AP Placement for Optimal Performance
AP Placement for Optimal Performance
There is a contradiction between the two essential requirements for optimal AP placement. Good
performance requires good coverage, but “over-coverage” reduces the performance.
As described in
on page 14, enough overlap between adjacent cells is need-
ed to have sufficient radio signal strength at all places and enough margin when roaming be-
tween cells. However, the co-channel interference problem, described in
on page 18, is reduced by increasing the distance between APs working on the same
channel.
This means that for every unique combination in the cell planning, these two requirements must
be proved against each other to obtain the optimal placement.
The AP distance to avoid co-channel interference is described in
on page 18. The CCA does not introduce any transmission interrupts if the APs or STAs are
separated to -76 dBm. However, if two APs on the same channel are transmitting at the same
time, the handset requires the interfering signal to be attenuated at least 15 dB compared to their
“own” signal.
Different systems have different RF characteristics in terms of co-channel interference suppres-
sion, adjacent channel rejection, and clear channel assessment. This might have some effect,
and different systems behave differently with the same set-up.
It is important not only to think of coverage but also on people’s moving patterns, and place the
APs so it gives coverage around corners, along walking paths, and through thick doors. For opti-
mal coverage around corners, it is recommended to place an AP in the crossroad, see
Recommended placement of AP to receive coverage around corners
on page 21.
Figure 6: Recommended placement of AP to receive coverage around corners
A31003-M2000-P103-01-76A9, 29/04/2020
System Planning, Planning Guide
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