802.11n - What's the Problem?

OK, there's a chance I‘ve been a tiny bit irrationally exuberant when it comes to 802.11n, but I really don't think so. I first learned about MIMO in the mid-90's (yes, it sounded like magic the first time a Ph.D. explained it to me), and started working on MIMO-based systems in 2003. I published my first White Paper on this topic in December of 2003, and I've since spent countless hours working on and with many types of MIMO-based systems, including many of the Draft .11n products available today. My advice has been uniform and consistent - buy it. Now. There's no need to wait; the Wi-Fi Alliance's blessing of Draft 2.0 should be all the assurance one needs. I see no issues in upgrading Draft 2.0 products (the ones I've tested, anyway) to Draft 5.0 and the final standard. And, while some are better than others, all .11n products I've tested have performance that is certainly much better than .11g or .11a.

And yet I still hear and read that not everyone agrees, and many still buy .11g. Adapters, sure; sometimes we don't have a choice. But enterprise-class (or, for that matter, residential) infrastructure? Yes, many do, and what I want to know is why. In a recent article by Computerworld's Matt Hamblen, who also lives in beautiful Ashland, Massachusetts, it's written that half of all purchases next year will be .11n-based products, with the rest being stuff based on older WLAN technologies. I can't imagine why anyone would do this in 2009. All .11n products are backwards compatible to .11g and/or .11a. When running in backwards-compatible mode, they uniformly yield "better g than g" performance, so purchasing .11n to work in .11g mode with an eye towards an eventual .11n infrastructure can make sense. But buying pure-g or g/a infrastructure? Why would anyone do that? This stuff isn't going to all of a sudden become obsolete, sure, but its price/performance is certainly and dramatically inferior.

I think .11n is going to account for much, much more than half of all Wi-Fi sales next year. I can't imagine any objections to purchasing it once prices fall a little more, and they will, and this year. What else could possibly account for buying anything but .11n? I'm at a complete loss here. Any suggestions or ideas?

And if you want more, I'm very pleased to be participating in a Network World Webcast on "Key Considerations for a Successful 802.11n Deployment" this Thursday, 24 July, at 2:00 eastern time. Motorola will also be talking about their new .11n products, and we'll have plenty of time for questions, so please join us for this one.