User Guide

NETNode Operations Guide
Commercial in
Confidence
IP Mesh Systems
000-130
R1.8 2015-07-24
Commercial in
Confidence
Page 6-104
A
Means…
Antenna
An antenna (or aerial) is a transducer designed to radiate or
receive electromagnetic energy (generally RF).
Antenna Bandwidth
The frequency range over which a given antenna will accept
signals.
Antenna Gain
The effectiveness of a directional antenna as compared to a
standard non-directional antenna. It is usually expressed as the
ratio in decibels of standard antenna input power to directional
antenna input power that will make the same field strength in the
wanted direction. For a receiving antenna, the ratio of signal
power values produced at the receiver input terminals is used. The
more directional an antenna is, the higher is its gain.
Attenuation
Power loss resulting from conductor resistance and dielectric loss
in the insulating material used to isolate the conductors.
B
Means…
BNC
Bayonet Neill-Concelman – A very well-known type of RF
connector used for terminating coaxial cable.
Bandwidth
The width of a band of frequencies used for a function.
C
Means…
COFDM
Coded Orthogonal Frequency Division Multiplexing is a
frequency-division multiplexing (FDM) scheme utilized as a digital
multi-carrier modulation method. A large number of closely-spaced
orthogonal sub-carriers are used to carry data.
D
Means…
D/C
Downconverter. A device which changes microwave frequencies to
UHF frequencies for operation in Cobham receivers.
Digital
A digital signal is a discontinuous signal that changes from one
condition to one more condition in discrete steps.
Decibel
The standard unit used to express transmission gain or loss and
relative power levels. Also written as dB.
Decoder
Processor in a video receiver that changes digital video data to
analogue signals for replay on analogue monitors; or in some
cases a software decoder, a program that decodes digital data for
replay on the PC (decompression etc.).