In my series on 802.11ac, I've discussed major enhancements in the new Wi-Fi standard and current as well as future products based on it. In this part, I look at 802.11ac adoption and what's driving organizations to move to the new standard.
Nearly 250,000 11ac enterprise-class APs shipped in 2013, according to IDC, including models from Aerohive Networks, Aruba Networks, Cisco, Dell, D-Link, Elecom, and Meru Networks. The research firm expects 2014 shipments to spike to 1.6 million.
On the client side, 60% of today's Wi-Fi Certified ac products are dual-mode smartphones, along with about a dozen (mostly Samsung) tablets. Given a two-year smartphone refresh cycle, one might reasonably expect accelerated client growth in 2014. But according to Robert Fenstermacher, director of marketing at Aruba Networks, 11ac adoption is occurring differently than it did for 11n.
"One factor is that 11n is no longer even a choice in new laptops and smartphones -- for example, over 40 million Samsung Galaxy S4's sold with 11ac," Fenstermacher said. "Our customers are seeing 10% to 15% 11ac clients already, and we expect a big bump after the 2013 holidays -- perhaps 5% to 10% in enterprise WLANs and 20% to 30% in education."
Nonetheless, many vendors acknowledge that adoption is being driven not by pressing needs for gigabit throughput, but rather by desire to build WLAN capacity.
"Most of our customers don't have an immediate need, but have a road map for growth over the next two to three years," explained Gary Singh, WLAN product marketing manager at Motorola Solutions. "They know they will need 11ac to handle many more users in 2014 and 2015, and also to increase AP density for more accurate indoor locationing."
Of all speed-related 11ac features, dynamic per-frame channel width gains are proving to be the most important, said Matthew Gast, director of product management at Aerohive Networks. "Larger channels can be used by any device. Many phones, though single stream, support 80-MHz channels and thus see a big speed gain," he said.
[Read Lee Badman's advice for what to consider when evaluating WLANs in "How To Shop For A WLAN: 7 Steps."]
So what should 11ac Wave 1 customers realistically expect in terms of speed? "Individual clients see strong gains in throughput, up to about double," said Gast. "Older clients don't gain throughput except at the margin, and the gains for clients far from the AP depend on being able to use the wider channels. This is another reason why wider channels are such a key feature: They work even at longer range."
And better airtime utilization and radio components improve performance for all clients, according to Fenstermacher. "We're finding about 30% improvement for nearby 11n clients and up to 300% for those 120 feet from the AP. Lab speeds for 11ac clients are of course much higher, but we're seeing real-world sustained speeds of 400 Mbps for 11ac clients, even on heavily loaded APs," he said.