While core network architecture, AI integration and service frameworks will all evolve, it is the radio access network (RAN) that determines how spectrum is used, how coverage is delivered and how new capabilities are exposed to customers. For operators, it represents the largest share of capital investment and operational complexity. For vendors, it remains the primary arena for differentiation and long-term revenue.
In a break from our usual weekly news updates, this extra edition takes a deep dive into RAN. There may well be some unfamiliar terminology, but hopefully this gives an early indication of what a 6G RAN will need to support.
Background
Commercial deployment of 6G is not expected until 2030, but early work on the all-important global standards is already underway. This is being undertaken by the 3GPP stakeholders group, and it represents a huge body of work - as well as considerable negotiations between hundreds of different parties in an attempt to reach consensus on the technical specifications.
Normative work on the standards (actually writing the specifications) will form the bulk of what is known as Release 21, which will start later this year - exact timeframe will be decided in June. The current work of 3GPP is focused on Release 20, and although much of that is connected to the ongoing evolution of 5G, it also includes detailed study work on 6G technologies.
The 3GPP holds a quarterly plenary for its three technical work groups, of which RAN is one. The next is due in March so it is well worth taking a look at the outcomes from December’s meeting.
Study Framework
A 6G RAN study framework for the architecture and migration of radio access technologies (RAT) was agreed at the December meeting and although it does not define the technical specifications of 6G, it sets out a series of requirements that effectively constrain what the final system can and cannot become. These “guard rails” signal the direction for the next phase of normative work and, importantly, reflect the lessons learned from 4G (LTE) and 5G.
The industry is attempting to avoid repeating the transitional compromises that characterised early 5G deployments. Non-standalone 5G anchored to LTE enabled rapid time to market, but at the cost of architectural complexity and prolonged dependency on legacy layers.
Importantly, the 6G framework explicitly requires support for a standalone RAN architecture. That does not mean operators will switch off 5G overnight. Far from it - 5G will be operational and essential for years or decades to come. The 3GPP study stipulates multi-RAT spectrum sharing between 6G and 5G NR, inter-RAT mobility between the two, and idle-mode mobility with LTE. In practical terms, this recognises that 6G will coexist with 5G and 4G for many years.
For operators, spectrum strategy becomes the migration strategy. Multi-RAT spectrum sharing will provide the mechanism that will allow 6G to be introduced without large-scale, immediate spectrum re-farming. The ability to dynamically share spectrum between 5G NR and 6G radio technologies will determine how quickly meaningful 6G coverage can be delivered. Inter-RAT mobility requirements suggest that user experience continuity is being prioritised from the outset, reducing the risk of early 6G deployments becoming isolated islands.
The framework also points to a more distributed and coordinated RAN. Requirements for connectivity through multiple transmission and reception points, whether collocated or non-collocated, combined with spectrum aggregation across those points, indicate that 6G is expected to support highly coordinated radio behaviour. This could encompass advanced forms of coordinated multi-point transmission, distributed MIMO or cell-free architectures.
Another notable element is the requirement that 3GPP-defined interfaces for 6G RAN be open for multi-vendor interoperability. While 3GPP interfaces are, by definition, standardised, the explicit emphasis on openness suggests an awareness of operator concerns around vendor lock-in and fragmented interpretations. This does not automatically guarantee seamless multi-vendor deployments. The whole issue of “Open RAN for 6G” is contentious, specifically around open fronthaul, and we will do a deeper dive on this later, including the geopolitical aspects.
Multi-tenancy is being embedded as a design principle. The architecture must allow control plane and user plane separation, support RAN sharing between multiple operators, enable network slicing and allow non-public networks. This combination signals that 6G RAN is expected to operate in environments ranging from nationwide public networks to enterprise-specific deployments and neutral host models. The separation of control and user plane functions may also facilitate more flexible deployment topologies and improved scaling.
Non-terrestrial networks
The inclusion of both terrestrial and non-terrestrial networks in the architectural considerations reflects the growing importance of satellite and high-altitude platform integration. Rather than treating non-terrestrial access as an adjunct, the framework requires that 6G RAN design take it into account from the outset. This may influence assumptions around latency, mobility management and link variability. For operators, it opens the possibility of more seamless coverage extensions and resilience strategies, particularly in rural or mission-critical contexts.
Data and intelligence also feature prominently. The architecture must support enhanced service awareness in the RAN, enable network performance monitoring and allow the collection and transport of standardised measurement data, including AI and sensing data, in an efficient manner under operator control. Privacy, anonymity and user consent are explicitly referenced, with operator control over data collection emphasised. These requirements suggest that 6G RAN is expected to be tightly integrated with analytics and AI-driven optimisation from the beginning.
Resilience, cost and sustainability are also codified as design objectives. The 6G RAN architecture must enable enhanced resilience compared to 5G NR where applicable, lower CAPEX and OPEX relative to current networks and reduced energy consumption to support sustainability goals. These statements might be aspirational but they are also consequential - they create a baseline expectation that 6G should not simply deliver incremental performance at higher cost and energy footprint. Vendors will need to demonstrate that new coordination features, AI integration and additional capabilities do not undermine efficiency gains.
Finally, coexistence with NB-IoT and eMTC is mandated, along with idle-mode mobility to LTE. This underlines the industry’s recognition that long-lived IoT deployments and legacy coverage layers will persist well into the 6G era. 6G must therefore integrate into a heterogeneous environment rather than replace it wholesale.
For operators, active engagement in the standards process will be essential to ensure that the final architecture aligns with operational realities and commercial priorities. For vendors, the challenge will be to innovate within these boundaries while proving that 6G can deliver measurable gains in performance, efficiency and flexibility.