Using Dynamic Frequency Selection (Dfs) On Access Points - Cisco 7925G Deployment Manual

Using Dynamic Frequency Selection (DFS) on Access Points

For Cisco Autonomous Access Points, select Dynamic Frequency Selection (DFS) to use auto channel selection.
When DFS is enabled, enable at least one band (bands 1-4).
For Cisco Unified access points, enable Auto RF unless there is an intermittent interferer in an area, which select access points
can have the channel statically assigned.
If there are repeated radar events detected by the access point (just or falsely), determine if the radar signals are impacting a
single channel (narrowband) or multiple channels (wideband), then potentially disable use of that channel or channels in the
wireless LAN.
The presence of an AP on a non-DFS channel can help minimize voice interruptions.
In case of radar activity, have at least one access point per area that uses a non-DFS channel (UNII-1). This ensures that a
channel is available when an access point's radio is in its hold-off period while scanning for a new usable channel.
For Cisco Autonomous Access Points, enable band 1 only which allows the access point to use only a UNII-1 channel.
For Cisco Unified access points, can manually select a UNII-1 channel (channels 36, 40, 44, 48) for the desired access points.
A UNII-3 channel (5.745 - 5.805 GHz) can optionally be used if available.
In this diagram, 5 GHz cells use a non-DFS channel while other nearby cells use DFS channels to permit maximum call
capacity under all conditions.
Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Deployment Guide
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