ubuntu-phone team mailing list archive

[Michał Łazowik <mlazowik@xxxxxx>]

Hi,

Wiadomość napisana przez Sayantan Das <sayantan13@xxxxxxxxx> w dniu 1 wrz 2013, o godz. 11:39:

> Hi all,
> 
> Was wondering why channel13 is not available for ubuntu touch. It doesnt scan any wifi network on channel 13.
> 
> root@ubuntu-phablet:/# iwconfig wlan0 channel 13  
> Error for wireless request "Set Frequency" (8B04) :
>     SET failed on device wlan0 ; Invalid argument.
> 
> I have tested two routers- the phone is unable to pick signal from either of them. If I change the channel to any other than 13, it connects. I am testing using Nexus 4.

That's most probably related to region-related (legal) wifi restrictions. They include both the maximum
power of signal _and_ allowed channels. Wikipedia [0] says that for North America channel 13 is not
allowed.

To accomodate legal needs of different regions without creating region specific hardware, the limiting
is done through software. The general way to change that in linux is by using iw reg [1], though
in ubuntu it might be also related to some localization settings. Either way iw reg set should
get you going.

Michał

[0] https://en.wikipedia.org/wiki/List_of_WLAN_channels#Interference_Concerns
[1] http://wireless.kernel.org/en/users/Documentation/iw#Updating_your_regulatory_domain