10 BASE-T - A network designed to operate over a star topology with a
central hub acting as the network distribution point, with each node or workstation
connected to the hub by a link segment of unshielded twisted pair cabling.
Address - The set of numbers that uniquely identifies the location of a
terminal, peripheral device, node, or any other component in a network.
Amplitude - The distance between the high and low points of a waveform
or signal; the strength of a signal.
Asynchronous Transfer Mode (ATM) - A multiplexing technique which uses
fast, packet-like switching, high bandwidth, and low delay.
Attenuation - The difference between transmitted and received power due
to loss through equipment, lines, or other transmission devices, measured in decibels.
Bandwidth - The difference, expressed in Hertz (Hz), between the highest
and lowest frequencies of a transmission channel; a measure of the information capacity of
the transmission channel.
Barrel Connector - A female connector used to connect two sections of
coaxial cable.
Baud - A unit of signaling speed equal to the number of signal symbols per
second.
Bend Radius - The minimum radius to which a cable or fiber can be bent before
excessive signal attenuation occurs.
Binding Post - Type of connecting device used in audio speaker circuits. A
knurled nut is tightened over a speaker wire conductor inserted through a hole in a threaded post.
Bit - Binary digit; fundamental unit of information expressed in digital
form as the choice between two states, 0 or 1.
Bridge - A bridge (not to be confused with a router) is a data network device
used to connect two network segments of different protocols. For example, if you want
computers on a TCP/IP network to talk to computers on a token ring network, you need a bridge
to connect the two segments.
Broadband - A method of communication in which the signal is transmitted
by being impressed on a higher frequency carrier. Broadband is a general term used to
describe any high-speed, high-bandwidth, "always on" Internet connection. Cable modems,
DSL modems, satellite link-ups, and T1 lines are all broadband devices.
Browser - Browsers are software programs that view Web pages and help
you move through the Web.
Bundled Cable - An assembly of two or more cables continuously bound
together to form a single unit prior to installation.
Byte - A collection of bits operated upon as a unit; most are 8 bits long
and most character sets use one byte per character.
Cable Modem - A modem used to link cable-supplied data to a computer network,
for example, when a CATV provider offers high-speed, cable based Internet service.
Cascade Cable - A specialized cable used to link compatible computer network
hardware (usually hubs) together.
Category 3 - Twisted pair cable, used for telephone signaling and LAN
protocols with data signaling under 16 Mhz.
Category 5 - High quality twisted pair cable, used for supporting fast
LANs with data signaling up to 100 Mhz in bandwidth.
Category 5e - An enhanced form of Category 5, supporting high-speed data
transmission per TIA-568A Addendum 5.
Coaxial Cable - A cable with at least one transmission line consisting of
two conductors, an inner conductor and an outer conductor, insulated from one another by a
dielectric.
Connecting Block - A flame-retardant plastic block containing metal wiring
terminals (quick clips) that establish an electrically tight connection between the cable
and the cross-connect wire.
Cross-Connect - A facility enabling the termination of cables as well as
their interconnection or cross-connection with other cabling or equipment.
Crosstalk - Unwanted transference of electrical energy from one
transmission medium to another, usually adjacent, medium.
Decibel - A unit of measure used to designate the ratio of two power
levels; used to indicate gains or losses of signals on a logarithmic scale; dB.
Demarcation Point - A point where operational control or ownership changes.
Demodulation - The process of separating a data (digital) signal from an
analog carrier signal; opposite of modulation.
Demultiplexing - The process of breaking a composite signal into its
component channels; opposite of multiplexing.
Dielectric - A nonconducting or insulating material that resists passage
of electric current.
Digital - Discretely variable as opposed to continuously variable;
contrast with analog.
Digital Subscriber Line (DSL) - A new digital connection method that
provides high-speed Internet or other network connections over standard telephone wire.
Direct Broadcast Satellite (DBS) - Satellite television service that is
purchased through a subscription (DIRECTV, Dish Network, Etc.).
Distortion - any undesired change in waveform of a signal in the course
of its passage through a transmission system.
Domain Name System (DNS) - The domain name system (DNS) is an Internet
service that translates domain names (like stellarplex.com) into IP addresses
(like 207.104.53.11). We use domain names because people can remember words better
than numbers, but Web servers still need the IP numbers to access the page. Every time
you use a domain name, a DNS server must translate the name into the corresponding IP address.
Dual Cable Systems - CATV systems in which the incoming service is provided
over two different cables, sometimes called A/B cable systems.
Duplex - Two-way data transmission on a four-wire transmission line.
Dynamic Host Configurstion Protocal (DHCP) - The dynamic host configuration protocol is an addressing protocol
for TCP/IP networks. Internal IP addresses are leased to individual computers on the network
from a DHCP server. The DHCP server translates information from the IP address provided by
your ISP (this address is programed into your gateway device, i.e. cable or DSL modem) to
the internal addresses provided by the DHCP server. DHCP is useful in homes with several
computers sharing a single high-speed Internet connection.
Ethernet - The common name for the most widely used local area network
(LAN), generally conforming to the IEEE 802.3 Standard.
External Video - A video signal provided by an external source, such as
cable, satellite, or antenna-received broadcast.
F Connector - a 75 ohm connector used to connect coaxial cable to
equipment.
