As we've seen with 802.11n networks, real-world throughput will likely be one-third to one-half as fast as the theoretical maximums. Still, even mobile devices outfitted with 802.11ac chipsets and just one transmit and one receive antenna--think smartphones and tablets--should be able to handle more than twice the bandwidth that today's devices with 802.11n chipsets can manage. With bandwidth-intensive applications such as videoconferencing and Customer Relationship Management (CRM) moving from the desktop to smartphones and tablets, 802.11ac networks will become essential infrastructure elements for businesses large and small.
To overcome the 5GHz band's shorter range, 802.11ac chipsets will utilize transmit and receive beam-forming technology. Beam forming was an optional element in the 802.11n spec, but its implementation is mandatory in 802.11ac. Most of today's 802.11n devices use omnidirectional signal transmission and reception. Signals propagate in a series of concentric rings, like the ripples you create by dropping a stone in a pond.
With beam forming, the router and its clients develop an awareness of each other's relative location, so they can coherently focus their transmission streams at each other. Without beam forming, reflected signals may arrive out-of-phase and cancel each other out, reducing total bandwidth. A beam-forming chipset can adjust the signals' phase to overcome that problem, thereby substantially increasing usable bandwidth.
The first generation of 802.11ac routers, such as the Trendnet TEW-811DR, will be concurrent dual-band models that support 802.11n clients on the 2.4GHz frequency band and 802.11ac clients on the 5GHz band. These devices are likely to reach the market in the third quarter of this year. Laptops with 802.11ac chipsets should arrive in time for the winter holiday season, with mobile devices such as smartphones and tablets following in early 2013. The Wi-Fi Alliance, the marketing consortium that has assumed responsibility for ensuring that wireless networking products interoperate properly, plans to begin its 802.11ac certification program in early 2013.
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