Deep in the pandemic-emptied rooms of the University of Surrey, 30 miles southwest of London, a bank of computer servers has been running hot for months. Its workload: supporting cutting-edge research among some 200 remote academics and students creating the next generation of wireless technology.
No, it’s not 5G. It’s 6G. As in the sixth generation of wireless.
While it may seem like an example of technologists jumping the shark—with 5G towers only now being widely deployed and businesses gaming out how best to leverage its lightning-fast, low-latency networks—it’s a crucial next step in computing and communications. It will one day redefine edge computing, transform governments, create new industries, and raise a host of never-before-seen cybersecurity issues.
Tafazolli is helping lead the effort to define that vision. He says the first step is determining the capabilities that should be added to 5G as part of an interim update in five or six years that experts call 5.5G. “The strategies right now are focused on getting 5G, a very capable system, to the next level and then building on that,” he says.
The race to 6G is so important that the U.S. and China are vying to define it and own the patents around it. Industry giants like Qualcomm, Samsung, and Nokia are also in that race, and are trying to game out how to monetize and secure it.
How these entities build on 5G is anyone’s guess. But much of the speculation revolves around ways to move beyond the fast speed and low-latency leaps in 5G to bring even faster, more synchronized, and secure wireless connectivity to every person, place, and object on the planet.
Stephen Douglas heads up 5G strategy at U.K.-based Spirent Communications. But he’s spending ever bigger parts of his day on what lies beyond. Douglas breaks down the future of communications like this: Our current 4G networks have enabled things like high-definition mobile video. 5G will facilitate the deployment of augmented reality (AR), virtual reality (VR), and artificial intelligence (AI) at the edge. 6G will do something that seems like sci-fi: It will bridge our physical, digital, and biological worlds.
Imagine a doctor performing a surgery on a patient 1,000 miles away and feeling the robotic instruments she’s manipulating.
For example, says Douglas, 6G could move us past wide area networks (WANs) and accelerate the arrival of body area networks (BANs). This decades-old concept allows low-power sensors on, around, or even inside of human bodies to connect to vital online services, such as health and wellness monitoring.
BANs could lead digital technology out of its traditional realm of sight and sound to address our other senses (smell, taste, and touch). So, for example, imagine a doctor performing a surgery on a patient 1,000 miles away and feeling the robotic instruments she’s manipulating. Or consider a food critic using a BAN to remotely assess the taste and smell of menu items for their weekly column.
“I think the desire to deliver personalized BANs is seen as one of the big potentials for 6G wireless,” says Douglas. “But, of course, any time you’re dealing with information involving our bodies, it will immediately raise security and privacy concerns that will have to be addressed.”
Bouncing off walls
Researchers are also looking at how to integrate terahertz radio frequencies into 6G wireless to solve an annoying problem: Cell tower signals often fail to penetrate buildings. But 6G using THz frequencies might be able to do that. The problem, says Douglas, is that radio signals in the 100 GHz to 10THz range tend to suffer high propagation loss (a reduction in power density). So, as a solution, the industry is looking at intelligent reflecting surfaces.
Instead of trying brute force to get wireless to pass through walls, you line every surface with reflective materials that divert and amplify signal strength. Douglas likens them to those little silvery balls in pachinko machines. The signals could conceivably ping off any treated object to penetrate far into buildings.
Signals could also reflect across city surfaces to reach around corners, down the block, or all the way to cell tower–less suburbs. To prevent the random and chaotic bouncing of signals, you could print directional logic into paper-thin “metamaterials” to help better manage and strategically direct those signals, no matter the generation of signal, whether 5G or 6G and beyond.
This has the added benefit of improving energy efficiency. “The way we solve a lot of radio challenges today is to amplify power supply to radio antennas in an effort to boost signal and get through things,” he says. “But if I don’t need to do that, I can reduce the cost of energy consumption for [endpoint device] radios.”
We are going to focus on making the whole system more energy efficient and environmentally friendly.
Prof. Tafazolli of Surrey, whose team was first to make a prototype of intelligent reflective surfaces, agrees and says sustainability will probably be a core part of any future 6G wireless architecture.
