Ericsson’s 2021 5G forecast a question of definition

Ericsson has said there will be 150 million 5G subscriptions by 2021 – a large number for the industry to have achieved just a year after standards-compliant 5G networks are expected to be launched commercially.

On the face of it – that looks like a massive success for 5G. Ericsson seems to think so too, as it makes it the lead stat on Ericsson’s publicity for the report.

Consider that there are even now “only” 850 million LTE subscriptions, fully six years after the first network launches. Not only that – the majority of LTE subscriptions are really being added now: for instance Ericsson said 120 million were added just in the last quarter. And LTE was a backwards compatible technology that largely (not entirely, obviously) mapped to existing network grids and could even in some cases first be deployed in refarmed existing spectrum.

So for 5G to get to a sixth of that total in its first year… well that looks like any operator would want a piece of that action and should start investing now.

But wait, take a look at Ericsson’s definition of what constitutes a 5G subscription.

First, let’s start with Ericsson’s definition of 5G. In fact its definition of 5G explicitly contains pre-5G technology. Its report states, “5G consists of a new radio access (NX), an evolved LTE access and an enhanced core network.”

That an evolved LTE access is part of 5G is not, in fact, a universally accepted definition. For instance, 3GPP has just stated that it sees the evolution of LTE existing parallel to, not as a part of, 5G specifications. It has even decided on a name for this path – LTE-Advanced Pro.

So, on to the 150 million prediction. A note on page 6 of Ericsson’s report says: “A 5G subscription requires a device capable of supporting LTE Evolved or NX, connected to a 5G-enabled network, supporting new use cases.”

So Ericsson is saying that a device capable of supporting LTE Evolved, by which we should probably infer any LTE Release past R13, is a 5G connection.

In that regard, given that Huawei is looking to commercialise some of its pre-standards 4.5G/LTE-Advanced Pro (LTE Evolved in Ericsson’s terminology) features in 2016, then 150 million capable devices by 2021 starts to look a little low.

So is it valid that Ericsson included LTE Evolved within its definition of 5G? Is a device connected to a network supporting LTE-Advanced Pro features, with perhaps an enhanced core network providing new means of control and service management, fairly counted as a 5G device? Or does 5G de facto require a connection to a non-LTE, however advanced, air interface?

Sure, some technologies that may be used in 5G are also likely to be used in LTE, things like higher order MIMO and modulation schemes, or perhaps multi-carrier aggregation from across licensed and unlicensed bands. But it doesn’t necessarily then follow that any network equipped with antennas capable of multiple MIMO is now to be counted as 5G.