When you think of 6 GHz and wireless, it’s natural to think of 5G. It’s the top end of the LTE frequency range, and above where you think of other wireless technologies like Wi-Fi operating. But it turns out that Wi-Fi has been feeling cramped in its current bands. It wants to again expand up-town and can, thanks to an announcement from the chairman of the FCC, who intends “..to accommodate (an) increase in Wi-Fi demand, (by) aiming to increase the supply of Wi-Fi spectrum with our boldest initiative yet: making the entire 6 GHz band available for unlicensed use”. The Wi-Fi Alliance is jazzed and is targeting a new Wi-Fi 6E standard to this band.
Wi-Fi bandwidth squeeze
The motivation behind this change is that Wi-Fi demand is growing rapidly. Cisco projects that nearly 60% of global mobile data traffic will be off-loaded to Wi-Fi by 2022. However, the traditional 2.4 GHz band for Wi-Fi has become crowded, competing with other technologies such as Bluetooth and ZigBee. Wi-Fi expanded a while ago to 5 GHz starting with Wi-Fi 2 (802.11a) but even that demand is now overflowing capacity of Wi-Fi 4, 5 and 6 due to increased internet connection.
Another challenge for Wi-Fi 6 is that the top-end of supported bandwidth – 160MHz – has never been practically useful. One very clear example is how access points (APs) in airports are used. In principle these can be configured for two 160MHz bands, though interference from other traffic is problematic. In practice, airports use five 80MHz bands – more net bandwidth and less interference. Which is disappointing for the wireless chipmakers. They put a lot of effort into supporting 160MHz bandwidth and it’s never used.
The only way out was up, so that’s where the FCC and the Wi-Fi Alliance have gone, to the 6GHz band, with up to 1200 MHz of bandwidth. This increases the spectrum available for Wi-Fi by almost a factor of five – a truly meaningful expansion with up to seven additional usable channels of 160MHz each.
Wi-Fi 6E applications
Wireless VR/AR headsets are expected to jump on this new bandwidth. Today they are using WiGig at 60GHz, but these systems are big and power hungry, demanding a bigger battery and adding to user fatigue. Worse still, it must be built using niche technology. Wi-Fi 6E doesn’t have the latency or bandwidth advantages of WiGig, but it’s good enough for most VR/AR applications, it’s much lower power (so smaller batteries) and can be built with mass-market mobile chip technologies, so much cheaper than WiGig chip.
There are always tradeoffs of course. Wi-Fi 6E will have slightly shorter range than the 5GHz band and power consumption will increase a bit, though neither will be much worse. Still, power consumption will likely make the new standard unattractive for wearables. It will still be good for airports, stadiums and our homes, best suited to fat pipes like video distribution though we will need to provide more APs to ensure good coverage.
Chips to support the new standard are already underway, from Qualcomm and Broadcom. The certification program is not yet finalized but is expected to appear later in the year.
Anyone designing next generation wireless chips and who wants to take advantage of Wi-Fi 6E is going to need IP. Outside of the actual radio circuitry, the changes required in CEVA’s current RivieraWaves 802.11ax IP to support Wi-Fi 6E are fairly straight forward, and this IP will be available to the general market as soon as the standard is ratified. You can learn more about RivieraWaves Wi-Fi HERE.
