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13 December 2022

First major WiFi 6E deployments herald era of coexistence in private 5G

Major WiFi 6E deployments during 2022 in the USA in academia, healthcare and entertainment herald an era where WiFi and private 5G will increasingly be pitched as alternatives for higher performing wireless enterprise connectivity, while also coexisting in many cases. With growing overlap in spectrum occupancy now that WiFi has moved up into the 6 GHz band, as well as some technological convergence, we can begin to envisage an era where the two are finally unified, or at least the boundaries blur with more transparent switching between them.

Currently WiFi is more likely to be preferred indoors and has the advantage of incumbency, which has proved decisive in some of the recent 6E deployments. Private 5G has the advantage of superior range and coverage outdoors, and also for use cases demanding the very lowest latencies down to 1ms, primarily in manufacturing and engineering.

Glimpsing these recent deployments, the first and largest was at The University of Michigan (U-M), for a colossal campus serving over 63,000 students across 225 buildings and outdoor areas. In this case private 5G would barely have been considered as WiFi was already entrenched around a robust core IT network. It was almost a straight upgrade, replacing 16,000 legacy WiFi access points (APs) with slightly fewerWiFi 6E APs, about 15,500, from Aruba Networks.

WiFi 6E increases capacity about 2.4 times but is also far better than WiFi 5 at sustaining performance in dense environments, important given that some of the university’s classrooms can accommodate 500 students. Overall activity required the network as a whole to be capable of supporting a maximum of 70,000 concurrent WiFi connections at download speeds up to 750Mbps, according to Ravi Pendse, U-M’s CIO.. He highlighted the baseline requirement that all personal devices should be able to receive at least an HD-quality video stream at the busiest times in the most densely populated areas.

Another requirement was support for the WiFi Alliance’s Passpoint standard to enable transparent roaming around the campus as devices move between APs. This is critical for overcoming one of WiFi’s bugbears, the need to sign on to networks that the device has not encountered before. Passpoint has been knocking around for a while, but has never been deployed on this scale before, so to some extent the U-M network will be a proving point for truly ubiquitous WiFi access over a larger area. Certainly, this is a candidate for being the world’s biggest Passpoint-capable installation so far.

Pendse also alluded to latency with comments about the network serving university activities in R&D beyond personal communications, including robotics. On that count the university has taken a slight leap of faith, certainly looking to the next generation WiFi 7 to deliver capabilities more closely approaching 5G, with inclusion of time-sensitive networking (TSN), aiming to match the more deterministic and predictable latency enabled by 5G Standalone (SA) in licensed spectrum.

TSN brings three key functions, one being high precision time synchronization across all devices as a prelude for very low delay. Then comes scheduling and traffic shaping, allowing prioritization of traffic, and finally agreed rules for reserving paths, allowing for fault tolerance by avoiding a single point of failure. The last point avoids the need for the network itself to be application-aware, which instead relies on devices adhering to these agreed rules and not cheating.

It may still be that WiFi 7 fails to match 5G SA for guaranteed ultra-low latency around 1ms over the radio links that will be required for some applications, in robotics and precision control more perhaps than interactive conferencing or even mobile gaming. It could be that WiFi will need to embrace some form of network slicing to assign dedicated radio resources to highly delay-intolerant processes.

At least two other recent major WiFi 6E deployments did occur in sectors where private 5G is being pitched more strongly as an alternative. One was by Novant Health in North Carolina, USA, the first significant healthcare provider to deploy WiFi 6E on a large scale around a campus comprising clinics, outpatient centers and hospitals. In this case the APs came from Extreme Networks, where the ability of 6E to operate in the 6 GHz band free from interference that might impact critical processes in the lower 5 GHz and 2.4 GHz bands was important, according to Rob Hale, manager of infrastructure and technical engineering at Novant Health. A key point was ubiquitous indoor access at an affordable price, where private 5G still has some work to do convincing doubters.

The other notable USA WiFi 6E deployment recently was at the Chase Center in San Francisco, home arena of the current NBA (National Basketball Association) champions Golden State Warriors. The arena deployed over 250 WiFi 6E APs from Aruba for fans to stream videos and share photos while listening to the play-by-play commentary, and pull up match statistics from the Warriors + Chase Center app.

This featured filtering across the threE-bands to mitigate interference, as well as integration with Bluetooth Low Energy (BLE) and Zigbee for IoT deployment in applications such as asset tracking.

This was significant in that WiFi 6E and later 7 will increasingly go head-to-head with private 5G in this venue and stadium sector. This Chase Center network may then become an important test case for WiFi 6E.

The future for WiFi, though, will also rely on further capacity and speed improvements to keep pace with 5G, on top of finally fixing the latency deficit. The extension into the 6 GHz band was critical for ensuring WiFi’s future and was instrumental in those three major deployments in the USA. But further gains will be necessary to counteract the advance of 5G into unlicensed territory.