File Server - a station dedicated to providing file and mass data storage
to other stations on the LAN.
Full Duplex - a circuit or device permitting transmission in two
directions at the same time.
Frequency - The number of cycles completed by a signal in one second;
measured in Hertz.
Gateway - A special node that interfaces two or more dissimilar networks,
providing protocol translation between the networks.
GigaHertz - A unit of frequency equal to one billion Hertz.
Ground - A conducting connection, whether intentional or accidental,
between an electrical circuit or equipment and earth, or to some body that serves in place
of the earth.
Half-Duplex - A circuit or device capable of transmitting in two
directions, but not at the same time.
Hertz - A unit of frequency equal to one cycle per second; Hz.
Home-run Cabling - A distribution method in which individual cables are
run directly from a common termination point to each structured wiring outlet. This
configuration is also known as a star topology.
Home Theater - Home entertainment system using television video and
multi-channel audio to more closely approximate a movie theater experience.
Hub - Equipment that serves as the centralized connection point for a
network or portion thereof.
Hybrid Cable - An assembly of two or more cables, of the same or
different types or categories, covered by one overall sheath.
Impedance - The resistance or opposition to the flow of alternating
current within a circuit.
Impedance Matching - Matching impedences of adjoining circuit elements
so that power transfer across the interface is maximized, in order to improve performance
or to accomplish a specific effect.
Insulation Displacement Connection (IDC) - An electrical connection made
by "punching down" a wire in a terminal, which cuts through the insulation to make contact
with the conductor.
Internal Video - A video signal provided by in-home sources such as a DVD
player, VCR, security camera, etc.
Integrated Services Digital Network (IDN) - An integrated digital
network in which the same time division switches and digital transmission paths are used
to established connections for different services such as telephone, data, and fax.
Jack - A device into which a plug is inserted in order to make electrical
contact in a communication circuit.
Local Area Network (LAN) - A data communications network consisting of
host computers or other equipment interconnected to terminal devices, such as personal
computers.
Modem - A modulator/demodulator unit used for data transmission. It
converts digital data into analog tones when transmitting over standard voice-grade
telephone lines and reverses this process when receiving.
Modular Jack - A female interface connector. Modular jacks are
typically mounted in a fixed location.
Modular Plug - A male interface connector.
Modulation - A process by which a message is added to a carrier wave.
Multimedia - Applications which communicate information using more than
one cabling means.
Multiplex - The use of a common physical channel in order to make two or
more logical channels, either by splitting the frequency band (frequency division
multiplexing) or by using this common channel at different points in time (time division
multiplexing).
Multiplexer - MUX; a device allowing two or more signals to pass over and
share a common transmission path.
Network - An interconnection of computers, perpherals, and data/voice
communications facilities.
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.
Outlet - A fixed connecting device where the home-run cable terminates.
Pair - Two wires twisted together with a recprocial color code.
Patch Cable - A length of cable with connectors on one or both ends used
to join links at a cross-connect.
Patch Panel - Connecting hardware that typically provides a means to
connect home-run cabling to an arrangement of fixed connectors that may be accessed using
patch cables to form cross-connections.
Peripherals - Devices used to extend the capability of a computer or
network. These can include printers, scanners, modems, etc.
Private Branch Exchange (PBX) - A telephone switching system, serving one
organization or business, which is connected to the public telephone system.
Pulling Tension - The amount of pull (foot-pounds of tension) placed on
a cable during installation.
Punch Down - A method for securing wire to a quick clip in which the
insulated wire is placed in the terminal groove and pushed down with a special tool
(punch down tool). As the wire is seated, the terminal displaces the wire insulation to
make an electrical connection. The punch down operation may also trim the wire as it
terminates.
Quick Clip - An electrical contact used to provide an insulation
displacement connection to telecommunications cables.
Registered Jack (RJ) - Telephone and data jack applications registerted
with the FCC.
Ring - The negative conductor of a pair in a basic telephone circuit.
RJ-31X - A specialized jack which allows a security system to take
immediate control of a telephone line, even when it is in use.
Rough In - The stage of installation in which boxed are mounted and
cabling is run.
Self Modulating - A video device, such as a security camera, which supplies
video signals to a specified CATV or UHF channel; a seperate modulator is not required.
Service Loop - The slack which should be left at the communications outlet
in a cable run in order to accommodate future needs.
Star Topology - A method of cabling each outlet directly to a cross-connect
in a home-run cabling system.
Statistical Multiplexing - A method of transmitting multiple signals over
a common communication channel by inserting packets of various messages into idle time
slots as they become available.
Telecommunications - Any transmission, emission, or reception of signs,
signals, writings, images, sounds, or information of any nature by cable, radio, visual,
optical, or other electromagnetic systems.
Time Division Multiplexing - An efficient method for using channel
capacity in which each node is allotted a unique time interval, during which it has
exclusive command of the channel and may transmit a message or portion of a message.
Tip - The positive conductor of a pair in a basic telephone circuit.
The tip is grounded.
Topology - The physical or electrical configuration of a local
communications network; the shape or arrangement of the system.
Unshielded Twisted-Pair (UTP) - A cable with multiple pairs of twisted,
insulated copper conductors bound in a single sheath.
Voice-Grade - The type of cabling that supports analog transmission,
but does not adequately meet the needs of digital data transmission.
|
