User's Manual

PN 8100-40 Help Hot Line (U.S. only): 1-800-530-9960 7-27
620004-0 Rev. B
Estimating RF Coverage
sq. meters (60,719 sq. ft.) per RAU (see Section 7.2.1 for details on path loss esti-
mation). For this case we assumed a circular radiation pattern, though the actual
area covered will depend upon the pattern of the antenna and the obstructions in the
facility.
If the area to be covered is essentially an unobstructed hallway with some cover-
age for the offices on either side of the hallway, a more aggressive design using a
lower PLS should be used.
6. Equipment Required: Since you know the building size, you can now estimate
the LGCell equipment quantities that will be needed. Before any RF levels are
tested in the building, you can estimate that 2 antennas per level will be needed.
a. 2 antennas per floor × 8 floors = 16 RAUs
b. 16 RAUs ÷ 4 (max 4 RAUs per Expansion Hub) = 4 Expansion Hubs
c. 4 Expansion Hubs ÷ 4 (max 4 Expansion Hubs per Main Hub) = 1 Main Hub
Check that the MMF and Cat-5 cable distances are as recommended. If the dis-
tances differ, use the tables in Section 7.3, “System Gain,” on page 7-28 to deter-
mine 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
LGCell equipment quantities required for the building. The site survey measures the
RF losses within the building to determine the actual PLS, which will be used in the
final path loss formula to determine the actual requirements of the LGCell.