Basic Cell Planning
Basic Cell Planning
Normally, a sufficient number of channels are available to plan the cells for frequency reuse at a
distance large enough to limit the effects of co-channel interference.
2.4 GHz
IEEE 802.11 operation in the 2.4 GHz band only provides the use of three non-overlapping chan-
nels, channel 1, 6, and 11. The use of other channels has a negative impact on the performance
in the system since those channels interfere with each other. The usage of channels other than
1, 6, and 11 cause a performance reduction. This is not only due to RF interference, but also due
to the protocol specification.
NOTICE:
The use of 802.11n 40 MHz double channels is not recommended
since the amount of channels are reduced to only two (ETSI) or one (FCC).
5 GHz
In the 5 GHz band there are plenty of non-overlapping channels to choose from. The specific us-
age and amount of channels that can be used varies with country regulations. The support of the
802.11d in an AP and in the handset automatically adjusts the usage to the so-called regulatory
domain.
NOTICE:
802.11d is not allowed in the US.
The 5 GHz band consists of several sets of channels listed in the table below. See also
Radar Protection in DFS Channels
on page 7.
NOTICE:
If using even wider 802.11ac channels, the number of available chan-
nels is further reduced.
Radio
ETSI
FCC
2.4GHz, 802.11b/g/n 20MHz
3
3
5GHz, 802.11a/n 20MHz
4 + 15 (DFS)
9 + 12 (DFS)
2.4GHz, 802.11n 40MHz
2
1
5GHz, 802.11n 40MHz
2 + 7 (DFS)
4 + 5 (DFS)
NOTICE:
For examples on channel placing layouts refer to the manufacturers
planning documentation.
NOTICE:
Using 40/80/160 MHz channels reduces the number of non-DFS chan-
nels. Make sure that all non-DFS channel are used before adding DFS channels.
Multi-cell System
For a multi-cell system based on 802.11 the following factors affects the cell planning:
• Coverage
• Capacity
A31003-M2000-P103-01-76A9, 29/04/2020
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System Planning, Planning Guide
