User's Manual

Glossary
SpotCell 100, Release 1.0
39
Directional Donor
Unit DDU
This is the SpotCell 100 system element that
is installed with a directional antenna aimed at
the nearest cellular base-station. This unit
may often be installed outdoors. The term
donor is widely used in the repeater industry
for the antenna that supports the air interface
to the network.
Effective Radi-
ated Power
(ERP)
Effective radiated power. It is equal to the sum
of the antenna gain (in dBi) plus the power (in
dBm) into that antenna. For example, a 12
dBi gain antenna fed directly with 15 dBm of
power has an Effective Radiated Power (ERP)
of:
12 dBi + 15dBm = 27 dBm or 500mW.
Franklin Rod Grounded metal Rods that are placed on or
near structures to provide protection against
lightening strikes.
In-Building
Repeaters
These are cellular repeaters that are used to
provide coverage throughout a building, using
multiple antennas or leaky coax to distribute
the signals over different floors. Such systems
are expensive to purchase and install, and
require a significant amount of systems engi-
neering and planning to prevent instability.
These systems are also managed as part of
the cellular infrastructure.
Isolation RF isolation is a measure of the path loss or
attenuation between two antennas. Path loss
typically must be 15dB or higher than the
required system gain for a repeater to function
properly.