WiFi channels

Daniel Drake dsd at laptop.org
Fri Nov 6 14:32:55 EST 2009

2009/11/6 John Watlington <wad at laptop.org>:
> The XO-1 supports 802.11b/g channels 1 - 13.
> Is there any reason to believe that we only need
> to support channels 1 - 11 ?
> How does Network Manager handle this ?   How
> does it know that it is in a country where use of
> channels 12 and 13 is allowed ?

This policy is dictated by the driver in the kernel.
The usual approach is that the hardware manufacturer knows the region
of use at manufacturing time, and ships the device with that region
programmed in. The driver asks the device for its region and applies
the usual regulatory rules including allowed TX power and available

libertas does the same through lbs_update_hw_spec() (cmd.c) - the
device responds with a region code which is then looked up in
region_cfp_table (main.c)


More information about the Devel mailing list