How Wi-Fi 7 addresses Wi-Fi 6 pitfalls

‘We didn’t quite realize the magnitude of taking a well-adopted, single-user technology and making it multi-user,’ says LitePoint exec

Certified by the Wi-Fi Alliance in 2019 and based on the IEEE 802.11ax standard, Wi-Fi 6 is designed for high-density, multi-user environments and features uplink and downlink OFDMA, 8×8 multi-user MIMO and 1024 QAM. Its introduction signaled improved performance and capacity for mobile, IoT devices and even critical applications that require low latency. However, according to LitePoint’s Director of Marketing Adam Smith, the wireless industry may have bitten off a bit more than it could chew.

“Wi-Fi 6 is such a big change to Wi-Fi that we didn’t quite realize the magnitude of taking a well-adopted, single-user technology and making it multi-user,” Smith told RCR Wireless News. “It has been a bigger challenge than I think many people thought it was going to be.”

He acknowledged that yes, when you look at the number of shipments of access points, Wi-Fi 6 has likely surpassed those of Wi-Fi 5, but this is mostly because there is no longer a cost advantage to sticking with Wi-Fi 5. “The chipmakers have made Wi-Fi 6 the new standard, if you will,” he explained, adding that despite what the shipment logs say, “the dirty little secret” is that multi-user — Wi-Fi 6’s headlining capability — has yet to be deployed in “any significant way,” particularly in the 5 GHz band.

“So, what I might say is that peaceful coexistence between Wi-Fi 5 and Wi-Fi 6 is kind of a joke right now,” Smith continued. Providing additional context, he argued that in order for a device to operate in a multi-user fashion, it has to be a Wi-Fi 6 device, meaning Wi-Fi 5 or earlier devices — which make up more of the devices currently in operation — will always be single user. “If you’re trying to lay a Wi-Fi 6 network on top of it, you either to need to rip and replace — to use a cellular term there — or you need to somehow figure out of to coexist,” he added.

Further, Smith said that Wi-Fi operation in the 6 GHz band, known as Wi-Fi 6E, is also hitting some obstacles. “6 GHz adoption is on its way, but it’s still got a long way to go,” he said, referring largely to the reality that not every country has opened up this band, or has only partially done so, for use by Wi-Fi devices.

Much of North and South America have fully implemented Wi-Fi 6E, according to the Wi-Fi Alliance; however, Australia, Colombia, Hong Kong and Mexico are the only other countries currently considering opening up the full band, and others still, like China, have suggested they won’t use 6 GHz for Wi-Fi at all. And while the 6 GHz band isn’t a requirement for Wi-Fi 7, it will allow user to get most out of the latest generation of wireless technology.

All hope is not lost, though. Several standards for Wi-Fi 7, the next generation of wireless technology currently awaiting certification, will directly address the multi-user challenges of Wi-Fi 6. While Wi-Fi 7 boasts a number of notable features like support of both 320 MHz transmissions — double the 160 MHz of Wi-Fi 6 — and 4096-QAM, which delivers significant speed increases, one of its most exciting enhancement might be Multi-Link Operation (MLO). 

With MLO, a device connected in the 5 GHz band that is suffering from degraded performance due to another device popping up on the network will automatically — and very quickly — switch over to the 6 GHz band. In this way, Wi-Fi 7 will actually enable the promised multi-user capabilities first outlined in Wi-Fi 6 standards.

In addition, one of Smith’s favorite Wi-Fi 7 features, preamble puncturing, will help those regions not intending to use 6 GHz, or all of 6 GHz, for Wi-Fi. This feature improves spectral efficiency by allowing a Wi-Fi AP to transmit a “punctured” portion of the spectrum channel if some of the channel is being used by legacy users. By avoiding a channel that is already in use by incumbents, a wide swath of spectrum can still be obtained, even for those without the full 6 GHz band available.

Traditionally, for instance, if an incumbent user is occupying a portion of an otherwise free channel, an AP will be prevented from using this spectrum. Preamble puncturing, however, lowers the overall bandwidth by the punctured amount and delivers a wider channel.

The headlines for Wi-Fi 7 are higher-data rates and capacity, but Smith summarized: “Largely what it’s doing is fixing some of the things in Wi-Fi 6 to make it more flexible to deploy.

The Wi-Fi Alliance is expected to certify W-Fi 7 at the end of 2023.