WiFi6, Wait no more
Like us, you’ve probably heard about the upcoming new wireless technology – WiFi6, specifically 802.11ax – and are probably getting a little excited about the possibilities of wireless networking finally catching up to, and maybe surpassing, wired networking.
Don’t get me wrong, the current standard – 802.11ac – is pretty good and Wave 2 provides an experience that is pretty darn close to wired gigabit Ethernet networking. But, as with most wireless networks, it still has a few issues with high-density scenarios.
As WiFi has become an essential part of our working, and personal, lives it is more or less presumed that you’ll be able to connect wherever you go. Wireless technology has, of course, evolved to meet the growing consumer, and business, demands to the point where we have 802.11ac Wave 2; the latest iteration of “WiFi 5”. This iteration makes use of MU-MIMO (Multi-User-Multi-In-Multi-Out to deliver wireless speeds (not necessarily throughput) in excess of 2 Gbps and, with some clever design and configuration, there’s a theoretical maximum of 6 Gbps.
In WiFi 5, MU-MIMO only operates on the downlink and could only support groups of four clients on one frequency. WiFi 6, however, works on both the uplink and downlink allowing up to 8 clients to be grouped together on the same frequency. This, coupled with other improvements to the standard, significantly improves the density of connections that can be supported on a single access point.
As with previous iterations of 802.11 such as 802.11n and 802.11g, WiFi 5 still has an issue with the number of connections a single AP can support. This is due, almost entirely, to the collision-detection method – CSMA-CA (Carrier Sense, Multiple Access – Collision Detection) – which is essentially the same method used in Ethernet networking. If a channel is used, the client, or AP, can’t transmit data.
Conversely, if the channel is free, the client or AP reserves the channel and then transmits the data. Once transmission is complete, it makes the channel available again. Mostly, this happens in microseconds so it isn’t particularly noticeable. Unless there’s a large number of clients associated with a single Access Point.
For hospitality, this causes the perception of poor wireless.
The primary development focus of 802.11ax has been to increase support for higher density deployments. A by-product of that has been, of course, an increase in speed – approximately 40% over 802.11ac Wave 2. Thanks to other technologies included in the new standard, performance is unlikely to degrade as the number of device connections increase.
One huge difference between WiFi 5 and WiFi 6 is that WiFi 5 only applied to the 5 GHz band. WiFi 6, on the other hand, will use both. This’ll help make the highly congested 2.4 GHz band more usable. It’ll also, as with previous wireless standards, be backwards compatible with WiFi 5.
That said, there won’t be many benefits of WiFi 6 actually realised unless both the AP and client supports it. Both of which are coming.