IPIQ: Wireless Networking
The next generation of Wi-Fi has arrived—802.11ac is the latest Wi-Fi technology standard that promises even greater wireless networking performance than products based on the still shiny and new 802.11n standard. Many might ask (with good reason) why there is yet another wireless technology standard available while 802.11n is still very much in its infancy and has not yet reached full potential. To better understand the answer to this question, let’s cover some of the key differences and enhancements introduced with 802.11ac.
What is 802.11ac?
The IEEE 802.11ac specification was developed by the IEEE Standards Association as a method and protocol for achieving Gigabit speeds wirelessly. The specification calls for single link throughput of at least 500 Megabits per second and multi-station throughput of at least 1 Gigabit per second. While real world performance is obviously going to be less than this lofty Gigabit number, 802.11ac represents some impressive advancements to wireless performance, especially as ISPs increase bandwidth and more 802.11ac devices become available on the market. Note that 802.11ac is still in draft state, meaning that there will continue to be modifications and improvements to ensure maximum compatibility with existing wireless technologies. While final ratification of the standard is expected in early 2014, a good number of 802.11ac routers and client devices are already on the market today. Some of the most recent client devices to support 802.11ac include the Samsung Galaxy S4 and the newest Mac Book Air, with a lot more expected over the coming months.
How is 802.11ac different than 802.11n?
When comparing 802.11ac to 802.11n, there are a number of enhancements designed to improve overall wireless network performance. Specific differences between the two standards include:
• Wider RF bandwidth—up to 160MHz compared to 40MHz maximum in 802.11n means 802.11AC is capable of passing 4x the data of 802.11N.
• Support for up to 8 MIMO spatial streams vs. 4 in 802.11n allowing 802.11AC to use twice as many data connections (ie Antennas) as 802.11N.
• Multi-user MIMO (MU-MIMO) allows for multiple devices—each with two or more antennas—to transmit or receive independent data streams simultaneously
• Higher Density Modulation—up to 256-QAM vs. 64-QAM in 802.11n. Allows 802.11AC to hold more data in the wireless wavelength.
• Beamforming, which improves signal reach and efficiency by shaping and adjusting the wireless signal output to help maximize the connection to a given client or router.
It is also important to understand that whereas 802.11n operates in both the 2.4GHz and 5GHz bands, 802.11ac is designed specifically for the 5Ghz band. 5Ghz allows for less interference and greater bandwidth than the 2.4GHz band, while 2.4GHz is better for wider coverage and signal propagation.