May 08, 2006, 12:38 PM — Well, that was quick. Just when I'd signed off from writing monthly columns, I recently completed a project that I thought you would find interesting, so here's a new column on the results of our first testing of so-called "draft N compliant" wireless LANs. If you've not been following the saga of the IEEE 802.11n standard, this is the next-generation physical layer based on MIMO. We're talking effective throughput of 100 to 300 Mbps, and improved range as well. There are a whole bunch of non-standard (other than backwards compatibility with 802.11g, anyway) MIMO products on the market, and we've often recommended them both for very high throughput when using MIMO on both ends, or "better g than g" performance with MIMO on only one end.
The "draft n" products are based on just that: the first draft of the standard now under development. The IEEE cautions against claiming compliance with the draft via a stern warning on the cover of the draft documents, but one can hardly blame marketers in the highly-competitive WLAN space from jumping the gun a bit.
Unless, of course, the "draft compliant" products are substandard, so to speak, in terms of performance. Unfortunately, a bunch of these we recently tested are indeed just that. In a weekend's worth of extensive benchmarking, the "draft n" products we tested were nowhere near as good in throughput and range as a Linksys non-compliant router and client pair that have been on the market for some time. And the "draft n" products would not interoperate with each other in MIMO mode, only 802.11g mode. This is not surprising, given the current state of the draft, but also not what we'd expect from products claiming to be complaint with a standard (even a standard that's not fully baked).
These products also claim software upgradeability to compliance with the final 802.11n standard when it's issued, but I'm skeptical of such claims. It's a bit early to guarantee such upgradeability, and indeed, the vendors do not. You won't get your money back if such an upgrade ultimately isn't possible. Taking all of this into consideration, it's hard to recommend the current crop of "draft N" products. We're going to do more testing in a month or so, so as to take advantage of newer drivers and firmware where available. In the meantime, you can read our current report here.
Despite a few bumps in the current road, I still think 802.11n is going to be a killer standard and will carry wireless LANs for a good long while. It's too bad the standard isn't here today, but there are a number of good non-standard MIMO-based WLANs on the market regardless, and we're still quite comfortable in recommending those.
