User's Manual

226 WatchGuard Firebox X Edge
two 5.1 dBi swivel-mount whip antennas. The whip antenna has a
radiation pattern similar to a sphere that is squashed in the center. If
the antenna points up, the gain is largest in the horizontal direction
and less in the vertical direction.
Signal attenuation
Signal attenuation refers to the loss of signal power. It can be
caused by multi-path reflection. Multi-path reflection occurs when
RF signals that come to the receiver must move along more than
one path because of walls and other surfaces between the transmit-
ter and the receiver. It changes based on the phase at which the sig-
nals come, but signal strength can be increased or decreased by as
much as 30dB.
To decrease the effect of multi-path reflection, the Firebox X Edge
Wireless uses two antennas spaced some distance apart. This
decreases signal cancellation and allows the software to find the
best antenna to receive and transmit as conditions change.
Wireless clients usually have one antenna and are more sensitive to
the effects of antenna location. Because of this, the Firebox X Edge
e-Series Wireless can receive signals from a wireless client even if the
client does not receive signals from the Firebox X Edge.
Channel data rate
Channel data rate changes with the modulation type, which changes
based on conditions including noise and the distance between
transmitter and receiver. In general, the available data rates for an
IEEE 802.11g/b device change from 1 Mbps in the worst conditions
to 54 Mbps in the best conditions