What Is 802.11ac in Wireless Networking?

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802.11ac is a standard for Wi-Fi wireless networking more advanced than the previous generation 802.11n standard. Counting back to the little-known original version of 802.11 defined back in 1997, 802.11ac represents the 5th generation of Wi-Fi technology. Compared to 802.11n and its predecessors, 802.11ac offers better network performance and capability implemented through more advanced hardware and device firmware.

History of 802.11ac

Technical development of 802.11ac began in 2011. While the standard was finalized at end of 2013 and formally approved on January 7, 2014, consumer products based on earlier draft versions of the standard appeared earlier.

802.11ac Technical Specifications

To be competitive in the industry and support increasingly common applications like video streaming that require high-performance networking, 802.11ac was designed to perform similarly to Gigabit Ethernet. Indeed, 802.11ac offers theoretical data rates of up to 1 Gbps. It does this through a combination of wireless signaling enhancements, in particular:

  • channels that utilize a larger (wider) expanse of signal frequencies, and
  • a larger number of MIMO radios and antennas to enable more simultaneous transmissions

802.11ac operates in the 5 GHz signal range unlike most previous generations of Wi-Fi that utilized 2.4 GHz channels. The designers of 802.11ac made this choice for two reasons:

  1. to avoid issues of wireless interference common to 2.4 GHz as so many other kinds of consumer gadgets use these same frequencies (due to government regulatory decisions)
  2. to implement wider signaling channels (as mentioned above) than the 2.4 GHz space comfortably allows

To keep backward compatibility with older Wi-Fi products, 802.11ac wireless network routers also include separate 802.11n-style 2.4 GHz protocol support.

Another new feature of 802.11ac called beamforming is designed to increase the reliability of Wi-Fi connections in more crowded areas. Beamforming technology enables Wi-Fi radios to target their signals in the specific direction of receiving antennas rather than spreading the signal across 180 or 360 degrees as traditional radios do.

Beamforming is one of a list of features designated by the 802.11ac standard as optional, along with double wide signal channels (160 MHz instead 80 MHz) and several other more obscure items.

Issues with 802.11ac

Some analysts and consumers have been skeptical of the real-world benefits 802.11ac brings. Many consumers did not automatically upgrade their home networks from 802.11g to 802.11n, for example, as the older standard generally met basic needs. To enjoy the performance benefits and full functionality 802.11ac, devices on both ends of the connection must support the new standard. While 802.11ac routers came into the market fairly quickly, 802.11ac-capable chips have taken much longer to find their way into smartphones and laptops, for example.