What is WiFi 6?

Written by Don Schultz, trueCABLE Senior Technical Advisor, Fluke Networks Copper/Fiber CCTT, BICSI INST1, INSTC, INSTF Certified

There's a new WiFi kid on the block, and it’s named “6”. What is this new WiFi 6 technology getting hyped up? Is it better than regular WiFi? Can I get away without using Ethernet cable now? Oh, and what is this “6” number? There was a “5”? Let’s put up a signal block so we can have a quiet discussion…

Old technology in a new wrapper

IEEE is the organization that sets the standards for many technologies, including wireless communication. They recently launched 802.11ax. This new protocol, or “AX WiFi” promises to reduce congestion in data intensive environments, improve speeds, and increase efficiency.

To reduce consumer confusion (well, that’s the goal anyway) the WiFi Alliance has decided to rebrand some of the common protocols still in use, and not bothering to label the older ones.

Current Wifi Protocols:

• WiFi 4 means 802.11n (operates on 2.4 GHz and 5 GHz)
• WiFi 5 means 802.11ac (operates on 5 GHz only)
• WiFi 6 means 802.11ax (operates on 2.4 GHz and 5 GHz)

Older Wifi Protocols:

• 802.11a (operated on 5 GHz only)
• 802.11b (operated on 2.4 GHz only)
• 802.11g (operated on 2.4 GHz only)

Let’s take a walk through WiFi history to put this into perspective:

WiFi started out on the 2.4 GHz frequency band for consumers and had a few channels on 5 GHz for businesses to support the very old 802.11a protocol. The 2.4 GHz band was able to carry protocols like 802.11b (wireless B), and g (Wireless G). Only 802.11a operated on the 5 GHz band and stayed that way until it fell into oblivion. Very few consumer devices supported 802.11a, so it fell to the wayside. If the device in question only supported one or the other, then it was known as a “single band” device.

The protocols built upon each other and each iteration improved error handling, speed, and so on.

The 2.4 GHz band, at one time, was relatively uncongested. It offers:

• 11 different “channels” (not really...all but three were “hashes” that shared signal space with an adjacent channel)
• Three truly separate channels (1,6, 11), that if used separately, don’t “step” onto each other
• 2.4 GHz offers good solid object penetration and range (through cinder block walls to an extent as well)

On the flip side, 2.4 GHz also had the following disadvantages:

• Only three truly distinct channels--not very many to choose from if you are in an apartment complex
• Prone to interference with not only your neighbor’s WiFi due to limited channels, but also had the unfortunate issue of being on the same operating frequency as many other common consumer devices like microwaves, cordless phones, Bluetooth, remote controls, garage door openers, and baby monitors.

Add the rapidly increased commonality of WiFi devices like smartphones in recent years, and things quickly got out of control.

“We need more speed Scotty…”

Just to add to the pain, when newer protocols like 802.11n were added they provided the capability of combining more than a single 2.4 GHz channel together for the purposes of increasing speeds. If you have looked at WiFi routers in recent years you will see claims of 300 Mbp/s speed and up. This is combining two theoretically 150Mb/s channels to get a theoretical 300 Mb/s on 802.11n. I use “theoretical” quite a bit. In theory it would increase speeds, but actually it ended up adding more interference into the equation. This is called MIMO, but more on that in a bit. 

WiFi 4 to the rescue…enter “dual band” and 802.11n

As the wireless airwaves became increasingly congested, IEEE and the Federal Communications Commission (FCC), became aware that a previously restricted frequency band, 5 GHz, was necessary to overcome many of the issues. However, there is no such thing as a free lunch.

5 GHz offers:

• Up to 25 actual distinct channels that don’t overlap each other (802.11n does not take advantage of all 25)
• Immunity from most other consumer devices
• Much higher speeds since non-overlapping channels could be combined with less risk of causing interference for your network and neighboring ones

5 GHz downsides:

• Consumer device manufacturers started introducing cordless phones that operate on 5 GHz, so the 5 GHz band was no longer quite as quiet
• Susceptible to weather radars
• Much less ability to penetrate solid objects, which meant forget about getting a good signal through a cinder block wall
• Less range than 2.4 GHz

Initially, the 5 GHz spectrum made a come back and was offered as an alternative to operating 802.11n on 2.4 GHz. So that is right, 802.11n could run on both 2.4 GHz and 5 GHz. This is known as a “dual band” device. To some extent, this helped solve the congestion when both devices supported dual band. The idea was older devices that only support single band, or 2.4 GHz, would continue to use that band and your newer devices would connect up to the 5 GHz band if they supported dual band via 802.11n.

