Hands up who has a 5G phone already? No, not me, either. Lockdown year has not been a time to be an early acquirer: I mean, I’ve hardly been more than 15 minutes’ walk away from my house since March. But it should not surprise you that work has already started on what we might need from 6G, the next generation of wireless communications.
But isn’t this really early to be thinking about the next generation, when 5G is really rolling? According to the Global Mobile Suppliers’ Association (GSA), in mid-November 2020 there were 249 commercially available 5G devices, and 125 operators in 52 countries or territories had launched public services with another 58 carrying out trials, bidding for licences or building networks.
But, hold on. Think of the timetable for the current generation, 4G — still sometimes called LTE, an abbreviation for “long-term evolution”. Work on what was to become 4G started at the beginning of the century, as a successor to 3G, which was still only gently making its way into the commercial world.
Telia was the first operator to install 4G networks, in Stockholm and Oslo in 2009, and 11 years later the technology is widespread across the world. According to the GSMA more than 800 operators are running 4G networks and another 100 have plans to do so.
And the industry has learned from its past mistakes. On the whole, 4G is 4G: my phone works in Canada, China and the US as well as it does at home in the UK.
(Incidentally, it is true that the industry chose the “long-term evolution” name deliberately to sound dull. The industry had suffered a huge outflow of money around 2000 when governments auctioned 3G licences. It was the industry’s fault that they paid so much in their exuberance but, having experienced it once, companies did not want to alert the authorities that here was another excuse to extract billions in licence fees. Another case of the business learning from past mistakes.)
God send mobiles
The 2G revolution, bringing the first digital mobile systems, started in 1990 (with the resigned comment that GSM really stood for “God, send mobiles”). The 3G started in 2000, with the spectrum auctions, and 4G started in 2010. And now, 5G is moving. The logical conclusion is that 6G will be in commercial service in 2030.
Moore’s law, which observes that the number of transistors in an integrated circuit doubles about every two years, has applied to the semiconductor industry for 55 years, since Intel co-founder Gordon Moore wrote about his observation in a business magazine, Electronics.
In mobile, 10 years per generation has been a commonplace for the past few years, though it isn’t so far attributed to anyone. Like Moore’s law, this is an observation: a bit like a law of physics, which is an attempt to describe the observed universe as a way of helping to understand it. With understanding comes, we hope, enlightenment.
Alan Carlton is a good person to talk to on this. With a 30-year record in wireless communications, he’s now VP of InterDigital’s labs: that’s one of the prominent research companies in the industry that’s independent of the major vendors. “The next generation of wireless is our core business,” he says, admitting: “It’s still a long way off.” He’s been around for all standards since 2G. Work on 5G started in 2010, he says, “with five years driving consensus and standards from 2015-16”.
The early years were taken up with thinking about what people expect of a new system; then really hard work defining the standards in detail — work that is truly international, with radio engineers and software specialists from universities and companies around the world dividing up the tasks and working closely together. There are committees in which Huawei people work with Ericsson people, AT&T people work with ZTE people, and so on.
Carlton is looking forward to the next task, 6G. He believes 2025-26 will be when the industry crystallises its ideas. “That’s how we see it,” he says. That means it’s time for people in the telecoms industry and outside it to talk about their ideas.
The process has started. The National Science Foundation (NSF) in the US has its Platforms for Advanced Wireless Research (PAWR) programme; the university of Oulu (pictured) in northern Finland has its Centre for Wireless Communication which is looking at 6G; and in October 2020 InterDigital itself and the Institute for the Wireless Internet of Things held a conference — virtually, of course — at Northeastern University in Boston.
Multisensory extended reality
What next? “We’re talking of multiple gigabits a second,” says Carlton, with 6G operating at frequencies around 100GHz — that’s a wavelength of 3mm. For what? “Multisensory extended reality,” says Carlton, throwing out a new abbreviation, XR. And another, MR, for mixed reality.
“To make XR really impressive you’ll need a gigabit everywhere,” he says. At least. “It’s the internet of senses, a fusion of the physical and virtual worlds,” he says, pointing to holograms in Star Wars as an example of what he’s talking about. Robotics control systems will require
really low latency, and high reliability.
“We will need something new, a new defining service, something the existing technology can’t do.” The killer app for 6G, that will be.
