User's Manual

Compliance with radio regulations
Reference information
4-16
pmp-0047 (June 2013)
DFS for 5.4 GHz Radios
Dynamic Frequency Selection (DFS) is a requirement in several countries and regions for 5 GHz unlicensed
systems to detect radar systems and avoid co-channel operation. DFS and other regulatory requirements drive the
settings for the following parameters, as discussed in this section:
 Country Code
 Primary Frequency
 Alternate 1 and Alternate 2 Frequencies
 External Antenna Gain
On the AP, the Home => DFS Status” page shows current DFS status of all three frequencies and a DFS log of past
DFS events.
Figure 27 AP DFS Status
Background and Operation
The modules use region-specific DFS based on the Country Code selected on the module’s Configuration, General
page. By directing installers and technicians to set the Country Code correctly, the operator gains confidence the
module is operating according to national or regional regulations without having to deal with the details for each
region.
Some regions have requirements to avoid certain 5.4-GHz frequencies used by some weather radar. To meet this
requirement, modules set to Europe will display the center channel frequencies shown in
Table 41 Center channel details based on Country Code, 2.4-GHz