In LANconfig you access the DFS settings under , then click Physical WLAN settings and select the Radio tab.
- Time of DFS rescan
- This entry determines at what time (0 - 24h) the device deletes the DFS database and performs a DFS rescan. If this item is
left empty, the device only performs a DFS rescan when no further free channel is available. This is the case when the number of
channels determined during the initial DFS scan falls below the minimum number of free channels.
Tip: The cron command options can be used to define the time: The entry '1,6,13' starts the rescan at 01:00h, 06:00h and 13:00h. The entry ' 0-23/4 ' starts a rescan every four hours between 00:00h and 23:00h.
- Number of channels to scan
- This entry determines the minimum number of free channels that a DFS scan has to achieve. The default value of '2' means that the device performs a DFS scan for as long as it takes to detect 2 free channels. If the device has to switch channels, for example if it detects an active radar pattern, the second channel is immediately available for the change. A value of '0' disables the restriction. The physical WLAN interface performs a DFS scan on all available channels.
- Rescan free channels
- With this item you select whether, following the completion of a DFS rescan, the physical WLAN interface deletes occupied
channels or saves them for subsequent DFS rescans.
- Yes: The physical WLAN interface deletes occupied channels after completing a DFS rescan so that they are available again for a new DFS rescan.
- No: The device saves occupied channels after completing a DFS rescan and so that the device immediately skips them during a new DFS rescan.
You can select a preference for certain channels. LCOS is trying first, whether a channel set in Channel number can be used, then it tries the channel set in the Channel list through the channels listed. If all these channels are not available due to radar detection, then the possible channels for the selected country will be tried.
After the DFS locking time has elapsed, an attempt is made to switch back to the set channel. If this channel is still not available, a channel configured in the channel list is used. The DFS blocking time becomes effective as soon as a channel is blocked due to radar detection and it is usually 30 minutes.
This preference helps to be able to use fixed channel schemes in 5 GHz, because this allows the full channel scheme to be restored faster after DFS events.
If no dedicated channel is configured for the WLAN module (channel list empty and radio channel "0" or "Automatic"), then after a channel change triggered by radar detection, the new channel is retained and not changed to the last channel used.
