WiFi 6 Why We Need It And What It Isn’t

Wireless networks have been around for a long time. We all know the history of the industry starting as a nice to have feature that we could work without a cable. Today wireless has become the primary medium for connectivity in most industries and most households. As the shift has occurred, wireless technology has had to try and keep up. The latest phase of this race is the 802.11ax, or WiFi6, amendment.

Why do we need WiFi6?

By now everyone has heard that 5G is coming and the crazy fast speeds that it will bring from a cellular-side. We will look at that more in another post. But WiFi is fighting the same issues as cellular in today’s world. We are oversubscribed on WiFi, speeds suffer because of older technology, wireless is the primary connection method of almost every device in the world and IoT is coming. Enter WiFi6.

To be upfront as we begin this, ratification of the 802.11ax standard looks to be at least a year away with most stating a date of September 2020 before this will happen. Even without full ratification manufacturers are starting to put out access points and a few clients are starting to trickle into the market.

So with ratification still a year away, why do we need to worry about WiFi6 now? WiFi6 is more about capacity than speed. As more and more devices are accessing the wireless network, bottlenecks begin appearing. The way WiFi6 will handle this is a trick taken from the cellular industry with OFDMA (Orthagonal Frequency Division Multiple Access. The easiest way to explain it is we are taking a highway that has 8 lanes today and then funnels to a one lane road. Huge bottleneck occurs and all traffic grinds to a halt like the 405 in California. Now with WiFi6 and OFDMA, those 8 lanes stay 8 lanes and traffic can flow freely. With having these extra ‘lanes’ capacity is now increased. This is the key part of WiFi6. There is a great white paper on the traffic lanes with well done diagrams and more information on here (https://www.arubanetworks.com/assets/so/SO_80211ax.pdf ).

We have all heard about the speeds and how fast we can now send and receive traffic on WiFi6, but capacity is the key to the system. More capacity equals more opportunities for devices to be serviced on the network, especially for time-senstive data like Voice and Video over WiFi. As we move to Mobility First workplaces and stop pulling cables to desks, wireless is more and more important. Design is ever more complex now for wireless and how we can use the spectrum smarter to allow more of these devices to function and function well.

As stated previously, the key to the new ammendment for 802.11ax is not all about speed. It is about capacity. We need to be looking at how we handle these time-sensitive data and not how we push them faster. With WiFi6, yes the speed is there if you have the right client, but how do we service that least-capable device and make that function as if it is a WiFi6 device? Capacity is the key and as we continue to add more devices, i.e. IoT, wireless first deployments, nurse call devices. WiFi6 is the key to solving this issue and granting that capacity we so badly need.

802.11ax The Future Begins

The networking industry is full of buzzwords and hype; A.I., M.L., SDWAN and virtual everything. This is even more evident in the world of wireless networking; claims of speeds up to 1 Gbps, wired-like connectivity, mobility first, future-proofing and on and on. It all reminds me of one of my favorite Queen songs Radio Gaga, “All we hear is radio ga ga, Radio blah blah, Radio, what’s new?”.

The new 802.11ax amendment (not yet standard, thanks TheITRebel), or WiFi6 as it is now being called, is slated to be ratified later in 2019. This is causing all kinds of hype in some circles and not so much in others yet as end-user computing devices will probably not have chipsets to support 802.11ax until maybe the end of 2019. Looking forward, more full adoption will probably not happen until 2020 or even as late as 2021.

What is 802.11ax?

802.11ax will build on the features that the 802.11ac, or WiFi5, standard gave us as well as adding some cool new things to help with the ever growing demand on wireless networks. From a desire for mobility-first networks [to cellular offloading that is wanted (and sometimes needed) from the carriers,.11ax has it’s work cut out for it.

802.11ac gave us some significant improvements with additional channel widths in the 5GHz space to allow for 80MHz channels in Wave 1 and 160MHz channels in Wave 2, giving higher bandwidth availability to user devices if those devices had the chipset to support it. The drawback isnow with 80MHz and 160 channels is that we take the available 5GHz channels from a total of 24 down to 5 or 1 available non-overlapping channels, depending on the usage of DFS channels. This makes it much harder to channel plan in an enterprise or LPV style of deployment, so I still recommended to use 20 MHz channels, or perhaps 40MHz if done properly. However, when this style of deployment is done the whopping 1.3Gbps that is touted by the marketing folks cannot be met even when using 3×3 spatial streams. Again, an example of more hype that really is not too useful outside of a small business or home deployment.

802.11ax can achieve throughput speeds of up to 4.8Gbps according to the data sheets and marketing put out so far. But how can we get to those speeds?

As with 802.11ac, to reach the speeds marketing is telling us about we need two things, multiple bonded channels and clients that can support it. Let’s look at these one at a time.

802.11ac wave 2 began to support 160MHz channels as well as Multi-User Multiple Input/Multiple Output to support multiple streams of data. This implementation yielded multi-user downlinks from the AP to the client. However, uplink traffic from the client to the AP is a single client at a time, by contrast. 802.11ax looks to improve this by allowing MU-MIMO APs to talk bi-directionally to up to 8 devices simultaneously and to become almost ‘switch-like’ (I know more buzzwords, sorry). The new standard will also allow capable clients to take full advantage of MU-MIMO and to use dual-streams to an AP which would potentially double the bandwidth to that client.

The best analogy I have seen of this so far is with 802.11ac there is an eight-lane road, that funels down to one-lane creating a bottle neck and allowing only a single car thorugh at a time. This is how MU-MIMO worked previously with legacy uplink/downlink mechanisms. Now with 802.11ax that one-lane road is extended to a full eight-lanes, eliminating the bottle neck and allowing traffic to flow freely.

More to come on this subject soon.