A new position paper from Next Generation Mobile Networks Alliance (NGMN) counsels the industry to give itself enough time to define the architecture that should underpin 6G, to avoid the complexity and difficulties it encountered with 5G.
The paper, which was written as a collaboration between a group of operators, says that it is important that 6G avoids the complexity and confusion of core network architecture options that created Non Standalone and Standalone options for 5G, and the numerous deployment options that operators were faced with to combine and migrate from one to the other.
The authors explained that 6G could be designed with a network architecture that “can integrate multi-dimensional capabilities, with appropriate inclusion of Artificial Intelligence (AI), computing, sensing, and enhanced security.”
At this point, detailed discussions about specific architectural options are premature.
“However,” the paper continued, “consensus on 6G network architecture has yet to be reached. NGMN Mobile Network Operator Members are currently at different stages of their 4G and 5G network evolution. Some have transitioned to 5G Standalone (SA), while others are still in Non- Standalone (NSA) configurations or progressing through intermediate stages.”
Accordingly, the paper says it wants to “guide the industry in re-thinking the values and requirements of 6G networks, with the goal of fostering early consensus on key aspects.”
Recognising these challenges, the majority of NGMN MNO Members believe that now is the appropriate time to commence studies on 6G network architecture, with many emphasising the urgency of achieving alignment prior to 3GPP standardisation.
“At this point, detailed discussions about specific architectural options are premature. It is imperative to allocate sufficient time for 6G architecture studies to avoid repeating the challenges encountered with the 5G design process. As we witnessed, implementation with early support for 5G NSA created challenges for the subsequent migration towards 5G-SA.”
“Finding appropriate balance between the need for flexibility, accommodating diverse levels of 5G network evolution among operators, and the need to ensure simplicity for 6G remain a critical challenge.”
It’s going to be hard to define a core architecture when it is still unknown if 6G will incorporate a new air interface, what that interface might look like and if it will interact with previous generations. The NGMN paper says options on the table for 6G include a completely new 6G core, extending and enhancing the existing 5G core, or even integrating elements of the 4G EPC into a hybrid core.
The authors say that if a new 6G air interface is adopted, 60% of the MNOs it surveyed internally prefer to anchor it with the 5G SA core network, while 40% prefer a dedicated 6G core network.
Potential enhancements to the core network for optimal 6G RAN evolution include tight integration with AI/ML, a more distributed architecture with edge computing, and enhanced network slicing to provide more flexible and customised network services to meet diverse application requirements. However, NGMN would like to see an architecture that enables such features to be deployed in a modular manner.
“New features should be deployable on-demand when needed without compromising existing core connectivity services. This concept of modularity can apply to both networks and devices.”
The paper serves as a reminder that achieving consensus for a new mobile network “G” is going to be harder than ever, given that what the industry is asking for is not a technology forklift, but a “graceful evolution”, to borrow NGMN’s words, to a platform that gives it the ability to continuously develop and iterate.
