On Moving House, Internet Shopping and High Efficiency Wireless

They say the only constant is change.

And certainly, within the technology space, that is an understatement.

Technology has been changing at an unprecedented rate, with each evolution building upon what came before, and revolutions resulting as different technologies are combined in innovative ways.

Wi-Fi 6 is the latest transition in the wireless space, and together with 5G, it will evolve how we define Mobility, and deliver revolutionary new applications and services.

Both Wi-Fi 6 and 5G have been designed from a common technology foundation, and they both focus on common emergent use cases. Each iteration has brought an increase in throughput. New applications, particularly around video, have been the driver for such advances. We continue to see 4K video adoption increase, and 8K video is on the horizon. And now, both Virtual Reality and Augmented Reality are building on that foundation, delivering new innovations.

Bandwidth, however, only solves part of the problem.

With 802.11ac Wave 2 delivering speeds upwards of 1.2Gbps, the gating factor for high bandwidth applications was no longer the throughput the network could provide, but rather the ability of those applications to gain access to the network. 

Wi-Fi’s greatest strength has also been its greatest weakness: shared spectrum.

The openness of the 2.4 and 5GHz spectrum is what allowed Wi-Fi to become so completely pervasive in such a relatively short period of time. The simplicity and politeness of the 802.11 protocol, with its listen-before-talk approach, ensures that as more devices contend for access, there is still some sense of order… that no one is rudely interrupted. Improvements in bandwidth allowed people to effectively “talk faster”—to get on and off the channel more quickly. But as more devices contend for access, everyone needs to wait longer for their turn.

And this is the fundamental change that Wi-Fi 6 will bring.

Wi-Fi 6 is based upon the emerging IEEE 802.11ax High Efficiency Wireless standard. Not high throughput or high bandwidth—high efficiency.

Every wireless standard, going back to 802.11a and 802.11g, has been based on a modulation scheme known as OFDM (Orthogonal Frequency Division Multiplexing). OFDM delivered high spatial efficiency—which is a fancy way of saying that it let us cram a lot of bits into the pipe. The successive iterations, 802.11n and 802.11ac, delivered more bandwidth based on this underlying approach.

Think about OFDM like moving house. You rent a truck and fill it up with your stuff. Invariably, there’s some empty space left. You’ve selected a truck with enough room for all your things, but there’s always going to be wasted space. You’ve paid for the whole truck, and not just how much space you use.

Every generational improvement to the 802.11 standards allowed to make bigger trucks. This let us cram more stuff in the truck, but it did not help avoid the wasted space. This is why Wi-Fi 6 is so important. Not just because it gives us yet an even bigger truck, but because it helps us to use those trucks more efficiently.

802.11ax is the first Wi-Fi standard to move away from OFDM, building on a new modulation technique: OFDMA (Orthogonal Frequency Division Multiple Access). OFDMA still provides the high throughput benefits of OFDM, but also enables multiple devices to share that increased bandwidth more efficiently.

This means OFDMA works more like a delivery truck. When you shop online, you don’t get a truck dedicated for your individual package. A truck is used for all the packages going to all the different people who ordered something in your area. There’s no wasted space in the truck because the truck is filled to capacity with packages destined for multiple people.

OFDMA therefore, allows Wi-Fi 6 to deliver high capacity as well as high throughput. Any high density environment, from Universities and Stadiums to Shopping Centres and Airports, will be early winners with Wi-Fi 6. In fact, some of the early field trials we ran here in Australia with the Catalyst 9115 Access Points were in the Higher Education space.

And OFDMA has potential beyond high density environments and high bandwidth applications—consider the Internet of Things.

IoT applications are rarely about throughput. They typically involve low bandwidth control and data packets. What they require most is determinism. Contending for access has been a major challenge for wireless IoT applications. OFDMA allows high bandwidth real-time applications to share the medium more efficiently with low bandwidth deterministic applications.

If 802.11n and 802.11ac were technology evolutions, then Wi-Fi 6 is the revolution.

And the real changes are still yet to come.

Originally Posted at: https://apjc.thecisconetwork.com/site/content/lang/en/id/10490