Regulatory daemon question

I'm slightly baffled by the Intel-provided ipw3945d regulatory daemon I
have running for my Intel 3945ABG wireless card under Linux. My laptop
is American and I found I couldn't connect to a Japanese 802.11a
network.

As far as I can tell it's actually limiting which channels the card will
talk on at all. For instance, in the 5.2GHz band, it will listen on
channels 36, 40, 44, 48, etc. but not 34, 38, 42, 44 or whatever.

What I want to confirm is, I can understand wifi NIC vendors wanting to
restrict what frequencies it will broadcast on, because of FCC
requirements, but do they normally even restrict on what frequencies the
card will respond to an access point's beacon on? It won't even listen
and broadcast even if the surrounding access points are obviously
operating in a different regulatory environment?

It just seems so silly when people obviously travel with their laptops
and whatnot. What do 'b/g' people do when travelling to Israel with a
Spanish laptop? What do 'a' people do when travelling to Japan with an
American laptop? Buy a NIC in each country? (Is the regulatory daemon
responding to some region code embedded in the NIC? It says something
about 'detected geography' but I very much doubt it can tell where my
laptop computer actually is.)

-- Mark

Mark T.B. Carroll wrote:
> I'm slightly baffled by the Intel-provided ipw3945d regulatory daemon I
> have running for my Intel 3945ABG wireless card under Linux. My laptop
> is American and I found I couldn't connect to a Japanese 802.11a
> network.
>
> As far as I can tell it's actually limiting which channels the card will
> talk on at all. For instance, in the 5.2GHz band, it will listen on
> channels 36, 40, 44, 48, etc. but not 34, 38, 42, 44 or whatever.
>
> What I want to confirm is, I can understand wifi NIC vendors wanting to
> restrict what frequencies it will broadcast on, because of FCC
> requirements, but do they normally even restrict on what frequencies the
> card will respond to an access point's beacon on? It won't even listen
> and broadcast even if the surrounding access points are obviously
> operating in a different regulatory environment?
>
> It just seems so silly when people obviously travel with their laptops
> and whatnot. What do 'b/g' people do when travelling to Israel with a
> Spanish laptop? What do 'a' people do when travelling to Japan with an
> American laptop? Buy a NIC in each country? (Is the regulatory daemon
> responding to some region code embedded in the NIC? It says something
> about 'detected geography' but I very much doubt it can tell where my
> laptop computer actually is.)
>
> -- Mark
Have you checked the "Country Region" in your wireless card properties?
You should be able to specify which region you want the card to work in.
I don't have that specific wireless card but having just checked a
couple of laptops with wifi I am able to specify a region I wish to use.

Kev <invalid@invalid.invalid> writes:

> Mark T.B. Carroll wrote:
>> I'm slightly baffled by the Intel-provided ipw3945d regulatory daemon I
>> have running for my Intel 3945ABG wireless card under Linux.
(snip)
> Have you checked the "Country Region" in your wireless card properties?
> You should be able to specify which region you want the card to work in.
> I don't have that specific wireless card but having just checked a
> couple of laptops with wifi I am able to specify a region I wish to use.

I haven't found such a facility yet. I've tried poking about in
/sys/module/ipw3945/ and /sys/bus/pci/drivers/ipw3945/ to see if I could
find a likely file to change, but it was all a bit unclear. Thanks for
the idea, though. iwpriv eth2 --all doesn't report anything juicy, alas.

-- Mark

Mark T.B. Carroll wrote:
> Kev <invalid@invalid.invalid> writes:
>
>> Mark T.B. Carroll wrote:
>>> I'm slightly baffled by the Intel-provided ipw3945d regulatory daemon I
>>> have running for my Intel 3945ABG wireless card under Linux.
> (snip)
>> Have you checked the "Country Region" in your wireless card properties?
>> You should be able to specify which region you want the card to work in.
>> I don't have that specific wireless card but having just checked a
>> couple of laptops with wifi I am able to specify a region I wish to use.
>
> I haven't found such a facility yet. I've tried poking about in
> /sys/module/ipw3945/ and /sys/bus/pci/drivers/ipw3945/ to see if I could
> find a likely file to change, but it was all a bit unclear. Thanks for
> the idea, though. iwpriv eth2 --all doesn't report anything juicy, alas.
>
> -- Mark
As an example:-
http://gentoo-wiki.com/HARDWARE_Gent...i_Installation

Mark T.B. Carroll wrote:
> Kev <invalid@invalid.invalid> writes:
>
>> Mark T.B. Carroll wrote:
>>> I'm slightly baffled by the Intel-provided ipw3945d regulatory daemon I
>>> have running for my Intel 3945ABG wireless card under Linux.
> (snip)
>> Have you checked the "Country Region" in your wireless card properties?
>> You should be able to specify which region you want the card to work in.
>> I don't have that specific wireless card but having just checked a
>> couple of laptops with wifi I am able to specify a region I wish to use.
>
> I haven't found such a facility yet. I've tried poking about in
> /sys/module/ipw3945/ and /sys/bus/pci/drivers/ipw3945/ to see if I could
> find a likely file to change, but it was all a bit unclear. Thanks for
> the idea, though. iwpriv eth2 --all doesn't report anything juicy, alas.
>
> -- Mark

http://ipw3945.sourceforge.net/news.php
"The host is responsible for middle and upper layer MAC services.

As a result of this change, some of the capabilities currently required
to be provided on the host include enforcement of regulatory limits for
the radio transmitter (radio calibration, transmit power, valid
channels, 802.11h, etc.) In order to meet the requirements of all
geographies into which our adapters ship (over 100 countries) we have
placed the regulatory enforcement logic into a user space daemon that
we provide as a binary under the same license agreement as the
microcode. We provide that binary pre-compiled as both a 32-bit and
64-bit application. The daemon utilizes a sysfs interface exposed by
the driver in order to communicate with the hardware and configure the
required regulatory parameters."

Kev <invalid@invalid.invalid> writes:

> Mark T.B. Carroll wrote:
(snip)
>> I've tried poking about in
>> /sys/module/ipw3945/ and /sys/bus/pci/drivers/ipw3945/
(snip)
> The daemon utilizes a sysfs interface exposed by the driver in order
> to communicate with the hardware and configure the required regulatory
> parameters."

Ah, thanks! It's in /sys/ somewhere, then, I just have to find it.
(It'll be one of those generically-named files with nothing but a number
in it, no doubt.)

-- Mark