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BPS (Bits Per Second) :
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The rate of
information bits transmit ted. The basic unit of data communications rate,
very often combined with metric prefixes, such as kbps for thousands of
bits per second and mbps for millions of bits per second.
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Bridge :
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The
interconnecting equipment and techniques used to match circuits to each
other ensuring minimum transmission impairment. Bridges function at the
data link layer of the OSI model. Contrast with gateway.
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Buffer :
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A temporary
storage device for blocks of data used to compensate for the difference in
either the rate of data flow or the time of occurrence of the events in
transmissions between devices.
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Byte :
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Some set of
contiguous bits operated upon as a single unit, usually six or eight bits
long. Most character sets use one byte per character, with storage device
capacity usually spoken of in K bytes (K = 1024 bytes) and M bytes (M =
mega, or million bytes).
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Cable :
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The
combined assembly of one or more conductors within a protective sheath and
constructed to permit the use of conductors separately or in groups
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Cable-Based LAN :
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A local
area network (LAN) that uses a coaxial or twisted pair cable as its
transmission medium.
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Coaxial Cable (Coax) :
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A
two-conductor wire transmission medium known for its wide bandwidth and
negligible susceptibility to crosstalk and distortion, since signals are
transmitted in a fully enclosed environment.
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Code :
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A system of
unambiguous rules and symbols for use in representing data, such as ASCII
and EBCDIC
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CODEC :
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device that
codes and de codes analog voice signals into and from digital signals. A
neologism of "COder" and "DECoder".
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Digital Switching :
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A process
whereby a connection is established and maintained through program control.
Digital information is routed between input and output.
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Digital Transmission :
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The direct
transmission of discrete pulses as opposed to analog transmission.
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Discrete Access :
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An access
method found in LAN environments using a star topology, wherein each
station has its own separate connection to maximize the LAN's switching
capabilities.
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Duplex Transmission :
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The
simultaneous, independent, 2-way transmission of data in both directions.
Contrast with "half- duplex transmission".
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Error :
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A term used
to describe a deviation from the expected, especially if data integrity is
jeopardized.
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Error Rate :
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The measure
of data integrity given as the blocks, bits or characters incorrectly
received, versus the number transmit ted. Error rate is sometimes seen as a
rate of one error every one million bits.
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Ethernet :
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The de
facto standard LAN of the Xerox corporation and later sponsored also by DEC
and Intel Corp. Characterized by 10 m bps baseband transmission using
CSMA/CD, Ethernet uses coaxial cable and is similar to the standard LAN
recommended by IEEE 802.3.
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Ground Station :
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Also known
as an earth station, a ground station is designed to send (transmit) and
receive signals to and from a communications satellite.
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IC (Integrated Circuit) :
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Also known
as a microchip, and as a semiconductor device, an IC performs numerous
functions in data processing such as processing, data storage and program
storage.
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IEEE :
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(Institute
of Electrical and Electronic Engineers) - An international institute that
issues its own standards and is a member of ANSI and ISO, perhaps best
known for its development of IEEE Project 802.
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Impulse Noise :
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A
communications line interference caused by electrical action, lightning,
on/off movement of switching equipment, etc., and appearing as high
amplitude and short duration.
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Infrared :
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A method of
data transmission using infrared light to transmit data on fiber optic
medium or open-air transmission over short distances.
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Interface :
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Two related
definitions exist in common computer usage: 1) A common boundary or
connection defined by identical signal and physical inter connection
characteristics and their meanings. 2) The necessary equipment needed to
provide a shared boundary connection.
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Internetwork Router :
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A Local
Area Network (LAN) device used for communications between sub networks,
transmit ting only the messages for the correct sub network. Inter network
routers function within the network layer of the OSI model.
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Interrupt :
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A device
generated signal notifying the CPU that it needs its assistance. Such a
signal may arise from either software or hardware and is usually task
oriented.
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ISO :
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(International
Standards Organization) - The International, voluntary standards
organization, closely aligned with the CCITT perhaps best noted for its OSI
model and OSI communications protocol. Membership includes other
international organizations issuing standards, with ANSI being the American
representative.
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kbps :
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(Kilo Bits
Per Second) - Thousands of bits per second (BPS) equal to 10 to the third
power.
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Keying :
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A method of
encoding data by modulating the carrier either by phase or frequency.
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kHz (kilo Hertz) :
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Abbreviation
for 1000 Hertz (cycles per second).
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