The Next Generation Mobile Networks Alliance has called for a simpler approach to 6G standardisation and migration, arguing that Multi-RAT Spectrum Sharing should be the baseline option.
The recommendation appears in one of two new operator-focused NGMN publications. The papers also argue that the industry needs more time to develop mature 6G standards before commercial launch, with current views pointing to standardised 6G features reaching the market in the early 2030s.
The first paper examines radio access network and core network migration choices as mobile operators move from 5G to 6G. It argues that the sector should agree early on a main migration path to avoid fragmentation across devices, radio networks and core systems.
Drawing on the experience of 5G standalone, NGMN warns of the risks of complexity when standards, deployment timing and ecosystem readiness do not align. In its view, a narrower set of migration choices would reduce market confusion and lower long-term operational burdens for operators.
At the centre of that position is Multi-RAT Spectrum Sharing, or MRSS, which would allow different radio access technologies to share spectrum. NGMN argues MRSS should be the starting point for 6G migration work, while acknowledging that it still requires further study on performance and implementation.
That includes improving efficiency beyond the level seen with 4G-5G Dynamic Spectrum Sharing and extending support across both Frequency Division Duplexing and Time Division Duplexing spectrum. Operators, it says, should focus their study work on whether MRSS can meet real deployment demands at scale.
Other migration models remain under consideration, including dual connectivity and dual stack approaches. But these should be used only if they can address specific deployment gaps that MRSS cannot cover.
Timing concerns
The second paper examines when 6G should reach the market and sets out operator concerns about moving too quickly. It says the first release of 6G standards should be simpler and better defined, rather than trying to cover too many use cases at the outset.
According to NGMN, operators want high-quality specifications completed before standardised 6G functions are introduced commercially. Large-scale deployment will also depend on a developed supply chain for both network equipment and compatible devices.
The papers were issued as the mobile industry enters a period of early 6G study work in 3GPP, the standards body that defines mobile specifications. NGMN argues that choices made during this phase will shape network architecture, migration costs and the overall structure of the 6G ecosystem.
The alliance represents a range of mobile operators and develops common technical positions intended to influence standards development. Its message in these papers is that 6G should avoid repeating what it sees as the more fragmented path taken in 5G.
Laurent Leboucher, Chairman of the NGMN Alliance Board and Orange Group CTO and EVP Networks, said: "The transition to 6G will present significant opportunities, but only if the industry prioritises migration paths that build on existing network assets, minimise operational complexity and deliver tangible benefits from the earliest deployment stages. Dedicating sufficient time to this process is crucial, otherwise risking unnecessary complexity and long-term challenges, limiting the value to operators and end users."
His comments reflect a broader concern among operators over cost control as they prepare for another generational shift in mobile infrastructure. Reusing existing assets and reducing unnecessary change have become more prominent issues as returns on large network investments come under pressure.
Greg McCall, Chief Networks Officer at BT and NGMN Board Director, said: "Alongside early evaluation of migration options, it is equally critical that decisions around architecture align cost with a realistic assessment of hardware reuse and enable scalable, multi‐vendor ecosystems. Migration and architecture solutions should support interoperability, cloud‐based deployments and long‐term operational efficiency."
The operator view also reflects concern about preserving a clear customer case for 6G. NGMN argues that the industry should avoid blurring the value proposition by introducing standards that add complexity without clear benefits for users or operators.
Guangyi Liu, Chief Expert of China Mobile and NGMN Board Director, said: "While flexibility is important, migration options need to be limited if we are to learn the lessons from 5G that hindered time-to-market. The current promise of MRSS as a migration path for 6G deployment is clear, but for this to be realised that means ensuring there is not unnecessary complexity on networks or devices."
NGMN has made 6G one of its main strategic priorities while continuing to work on 5G implementation and broader network issues. It argues that decisions on standardisation and architecture taken now will have long-lasting effects on whether 6G can be introduced in a way that is affordable for operators and clear to customers.
Anita Döhler, CEO of NGMN, said: "6G is one of NGMN's core areas of strategic focus and this year and next will be critical to pave the way. Decisions of today around standardisation, including migration options, will shape the entire 6G ecosystem and determine its long-term success with regards to ability to deliver value to customers. We will continue to provide operator-driven guidance around key requirements for design considerations and network architecture evolution to support the industry in the evolving 6G landscape."