In late December, the IEEE 11ac Task Group finally completed its six-year trek, putting the seal of approval on...
the final IEEE 802.11ac-2013 standard. This much-anticipated and very high throughput specification pushes wireless LAN data rates well into gigabit territory, maxing out just shy of 7 Gbps. But what does 11ac finalization mean to enterprise WLAN planners?
First and second waves will represent different challenges
As 11ac clients, application demands and user density escalate, the advantages offered by the second wave of 11ac APs will gain importance.
In the near-term, expect to see few product impacts. Why? The first Wi-Fi certified ac products have been shipping since mid-2013; new certification tests based on the final standard won't start until 2015 at earliest. In the meantime, a second wave of consumer-grade products that implement new-but-uncertified options will emerge, such as the Asus RT-AC87U router, announced at CES 2014.
As Aerohive Networks' Matthew Gast, author of 802.11ac: A Survival Guide, details in his blog, the first wave of Wi-Fi certified ac products are likely to be fully interoperable with second-wave products. That's because the features baked into today's certified ac products are based on draft 3.0 of the emerging standard and those features were not substantively revamped in the recently approved final standard.
Any differences that do emerge in the second wave of 11ac products that are based on December's final standard will be incremental. The most noteworthy additions: wider 160 MHz channels, access points (APs) with five to eight spatial streams and multi-user multiple input multiple output (MU-MIMO). Together, these options will boost maximum data rates from today's 1.3 Gbps to a blistering 6.9 Gbps.
Don’t miss the first wave, because it will provide a foundation
In practice, few enterprises really need 7 Gbps per-client throughput today. But simply migrating from 802.11n to first-wave 802.11ac products can triple throughput. Better yet, first-wave 11ac can noticeably increase WLAN capacity, client density and range. Moving 11ac and dual-band 11n clients onto 5 GHz, for example, reduces competition for airtime and improves connection quality for both old and new devices. This is why enterprises should take advantage of normal device refreshes and already-planned network expansions to gradually incorporate first-wave 11ac APs into their WLANs.
When it comes to the migration of WLAN clients, however, enterprise planners have less control. The bring your own device trend has already brought first-wave 11ac clients into enterprise WLANs; analysts expect 11ac client growth to accelerate quickly through 2014 as more and more new smartphones, tablets and notebooks ship with 11ac on board. When purchasing corporate devices, enterprises should insist on Wi-Fi certified ac, preferably with beamforming, thus laying a foundation to meet growing application demands and higher-density WLANs.
Do prepare for the second wave of 802.11ac-2013 devices
Adding first-wave 11ac APs to an existing 11n WLAN requires a little bit of planning, primarily to design 5 GHz spectrum allocation -- using wider 40 MHz and 80 MHz channels where higher data rates are needed. In the near term, a few 11ac APs here and there, servicing a mixture of 11ac and legacy clients, aren't likely to overwhelm back-end network infrastructure. In addition, those APs can probably make do with existing 1 Gbps Ethernet links and Power over Ethernet.
Yet as 11ac clients, application demands and user density escalate, the advantages offered by the second wave of 11ac APs will gain importance. In the enterprise, MU-MIMO will let a single AP simultaneously converse with up to four clients at once (for example, a 4x4 AP simultaneously servicing four single-stream smartphones). Upgrading will mean new second-wave 11ac APs with new chipsets that support MU-MIMO – but that kind of investment will be warranted in high-density areas that by then are pushing the limits of first-wave capacity.
At that time, second-wave 11ac APs will most likely need more power, 10 GB Ethernet/CAT6a backhaul links and beefier back-end infrastructure to avoid upstream bottlenecks that may emerge. Planning ahead for these upgrades now and rolling them out over the next two to three years will leave enterprises well-situated to deploy the second wave of enterprise-class 11ac products in 2016 and beyond.