Fretting Over 802.11ac

Call me a downer, call me a cynic. I'll counter with the stock answer I give my wife when she calls me out for being skeptical: I consider myself a realist. The not-yet-draft version of IEEE 802.11ac is building up steam just off the wireless stage, and I'm here to tell my fellow wireless network administrators that now is the time to start worrying.

If the 802.11ac twinkle has yet to land in your eye, let’s start with some simple familiarization. Take what you have learned about 802.11n, with its MIMO antennas and other tricks that let the standard promise data rates to 600 Mbps. Now paint it up bigger and sexier with even more technical sophistication and data rates to 1,000 Mbps under .11ac. The working group has yet to ratify a formal draft as I write this, but analysts are already easing into a full-court drama press about how wildly popular the new heir to the Wi-Fi throne will be even before the coronation is being planned.

Popular predictions regarding 802.11ac have millions of devices in users’ hands by 2012 and billions by 2015. Expectations are that as the IEEE does its thing in slowly working on draft versions on the way to ratification of the final standard, the Wi-Fi Alliance in parallel will be much quicker in certifying interoperability of .11ac draft products than it was for .11n when it was in draft. This is the key to the predicted device explosion. Couple that with .11ac likely being compatible with legacy .11n 5 GHz (and maybe 2.4 GHz) devices and promised data rates that boggle the mind, and it’s easy to see why we’re supposed to get excited.

But then there are those of us who live wireless networking every day who are slower to warm up to the hype. We design, install, and support wireless networks and have our own real-world perspective on the wireless networking industry and trends. Many of us have institutional knowledge that comes from having implemented every wireless and security standard since Wi-Fi become relevant, and know what it takes to get an organization and large numbers of clients onto a new generation of wireless network infrastructure. From that angle, allow me to share my worries about the .11ac storm clouds that are gathering on our collective horizon.

Many of us have had to grow our networks through the years to meet increased user demand and as society’s acceptance and expectations of wireless networking has matured. I currently upkeep 3,000 access points but can remember when the wireless side of my IT career started with a mere four APs. By the time .11ac becomes a consideration for me, my environment will probably be at around 3,500 access points. Let’s say each AP lists at a reasonable (for a new high-end access point) $1,500 and that I can get a steep discount to $750. I’m still looking at $2.5 million dollars in access point costs alone, not to mention labor and whatever is required in controller changes and the like.

There are arguments about not replacing APs one for one as technology gets better, but depending on the circumstances, reducing AP counts works against the promise of new super-high user throughputs in client-dense areas. So we’ll just cap this thought with the fact that, just based on how large our WLANs are becoming, upgrading today’s large wireless networks to .11ac is going to be big-time pricey.

And then there’s the question of when to move to .11ac. I do know that high-throughput wireless is wonderful for the likes of the right kinds of video, but at the same time all the advantages of a wireless hardware set like .11ac’s multiuser MiMO and x number of spatial streams are best realized when similarly capable clients are at the other end of a fancy AP’s transmissions. I also know that the same analysts are touting the explosive growth in mobile and handheld devices that won’t be able to fully take advantage of the full power of .11ac because of design constraints and if for no other reason that there is only so much you can humanly do with a highly portable device. For many users, good wireless is more than good enough, and better wireless isn’t even recognized as such.

If I could upgrade all of my 10,000 daily peak simultaneous clients to robust .11ac devices that got hundreds of megabits per second wireless throughput, how would I have to resize my uplinks to the core and Internet pipes? And in spaces where I have significant investment in Gigabit Ethernet to the desktop for stationary office workers, I’m finding now with .11n that, just because you can cut the cord and provide wireless connectivity to desktop workstations, it doesn’t mean that organizations want to just for the sake of going wireless. In these spaces, do I care whether someone can get 10-, 100- or 500-Mbps wireless throughput on their personal tablet that they insist on using occasionally? I’m not saying that I don’t care, I just don’t know if I do.

Costs. Timing. Clients that may or may not be able to leverage the upper end of the new hardware’s performance envelope. Balancing the siren song of new and hot with questions of true need and where precious IT dollars are best spent. These considerations are nothing new in our lines of work, but I have a feeling that 802.11ac and the inevitable mania that will herald its coming are going to have many of us worrying about them sooner than we might have planned for. Now’s the time to start pondering it, before the hype surrounding .11ac gets kicked into high gear and the boss starts asking, "Should we be thinking about .11ac?"