With a top speed of more than 300 mph, the Hennessey Venom F5 is believed to be the fastest production vehicle ever made. But put it on a two-lane road with bumper-to-bumper traffic and intermittent speed bumps and all that horsepower becomes pointless.
That’s a rough approximation of the basic problem with Wi-Fi networks in recent years. Evolving standards that focused on increasing peak speeds did not effectively address growing issues of network congestion and capacity limitations.
With the new 802.11ax standard for wireless LANs, the Institute of Electrical and Electronics Engineers (IEEE) is taking a new approach. Although the nominal data rate is just 37 percent higher than the current 802.11ac standard, 802.11ax networks will be four to 10 times faster than existing networks due to more efficient spectrum utilization and improvements for dense deployments.
Wi-Fi has been a victim of its own success. The IEEE’s original 802.11 Wi-Fi protocol was designed to deliver short-range connectivity for laptops and other mobile devices at a time when wireless was a secondary network providing service to a limited number of people using a limited number of devices and requiring limited bandwidth. Those limits have vanished.
The proliferation of smarter, more portable devices combined with advanced mobile application platforms has fundamentally altered WLAN requirements. Organizations need to support more wireless users, devices and traffic than ever before.
The 802.11ax standard, also known as High-Efficiency Wireless (HEW) or Wi-Fi 6, is capable of managing dense usage, increased data traffic and a diverse mix of applications and services with differing needs. It achieves this through the use of several new techniques and innovations, including some borrowed from the cellular word.
One change is the use of a wider spectrum channel at 160MHz, which is four times larger than the channels used by 802.11ac. Additionally, the standard operates in both 2.4GHz and 5GHz spectrums and will incorporate additional bands as they become available. This reduces congestion by creating more channels for data.
802.11ax also uses spatial multiplexing technology known as MIMO (multiple in, multiple out) and MU-MIMO (multiple-user MIMO) to allow multiple streams of data to travel across different physical paths. While 802.11ac (Wi-Fi 5) used this technology to allow up to four simultaneous streams, the new standard supports eight streams and uses beamforming technology to accurately aim those streams at the receiver’s antennas.
One of the more significant performance enhancements borrows from cellular’s 4G/LTE (long-term evolution) standard for mobile Internet connectivity. Like LTE, 802.11ax uses a technology called orthogonal frequency division multiple access (ODMFA), which can break a Wi-Fi channel down into hundreds or even thousands of subchannels. This allows up to 18 clients to send data simultaneously without creating signal contention or congestion.
It is probably way too early to rip out your existing infrastructure and begin a wholesale migration to the new standard. Although some consumer and enterprise 802.11ax access points are already on the market, they are actually built on a partial implementation of the standard. The finalized standard is expected to be publicly released in early 2019, at which time fully compliant products will begin hitting the market rapidly.
However, it isn’t too early to begin making plans. We’re telling our clients to investigate and become knowledgeable about the benefits of 802.11ax now. As part of the process, we recommend conducting a WLAN survey to identify what standards your existing clients and access points currently support and what upgrades will be needed. Getting up to speed now can put you on the fast track to adoption when the time is right.