The 6G Symposium took place on October 18 and 19, 2023, in Washington, DC. This year, the talk was more about use cases, with less talk about sustainability than in the past.
One week before the symposium, I heard two contrasting views on 5G given at a virtual conference. In the morning, Chris Pearson of 5G Americas gleefully declared, “5G’s future is bright.” Two hours later, telecom analyst Joe Madden proclaimed, “5G is done; what’s next?”
“5G is not done,” declared Interdigital CTO Rajesh Pankaj on October 18 at the 6G Symposium. Pankaj went on to explain how work continues on 5G standards. 3GPP Release 18 will be completed in 2024, and Release 19 work is underway. Pankaj continued by saying that Release 19 will contain some early 6G technology, and Release 20 will look at 6G use cases while at the same time completing 5G. Release 21 will be the first 6G release. “6G will coexist with 5G and 4G,” he said. As the timeline shows, enhancements to 5G are continuing, with Releases 18 through 20 tagged as 5G-Advanced. These releases will contain 6G channel-sounding measurements.
To G or not to G?
“We need continuous progress,” said Igal Elbaz, SVP and Network CTO at AT&T. “Don’t think in G blocks.” That might work for engineers, Mr. Elbaz. Unfortunately, the marketers need another G to hype.
Elbaz gave his vision for future networks. “AT&T is migrating its networks to a 5G standalone core.” Doing so adds network slicing, lower latency, and speed. Furthermore, Elbaz explained how mmWave is part of the overall 5G network. Its use cases are primarily for connecting thousands of devices in stadiums and airports, plus mmWave delivers fixed wireless internet access (FWA). He did, however, state that the lower latency that comes from moving computing to the network edge will still not be enough and that 6G will have to address the issue. “We will need a highly distributable cloud, converged broadband and wireless, and open networks that minimize capex. Network enhancements will need to be software based. Most of all, we need high-power licensed spectrum and lots of R&D to bring 50 Gb/sec data rates to phones.”
While Elbaz downplayed the use of Gs, Anritsu’s Adnan Khan emphasized them. “Even-numbered Gs bring a revolution.” 5G could still bring new business efficiencies and applications, businesses tend to be risk averse and slow to adopt new technologies. In the meantime, consumers are not thrilled with 5G. Thus, it’s taking longer to catch on than most people expected. Perhaps that’s why Madden is looking for what comes next.
Regarding private networks, Qualcomm’s SVP of engineering Ed Tiedemann questioned if cellular private networks would ever take off. He asked, “How can we make cellular private networks as easy to use as Wi-Fi? People know how to set up Wi-Fi networks.”
Peter Vetter, President of Nokia Bell Labs Core Research, added “We see Wi-Fi and 4G private networks in use today. Wi-Fi is a safe path for risk-averse industries.” Vetter then described what he called “machine area networks,” such as a car, where users need low latency and six-nines reliability. “5G can do what 4G can’t,” he explained. “5G can connect hundreds of devices within a 100-yard radius. 6G will do even better.”
This discussion led to a question from the audience asking if cellular and Wi-Fi will converge. “Yes,” said RIot executive director Tom Snyder. “Innovation occurs in the unlicensed spectrum.” Tiedemann concurred on convergence, but not until at least Wi-Fi 8.
Here comes AI
It seems that every discussion includes some mention of AI. Networks are no exception. Indeed, AI could make its way into every network layer, from the physical layer to the application layer. Tim O’Shea, CTO if DeepSig, spoke of how AI will become part of the 6G physical layer. O’Shea sees AI being used to optimize transmitters and receivers in the air interface and in optimizing overall network performance. “5G standards don’t include AI.” O’Shea has for years investigated the use of AI for the physical layer. Indeed, AI was a topic of discussion at a 6G conference in 2020, long before it was an everyday word.
“AI is a set of technologies that needs to be integrated into systems,” said Interdigital’s Pankaj. “AI can’t simply run on top of other technologies. We have to look at volumetric data in systems from end to end, not just in each system component.” He stressed that AI needs to be used in IC design and manufacture because chips are the pinch point in the supply chain.
In his presentation, Prof. Tommaso Melodia of Northeastern University expects AI to be native processing in a disaggregated 6G network. Indeed, he and colleague Josep Jornet are investigating the use of AI in open, programmable networks starting at the air interface at frequencies above 100 GHz. Melodia sees networks using open-source software stacks and open network interfaces. “The near-real-time RIC (RAN intelligent controller) discussed today will not be powerful enough to run 6G networks,” said Melodia.
Because there will never be enough spectrum to carry data demands, researchers including Matti Latva-Aho, Director for 6G Flagship at University of Oulu are investigating AI for use in spectrum sharing.
AT&T’s Elbaz also sees AI playing a role in networks, from the physical layer on up. At the physical layer, he sees AI used in wireless channel estimation and controlling the radio beams for beam steering. Going up the protocol stack, Elbaz looks for AI to appear in load balancing, automation, data collection, data storage, security, and other functions.
What about sustainability?
Last year in 2022, sustainability was unquestionably the number one topic. This year, sustainability took a back seat but was still visible. It wasn’t so much about saving the world but about saving money. O-RAN Alliance chair Alex Choi cited the ever-increasing total cost of operations (TCO) as the driving force for better energy efficiency. IEEE and NIST fellow Nada Golmie cited sustainability, energy efficiency, and security as the top issues facing 6G.
When a question came from the audience regarding sustainability, Qualcomm’s Tiedemann looked not only at network energy consumption but at how wireless, through sensors and IoT, can reduce energy use in factories. He cited energy consumption in cell phones as a selling point in terms of battery life. Vetter noted that 6G should bring about the design of larger systems with more sensors to monitor and reduce energy use.
Northeastern’s Melodia presented TENORAN, a proposed system for measuring and reducing energy consumption in Open RAN networks funded through the CHIPS and Science Act. Melodia stressed the need to reduce energy consumption from end to end and not just for each network component. The concept of calculating energy use in networks was presented at the 2022 Brooklyn 6G Summit. EE World will be in Brooklyn on November 1 and 2, 2023, two weeks after the 6G Symposium. Let’s see if sustainability takes a back seat there, staying in view primarily for saving money rather than the environment.
Finally, here’s my quote of the conference: “Metaverse is a bad word,” said Interdigital’s Pankaj. The overhyped and nonexistent technology has, thankfully, gone to the back of the bus in 2023.