Basic Cell Planning
• Roaming
• Noise interference
The wireless cell planning is done using an AP placement tool which estimates the placement of
APs based on the building/campus characteristics. It is recommended that a site survey is done
using the built-in tools in the handset. The tool provides a true measurement of the RF environ-
ment based on the radio of the handset. Other wireless analyzers can be used to provide addi-
tional assistance during a site survey.
To avoid short disruptions/delays in voice calls, the basic approach to cell planning is to have
sufficient overlap between adjacent cells, see
Figure 3: Cell overlap between adjacent cells
on
page 15. This is done in order to ensure that sufficient radio signal strength is present during
a handover between the cells.
For other types of data traffic than voice, provided that there is adequate coverage, the cell plan-
ning can be a bit relaxed without affecting the user experience.
Figure 3: Cell overlap between adjacent cells
The distance between the APs is often a trade-off between the amount of APs and the coverage.
To make up for fading effects in an indoor office environment it is recommended that the radio
signal strength at the cell coverage boundary does not drop below -70 dBm. The APs should be
placed to overlap their boundaries by approximately 6–10 dB.
This means that when the STA reaches a point where the RSSI is -70 dBm, the STA is also in-
side the adjacent cell and the RSSI from that AP is between -60 to -64 dBm. For information on
distance attenuation and attenuation in construction materials, see
on page 16.
The recommendations above ensure a fading margin of approximately 20 dB, which should be
appropriate for “normal” environments.
NOTICE:
The illustration in
Figure 3: Cell overlap between adjacent cells
page 15 is valid when all APs’ transmission power are configured to 100 mW
A31003-M2000-P103-01-76A9, 29/04/2020
System Planning, Planning Guide
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