Estimating RF Coverage
6-22
InterReach Unison Installation, Operation, and Reference Manual
CONFIDENTIAL
D-620003-0-20 Rev J
6.
Equipment Required
: Since you know the building size, you can now estimate
the Unison equipment quantities needed. Before you test any RF levels in the
building, you can estimate that four antennas per level will be needed. This
assumes no propagation between floors. If there is propagation, you may not need
antennas on every floor.
a.
4 antennas per floor × 16 floors = 64 RAUs
b.
64 RAUs ÷ 8 (maximum 8 RAUs per Expansion Hub) = 8 Expansion Hubs
c.
8 Expansion Hubs ÷ 4 (maximum 4 Expansion Hubs per Main Hub) = 2 Main
Hubs
Check that the fiber and Cat-5/5E/6 cable distances are as recommended. If the
distances differ, use the tables in Section 6.3, “System Gain,” on page 6-23 to
determine system gains or losses. The path loss may need to be recalculated to
assure adequate signal levels in the required coverage distance.
The above estimates assume that all cable length requirements are met. If Expansion
Hubs cannot be placed so that the RAUs are within the distance requirement, addi-
tional Expansion Hubs may need to be placed closer to the required RAUs locations.
An RF Site Survey and Building Evaluation is required to accurately establish the
Unison equipment quantities required for the building. The site survey measures the
RF losses within the building to determine the actual PLS, used in the final path loss
formula to determine the actual requirements of the Unison system.
