WiFi regulatory rant
On a recent trip abroad, I brought my laptop and planned to work online at the airport while waiting for my flight. I found a power socket, opened my laptop, and got connected with no fuss at all. I was even able to connect my G1 phone at the same time, since the WiFi was free, and sync my calendar and RSS feeds.
After 15 minutes or so, my laptop fell off the network. I couldn’t even see the access point anymore. I spent the next few minutes grumbling and running terminal commands to try to understand what was wrong, and decided that the problem must be with the access point. Then I switched on my phone and noticed that it connected without a problem!
Grumbling louder, I spent quite some time trying to figure out the problem. The crucial clue was provided by Android, which provides a configuration setting for the number of WiFi channels to use. It can be set to 11, 13 or 14. I tried setting the phone to 11 channels, to match what was reported by my laptop:
iwlagn 0000:03:00.0: Tunable channels: 11 802.11bg, 13 802.11a channels
…and then the phone couldn’t connect either! I couldn’t get Android to show me the channel information for the access point, but by trying the settings, I could infer that it was using channel 12 or 13, and must have switched channels since I started working.
So, how to get my laptop to see these extra channels? I immediately suspected the regulatory settings, since a new regulatory framework had recently been developed and added to Ubuntu. I dug through man pages, I read database dumps, and I searched Google using my phone. Everything I found told me that I was doing the right thing already, and that channels 12-14 (which were perfectly legal in the country where I was) should be available.
Then I came across a few references which told me that my WiFi card (Intel Corporation PRO/Wireless 4965 AG or AGN [Kedron] Network Connection (rev 61)) was believed to be hardware crippled to support only 11 channels. I had purchased this laptop in the US, but don’t live there anymore, and certainly didn’t want to concern myself with US regulations while outside of the US.
Tough luck for me, it seems. If I want to be able to get online in other countries reliably, it seems I’ll need to buy a new card.