Does Wi-Fi 6E change how we define wireless LAN requirements? Now, the introduction of a new frequency band is going to change how we design Wi-Fi, but does it really change how we gather and define requirements? Now, while many things do stay the same, Wi-Fi 6E brings up a number of additional considerations. So let’s start with a definition. What is Wi-Fi 6E? Well, Wi-Fi 6E is a Wi-Fi Alliance certification of equipment which supports the HE or high efficiency physical layer defined in the IEEE 802.11ax amendment, which operates in the 6 GHz frequency band. Or maybe more simply put, Wi-Fi 6E is 802.11ax equipment operating in the 6 GHz band.
So what is special about Wi-Fi 6E? Well, the main thing that’s special is it’s all new. The 6 GHz band has only recently been approved by local regulatory authorities for Wi-Fi operations. And Wi-Fi 6E devices are the first devices to make use of this new spectrum. So we have new spectrum, new devices, new rules, and therefore some new approaches to wireless LAN design are also called for. Now, the first thing that should be considered is that the 6 GHz Wi-Fi spectrum allocation is not globally uniform. So for example, the FCC in the United States have opened up 1.2 GHz of spectrum from 5.925 GHz all the way up to 7.125 GHz. And this approach has been adopted not only by North America, but also some Southern American countries too. Whereas most of Europe, along with countries like Australia, have adopted just a first 500 MHz of 6 GHz spectrum. However, it should be said that this is an ever-changing landscape with countries such as the United Kingdom and Australia considering opening up the rest of this 6 GHz band.
So what does this additional spectrum give us? Well, the full 1.2 GHz of spectrum gives us a total of fifty-nine additional 20 MHz-wide channels, or twenty-nine 40 MHz-wide channels. Or we could say fourteen 80 MHz-wide channels. And just to put some context behind this, that is more 6 GHz 80 MHz-wide channels than we currently have 5 GHz 40 MHz-wide channels.
So how do we plan for all this extra spectrum at the defined stage? Well, the first thing we must decide is what do we want to use the new spectrum for? Now, while some wireless implementations still use the same SSID on both the 2.4 and the 5 GHz band, there’s been a considered move away from this approach over the last few years. And a common modern-day methodology would be to use a higher capacity, better performing 5 GHz band for corporate, latency-sensitive, and business critical applications while utilizing the 2.4 GHz bend for IoT and GAT services.
So the obvious question is, before deploying Wi-Fi 6E access points, what are we going to use this 6 GHz band for? Now, the 6 GHz band will undoubtedly provide more capacity, especially in countries where we have the full 2.4 GHz of spectrum available. And these 6 GHz channels are going to yield better performance due to less congestion and a lack of legacy devices. So why not just move all business-critical Wi-Fi operations to the 6 GHz band?
Well, one thing we need to consider is client support. You see, in most enterprises today, Wi-Fi 6E clients are going to be in the minority. So if we are going to offer business operations in the 6 GHz band, then we’ll also need to make some provision in the 5 GHz band for non Wi-Fi 6E clients. And this brings us to another important consideration. In the 6 GHz band, WPA version 3 is mandatory and therefore the only option. So if we are going to advertise a corporate SSID on both the 5 GHz and 6 GHz band, some sort of provision would need to be made for those client devices which don’t support WPA3. Now, the Wi-Fi Alliance does allow for a mixture of WPA2 and WPA3 clients connecting to the same SSID in both the 2.4 and the 5 GHz band. We call this mode “transition mode.”
Now, in Juniper-Mist, when a single SSID is configured on both the 5 GHz band and the 6 GHz band, what Mist does is it allows the 5 GHz band to use transition mode and the 6 GHz band to operate as pure WPA version 3. Now, while this is a really nice solution, there are a few considerations. You see, the hope of this approach is that clients who don’t support WPA3, well they will just connect using WPA2 and stay connected on the 5 GHz band. Whereas clients who do support Wi-Fi 6E, well they will always connect using WP3 regardless of which frequency band they connect to. Now, while that’s a hope, and we hope clients will exhibit that type of behavior, the reality of the situation is that we can’t control the clients. And because we are giving them the option of WPA2, they may choose to connect using WPA2 at 5 GHz, which means that should they subsequently then decide to roam to a 6 GHz radio, they may encounter a roaming issue as they transition from WPA2 to WPA3.
Now, the table here shows the results of some tasks carried out by Juniper. And as you can see, when transitioning between WPA2 and WPA3 Enterprise, no problems were experienced as they were essentially the same authentication method, 802.1x. However, WPA personal and open networks may experience interband roaming issues.
So what does all this mean for planning my SSIDs in 6 GHz? Well, I foresee two main approaches. Existing corporate SSIDs, which support 802.1x, that’s WPA Enterprise, could be added to 6 GHz radios to provide additional capacity and performance relatively seamlessly. But a second approach would be to create a 6 GHz-only SSID. These SSIDs may connect to the same backend VLANs as existing 5 GHz SSIDs, but this approach means that 6 GHz-capable clients have an exclusive SSID delivering consistent 6 GHz performance, and it negates any interband roaming issues. And this approach also allows then the organization to slowly transition the user base to 6 GHz as new devices are purchased. It should be noted that this approach does require a full 6 GHz coverage in all operational areas.
Now, when it comes to defining an RF specification, I suspect 6 GHz primary and secondary signal strength requirements will be similar to that at 5 GHz. However, it may prove wise to require a couple of dB strongest signals in the 6 GHz band to compensate for any transmit limitations which 6 GHz guys must adhere to.
Well, I hope you’ve enjoyed this video, and I hope it was helpful in highlighting some of the 6 GHz considerations when defining Wi-Fi 6E networks. And be sure to check out the Wi-Fi 6E design video over in the design section of this site, and I will see you next time. Goodbye.