All Things 802.11ac - Question 8: What’s in the Wi-Fi Alliance Spec?

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As expected, the Wi-Fi Alliance has issued an interim spec for 802.11ac, just as they’ve done for previous draft 802.11 standards. This makes sense – after all, the final standard won’t be (if history is any guide) all that different from the draft, and products are on the market now. So - what’s in the Wi-Fi 802.11ac spec? And – I’ve been asked – given that the chip vendors largely define standards-compliant technology today, and thus require compliance just to sell their products, does the Wi-Fi certification of finished-goods products still matter?
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Craig Mathias

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Posted 5 years ago

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Matthew Gast

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Wi-Fi certification matters. 802.11ac is my third PHY transition (802.11b -> 802.11a/g, followed by 802.11a/g -> 802.11n). Every time, I've found that a significant fraction of customers are interested in a program that demonstrates interoperability for a draft specification.

One of the most valuable things the Wi-Fi Alliance certification work does for the industry is that it "freezes" the draft specification in a known state. One there is a demonstrated plan for interoperability, it tends to accelerate adoption of draft specifications, both by end users and by those of us who use 802.11 parts in our products. The confidence that we at Aerohive have to build products with the knowledge that the specification is stable directly translates into customer confidence to purchase products based on emerging standards. (I should also note that part of the reason a certification program "freezes" the specification is that it causes hardware to be produced; once hardware is shipping, changing the specification requires strong consensus from across the entire industry.)
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Matthew Gast

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Wi-Fi certification also matters in higher-end equipment of the sort sold by Aerohive. Although we commit to interoperability, certification means that we have demonstrated that our software is consistent with the interoperability test plan, too. There's value in that because the software at the enterprise end of the market is substantially more feature-rich and complex than the software on devices sold in retail channels.
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Craig Mathias

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Anything new in the spec this time, or does it pretty much follow the process they've used in the past?
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Matthew Gast

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This is a well-trod path at this point. If anything, the process worked so well with 11n it was fairly well understood that we'd do the same thing with 11ac. Figure out what features give us the best bang for the buck (in this case, 80 MHz channels, dynamic channel bandwidth selection, and 256-QAM), build an interoperability testbed, and start working on certification as soon as possible!