Another new wireless technology, already? Darien Graham-Smith looks ahead to the seventh generation of the IEEE networking standard.

CREDIT: Rawpixel Ltd/iStock/Getty Images Plus

f you’re not ready for Wi-Fi 7, that’s understandable. Most of us haven’t caught up with Wi-Fi 6E yet, which only hit the I mainstream around 2020 while we were distracted by other issues. Strictly speaking, though, Wi-Fi 6E wasn’t a new standard. While it introduced support for wireless networking in the 6GHz frequency range, it’s otherwise based on the same 802.11ax spec as Wi-Fi 6. It could have been called Wi-Fi 6.1.

So it’s getting on for four years since the last major Wi-Fi update – which is about par for the course. From the original 802.11b release in 1999 onwards, each generation has reigned for between four and six years, before being replaced by something smarter and faster. Wi-Fi 6 was adopted in 2019, and Wi-Fi 7 is due to be finalised in 2024 – so it fits the pattern perfectly. That doesn’t mean you’ll necessarily have to wait until next year to move up to Wi-Fi 7. The core features and technologies are already firmly defined, allowing manufacturers to build and release Wi-Fi 7 hardware well ahead of the final sign-off. Indeed, as we’ll discuss, you can already buy a handful of Wi-Fi 7 devices.

That’s how it goes in the world of Wi-Fi: 802.11n and 802.11ac routers were widely available long before the standards had been finalised. Indeed, while Wi-Fi 6 was released in 2019, the standard wasn’t fully signed off until February 2021 – 16 months after we’d tried our first Wi-Fi 6 router, the Asus RT-AX88U.

QAM jam

Wi-Fi 7 uses the same OFDMA technology as Wi-Fi 6, which divides up the airwaves according to demand (and the router’s QoS rules), so that multiple devices can smoothly share the available bandwidth.

However, each ‘slot’ in a Wi-Fi 7 connection carries more data than before, thanks to the use of higher-order QAM – quadrature amplitude modulation. This is a technique used to encode data in a radio signal by adjusting the amplitude and phase of a pair of carrier waves. Different combinations create different wave patterns, used to represent different binary values.

Since the radio waves themselves are analogue, the number of values that can be represented is effectively infinite – the only limitation is how precisely the radio transceiver can modulate and decode the waves. Wi-Fi 5 used a 256-QAM system, where each wave pattern encoded eight bits of data, while Wi-Fi 6 increased this to 1,024-QAM, supporting 10 bits of data. The latest Wi-Fi 7 standard further boosts this to 4K-QAM, meaning that the same radio patterns that used to convey eight or 10 bits of data can now carry 12.