Edge Computing Benefits Start with Latency, Do Not End There

Even if ultra-low latency is the distinctive value offered by edge computing, it is not the only key driver. In fact, the history of value provided by content delivery networks might be the best way to understand where value lies.

The traditional reason content delivery networks became valuable is that it avoids huge amounts of data transfer across the wide area network. In the past the argument was that local caching of video prevented a whole lot of video unicasting across the WAN.

It is a prosaic but nevertheless genuine value to note that as more entertainment video consumption switches from linear broadcast (multicast) to on-demand (unicast), and image formats become more dense (4K, 8K), there is simply more image data to push. That has practical, everyday implications whenever users push a remote or click a button to pull up a new stream. In those use cases, local caching improves experience by reducing the lag time to display full-motion video in a new screen or on a new channel.

In addition to latency value, edge processing can have a meaningful impact on WAN traffic load, and therefore WAN transport cost.

source: Senz Fili

Edge computing becomes more valuable precisely when WAN network load is high. High traffic loads generate radio network congestion, and that in turn increases latency.

Latency reduction is important for other apps and use cases as well. For gaming apps, a human requires 13 milliseconds or more to detect an event. A motor response might add 100 ms. But then consider artificial reality or augmented reality use cases.

To be nearly indistinguishable from reality, one expert says a VR system should ideally have a delay of seven milliseconds to 15 ms ms between the time a player moves their head and the time the player sees a new, corrected view of the scene.

The Oculus Rift can achieve latency of about 30 ms or 40 ms under perfectly optimized conditions, according to Palmer Luckey.

There also are other latency issues, such as display latency. A mobile phone, for example, might add 40 ms to 50 ms to render content on the screen.

The point is that end-to-end latency is an issue for VR apps, and edge computing helps address a potentially-important part of that latency.