Antenna Diversity; Antenna Polarization; Antenna Seal; Cell Size - Alvarion BreezeNET DS.11 User Manual

2.6.5 Antenna Diversity

In applications where no multipath propagation is expected, a single antenna is
sufficient for good performance levels. However, in cases where multipath
propagation exists BreezeCOM recommends using two antennas in order to utilize
the space diversity feature. 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 page 3-18).

2.6.6 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.

2.6.7 Antenna Seal

When using outdoor antennas, you must seal unused antenna connectors against
rain with the antenna connector seals provided with the unit. The antenna cable
connectors must be sealed against rain.

2.6.8 Cell Size

Cell size is determined by the maximum possible distance between the BU-DS.11
and the RB-DS.11 unit, usually related to point-to-multipoint installations using
external antennas. For open outdoor areas with an unobstructed line of sight
between the BU-DS.11 and the RB-DS.11 units, the suggested maximum distance
BreezeNET BU-DS.11/RB-DS.11
2-9
Installation
User's Guide