The project has completed the overall 5G radio access network (RAN) design and addressed the technical enablers needed for an efficient integration and use of the various 5G technologies and components. After two intense years, the major results can be grouped under three areas:
• 5G Overall RAN design based on novel technology components
• Evaluations of the 5G KPIs and the definition of the associated evaluation methodology
• Development of a 3D visualization platform for easy demonstration and interaction with project results
The 5G RAN design has now reached a maturity level that is adequate for standardization. Some concepts developed in the early phase of the project have already been included in the first 3GPP release of NR and technologies developed later in the project are suitable for later releases. METIS-II has identified eleven key RAN design questions that should be answered to be able to build a 5G system, and the developed 5G RAN design addresses these questions.
The innovations of the project are both in the control plane and the user plane. For the control plane, an agile RM architecture is developed and described in detail from functional, protocol and deployment perspectives. This architecture operates over the envisioned air interface (AI) which consists of novel 5G and legacy AI variants. The new technologies include, for example multi-AIV/multi-Slice resource management, dynamic traffic steering, energy-efficient RAN Moderation, and Interference Management in fixed and dynamic radio topologies.
Other innovations include a new “inactive UE” state that will enable lower latency and battery savings, inclusion of D2D and self-backhauling as an integral part of 5G and a make-before-break and LTE-NR tight integration concept that enable more reliable connections. Another innovation is a new initial access scheme that improves access capacity and allows service prioritization, which is vital for mission-critical services.
The 5G RAN design also includes a common user plane framework where the MAC layer allows the coexistence of different numerologies and frame structures. The framework also contains a superfast harmonized multi-service HARQ and a common PDCP layer for user plane aggregation. The holistic AI enables harmonization across the protocol stack and co-existence for all AIVs including LTE.
For the 5G RAN design METIS-II has also produced system evaluations of the 5G KPIs in five use cases (UCs). The results show that it is possible to meet almost all of the KPIs using the technologies developed in the project. For a few KPIs, the set goals are not fully met, e.g. the achieved range for 99.999% reliability is 45m and not 50m as defined in the 5G KPIs. To be able to conduct the evaluations, the models to be used for all UCs have been specified. In addition, METIS-II have led the work on aligning these models and assumptions across all 5G PPP projects. This work has resulted in a joint document capturing the models that have been used by other projects. The document can be used by projects in later phases of 5G PPP. The evaluations and models have also been used as a basis for the upcoming 5G evaluations in 3GPP and ITU-R.
Another key achievement of METIS-II is the 3D visualization platform. The visualization platform the user of the platform to interact in real time with some of the most important achievements of METIS-II. For example, it is possible to demonstrate, in a virtual world, how a system based on the 5G RAN design would “feel” for a user in reality. The figure shows a snapshot of what a user of the platform sees. The platform also encompasses some static material, showing the main achievements of the technical work. For Janmedia, an SME, the platform will be used to offer new services after the project end.
In addition to the three main achievement areas highlighted above, METIS-II has also introduced new ways to authorize the use of spectrum, allowing for more dynamic and local use of spectrum, and has designed a holistic functional architecture based on enhanced LSA. The economic aspects of deploying 5G has also been studied to determine how to best roll out 5G.
METIS-II has held three cross-project 5G PPP workshops where the projects have had a chance to discuss and exchange ideas on RAN design. METIS-II also championed a joint 5G PPP document on 5G use cases and evaluation models, which was endorsed as the basis for KPI evaluation in 5G PPP. METIS-II has initiated a series of 5G RAN design workshops at IEEE conferences, jointly organized by multiple 5G PPP projects.
METIS-II has been very active in the discussions with and contributions toward standards and regulatory bodies, e.g. with direct contributions toward 3GPP on modelling assumptions. The project has also contributed to the 5G PPP activities toward regulatory bodies, e.g. RSPG and directly to ITU discussions.
