• The focus of 6G is shifting from raw speed to user experience
• Network slicing needs significant improvements
• There is limited enthusiasm for mmWave and THz bands
• It is felt that 5G neglected voice and enterprise market opportunities

For the second report in our new ‘Defining 6G Networks’ series, we focused on the views and requirements of network operators. What do they really want from the 6G standardisation process? To find out, we analysed the submissions to the 3GPP 6G Workshop that was held in March. A total of 30 operators made detailed submissions for discussion; covering their overall 6G vision; RAN technology; and system architecture, core networks and protocols. You can download our comprehensive report here.

One area we wanted to explore was how the 6G process may differ from 5G. In particular, we wanted to see if there were any admissions of shortcomings with the 5G process (always easier to spot in hindsight) and lessons learned that will be applied to the 6G process that will take us right up to 2030. We were pleasantly surprised by the degree of honesty within the submissions, which gives us confidence that 6G will address the needs of the operators.

Throughout the operator submissions, there was a high degree of consensus on specific aspects of 5G standards and the standardisation process that proved problematic. The most frequently cited issue was the overwhelming complexity and excessive optionality in 5G standards. The flexibility in 5G new radio (NR) has proved unnecessarily large and caused too much complexity for both standardisation and deployment. For example, with fragmented network functions, there are too many user equipment (UE) features and band combinations.

But it was the multiple architecture option of non-standalone/standalone (NSA/SA) that created the biggest implementation challenges and inefficiencies. Many operators claimed that the migration path from 5G NSA to SA was unnecessarily complex. Needless to say there is very broad consensus not to repeat this process.

Operators tended to agree that 5G standards often failed to prioritise commercially viable features, noting the gap between 5G vision recommendations and actual customer experience. And whilst it was hoped that 5G would be the generation built for enterprises, the reality fell short. AT&T said that “specification support for specific verticals is often siloed and introduced late in a G” and that specification support for specific verticals has had limited market success.

For a cellular system to neglect voice was another area of high concern. Vodafone was one of many that bemoaned “voice and regulated services were not available from day one” and required complex fallback mechanisms that could have been avoided with better prioritisation in standards. Voice for day one is now one of the most popular requests for 6G.

Evolving beyond speed

In previous technology generations, faster download or downlink speeds were a major feature and driver of the standards, with claims that this would provide better service to customers and, therefore, be profitable to network operators. However, this no longer appears to be the case for 6G and this feature is notably absent from most operator submissions.

Instead of peak speeds, operators are emphasising performance characteristics and a positive increase in the perceived user experience. For consumers and smartphones, the theoretical peaks of 5G speeds are far in excess of most use cases, and any additional increases in raw speed are only going to offer diminishing returns. What’s more, many operators have faced challenges in monetising 5G speed improvements – charging for faster speeds proved largely unsuccessful.

Interestingly, there is more of a focus on uplink speeds, with calls to improve the performance here, especially as usage patterns continue to evolve and there are greater synchronous interactions with cloud services.

Network slicing

Network slicing is another area of 5G that has come in for scrutiny and criticism. The 6G Workshop submissions from operators reveal a mix of views: Most acknowledge that the 5G implementation of slicing fell short of expectations, although they still believe in its potential value for 6G, provided it is significantly improved.

“Network slicing falls short of its flexibility promises and poses challenging issues for operators, even in the simplest use scenarios,” wrote Bouygues Telecom. “These rigidities are unacceptable for 6G.”

No operator explicitly advocates for abandoning network slicing in 6G. Instead, they propose significant improvements to address current limitations. These include: Simplified configuration, enhanced flexibility, operational practicality, and service-specific optimisations. Interestingly, many operators discuss concepts related to network slicing without explicitly using the term. Perhaps it’s time for a rebrand?

From mmWave to THz

There’s not too much operator love for mmWave and THz bands, and they rarely feature in the submissions. However, several operators said they were interested in exploring higher frequency bands for 6G, although the emphasis is on “exploring”, there’s no indication that this is going to be a day one priority. There’s some sense that there is strategic value in mmWave and potential THz frequencies, but only for specific use cases and possible capacity enhancements.

• China Mobile stated that the 26GHz band (mmWave) should be considered for 6G and that there should be continued investment in higher frequency technologies.
• China Telecom confronts the coverage challenges of ever-higher frequencies (the higher the frequency, the shorter the wavelength and propagation), but rather than abandoning these spectrum bands it suggests employing enhanced coverage technologies to overcome these limitations – reconfigurable intelligent surface (RIS) being one of the possible solutions).
• NTT Docomo adds that mmWave and potentially higher bands remain strategically important for certain deployment scenarios.

So yes, capacity requirements in ultra-dense urban environments still need to be addressed, though it looks like mmWave alone is not going to cut it. There’s also the case for the integrated sensing and communication (ISAC) use case, which has emerged as the leading new use case proposal across all stakeholders. Will ISAC require or benefit from higher frequency bands that may offer superior performance for sensing applications?

Still, the primary focus from operators is to ensure support for sub-6GHz and upper 6GHz (6.425-7.125GHz) bands for initial 6G deployments.

To find out what operators want to ‘fix’ with 6G, then download the report here.

- Guy Daniels, Director of Content, TelecomTV