Draft 802.11n Still a Neighborhood Killer?

By Michael Santo
Executive Editor, RealTechNews

After getting my Dell XPS M1710 late last year, and noting that it had a built-in 802.11n mini-PCI card, I decided to make the jump to Draft n. Now, I’d already heard that 802.11n had problems with stomping on your neighbor’s older wifi, but I’d also heard the Draft 2.0 spec was supposed to take care of that. However, it seems things may not be quite up to snuff yet.

I spent a few days last week testing a D-Link DIR-655 router and DWA-652 Cardbus card, which are based on Atheros XSPAN silicon. These are the first products to have firmware and drivers posted that allegedly implement 11n Draft 2.0 compliance. My primary focus was to see whether the legacy protection mechanisms added in 802.11n Draft 2.0 were working in actual product.

My initial tests didn’t look very promising and after some back-and-forth with D-Link, I’m even less encouraged. I’ll have full details in an upcoming review, but basically I see no sign that the Clear Channel Assessment (CCA) mechanism added in Draft 2.0 is working properly. Source: SmallNetBuilder

We Say: Basically if a legacy device is detected on the extension channel (n uses an extension channel to get higher throughput), the router is supposed to back off to using the legacy-friendly 20 MHz channel mode. According to the tests in the article, it’s not yet doing that. Well, I haven’t gotten any complaints yet, even though my router has not yet been certified or received a firmware upgrade to Draft 2.0. And I see plenty of wi-fi networks in my neighborhood. Hopefully I’m not affecting anyone, though I’m not going to tell you where I live, just in case …