User Manual Part 2

Lynx.GX Installation and Management
dBm
Used to define signal strength in wires and cables at radio and
audio frequencies. The symbol is an abbreviation for "decibels
relative to one milliwatt," where one milliwatt (1 mW) equals
1/1000 of a watt (0.001 W or 10
-3
W).
elevation
See azimuth.
ERP
Effective Radiated Power. The product of the power supplied to
the antenna and its gain relative to a half-wave dipole in a given
direction.
DC
Direct Current
fade margin
Difference between the actual received signal level and the
radio’s threshold.
DCE
Distributed Computing Environment. An industry-standard
software technology for setting up and managing computing and
data exchange in a system of distributed computers.
FCC
Federal Communications Commission.
demux
De-multiplexer
FEC Forward Error Correction.
Forward Error Correction is a coding scheme used to improve
the performance of digital signal transmission. It utilizes a
mechanism for correcting bits that may otherwise be received
incorrectly.
diffraction
The apparent bending of light waves around obstacles in its
path.
digital
Electronic technology that generates, stores, and processes data
in terms of two states: positive and non-positive.
Fresnel Zone
Parabolic areas around the visual line-of-sight that define the
even and odd reflection points where multipath signals will either
be constructive or destructive to the radio waves. Based on the
frequency of the signal, the Fresnel zones help define the proper
antenna heights to establish ideal path clearance for optimum
signal reception.
diplexer
Combines signals so only one coaxial wire needs to be run.
dipole antenna
A straight electrical conductor measuring ½ wavelength from end
to end and connected at the center to a radio-frequency feed
line.
FTP
File Transfer Protocol. A standard Internet protocol; the simplest
way to exchange files between computers on the Internet.
direct current
DC (Direct current) is the unidirectional flow or movement of
electric charge carriers, usually electron.
gain
A ratio, expressed in decibels, of the action of an antenna
increasing the strength of a signal.
DTE
Data Terminal Equipment. In computer data transmission, the
RS-232C interface that a computer uses to exchange data with a
modem or other serial device.
GPS
Global Positioning System. Lets you ascertain your location
anywhere on earth.
HD
High Density.
duplex
Duplex communication means that both ends of the
communication can send and receive signals. Full duplex
communication is where this happens simultaneously. Half
duplex is also bidirectional communication, but signals only flow
in one direction at a time.
heatsink
A device that is attached to a microprocessor chip to keep it from
overheating by absorbing its heat and dissipating it into the air.
Most heatsinks are aluminum and have "fins" that extend from
the base.
DVM
Digital Volt Meter.
hertz
The unit for expressing frequency, ( f ). One hertz equals one
cycle per second.
E1
E1 (or E-1) is a European digital transmission format devised by
the ITU-TS and given the name by the Conference of European
Postal and Telecommunication Administration (CEPT). It is the
equivalent of the North American T-carrier system format.
HTTP
Hypertext Transfer Protocol. The set of rules for exchanging
files (text, graphic images, sound, video, and other multimedia
files) on the World Wide Web.
The E1 signal format carries data at a rate of 2.048 million bits
per second and can carry 32 channels of 64 Kbps each. E1
carries at a somewhat higher data rate than T-1 (which carries
1.544 million bits per second) because, unlike T-1, it does not do
bit-robbing and all eight bits per channel are used to code the
signal. E1 and T-1 can be interconnected for international use.
HyperTerminal
A program that you can use to connect to other computers,
Internet telnet sites, bulletin board systems (BBSs), online
services, and host computers, using either your modem or your
network card.
EIA
Electronic Industries Association. Comprises individual
organizations that together have agreed on certain data
transmission standards such as EIA/TIA-232 (formerly known as
RS-232).
IDU
Indoor Unit.
IF
Intermediate Frequency.
IP
Internet Protocol. The method or protocol by which data is sent
from one computer to another on the Internet. Each computer
(known as a host) on the Internet has at least one IP address
that uniquely identifies it from all other computers on the Internet.
EIRP
Effective Isotropic Radiated Power. The product of the power
supplied to the antenna and the antenna gain in a given direction
relative to an isotropic antenna.
Acronyms / Glossary 104