission channel to the resultant
differential signal measured at the same end.
Used to quantify the longitudinal signal seen at the
transmitter due to the differential signals present on
the cable or transmission channel which influences
the electromagnetic emissions. Usually expressed in
decibels (dB).
LCTL (Longitudinal Conversion Transfer Loss): Ratio
of the common-mode (longitudinal) signal applied at
the near-end of a cable or transmission channel to
resultant differential signal measure at the far-end.
Used to quantify the undesired differential noise seen
at the receiver due to longitudinal noise coupled onto
the cable from external sources. Usually expressed
in decibels (dB).
LEC (Local Exchange Carrier): Any carrier that
has been given permission by the state public
utility commission to provide local voice level
telecommunications services within a
predetermined area.
MB/s (Megabit per second): A million bits per
second.
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.
nm (Nanometer): One-billionth of a meter;
10
-9
meter.
ns (Nanosecond): One-billionth of a second;
10
-9
second.
OEM: Original Equipment Manufacturer
Ohm: The electrical unit of resistance. The value
of resistance through which a potential difference
of one volt will maintain a current of one ampere.
Outside Plant: Usually considered all cable and
equipment used outside of the central office and
customers’ premises.
Pair: Two wires forming a single circuit, held
together by twisting, binding, or a common jacket.
Pedestal: An above ground watertight housing for
splicing and terminating buried cables.
Plant, Inside: Usually considered being all cable and
equipment inside the central office and
customer’s premises.
Plenum: A compartment or chamber to which one
or more air ducts are connected and that forms part
of the air distribution system (i.e. the space above
the drop ceiling).
Plenum Cable: Cable made of fire-retardant materials
that generates little smoke. These cables are
installed in plenum air ducts, vertical shafts etc.
Polyethylene: A thermoplastic material having
excellent electrical properties.
Polyurethane: Broad class of polymers noted for
good abrasion and solvent resistance. Can be in solid
or cellular form.
Polyvinyl Chloride (PVC): A general purpose
thermoplastic used for wire and cable insulation
and jackets.
POTS (Plain Old Telephone Service): The only
name recognized around the world for basic analog
telephone service. POTS takes the lowest 4kHz
of bandwidth on twisted pair wiring. Any service
sharing a line with POTS must either use frequencies
above POTS or convert POTS to a digital signal.
POTS splitter: A device that uses filters to separate
voice from data signals when they are to be carried
on the same phone line, required for several types
of DSL service.