MA REV A
7
INSTALLATION
Pre-installation Survey
Note:
The Installer should refer to the
Safety Precautions,
in the
following section, for proper antenna selection and installation
A pre-installation survey should be performed prior to commitment to installation. Measurement of
Received Signal Strength Indication (RSSI) should be recorded throughout the building in all areas
where cell phone coverage is desired. RSSI levels around the exterior of the building as well as on the
rooftop or as close to the point where the exterior antenna will be installed should also be recorded.
RSSI readings at the position where the outside antenna will be installed should be greater than –90
dBm. (E.g. –85dBm) Successful installations may be made with lower readings in some cases.
The exact location of the proposed outside antenna should be measured with a GPS
unit and the coordinates of the cell sites closest to the building in which the system is
being installed should be obtained. With these coordinates the distance and bearing
to each of the local cell sites can be computed and made available to the installation
team. The first choice should be the closest site unless there is blockage in the form
of buildings or terrain between the building and this cell site. If blockage exists an
alternate site may be available.
If GPS coordinates are not available there is an alternative method of locating the
dominant site: connect a handset via SMA female to N male adapter to the
directional donor antenna. Rotate the antenna until maximum RSSI and SQE
readings are obtained and secure it.
The location of the IBA and the interior antennas should be determined through the
use of floor plans of the building in which the system is to be installed. It is important
to locate the IBA at a central location and try to keep the coax runs from the amplifier
to the antennas as short as possible. A maximum length of 150 feet is suggested
although longer runs might be accommodated. This assumes that a coax with loss at
4.0
!!!!
WARNING!
AMPLIFIER DAMAGE
WILL
OCCUR IF A HANDSET IS
CONNECTED DIRECTLY TO THE IBA OR THE COAX THAT
LEADS TO THE IBA.
