User Manual

AirLink VoiceXtender VX64 Modem Installer’s Guide
Glossary
Rev. A - 8/97 C-3
Hub Configuration A system configuration in which several master AirLinks and
terminals are co-located. Usually, one acts as the synchronizing
modem to the others at the site.
Indicator A device that emits a visible light on the front of the AirLink
modem.
Line-of-Sight An unobstructed view from the transmit antenna to the receive
antenna.
Master Modem The master modem is the modem which controls the slave
modem. The master modem always transmits the initial burst to
which the slave modem must respond. The master modem is the
only modem capable of initiating any activity on its own.
Modem An acronym for MOdulator - DEModulator. A device used to
convert digital signals into a form suitable for long distance
transmission, and to reconvert received signals.
Omnidirectional Antenna An antenna with a radiation pattern that is the same in all
horizontal directions.
Over Sampling The process of sampling a signal at a higher than the minimum
acceptable rate to ensure greater accuracy.
Overlapping Channels A situation in which the operating channel frequency bandwidth
of one transmitting device shares part of the frequency
bandwidth of another transmitting device.
Path Loss The total amount of radio signal attenuation (loss) between the
transmitting antenna and the receiving antenna; the sum of
attenuation caused by obstacles located in the path and the free
space path loss.
Point-to-Point
Configuration
A system configuration in which only one master modem
communicates with its one slave modem between the two sites.
Point-to-Multipoint
Configuration
A system configuration in which one master modem communicates
with one or more slave modem.
Pseudo-Random Noise
Sequence
An operation in which a random stream of data bits is generated
within limited parameters. The stream (sequence) is typically
used for encoding data for communication.
Receiver Sensitivity The measure of the ability of a receiver to differentiate between
the selected signal and background noise for a specific
performance.