By Claus Hetting, Wi-Fi NOW CEO & Chairman
A new study released by Strategy Analytics says 8×8 MU-MIMO is the key to top-tier Wi-Fi 6 performance. It also says that 8×8 MU-MIMO (uplink & downlink) is even more important than OFDMA for delivering Wi-Fi 6 capacity today and that nearly all new Wi-Fi 6 client devices already support the feature.
What Wi-Fi 6 features should Wi-Fi AP and client device manufacturers focus on bringing to market right now? That’s one of the new billion-dollar questions in play as Wi-Fi 6 begins its global rollout across a widening expanse of routers and devices. A new study by Strategy Analytics says 8×8 MU-MIMO is “clearly the defining feature for the premium tier” of new Wi-Fi 6-based APs.
The report says there are multiple benefits of 8×8 MU-MIMO including the capability of delivering up to 1.2 Gbps of bandwidth to each of four 2×2 client devices for a total aggregate bandwidth (on the 5 GHz band) of 4.8 Gbps. The report also documents that contrary to popular belief nearly all (twelve of thirteen) Wi-Fi 6 client devices released to date already support ‘8×8 sounding feedback’ – the function required for client devices to make use of the 8×8 MU-MIMO feature.
Add to this the 3 dB signal strength improvement coming from 8×8 beamforming gain (compared to 4×4 systems), which in turn improves coverage in the home. Strategy Analytics says “carriers typically want to provide customers with APs with dual-band 4 x 4 for apartment flats, 8 x 8 for houses, and 8 x 8 plus 4 x 4 extenders – with either wired or wireless backhaul – for large houses.”
About 40% of all Wi-Fi 6-capable APs released as of May this year are 8×8 MU-MIMO (at 5 GHz) capable while the remainder is typically 4×4 MU-MIMO capable, the report says.
The report also points out the little-known fact that in Wi-Fi 6 Release 1 an AP can operate in one of three modes at a time (per frame), meaning MU-MIMO, OFDMA-mode, or SU-MIMO. “OFDMA is important especially for small packet size data and very congested conditions, reducing contention, but MU-MIMO can dramatically increase total system throughput. Both are key features of Wi-Fi 6,” the report says. The report suggests that all carriers and equipment vendors “evaluate 8 x 8 carefully vs. tri-band and dual-band 4 x 4 for the target application and available budget.”
Below: Typical Wi-Fi 6 AP portfolio for ISPs. Source: Strategy Analytics report, June 2019.