“We are going to focus on making the whole system more energy efficient and environmentally friendly,” he says. “We’ll use renewable energy sources for everything from the antenna to the base station and network.”
Another major area of 6G research under discussion involves time synchronization, a vital capability for enabling digital interaction between the physical and cyber worlds. In a nutshell, time synchronization makes it possible to detect movement, location, and proximity. For example, if somebody using AR goggles wanted to remotely shake hands with a person or robot—and “feel it”—the contact would have to be orchestrated. This isn’t possible yet with 5G systems, Tafazolli notes, but would be with 6G.
A massive attack surface
An upshot of all these 6G possibilities is that if even a fraction of them come to fruition, they could completely change the definition of endpoint devices. Today, most businesses define endpoints as connected PCs, laptops, tablets, smartphones, and printers. But if 6G turns all surfaces into connected devices, then almost any physical object could conceivably become an endpoint.
That’s a massive attack surface, and it certainly puts pressure on researchers to think about security in more innovative ways, says Jeff Kagan, a telecommunications industry author and analyst.
“The industry is fully aware of the risk, and they’re focused on it,” he says. “Every year, they get smarter. But it’s a constant battle because the bad guys are always out there looking for new ways to break in, and it’s getting harder to handle. The carriers and equipment makers have to think of a million ways to protect their networks, but a hacker only needs one way in to successfully launch a cyberattack.”
New trust models
One countermeasure 6G researchers are considering is a trust network: Endpoints would be allowed to join a connected system only if they are referred by peer endpoints or by demonstrating a history of good behavior. Researchers are already studying what defines a solid reputation and which techniques might help determine that. They are also debating how an endpoint’s history would be collected, stored, and processed, says Douglas. Distributed ledger technology, best known for its connection to blockchain and bitcoin, is thought to be one of the leading approaches for enabling this.
In addition to trust models, researchers are investigating quantum communication for securing 6G networks and endpoints. Quantum communication essentially involves quantum key distribution (QKD), which uses quantum states of particles, typically photons of light, for transmitting data. As Martin Giles, senior industry fellow at UC Irvine’s Center for Digital Transformation, explains, these particles take on a state of “superposition,” which means they can represent multiple combinations of 1 and 0 simultaneously.
“The beauty of (these quantum bits, or qubits) from a cybersecurity perspective is that if a hacker tries to observe them in transit, their super-fragile quantum state ‘collapses’ to either 1 or 0,” Giles writes in MIT Technology Review. “This means a hacker can’t tamper with the qubits without leaving a telltale sign of activity.”
Quantum communication is in its infancy. But at least one country, China, is trying to take an early lead in its development. Indeed, in 2016, China launched what it said was the world’s first satellite (called Micius or Mozi, after the Chinese philosopher) for enabling the technology, considered by many to be all but unhackable. If quantum communication becomes standard, experts believe it could make current cryptographic methods obsolete.
“But the big challenge at the moment is quantum itself because of the high cost of processing,” Douglas says. “At this stage, it isn’t really viable for commercial systems, and there are still issues with controlling it. But in the next 10 years, there is ample evidence to suggest those problems will be resolved.”
AI could also offer value for securing 6G networks and endpoint devices. The idea is that with billions of new endpoint objects suddenly in play, securing everything would require a level of harmonization that doesn’t yet exist. Automating security processes with AI, however, would allow organizations to proactively discover threats and initiate security processes without humans ever having to do anything. The age-old dream of self-defending, self-healing networks and devices could be achieved.
Tafazolli says that although “no system is secure enough,” 6G is likely to be solid in that regard. Each G, or generation, he says, has gotten progressively better. Even 5G, which will continue to be updated and improved, is far more secure than 4G. But, he adds, it will be critical to design privacy-enhancing capabilities into 6G given how much confidential digital and biological data sharing it may enable.
All of these 6G security options will continue to be discussed as researchers, industry leaders, and government agencies refine their thinking en route to eventual standardization.
“We all still need to agree on a common vision of what 6G is going to do,” says Tafazolli. “Then we can fully assess what types of security and privacy we will need.”