47
Avoiding WLAN Channels with DFS
The FRITZ!WLAN USB Stick N loses the WLAN connection
in the 5-GHz frequency band for no apparent reason.
8.4
Checking the IP Settings
A WLAN access point, for instance, a FRITZ!Box WLAN, has
its own DHCP server, which assigns IP addresses to the
connected computers. For this the computers must be
configured to obtain an IP address automatically from the
DHCP server of the access point. The steps for checking
and adjusting this option differ among the operating sys-
tems. See the relevant section for your operating system.
Obtaining an IP Address Automatically in Windows 7
Proceed as follows in Windows 7:
1.
Click the “Start” button in the task bar and select the
“Control Panel / Network and Internet”.
2.
Under “Network and Sharing Center”, click “View net-
work status and tasks”.
3.
From the left column, select the “Change adapter set-
tings” command.
4.
Click the “Wireless Network Connection” icon with
the right mouse button and select “Properties”.
5.
Under “This connection uses the following items”,
select the “Internet Protocol Version 4 (TCP/IPv4)”
entry and click the “Properties” button.
Possible Cause
In the 5-GHz band the access point is programmed to
change the channel whenever a radar source transmits
on the same channel (DFS: Dynamic Frequency Selec-
tion).
Remedy
A forced channel change can be avoided by selecting a
channel on the access point that does not use DFS
(channels 36, 40, 44, 48).