802.11a/n

Ed W lists
Thu Aug 18 02:31:05 PDT 2011


On 17/08/2011 19:29, Grant wrote:
>>> What a drag.  So no Linux AP is capable of operating on any 5Ghz channel?
>>>
>>> For when I travel outside of the US, EU, and Japan, can this be
>>> overridden with a kernel patch?  If so, is such a patch available?
>>
>> I presume this is driven by the CRDA regulatory stuff? (Please correct me?)
>>
>> If you are using some modern distro then it's probably done in userspace
>> using the crda service (more on the wiki). If you are building your own
>> then you can compile into the kernel your own regional settings (ie what
>> *you* are allowed to use) by editing: linux/net/wireless/db.txt
> 
> I switched to kernel control of regional settings and channels without
> editing db.txt and the channels which are supposed to work in the US
> without DFS started working: 36, 40, 44, 48, 149, 153, 157, 161, 165.
> I noticed in dmesg I had:
> 
> cfg80211: Calling CRDA for country: US
> 
> Switching back from kernel control to crda again disabled all 5ghz
> channels and in dmesg I only get:
> 
> cfg80211: Calling CRDA to update world regulatory domain
> 
> I noticed that the channel allowances for country 00 match what is
> enabled for me under crda.  The kernel must set my country to US and
> crda must set it to 00.  I'm using crda-1.1.1 and
> wireless-regdb-20101124 which are Gentoo's latest versions.  Does
> anyone know what could be wrong?  Are these packages created by
> Gentoo, meaning I should file a bug with them?

Hi, I am also using gentoo:

a) I think you will see that there is some 2011 package if you unmask it?
b) I seem to remember fiddling with this and deciding that userspace was
a lot of work given that I update kernels more frequently than the
userspace tool was being updated...

I *think* you will find that you need to watch VERY closely what is
really going on here.  I think that there is a) card default regulatory,
b) kernel default, c) regulatory spotted from nearby basestations, d)
some peculiar choices if there isn't a regulatory exactly matching what
it's trying to search for (goes to "world" instead?)

So in your regulatory DB, check what the 00 world settings are and it's
likely that you are getting these rather than US?

Anyway, fiddle with it and you might come to the conclusion that right
now it's simpler to edit db.txt and set the 00 settings to be the
correct ones for your regulatory area, delete everything else from that
file and use only kernel regulatory domains...  Just a thought, make
sure what you do is legal in your domain...

GOod luck

Ed W



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