The Mobile Network (TMN) did a good job summarising the announcement from August that 3GPP had agreed to use CP-OFDM and DFT-s-OFDM as the 6G waveforms. This initial decision for Release 20 triggered a wide range of reactions across LinkedIn, with many industry voices weighing in on what it means for the future of the 6G air interface.
Prof. William Webb's post, 6G air interface will be the same as 5G, which I have shared before, continues to attract attention and spark debate. His point was simple. The 6G air interface will be the same as the 5G air interface, which itself was essentially the same as the 4G air interface, only with more flexibility and capability.
Prof. Emil Björnson offered a detailed clarification. He noted that the use of OFDM in 4G, 5G and 6G does not mean the air interface is identical. The waveform only defines the shape of the resource grid, not the advanced features that fill it. 5G introduced Massive MIMO and extensive beam management that made mmWave deployments feasible. What 6G will add or reimagine remains an open question.
Another experienced wireless expert, Jim Lansford, made a related point. An air interface is not defined solely by its modulation and coding. Even if 6G keeps OFDM, there is plenty of room for new ideas such as AI native OFDM or novel coding and constellation schemes. He also highlighted that Wi-Fi has used OFDM since 802.11a. The fact that Wi-Fi 4, 5, 6, 7 and now 8 all rely on OFDM has never held back innovation. In fact, improvements at higher layers have continued to deliver major performance gains. From a consumer perspective, names like 6G or Wi-Fi 8 still matter because they signal when older technologies are approaching the end of their usable life.
Returning to the TMN article, the summary correctly highlights that the 3GPP decision reflects a continuity driven approach. Alternative waveforms such as OTFS, often suggested for high mobility or greater spectral efficiency, are not part of the baseline design for now. However, the door remains open for future enhancements. Delegates noted that OFDM can still be improved and that new use cases may justify additions later. The industry consensus is that the foundational layer should remain stable while innovation continues elsewhere.
This position aligns closely with what mobile operators have been requesting. They want 6G to be an evolution of 5G rather than a wholesale redesign. Many 5G features have not yet been deployed widely, and operators have little interest in a new physical layer that would require costly upgrades or repeat the complexities seen when shifting from NSA to SA.
While many people commenting on LinkedIn welcomed the decision due to cost efficiency, backward compatibility and platform maturity, others expressed concern that this path could limit more disruptive advances at the physical layer. By prioritising continuity, the industry risks delaying breakthroughs in waveform innovation and finding itself in a comfort zone that delivers only incremental change.
At the same time, a growing number of voices argue that the most meaningful 6G innovation will not occur in the waveform. It is more likely to arrive in the architecture, in AI native design, in the computing continuum, in new spectrum strategies and in deeper integration with non terrestrial networks. If this view holds, a familiar and predictable physical layer could be the right foundation for significant change elsewhere.
One industry participant captured the pragmatic operator viewpoint. For them, the waveform is not the core issue. The real challenge lies in the rigidity of the end to end system and the difficulties in guaranteeing performance at scale. A well understood and stable air interface helps reduce risk, preserve capital and create breathing space to evolve the rest of the network. It also allows time to refine capabilities such as slicing without being constrained by legacy architectural assumptions.
3GPP's early direction for 6G shows that the industry values stability at the physical layer. This does not mean that 6G will resemble 5G in its entirety. It simply means that the most significant advances may come from higher layers, from AI integration, from new network designs and from the ability to support extreme mobility and immersive applications. The waveform may remain familiar, but the network built around it is likely to change in profound ways.
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