Wi-Fi 7 Signals the Industry's New Priority: Stability (ieee.org) 45
Multi-link operations and the 6-GHz band promise more reliability than before. From a report: The key to a future Wi-Fi you can depend on is something called multi-link operations (MLO). "It is the marquee feature of Wi-Fi 7," says Kevin Robinson, president and CEO of the Wi-Fi Alliance. MLO comes in two flavors. The first -- and simpler -- of the two is a version that allows Wi-Fi devices to spread a stream of data across multiple channels in a single frequency band. The technique makes the collective Wi-Fi signal more resilient to interference at a specific frequency. Where MLO really makes Wi-Fi 7 stand apart from previous generations, however, is a version that allows devices to spread a data stream across multiple frequency bands. For context, Wi-Fi utilizes three bands-2.5 gigahertz, 5 GHz, and as of 2020, 6 GHz.
Whether MLO spreads signals across multiple channels in the same frequency band or channels across two or three bands, the goals are the same: dependability and reduced latency. Devices will be able to split up a stream of data and send portions across different channels at the same time -- which cuts down on the overall transmission time -- or beam copies of the data across diverse channels, in case one channel is noisy or otherwise impaired. MLO is hardly the only feature new to Wi-Fi 7, even if industry experts agree it's the most notable. Wi-Fi 7 will also see channel size increase from 160 megahertz to a new maximum of 320 MHz. Bigger channels means more throughput capacity, which means more data in the same amount of time.
That said, 320-MHz channels won't be universally available. Wi-Fi uses unlicensed spectrum -- and in some regions, contiguous 320-MHz chunks of unlicensed spectrum don't exist because of other spectrum allocations. In cases where full channels aren't possible, Wi-Fi 7 includes another feature, called puncturing. "In the past, let's say you're looking for 320 MHz somewhere, but right within, there's a 20-MHz interferer. You would need to look at going to either side of that," says Andy Davidson, senior director of technology planning at Qualcomm. Before Wi-Fi 7, you'd functionally be stuck with about a 160-MHz channel either above or below that interference.
Whether MLO spreads signals across multiple channels in the same frequency band or channels across two or three bands, the goals are the same: dependability and reduced latency. Devices will be able to split up a stream of data and send portions across different channels at the same time -- which cuts down on the overall transmission time -- or beam copies of the data across diverse channels, in case one channel is noisy or otherwise impaired. MLO is hardly the only feature new to Wi-Fi 7, even if industry experts agree it's the most notable. Wi-Fi 7 will also see channel size increase from 160 megahertz to a new maximum of 320 MHz. Bigger channels means more throughput capacity, which means more data in the same amount of time.
That said, 320-MHz channels won't be universally available. Wi-Fi uses unlicensed spectrum -- and in some regions, contiguous 320-MHz chunks of unlicensed spectrum don't exist because of other spectrum allocations. In cases where full channels aren't possible, Wi-Fi 7 includes another feature, called puncturing. "In the past, let's say you're looking for 320 MHz somewhere, but right within, there's a 20-MHz interferer. You would need to look at going to either side of that," says Andy Davidson, senior director of technology planning at Qualcomm. Before Wi-Fi 7, you'd functionally be stuck with about a 160-MHz channel either above or below that interference.