A look under the hood of WiFi 6

Wi-Fi Alliance certification for IEEE 802.11 ax technology (aka. WiFi 6) will begin during the third quarter of this year. ABI Research is already predicting WiFi 6 chipset shipments will break 1 billion by 2022, and ...

Jan 12th, 2019
WiFi? 'Wi,' yes
WiFi? 'Wi,' yes

Wi-Fi Alliance certification for IEEE 802.11 ax technology (aka. WiFi 6) will begin during the third quarter of this year. ABI Research is already predictingWiFi 6 chipset shipments will break 1 billion by 2022, and IDC is predicting that the bulk of the early-stage WiFi 6 rollouts will be in mid 2019, with a significant ramp in late 2019 or early 2020.

"The expected adoption rate of WiFi 6 (ties) very closely with what we see (with the) certification program," said Kevin Robinson, VP of marketing,Wi-Fi Alliance. "The availability of WiFi Certified 6 serves as an inflection point for more mass market adoption of the technology."

The improvements that WiFi Certified 6 is designed to bring address the proliferation and diversity of WiFi devices. This is a change over previous generations, which focused more on the topline number or the max data rate that the WiFi tech could provide. WiFi 6 aims to meet expectations for all devices in a network, by offering improvement in aggregate performance.

"It's no longer sufficient to (deliver) high performance to a single client device," Robinson said.

"The benefits of WiFi 6 are most pronounced as you add devices to the network" Robinson added. "When you look at how much total traffic is going to all devices, the network can approach much more closely the total capacity of that broadband connection."

Specifically, WiFi 6 utilizes multiuse MIMO; one access point can transmit to a larger number of clients at once. With WiFi 5 (IEEE 802.11ac), there were four spatial streams that the network could allocate for concurrent transmission. WiFi 6 has upped that number to eight spatial streams that allow for simultaneous transmission to multiple clients.

Robinson compared each spatial stream to a truck in a fleet. Each truck can be sent out at the same time to deliver packages.

Multiuse MIMO is closely aligned with orthogonal frequency division multiple access (OFDMA), the same base technology used forDOCSIS 3.1 upstream traffic. The benefit here is network efficiency and the ability to lower latency for higher demand environments. Back to the truck analogy, before OFDMA, a truck might only have a quarter of its payload utilized; it makes the delivery, but space is wasted. With OFDMA, it's like additional packages are being delivered on the same trip. In the case of WiFi, certain types of traffic - like voice - are given priority due to their time sensitivity, kind of like a package sent out for overnight delivery on a truck.

OFDMA and MIMO layer on top of each other. In other words, each of the eight trucks in the fleet can be filled to capacity and sent on a different route.

WiFi 6 is bringing other changes, including 1,024-QAM, a higher order of modulation that will increase throughput to devices and the density of the transmission, Robinson said. Target wake time will improve battery life in IoT devices, by coordinating when the device needs to wake up. And the requirement that WiFi Certified 6 devices support WPA3 will increase security.

What about the new numerical naming scheme? The Wi-Fi Alliance found that more than half of users want the latest tech in their devices, but almost three-fourths of them avoid buying devices if they don't understand the technical labels and descriptions.

"Polling (spoke) to the need and the power of the new naming scheme. One of the key pieces of the poll (was) that 60% of respondents incorrectly identified 802.11," Robinson said. "Very few could put the generations of WiFi or the IEEE naming scheme in order. The new naming scheme is important."

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