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.)