Antenna Diversity - Alvarion BreezeNET PRO.11 Series User Manual

6. Synchronize the units by aligning the antennas manually until the WLNK
indicator LED on the front panel of the wireless Bridge and/or Station Adapter
illuminates.
7. Align antennas at the main and remote sites until maximum signal quality is
obtained. (Check QLT LEDs on the front panel of the Station Adapter and the
wireless Bridge.)
If the received signal quality is lower than expected for this antenna/range
combination, change antenna height and verify RF cables connections.

5.3.3.4 Antenna Diversity

In applications where no multipath propagation is expected, a single antenna is
sufficient to ensure good performance levels. However, in cases where multipath
propagation exists, BreezeCOM recommends that two antennas be used. This takes
advantage of space diversity capabilities. By using two antennas per unit, the
system can select the best antenna on a per-packet basis (every several
milliseconds).
Multipath propagation is to be expected when there are potential reflectors between
the main and remote sites. These reflectors may be buildings or moving objects
such as airplanes and motor vehicles. If this is the case, the radio signal does not
travel in a straight line, but is reflected or deflected off of the object, creating
multiple propagation paths.
When installing a single antenna, modify the transmit diversity option to either
antenna 1 or antenna 2, according to the antenna being used (refer to Section 3.4.3).
5.3.3.5 Antenna Polarization
Antenna polarization must be the same at either end of the link. In most
applications, the preferred orientation is vertical polarization. Above-ground
propagation of the signal is better when it is polarized vertically. To verify antenna
polarization, refer to the assembly instructions supplied with the antenna set.
BreezeNET PRO.11 Series
Planning and Installing Wireless LANS
5-19
User's Guide