By Caio Castro

Spectrum has been a controversial topic in 6G since its beginning. While researchers have elected the terahertz band as the most likely frequency range to unlock the future network’s potential from the start, some have been skeptical about whether we should go that high.

Four years after the first 6G paper was released, the landscape has become a bit clearer. While a recent study has shown that terahertz transmissions are possible for long distances, there has been a movement towards adopting other ranges in 6G.

“There’s always a need for spectrum,” said Head of Spectrum at GSMA, Luciana Camargos. “I can only assume there are going to be more use cases, and [more] spectrum will be needed with 6G. We need to start thinking about network sharing, identifying where the demands come from, and start planning in advance,” the expert added in a panel at MWC23.

Camargos is not alone. Ericsson, for instance, sees all ranges as suitable for 6G – of course, with some differences in how the network will operate in each frequency:

The company expects extreme performance in very local areas for the range between 90 GHz and 300 GHz (sub-terahertz).

Between 24 GHz and 47 GHz (mmWave), high-speed and very low latency in local areas.

The range between 7 GHz and 15 GHz (centimetric waves), according to Ericsson, is “essential for 6G, [offering] good coverage and capacity.”

For the range spanning from 2.3 GHz to 7 GHz (mid-band), wide area and good capacity.

Finally, the low-band, below 3.6 GHz, will provide nationwide coverage and deep indoor penetration.

Ericsson is not the only player eyeing a broader spectrum use for 6G. “A lot of the 6G use cases will need the capacity to meet the demands,” explained  Director of Spectrum Policy & Analysis at the British regulator Ofcom, Cristina Data.

“There’s a lot of mmWave spectrum that we made available as a regulator [in the United Kingdom]. There are a lot of users in the range between 7 GHz and 15 GHz. Sharing will become more important when we’re trying to enable use cases in society,” she pointed out.

Before adopting new frequencies, however, both experts see room for mmWave to show its full potential and how it can benefit 6G. Besides, with such a high demand for spectrum across several areas, operators should take advantage of every potential frequency. 

“Millimeter wave was the pioneer band for 5G. We’d like to see more use adopted across the world. You look at the dream of going to higher frequencies, but then you hit the challenges on the ground,” Data said.

One Way Out?

If the spectrum is becoming increasingly scarce, how do we work around the challenges and make sure there will be space for 6G?

“There’s a perception that spectrum for private and local licensing has to be set aside. And we don’t know where this perception comes from,” Camargos observed.

Indeed, Ofcom has been looking into new licensing models in the UK – as Cristina Data put it, an innovative approach.

“We have been proposing to award licenses in cities. We’ve identified a number of cities that will be awarded a license, but then, in another area, let’s allow a more shared access, ‘first come, first served’ approach, so that other players can also benefit,” Data explained.

“The capacity needed may be localised. So how can we look at local? Local doesn’t need to be a city, it can be anything. We must make sure that the spectrum is available when the spectrum is needed,” she added.

These attempts to overcome the impending challenges surrounding 6G deployments have one common goal: the end-user. But how can we measure success?

“Success in 6G, to me, will be about the consumer having the best services, whatever the service is,” Data said.

Camargos gave a similar, but slightly different, point of view. “Success is when we have connected everyone and everything to a better future.”