My colleague and friend Dori Smith has every confidence in me that I'll analyze the latest and greatest Wi-Fi news. Fortunately, I beat her 24-hour deadline with the following.
Robert X. Cringely writes about the threats to Wi-Fi's band and the nature of interference and the FCC: he's absolutely right on all counts. Steve Stroh will get credit when the day comes that cities light up their night skies with RF systems, and all of our 2.4 gigahertz networks sputter and fail. It won't happen all at once, and we have an exit plan.
As I wrote yesterday, 5 GHz, the band in which 802.11a operates, may become increasingly popular in the way that the open frontier always has a ring to it: you need some land, and your neck of the woods is full of houses and hotels. Time to head out to uncharted wilderness where you won't bump elbows with neighbors or natives. (This frontier doesn't have existing inhabitants, unlike the American West.)
Put it another way with another metaphor: when this planet is too polluted to live on, we all hop on our rockets and fly to the next one. Over the next few months, we will see many examples of dual-band radios that will incorporate both 802.11a and 802.11b/g. These radios will be both in PC cards, PCI cards, and access points. If 2.4 GHz becomes untenable, we may find ourselves already with enough equipment to make simple transitions up the spectrum.
Steve is right to wave a bloody shirt about RF lighting because the impact hasn't been raised yet to general consciousness, despite his lengthy and earnest article last summer and a recent Slashdot of same.
RF Lighting isn't all of the problem, of course, just one of a myriad of elements, as Cringely writes. There are a lot of interferring devices and uses that I've written about in the last few weeks that may increasingly hamper deployment of Wi-Fi networks. And a lot of competing services that haven't so far had to worry about deep-pocketed neighbors who want to want through the FCC complaint process. As noted a few weeks ago, only a single letter has ever been issued (not a complaint, just a warning letter) about interference between a licensed and non-licensed user of the 2.4 GHz space. I can't find anything about competing unlicensed uses.
Cringely points out, rightly as well, that frequency hopping works quite well in spaces that direct sequence (Wi-Fi's method) does not. A number of point-to-point firms I've spoken to, like the ISP on the coast of Maine I've written about before, use 802.11FH for this very reason. FH may again become popular for certain kinds of links. HomeRF has a leg up in this department as well with their FH-based technology.
We're not going to see immediate widespread failure of Wi-Fi as a spec. But we will witness ever more incidents that make us question how we continue to deploy it. The 5 GHz band has its own limitations, but a lot of benefits, and any intelligent information systems consultant or manager would be looking very closely into the future of 802.11a.