Breaking Down the Evolution of 802.11 Wireless Standard

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The latest official standard of wireless that is being more widely adapted is 802.11ac. Although it’s not everywhere yet, the IEEE recognize it as the official upgrade over 802.11n. But 802.11ac isn’t the only standard out there, in fact there are many 802.11 standards that offer different things are are constantly being developed. Here’s what you need to know about 802.11n, 802.11ac and some of the other more popular forms of 802.11 technology.

First of all, the 802.11 is a set of standards used by IEEE. The most commonly deployed are 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac. These standards can be found in homes and businesses today. Most businesses are using 802.11n and are looking to adopt 802.11ac as it is the fastest and latest available.

802.11a was the most popular standard in 1999 and was the first form of 802.11 technology. It was very fast by 1999 standards and was improved upon by 802.11b and 802.11g. These early standards are no longer viable in today’s wireless deployment because there is no point to installing them when 802.11n and 802.11ac are available.

802.11n has dominated wireless since it was introduced in 2009. It uses multiple antennas to significantly increase the net data rate from 54Mbit/s to 600Mbit/s. It is also the first standard to support multi-input multi-output (MI-MO) in order to multiply the capacity of a radio link using multiple transmit and receive antennas. This technology has revolutionized the ways we have been able to use wireless internet.

We’ve been decently happy with our 802.11n connections but as always, wireless speeds can always be improved. The ultimate goal with developing new wireless standards is to get wireless speeds and reliability up to and even past a standard wired connection.

The next step in the 802.11 train is 802.11ac. Introduced in 2014, 802.11ac has taken over and greatly improved on all the things that made 802.11n great, and introducing elements that allow for more devices to be connected smoothly. 802.11ac operates with eight antennas which is double the amount from 802.11n. It also uses downlink multi-user MIMO (up to four clients), and high-density modulation (up to 256-QAM).

 

New technologies introduced with 802.11ac include the following:

  • Extended channel binding
    • Mandatory 80 MHz channel bandwidth for stations (vs. 40 MHz maximum in 802.11n), 160 MHz available optionally
  • More MIMO spatial streams
    • Support for up to eight spatial streams (vs. four in 802.11n)
  • Downlink Multi-user MIMO (MU-MIMO, allows up to four simultaneous downlink MU-MIMO clients)
    • Multiple STAs, each with one or more antennas, transmit or receive independent data streams simultaneously
      • “Space Division Multiple Access” (SDMA): streams not separated by frequency, but instead resolved spatially, analogous to 11n-style MIMO
    • Downlink MU-MIMO (one transmitting device, multiple receiving devices) included as an optional mode
  • Modulation
    • 256-QAM, rate 3/4 and 5/6, added as optional modes (vs. 64-QAM, rate 5/6 maximum in 802.11n)
    • Some vendors offer a non-standard 1024-QAM mode, providing 25% more bandwidth compared to 256-QAM
  • Other elements/features
    • Beamforming with standardized sounding and feedback for compatibility between vendors (non-standard in 802.11n made it hard for beamforming to work effectively between different vendor products)
    • MAC modifications (mostly to support above changes)
    • Coexistence mechanisms for 20/40/80/160 MHz channels, 11ac and 11a/n devices
    • Adds four new fields to the PPDU header identifying the frame as a Very High Throughput (VHT) frame as opposed to 802.11n’s High Throughput (HT) or earlier. The first three fields in the header are readable by legacy devices to allow coexistence

But 802.11 doesn’t end there. Like I mentioned earlier, there is no end to improvements to be made to wireless speeds and security. There are other standards that aren’t available yet, but are in development like 802.11ad, 802.11af and 802.11ah.

“802.11ac is an interesting position,” says Nick Espinosa, CIO of BSSi2 LLC.  “It’s by far superior to 802.11n however it is already lagging behind the soon to be released 802.11ad (aka Wi-Gig), and 802.11ah though there can also be a case made for the 802.11af standard being superior as well.”

“The next standard 802.11ad is so short range it won’t be used for much beyond super-fast file transfer without plunging in your device or use if other networks are congested,” says Andrew Bernstein, Project Manager at the Demski Group. “It won’t really penetrate walls so 802.11ac will likely gain widespread adoption before an alternative next gen technology arrives.”

We have a lot to look out for when it comes to new wireless standards. As it goes right now, it’s you’re looking to upgrade 802.11ac will be the best choice. While not all devices are able to fully utilize what makes 802.11ac so desireable, but it is backwards compatible, so the devices that are 802.11ac compatible will benefit and the other devices will continue enjoying great internet speeds and when they’re ready to upgrade devices, the benefit will be instant.