Marvell regulatory domain info storage?
pjones at redhat.com
Fri Oct 6 18:21:26 EDT 2006
On Fri, 2006-10-06 at 00:56 -0700, Scott Lamb wrote:
> 3) Khaled said this: "You don't reconfigure your network card every time
> you travel." This is because the laptop gets its regulatory domain
> information from the Access Point via 802.11d. You can't legally operate
> Access Points in different regulatory domains without adjustment. Now, I
> have absolutely no idea what this means for mesh networking...
Huh? That doesn't quite follow. You can't know if it's legal to
associate with an AP during scanning, or even know what channels you're
allowed to scan, until you've selected your regulatory domain.
When a scan is initiated, you already have a list of channels that's ok
to talk on, and it's determined by a static table in the driver, indexed
by the geo code read from the firmware on the machine -- typically the
firmware of the WiFi device itself.
See, for example, wlan_scan_create_channel_list() in
libertas/wlan_scan.c, or ipw_request_scan() (and its helper
ipw_add_scan_channels() ) in ipw2200.c .
It's certainly possible to hack things up to use a user-settable geo,
but that is not what drivers currently do.
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