- 802.11ac is 5 GHz only. This “limitation” is possibly the most important development because it will bring about a shift in client device support for the cleaner band with more usable spectrum. Mobile devices should adopt quickly if they want to stay “cutting edge” on the spec sheet, and because mobile devices are consumer products, the marketing of speed-based specs carries vast importance. Pervasive client adoption of 5 GHz will improve aggregate performance across the enterprise. 2.4 GHz is a garbage band; Wi-Fi is taking the goods to 5 GHz and leaving its refuse in 2.4.
- The IEEE has a “reach for the stars” attitude with the 802.11ac spec. Unfortunately, the marketing hype of “gigabit Wi-Fi” is way overdone. The few features that really drive the maximum data rate up are not immediately, or possibly ever, relevant to the enterprise.
- Very large channels—certainly 160 MHz, and likely 80 MHz as well—can ruin aggregate capacity, especially with high client densities and lots of 20 MHz only mobile devices. Some experts call these large channels a “gimmick.” Marketing departments love it.
- The other big data rate boost is more spatial streams (up to 8). As a reminder, today’s products incorporate only 3 (and rarely utilize them all) of the possible 4 spatial streams specified in 802.11n, so the likelihood of ever utilizing 8 is very slim. Adding more spatial streams to real-world products will take a lot of time.
- MU-MIMO promises better spectral efficiency with simultaneous transmissions to multiple users. However, this feature relies on better support (heck, let’s start with some support) of client beamforming as well as significant queuing modifications, and even then, there are still questions about achieving sufficient signal isolation between target clients. MU-MIMO doesn’t change the raw data rate, but it’s one of those marketed theoretical features that won’t be in the first, or first several, generation of products.
- Both 802.11ac and 11ad will be hot in the consumer market, and like previous technologies, will filter into the enterprise as use cases develop. This is especially true for 11ad, which is almost exclusively focused on consumers, but may find niche uses in enterprises. 11ac will be a mainstream enterprise technology, but many of its gains are muted in the enterprise.
- 3 out of 4 experts had reservations about the significance of “gigabit Wi-Fi.” The dissenting 1 out of 4 is optimistic.
- Products will not hit the market until late 2012 or early 2013, so we still have time to wait and let the many marketers beat their drums.
But don’t trust me; form your own opinions and let us know what you think. The video is below. Thanks to Devin Akin (Aerohive), Peter Thornycroft (Aruba), Paul Congdon (HP Labs), and GT Hill (Ruckus) for their great commentary at the symposium. Thanks also to Andrew VonNagy for co-moderating.
Gigabit Wi-Fi (802.11ac/ad) Discussed at the Wi-Fi Mobility Symposium from Stephen Foskett on Vimeo.
Thanks Marcus for the post and video.Has anyone addressed the issue of 802.11ac : site survey tools and using the product in an environment where 802.11a is used for voice over WiFi. If yes, what is the consensus ? Thanks in advance.
I haven’t had or heard of any conversations around those topics yet. We’re still a year away from any meaningful enterprise products, so I suspect those conversations will come when the 11ac skeleton has more skin on it.
I suppose the voice conversation has a lot of overlap with the more generic discussion of mobile devices. The consensus seems to be that most voice clients and mobile devices will still want to operate in a 20 MHz channel (a given for legacy 802.11a phones, of course) for power savings, which reinforces the idea that the big gains of 80 and 160s will be not as significant in many enterprises. In that sense, most channel plans will still default back to 20 MHz or possibly 40 Mhz channels instead of 80.
When it comes to site surveying and setting channel plans, I believe many vendors will adopt some type of adaptive channel selection technology that can dynamically assess the optimal channel settings (operating channels and sizes). This will be interesting to watch when products come out.
Thanks Marcus, that is my consensus on Voice at 20 MHz. The key demand on AC will be video, IMHO. Thing like Skype, FaceTime are applications of the younger techies …..Once one, 802.11ac SOHO AP is released in the wild and it is proved it can handle video well with little to no drops on voice and video. Vendors like Apple and Google will swiftly launch products that the BYOD buzzword..that will creep into the enterprise- first college campuses , and boardrooms….
Great video and interesting to see the panelists (and by extension Vendors) agree on the fundamentals limitations of wireless.