WiFi channels

John Watlington wad at laptop.org
Fri Nov 6 14:55:41 EST 2009


On Nov 6, 2009, at 2:32 PM, Daniel Drake wrote:

> 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
> channels.
>
> 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)

How is the region programmed in ?   With Libertas, the firmware comes
from the OS.   Does libertas on XO-1 ever respond with a different  
code ?
I do believe that the hardware supports channels 1 - 13 but don't  
think we
ever changed the region code, limiting us to 11.

wad



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