User`s guide

BreezeNET DS.11 Series User’s Guide
C-8
Signal Fading
Fading of the RF signal is caused by several factors:
♦ Multipath
The transmitted signal arrives at the receiver from different
directions, with different path lengths, attenuation and
delays. The summed signal at the receiver may result in an
attenuated signal.
Figure C-6: Multipath Reception
♦ Bad Line of Sight
An optical line of sight exists if an imaginary straight line
can connect the antennas on either side of the link.
Radio wave clear line of sight exists if a certain area around
the optical line of sight (Fresnel zone) is clear of obstacles. A
bad line of sight exists if the first Fresnel zone is obscured.
♦ Distance
♦ Weather conditions (rain, wind, etc.)
At high rain intensity (150 mm/hr), the fading of an RF
signal at 2.4 GHz may reach a maximum of 0.02 dB/Km.
Wind may cause fading due to antenna motion.