Sifting Through the 802.11 Alphabet Soup
IT history is defined by rapid advances in performance, value and capability that bring better, faster and cheaper technology, and Wi-Fi is no exception. The original 1997 IEEE 802.11 standard specified just 1 megabit per second to 2Mbps of throughput. Now we have wireless technologies capable of 7 gigabits per second, with even higher throughput on the way.
Today’s 802.11ac products are rapidly replacing the 802.11n systems that deliver 300Mbps to 450Mbps — rates that only a few years ago seemed astounding. But effective throughput is about half that rate, and the swelling ranks of mobile users have stretched many 802.11n systems to the limit, making current 802.11ac solutions the way to go.
Pending Developments
There’s no slowdown in innovation. Around the end of 2014, expect to see the first “Wave 2” 802.11ac products that push raw throughput to 1.8Gbps (and perhaps even as high as 3.5Gbps). A new feature called multiuser MIMO (MU-MIMO) enables multiple clients to be serviced with distinct data streams during a single transmission from an access point, boosting efficiency, especially as the base of lower performance handsets and tablets increases. While the 802.11ac specification theoretically can reach up to 6.93Gbps, the lower numbers likely represent the peak for practical implementations.
Two other key wireless developments loom on the horizon. The first is 802.11ad, which operates in the mostly open 60-gigahertz band. The specification defines four channels that are each capable of up to 7Gbps. Expect to see 802.11ad products next year and effective throughput of just over 3Gbps in open office environments. And 802.11ax, a new effort just getting underway within IEEE, promises speeds of more than 10Gbps, but not before 2018.
Organizations will need new client devices for Wave 2 of 802.11ac, ad and ax in order to realize peak throughput. The big question is, does waiting for what’s next make sense? As always, not if return on investment can be demonstrated today. There’s plenty of potential for improved productivity today, with more on the way.
Not Coverage, but Capacity
Some might be tempted to look at the performance gains in 802.11 specifications and conclude that fewer access points will be needed, but they’d be wrong.
Throughput in wireless is a function of the basic capabilities of the radio, but also of range — in simple terms, the farther you go, the slower you go, due to signal strength fading and assorted other radio artifacts.
What’s more, APs continue to improve in price and performance, and user demand continues to grow, so skimping on this gear doesn’t make sense.
