Even though 6G is a long way off, with many obstacles along the way, there’s still a general idea as to when and how to get there. Reaching 6G, which is slated to launch circa 2030, will take a largely unified approach, according to experts speaking on its eventual delivery at the Spring 2021 6GSymposium earlier this week.
Timing 6G Standardisation Just Right
The need for a unified approach can lead to complications, though. Speaking on Day 2 of the three-day virtual event, Diego Lopez, Senior Technology Expert at Telefonica I+D, described the circuitous terrain.
“Trying to actively coordinate with the other bodies that are participating in the current standards world, you cannot say ‘this is my stuff’ […] There are many bodies that are working in similar directions, in very similar areas with big overlaps and intersections. It is important to facilitate [in addition to everything that is formal] everything that is informal, the idea of cross-pollination, bringing ideas from one body to another. [It] facilitates the free flow of ideas,” he said.
Lopez presented as part of a panel discussion called “The Standardisation Roadmap.” He gave examples of bodies with which he is most familiar, including the European Telecommunications Standards Institute (ETSI), saying the organisation’s industry specifications groups will hopefully help shape the evolution of 5G to 6G.
On the same panel, ETSI Director of New Technologies David Boswarthick also spoke. He described the role of ETSI’s Research, Innovation and Standards Ecosystem (RISE) and the Technology Radar for Emerging New Domains (TREND) groups, of which he is a part. He said the groups look to European research initiatives for clues regarding the nature of potential technologies that may be involved with 5G’s evolution or even 6G. Using terahertz frequencies as an example, he said timing in creating standards is a challenge, but a necessary one.
“There are a number of Horizon 2020-funded projects that are working on terahertz technologies and there will be more projects starting under Horizon Europe this year that will further research into terahertz technologies,” Boswarthick said. “What we’re attempting to do at ETSI is to work with our members[…] to identify when the time is right to start either pre-standards work or full-standards work in ETSI, recognising that the full-standards work will need to be done inside [the 3rd Generation Partnership Project; 3GPP].
“ETSI’s pre-standards work for 6G is really done in order to accelerate and enhance the pre-standards activities that will eventually be taken by 3GPP and also solidify the input to 6G from the European research projects and investments.”
Terahertz Frequencies as a Starting Point
Prakash Moorut, Head of Spectrum Standardisation at Nokia Bell Labs spoke on “The Spectrum Roadmap” panel discussion that followed. He said Nokia’s view is 6G deployments should start in 2030, with 3GPP specs getting released around 2028, 2029. Moorut also acknowledged terahertz frequencies as a focus. However, he argued there should be others.
“We should not necessarily focus only on one part of the spectrum, like terahertz. I think going into [World Radiocommunication Conference 2023; WRC-23], it’s my view we should also have some candidates for mid bands, maybe even low bands, or the high bands, mmWave,” he said. “Maybe there are other opportunities, not just focus on whatever. Otherwise, we’re going to end up only with terahertz spectrum and we’re going to have another potential issue.”
Co-panelist Eric Fournier, the Director for Spectrum Planning and International Affairs at France’s regulator ANFR said he believed mid-band spectrum would still hold critical importance for 6G. Federal Communications Commission (FCC) CTO Monisha Ghosh agreed during her ensuing talk, saying she envisions the spectrum recently made available by the FCC over the last few years “to continue into the next generation.”
“Mid-band is where everybody wants to be, balancing coverage and throughput. In this area, the most recent action that the FCC did was to come up with proposed rules for the 3.45-3.55GHz band. This is the 100 MHz of spectrum sitting right below [Citizens Broadband Radio Service; CBRS], which is 3.55-3.7 and which was auctioned off last year. This is also going to be a shared band and we will see that the theme of sharing, co-existence, adjacent channels is going to grow in importance. It was very important in 5G and it’s only going to become more important as we look into 6G,” she said.
Opening the Door to OpenRAN
Ghosh continued, noting that, while much of the FCC’s role as a regulator is releasing or auctioning off spectrum, the Commission looks into efficiently managing it too. In that context, she spoke about OpenRAN.
“If you had an open radio access network, would that enable operators to better manage the spectrum, get better utilisation out of it so we don’t need to constantly allocate new spectrum as new Gs emerge?” she asked. “We really want to move to a state where we’re not constantly looking at 6G followed by 7G followed by 8G and constantly looking for new spectrum for these services.
“Instead, I think the holy grail is to have a methodology in place where systems can gradually evolve as new technologies mature, as new spectrum becomes available, as these networks become more controllable using AI and other methods that we constantly need more efficient use of the spectrum that we already have.”
Ghosh elaborated on the topic during the question-and-answer period. She clarified that OpenRAN is not something the FCC would rule on, but suggested OpenRAN could potentially factor into the use of AI moving forward.
“We had a Notice of Inquiry out recently on open radio-access-network architectures, and one of the key impacts that an open architecture could have is on making the use of AI and machine learning a lot more efficient by standardising interfaces, not only at the ends, but also in the guts of the network, because […] there is so much aggregation going on already and this is only going to increase as more bands become available.Really understanding how to do that efficiently is a challenge,” she said. “So, there are a lot of […] challenges, but huge opportunities too in using these tools to manage spectrum.”
AI and ML in 6G
Ghosh commented in response to an audience question on the potential role of AI in supporting more effective spectrum sharing. Simon Saunders, the Director of Emerging Technologies at the UK’s Office of Communications (Ofcom), said we’re already seeing the use of AI and machine learning managing today’s 4G and 5G systems, but not to as great a degree as we might see in 6G.
“What we haven’t seen is [it] tightly integrated into the very design of the networks, and there is an opportunity in 5G and 6G to do that,” Saunders said. “[Ofcom is] very keen to ensure that sharing of spectrum is done in a more efficient way […] Machine learning can really help with the challenge of assimilating and responding to that [real-time] data [exchange between systems].
“It does mean that different systems need to be standardised in terms of open interfaces, not just within the normal standards environments, but actually between systems; potentially not just within mobile but between mobile and licensed-exempt and other systems.”
The Spring 2021 6GSymposium concludes Thursday. Upcoming panel discussions are set to cover deep dives into technologies such as AI, Machine Learning, and Intelligent Edge and 6G Radio. To rewatch recordings of earlier panels, please visit www.6gworld.com.
Feature image courtesy of laremenko Sergii (via Shutterstock).
