User's Manual

Basic Installation
BreezeACCESS II Series 4 SU-R Installation Manual
• Keep the units well away from sources of heat, such as radiators, air-conditioners, etc.
2.4.2 Location of the Antenna
• Any physical object in the path between two units can cause signal attenuation. Common
obstructions are buildings and trees. If a unit’s antenna is installed indoors, the walls and/or
windows between the two sites are physical obstructions. If the antenna is positioned
outdoors, any buildings or other physical structure such as trees, mountains or other natural
geographic features higher than the antenna and situated in the path between the two sites can
constitute obstructions.
• Install indoor antennas as close as possible to a window (or wall if a window is not
accessible) facing the required direction. The UNI-7 antenna may also be attached to a fixed
window. Avoid metal obstacles such as metal window frames or metal film anti-glare
windows in the transmission path. Install outdoor antennas high enough to avoid any obstacles,
which may block the signal.
• Position the antennas clear of metal furniture and away from moving metal objects such as
metal fans or doors.
2.4.3 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 Access
Unit and Subscriber Units. 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.
2.4.4 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. For integral omni antennas (A model), make sure that the antennas are