Maybe 802.11ad Will Dominate After All

Hey, I know 802.11ac is being positioned as the successor to and logical upgrade path for 802.11n. But let’s stop and think about that for a moment – 60 GHz. may make a lot more sense.

My last posting on the subject of 60 GHz. WLANs and 802.11ad was a bit cautionary in nature. Following a briefing with the folks at the Wireless Gigabit Alliance (WiGig), I was surprised that I heard a lot about wireless docking, video streaming, and applications essentially WPAN in nature, but relatively little about the 802.11ad WLAN opportunity. I think all constituencies concerned with 60 GHz. need to make the case for WLANs at these rarefied frequencies, presumably via whatever 802.11ad turns out to be, as a primary focus. Streaming and docking are certainly important, and, yes, there are markets for these applications. But good old everyday wireless LANs, always in need by definition of more capacity, must by sheer volume drive the adoption of any short-range wireless technology, or that technology is going to become the next Bluetooth - a niche with little real application, declining innovation, and perhaps an early death. Sure, Bluetooth has a huge installed base (albeit with the only real application today being in-car telephony links), but remember the anointed successor the Bluetooth PHY, ultra-wideband (UWB)? I am likely wrong in my prediction from 2009 that there is still more to come here. There likely isn't.

I spoke yesterday with senior executives at 60-GHz. leader Wilocity, though, and was pleased to hear about their progress in all aspects of 60 GHz. Yes, they've got a good story to tell with respect to personal-area networks (wireless syncing, storage, and file transfer), HD video links, virtual bus-in-the-air, and docking. And there's excellent news with respect to beamforming, spatial multiplexing, range, power consumption, and backwards compatibility to existing Wi-Fi and even Bluetooth implementations. But there was a distinct emphasis here on wireless LANs, and, well, I'm encouraged at the very least.

60 GHz. has gotten a bad rap. Yes, it's the oxygen absorption band, but I'll bet we'll see 60 GHz. outperforming 5 GHz. at any given range over which both are operational - and that could easily be 30 meters or more (yes, even through walls in some cases), depending on the local environment, as is always the case. Yes, signals are very directional at those frequencies, but beamforming and appropriate antenna design can easily compensate. Yes, fabbing chips is hard, but far from impossible, and can be done in CMOS. Power consumption can indeed be very modest if the chip designers know what they are doing. But most important - in fact, vitally important - 60 GHz. represents the largest swath of unlicensed spectrum available - seven gigahertz in the US - and such is at the heart of my argument. You want throughput? You want capacity? You want unoccupied greenfield (except for some outdoor, point-to-point, and very line-of-sight links) spectrum, ready to provide real multi-gigabit service? There is, I'm afraid, no place else to look.

802.11ac is getting a lot of attention as the successor to 802.11n. Yes, it will be backwards-compatible, but, as is the case with 802.11n and 802.11g, and as is always the case with two different PHYs trying to simultaneously coexist in a given channel, a greenfield deployment will be essential to realizing the true potential of the newer technology - and 5 GHz., while (today, anyway) not exactly oversubscribed like 2.4 GHz., is getting good usage now. As .11ac likely won't be a rip-and-replace, as was the case with the .11 to .11n upgrade, there will be plenty of .11n installed and serving quite nicely over what in many cases will be the next decade. I'm thus still a huge believer in 60 GHz. and the potential of 802.11ad, and, after my conversation with Wilocity, more so than ever. And we should see excellent progress here during 2012.

I apologize for my absence over the past two weeks. I've been shooting and editing video (more on this project shortly), and I'm always amazed how many hours of work are required to end up with literally one minute of finished video. And I'm looking forward to a couple of days of just light editing work over the holidays, so more on wireless and mobile next week. My best wishes to everyone for a pleasant Thanksgiving!

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