Deployment and interoperability questions for Release-21 6G systems

Determine how 6G technologies can be deployed and certified across reused spectrum and existing site grids, governed under operator data obligations, and migrated onto terrestrial and non-terrestrial assets already in service or in orbit while maintaining multi-vendor operability.

Background

The transition from Release-20 studies to Release-21 normative specifications will make deployment, interoperability testing, and certification central concerns. The paper identifies unresolved issues involving spectrum reuse and carrier aggregation, the scope of AI standardization, agentic AI, two-sided AI models, energy efficiency, and harmonization of terrestrial and non-terrestrial networks. These questions are framed around deployability and multi-vendor operability rather than merely algorithmic capability, particularly because 6G must reuse existing spectrum and sites and accommodate assets already deployed on the ground and in orbit.

References

Several open questions will shape that interval, and the lessons collected in Table~\ref{tab:lessons} suggest which press hardest. Spectrum scarcity makes carrier aggregation and reuse of existing bands unavoidable, placing a premium on the $\sim$7~GHz upper-mid-band and on coverage techniques that match 5G's site grid. The scope of AI standardization remains a live debate: limited enough not to slow innovation, yet broad enough to guarantee testability and consistent behavior, with the role of agentic AI still being defined and two-sided models still posing inter-vendor training and validation challenges. Energy efficiency, given the RAN's share of operator energy use, is a first-class design constraint. And the harmonization of TNs and NTNs, native to 6G but demanding careful migration from in-orbit assets, will test the discipline of a single, unified design.

— 6G as It Is Actually Being Built: Insights from Early 3GPP Standardization  (2610.05694 - Tu et al., 5 Oct 2026) in Section 7, “Toward Trials and Commercial Launch”