Cambium PTP 450 series, User Manual

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PMP 450 Configuration and User Guide Glossary
ptp-450 (July 2014)
4-125
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 BHM, the Home => DFS Status page shows current DFS status of all three frequencies and a DFS
log of past DFS events.
Figure 27 BHM 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 certain channel frequencies on the BHM’s
Carrier Frequency pop-up and on the BHS’s Frequency Scan Selection List.
Details of DFS operation and channels available for each Country Code including whether DFS is active on
the BHM, BHS, which DFS regulation applies and any channel restrictions are shown in Table 57 on page
4-126 . DFS does not apply to 4.9 GHz.