Rockwell Automation 1783-WAPxxx Stratix 5100 Wireless Access Point User Manual - Manual (Page 259)

Rockwell Automation Publication 1783-UM006A-EN-P - May 2014 259
Configuring Radio Settings Chapter 7
*Mar 6 12:35:09.750: %DOT11-6-DFS_TRIGGERED: DFS: triggered on
frequency 5500 MHz
When radar is detected on a channel, that channel can not be used for 30
minutes. The access point maintains a flag in nonvolatile storage for each channel
that it detects radar on in the last 30 minutes. After 30 minutes, the flag is cleared
for the corresponding channel. If the access point is restarted before a flag is
cleared, the non-occupancy time is reset to 30 minutes when the channel
initializes.
Radar Detection on a DFS Channel
When an access point detects a radar on a DFS channel, the access point creates a
file in its flash memory. The file is based on the 802.11a radio serial number and
contains the channel numbers where the radar is detected. This is an expected
behavior and you can not remove this file.
CLI Commands The following sections describe CLI commands that apply to DFS.
Confirming that DFS is Enabled
Use the show controllers dot11radio1 command to confirm that DFS
is enabled. The command also includes indications that uniform spreading is
required and channels that are in the non-occupancy period due to radar
detection.
This example shows a line from the output for the show controller
command for a channel where the DFS is enabled. The indications listed in the
previous paragraph are shown in bold:
ap#show controller dot11radio1
!
interface Dot11Radio1
TIP The maximum legal transmit power is greater for some 5 GHz channels than
for others. When it randomly selects a 5 GHz channel where the power is
restricted, the access point automatically reduces transmit power to comply
with power limits for that channel.
TIP We recommend that you use the world-mode dot11d
country-code configuration interface command to
configure a country code on DFS-enabled radios.
The IEEE 802.11h protocol requires access points to include the country
information element (IE) in beacons and probe responses. By default, however,
the country code in the IE is blank. You use the world-mode command to
populate the country code IE.