Fujitsu Laptop User Manual page 85

The set channel for the station is different from those which can be
used by this computer.
Countermeasure
Set the channel of station within the range of 1~11. For the method of setting, refer to the station manual.
Unreachable electric wave due to poor condition of electric wave
Countermeasure
In case of ad hoc connection, retry connection after shortening the distance to the destination computer
or removing any obstacle for better sight. In case of infrastructure connection, retry connection after
shortening the distance to the station or removing any obstacle for better sight.
Active channel duplication due to multiple wireless LAN networks on
the same floor, etc.
Countermeasure
If there is any other wireless LAN network nearby, change channels to avoid active channel duplication.
The computer to be connected with is turned OFF
Countermeasure
Check if the computer to be connected is turned ON.
No right of access to the network to be connected with
Countermeasure
Check if you have a right of access to the network to be connected with.
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