6G bust-ups loom ahead of MWC and 3GPP gatherings6G bust-ups loom ahead of MWC and 3GPP gatherings

Mention 6G to many telco executives these days and there is a good chance they will bolt in the opposite direction, perhaps somersaulting over fellow attendees in the swamped halls of Mobile World Congress (MWC). It's no industry secret that 5G has been a major disappointment over the first five or six years of its existence, largely failing to excite consumers or businesses and generating no sales growth for operators. Few telcos want to hear about another potentially expensive generational upgrade in a few years' time.

"They are taking a very pragmatic approach on 6G because they feel like they did not get the return on investment in 5G," said Alain Mourad, a senior director at Interdigital, a research company in the mobile telecom sector, at a recent press dinner in London.

Ericsson, notably, did not even bother referring to 6G at its pre-MWC event in London last week. Much like its customers, the Swedish vendor is desperate to earn money from its 5G investments before it stakes a big sum on 6G. The latest message from Börje Ekholm, its boss throughout the 5G era, is that 6G, far from being a "new type of generation," will appear in 2030 or so as an "evolution of 5G." In other words, you won't reach 6G without investing in 5G first.

Some of this may delight members of the Next Generation Mobile Networks Alliance (NGMN), a club of Tier 1 telcos with headquarters in Germany. In a white paper published in late 2023, it insisted the new standard "must not inherently trigger a hardware refresh of 5G RAN [radio access network] infrastructure." Ideally, said the NGMN, 6G will be realizable through "software-based feature upgrades of existing network elements."

It has now followed up with a new white paper about "network architecture evolution" toward 6G. The timing is of interest. Four weeks from now, after MWC attendees have recovered from the excesses of Barcelona, some 800 people will travel to Incheon in South Korea for a critical workshop overseen by the 3GPP, the umbrella group for regional standards bodies in mobile. Its job is to sketch out a vision and priorities for 6G.

There's a RAT in the kitchen

The most interesting part of the new NGMN white paper concerns the RAN, simply because it consumes the biggest chunk of any telco's capital expenditure. When they deployed 5G, operators were at least making use of the same orthogonal frequency division multiplexing (OFDM) technology at the heart of 4G. But 6G holds out the possibility of adopting a completely new air interface, or what the NGMN refers to as a radio access technology (RAT, not to be mistaken with the furry form that chews through wires). And a new 6G RAT would lead to more network "complexity," a word chief technology officers loathe, because it would inevitably leave telcos with multiple RATs to manage, according to the NGMN.

Why bother? The obvious answer is that a new RAT would result in "improved efficiency and lower cost," writes the NGMN. Yet some telco executives, including Andrea Dona, the chief network officer of Vodafone UK, have previously downplayed the attractions of what they have seen. Nevertheless, Cohere Technologies, a startup much admired by Vodafone for its universal spectrum multiplier technology, has for a long time been touting orthogonal time frequency space (OTFS) as a possible OFDM successor and 6G candidate.

That's significant because the people now running Cohere are the same ones who sold Flarion, a pioneer in OFDM, to Qualcomm in 2006 for about $805 million. When LexisNexis recently published a new ranking of 5G patent owners based on the essential value of those patents, Qualcomm was out in front.

A technology that excites Earl Lum, the president of EJL Wireless Research, comes from an Austin-based startup called SpectralDSP. Its proprietary variant of "single carrier" OFDM (SC-OFDM) would easily meet 6G criteria, boosting wireless download speeds by 75% and upload speeds by 90%, said Lum on LinkedIn. SpectralDSP's tech, importantly, would require no hardware changes, according to Lum.

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