The key to reaping business benefits from 802.11ac is a smart plan for if, when and where to deploy. After all, widening a highway from two to four lanes is meaningless if it's traveled by just a few cars. Likewise, 11ac may add 80-MHz channels, but does your workforce really need them?
To prepare, take stock of your current and expected employee devices, your current WLAN setup and the technical particulars of 802.11ac. "Smartphones and tablets may prefer a single stream with wider channels to extend battery life," says Manish Rai, VP of marketing at Meru Networks. "In higher education, seasonal [churn], new devices and the number of devices doubling each year makes client density more important. And that is very different than backhaul, video surveillance or healthcare imaging, where 11ac must be optimized for capacity."
11ac's biggest single benefit is increased capacity, says Matthew Gast, Aerohive Networks' director of product management. "If you have a mix of laptops and tablets, 11ac will drive more time to tablets," says Gast. That's because laptops and tablets share airtime on a channel, and 11ac will let more-capable laptops operate at faster speeds and thus take a lot less time to transmit. That will free up airtime for less-capable devices like tablets, meaning new APs will increase performance even for older devices. "The first wave [of 11ac] might not bring multiuser nirvana, but it will still offer measurable improvements," says Gast. "Even if everyone operated at 48 instead of 36 Mbps, that alone would have a big impact."
Whether you're itching to deploy Wi-Fi Certified draft ac as soon as products hit the shelves or looking for a slow rollout once final 11ac APs with MU-MIMO become available, start planning for an upgrade. Plan around peak capacity rather than coverage, says Chris Spain, VP of marketing for Cisco's wireless business unit. As your mobile workforce and dependence on mobile applications grow, you'll be well-positioned to tap 11ac to increase user density.
Aerohive Networks
New APs due 1H 2013 | Start dropping new APs into existing WLANs to increase user density in hotspots and learn how 11ac performs.
Cisco Systems
New module due 1H 2013 | Deploy AP3600 with 4x4 11n radio, field-upgradable to new 11ac module. New 11ac AP to follow in three to six months.
Meraki
New APs due 1H 2013 | Use Cloud Controller predictive analysis to identify where to drop in 11ac APs.
Meru Networks
New APs in mid- to late 2013 | Use $499 investment protection coupon to trade in 11n APs for 11ac, mountable in same brackets.
Motorola Solutions
New APs due 3Q 2013 | 11n has long life; majority of customers will wait for second wave. Use WLAN Planner to evaluate implications.
Ruckus Wireless
New APs in mid-2013 | Think about AP density and plan for 5 GHz coverage. Draft 11ac may be underwhelming if goal is max capacity; focus on second wave.
Xirrus
New module due mid-2013 | Deploy field-upgradable XR-2200 Wireless Array with two open slots for modular 11ac APs (may be pre-purchased at discounted price).
Positioning your 11n access points to work well at 5 GHz is also important. Your existing mount points may not be perfect for 11ac, but they'll probably be good enough. When designing a WLAN for 2.4 GHz, we might end up putting APs farther apart to minimize installation cost. But if you're designing a WLAN for 5 GHz, it's worth putting APs a little closer together -- what's referred to as a dense deployment -- even if it means installing an extra AP here and there.
This dense deployment technique is already becoming a best practice for large 11n WLANs, at least in locations with lots of devices accessing them. Is the distance covered by 11ac at 5 GHz different enough from 11n at 5 GHz that you'd want to put your new APs in different locations? Yes, if you can start from scratch, because rate over range will improve for 11ac. But in general, redesigning an AP layout for 11ac probably isn't worthwhile.
Begin tracking client density and bandwidth utilization per application to see where your WLAN is hitting a wall. Migrate high-throughput applications to 11n 40-MHz channels now; that will help you learn where 40 MHz is sufficient and pinpoint cases where it isn't. As with 11n, 11ac APs will require more power to fuel additional transmit/receive chains and antennas. Early indications are that 802.3af Power-over-Ethernet won't be adequate, says Gast. Eventually, you'll need 802.3at PoE+ for 11ac, but that shift will probably happen during normal upgrades to Gigabit Ethernet switches anyway.
Speaking of wired network backhaul, 11ac is another reason to perform a wired network audit, assessing existing capacity, identifying potential bottlenecks and budgeting equipment upgrades to meet growing demands. For example, will your WLAN controllers need to be upgraded along with 11ac APs? Also plan ahead for network management, troubleshooting and wireless IPS updates.
Finally, talk to your WLAN infrastructure vendors about their 11ac upgrade paths and options to minimize expense and protect past investments. No matter how bullish you are on 11ac, client migration will occur gradually over several years. So think in terms of mixed 11n/11ac deployments, using equipment refresh to bring your WLAN into the fifth generation of very-high-throughput 802.11ac.
Lisa Phifer is president of IT and security consultancy Core Competence. Write to us at [email protected].
