It was, however, the First, the problem with the reinforced concrete walls and the fact that there were only Windows drivers are available for all previously purchased WLAN sticks. This meant that went permanently lost the connection and the driver running in this case only on Linux in a wrapper, adopted -> computer must be restarted.
This Wi-Fi stick of CSL but also runs under Linux / Ubuntu with correct, native drivers and the antenna brings at least a ~ 90% signal strength.
The connection will now cancel no longer apparent reason and it can hardly be slowdowns notice.
Strong buy recommendation.