6 GHz Wi-Fi Pitfalls in 2023/24

Yes, I’m on the 6 GHz trail at the moment, because I want to find out how useful that band currently is and where the limits are. So here’s another post on the topic. In previous articles I have already mentioned that one 6 GHz capable notebook of mine simply refuses to use the band at all, no matter whether Window or Linux is running, and the second one gets easily fooled into switching off the 6 GHz band for a while when it sees ‘rouge’ access points. But unfortunately, there is more.

Apart from fewer Wi-Fi networks populating the 6 GHz band, another advantage I was hoping for was the use twice as large channels compared to the current maximum of 160 MHz in the 5 GHz band. Turns out, however, that current 802.11ax chips (Wi-Fi 6E) are limited to 160 MHz channels. Also, channel bonding 5 GHz and 6 GHz remains a pipe dream in this revision. This means that with current Wi-Fi 6E chips, I don’t see a lot of benefits compared to using the 5 GHz band today. For details see Intel’s specification sheet of their AX211 chip.

All of this combined means that deploying Wi-Fi in the 6 GHz band only makes sense today when the access point also supports 5 GHz. This way, there’s a fallback option when one of your neighbors inadvertently takes down your network. Or, you return home and your notebook’s 6 GHz band is still blocked from a Wi-Fi network the notebook has seen earlier. The problem using several bands: The Wi-Fi access point has to split the maximum transmit energy between all supported bands because it is limited to a combined maximum output power. And then there are legacy devices which require a channel in the 2.4 GHz band.

But there is at least a bit of hope in sight. New Wi-Fi 7 devices will support 320 MHz channels. Here’s an Intel spec sheet with some details.