After 5G hangover, there’s not much telco love for 6G

Every ten years, after lots of noisy hook-ups in darkened rooms under the supervisory eye of standards bodies like the 3GPP, the global telecom industry gives birth to a new wailing generation of mobile technology. For anyone who’s been hibernating this decade, we’re currently about three or four years into the fifth of these generations (5G), which means everyone should naturally expect 6G to emerge from the womb of the industry in about 2030. Vendors that need to replace their dwindling 5G revenues might be eager to see it arrive. The operators may feel otherwise.

At least, it was hard not to come away from this week’s 6G Symposium, an event organized by 6G World and held at the University of Surrey, with that impression uppermost in mind. “Today, whether we like it or not, we are not making much money with current technology and have gone through lots of rip and replace,” said Andrea Dona, the chief networks officer of Vodafone UK, on a panel about 6G that featured several technology executives from some of the world’s biggest telcos. “It cannot be another hardware replacement. It needs to be a software overlay that brings the full potential of 5G.”

Dona’s remarks neatly encapsulate the frustration of the telcos. Billions of dollars have been invested in 5G and yet there has been little or no discernible impact on telco sales. Forget self-driving cars, remote-control surgery and other outlandish visions – for most telcos, it has barely moved the needle in the business sector so far. The best that can be said is that 5G, as a more capacity-rich technology, is more efficient than its predecessors and has helped to keep operating costs from spiraling. But with 5G’s value in doubt, the last thing many telcos want to hear is 6G hype.

“I don’t think the way we’re going – with ten-year cycles and ten times better than the previous cycle and whatever the KPIs [key performance indicators] might be – is a sustainable model,” said Maria Cuevas, who heads mobility research for BT. Her remarks on this week’s panel come weeks after Howard Watson, BT’s chief security and networks officer, looked horrified at the suggestion 6G might entail another huge investment splurge. “We’re not doing that again,” he told Light Reading at Mobile World Congress.

BT and Vodafone are not the only UK-headquartered telcos demanding a rethink of the habitual approach. “It is time to stop talking about 5G, 6G, 7G, whatever the G is,” said Kirsty Bright, the director of network innovation and transformation for Virgin Media O2. Rather than making a “big razzmatazz” about each new G, the industry should drop the ten-year upgrade cycle and focus on technology evolution instead.

Vendors under fire

This is probably not what parts of the equipment sector want to hear, and this week’s event had its share of hype from that community. Some degree of consensus seems to have formed that 6G’s biggest innovation will be sensing, whereby objects and clothes that feature hundreds of tiny sensors will be able to upload data to the network about their dimensions, location, movement and status.

With this, companies could spin up digital twins, virtual representations of physical objects that can be used to generate insights about them or even run simulations. “I see Iron Man doing things with 3D holograms and designing his outfit using 3D printing and it makes me think I’d love to have these types of technology today, but that is what it will hopefully bring,” said Milind Kulkarni, the vice president of engineering for Interdigital, a research company.

Today’s radio technology would not be able to support this feature, Kulkarni told Light Reading, noting that a new air interface or waveform might even be needed. But that is certainly not a given, he said, and operators have repeatedly downplayed the need for change. Orthogonal frequency division multiplexing (OFDM), the basis of today’s 4G and 5G networks, has few obvious challengers. “There is no new radio access technology,” said Dona.

There is clearly support from within vendors for the idea that 6G will not involve tinkering with the waveform. “When we’re looking at changes to the fundamental waveform, we need to be a little bit careful with scenarios,” said Matthew Baker, the head of RAN standardization at Nokia. “In terms of macro-cellular, wide-area, high-data-rate coverage, then Shannon’s limit remains Shannon’s limit. That hasn’t changed and tweaks around the air interface are not necessarily going to give massive gains.” Shannon’s limit – or Shannon’s Law, as it is usually called – specifies physical constraints in radio technology.

The industry also appears to have lost much of its previous appetite for pushing the technology into much higher spectrum bands. A lot of the earlier 6G talk was about making use of Terahertz bands, rich in spectrum but dire for coverage. After various 5G misfires in millimeter wave bands – lower than Terahertz but still much higher than the sub-6GHz bands that support most communications – attention has now turned to centimeter wave spectrum instead. “The pioneer band has to be 7 to 15 Gigahertz,” said Baker.

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