Beyond the optional 5 GHz frequency for 802.11n, WiFi 4 also introducedMIMO which means “Multiple Input Multiple Output”. This allowed the router and end device to communicate over multiple channels at the same time to increase speed. This is what caused the rapidly increased problems with 2.4 GHz and significantly improved speeds on 5 GHz. A double edged sword, if there ever was one. When configuring a WiFi router that supported 802.11n, experts knew to keep the 2.4 GHz band at a single channel to minimize issues, and to open up the 5 GHz band to two channels.

802.11n, like all previous WiFi flavors before it, could only talk to one device at a time. This is not a big problem if you only have a few devices in your home. 

And now, WiFi 5 to the rescue?

We are going to need more rescue dogs...now we are taking a step backwards! 802.11ac.

In the midst of all this rescuing, WiFi 5 or 802.11ac (Wave 1 followed by Wave 2) was introduced. But now, IEEE decided to restrict it to 5 GHz only. This had the negative effect of:

• Reduced range
• Your phone, computer, or tablet must absolutely support dual band and 802.11ac in order to use it (new phone time...but you wanted the latest anyway)

802.11ac allowed combining yet more 5 GHz channels to achieve (again, theoretically) extremely high speeds for streaming content and gaming.

At the same time, 802.11ac introduced a new, even fancier MIMO called MU-MIMO or Multiple User Multiple Input Multiple Output. If everything worked together like it should, not only could your WiFi router use multiple channels at the same time, but it could do it with four users at the same time. It could also do “beamforming” to better direct the signal towards the actual user.

This was all in Wave 1. Wave 2 introduced the ability to combine yet even more 5 GHz channels. If you wanted it, you would have to dump all of your Wave 1 hardware and upgrade. Again.

If all worked well, you might not be able to leave the room with the WiFi router in it. After suffering multiple iterations of wave after wave (pun intended) you might be poor as well.

Trying again--WiFi 6.

Introducing the latest and greatest old technology, but in a different way, 802.11ax.

802.11ax takes all of the previous technologies, throws it into a blender on high speed, and lets the better ideas from the previous technologies float to the surface.

• Keep 2.4 GHz and 5 GHz to get speed or range depending on your environment like 802.11n? Check.
• Keep the ability to combine 2.4 GHz channels to increase speed? Check.
• Keep the ability to combine 5 GHz channels to increase speed there too? Check.
• Keep around the MU-MIMO and beamforming concepts from both waves of 802.11ac? Check.

Now, add the following ingredients:

• Stronger WPA3 security protocol support. This makes breaking into your WiFi communications even harder than WPA2, which was pretty darn hard!
• Beefed-up MU-MIMO to allow communication with up to eight devices at the same time
• OFDMA or Orthogonal Frequency Division Multiple Access

While you probably have a good handle on MU-MIMO by now, this OFDMA thing requires more explanation. OFDMA takes the older MU-MIMO concept one step further by allowing the signal the WiFi router transmits to address more than one client at a time in the same signal burst. Think of MU-MIMO as eight UPS trucks delivering packages to eight different addresses at the same time, whether half full or not. OFDMA makes sure the trucks are full and now each UPS truck can deliver to multiple addresses as well. You get the ability to service quite a few addresses at once using the same number of trucks.

The idea of 802.11ax is not necessarily to increase speed to any one client device, although it can. The primary purpose of 802.11ax is to allow a large number of WiFi devices on the same network to communicate more efficiently. This has the effect of reducing WiFi network latency, which is one of the biggest problems for gamers.

Finally, 802.11ax does not eliminate the congestion and interference on the 2.4 GHz band. You will still be susceptible to a badly behaved microwave oven. The main thing is you have the option of 2.4 GHz again, so you can get longer range and better obstacle penetration.

Oh, if you want 802.11ax you have to dump all of your equipment yet again and upgrade everything from your router to your phone in order to use it. Otherwise, a 802.11ax router will communicate with older devices at the older protocols (like 802.11ac or 802.11n).

So, this means wired connections (aka Ethernet) are all but dead, right?

Not even close. While it is true that 802.11ax will improve WiFi, Ethernet still has the following advantages:

• Near total immunity from interference, and you have the ability to use shielded Ethernet in extreme circumstances
• Almost imperceptible latency, which means it is still top choice for gaming and streaming entertainment
• Potential for extremely high speed, depending on your equipment, and that speed is to every device, every time

That should clear up the whole “is this new WiFi the real Ethernet killer?” question permanently. WiFi is good, and has a place. However, WiFi will not ever be able to replace wired connections due to the very nature of how it operates. The mantra of networking has not changed: If you can wire it, it should be wired.

Happy Networking!