For those of you busy installing your Wave 2 802.11ac infrastructure, and even for those who still have that project...
on your to-do list, be prepared: The next wireless LAN standard, 802.11ax, is now in the late stages of development at the Institute of Electrical and Electronics Engineers.
We expect the 802.11ax standard, at least from a technical perspective, to be mostly complete soon. But as has traditionally been the case with new generations of wireless LAN (WLAN) specs over the years, chipsets based on the new specs are already appearing in the marketplace -- no surprise. Wi-Fi is a very competitive space, and faster-better-cheaper -- the driving force behind networking -- remains king.
First, let's talk about what's exciting and new in the latest WLAN standard. 802.11ax ratification means support for speeds up to 10 Gbps. For those of us who've been working in the wireless space since 1991, when 1 Mbps was essentially exotic and usually unobtainable, it's gratifying to see the realization of technologies that not so long ago seemed more magical than tangible.
Thanks to multiple input, multiple output (MIMO), beamforming, wideband channels and other more powerful technologies, 802.11ax delivers a meaningful improvement in the evolution of rate versus range performance -- how much throughput one can realize at any given moment in time at a given distance between transmitter and receiver.
Remember, since the power inherent in radio waves fades exponentially with distance and other factors, any increase in throughput without a corresponding boost in range is essentially just marketing. More is always better, so the 802.11ax standard is already a welcome addition to the technology arsenal. And as 802.11ax also seeks to improve signal reliability, that range parameter is looking good.
New features to beef up transmission
And, of course, there is more. The new spec includes bidirectional multiuser MIMO (MU-MIMO), allowing multiple stations to transmit unique data streams simultaneously to an access point during a single AP receive cycle. With 802.11ac, MU-MIMO only works from APs to client stations.
Additionally, 802.11ax ratification permits work in the 2.4 GHz bands now ignored by 802.11ac. This will enable more efficient use, and reuse, of that spectrum and perhaps provide the final incentive for enterprises to replace technologies older than 802.11n -- and perhaps even 802.11n itself. Much depends upon the availability of clients equipped with .11ax, but these will begin to appear in great numbers within two years or so.
Despite the enhancements in 802.11ax, there are some market forces that are working to extend the life of 802.11ac and, in the process, perhaps dampen demand for the 802.11ax standard. First, there isn't that much difference between the 10 Gbps possible in .11ax and the 7 Gbps supported in .11ac.
Second, MU-MIMO -- again, already available -- has given Wave 2 802.11ac products a very significant performance boost. This could mean that Wave 2 802.11ac may have a much longer shelf life than previous WLAN standards.
That said, by 2020, I believe 802.11ax ratification will have ushered in some major inroads anchoring new installations, even if much of the infrastructure continues to operate in 802.11ac mode. By 2028, 802.11ax will be standard -- at least until 802.11ad and 802.11ay come around. We'll explore those specifications in an upcoming column.
Editor's note: Author Craig Mathias is a member of the IEEE, but does not participate in the development of standards.