Concept & Methodology
Commercial deployments of 5G are now progressing worldwide, delivering new capabilities, improved performance and new applications for customers. For Mobile Network Operators, a set of features that are supported by 5G, including network slicing, disaggregation, and cloud-native design, are enabling the use of new applications and new business models. The gradual shift to the full digitization of the real world is expected to create vast amounts of generated data and applications, like immersive communication, and holographic telepresence, while social experiences powered by Extended Reality (XR) will become our default way of communication in the near future. These emerging applications exceed the current and future capabilities of 5G networks, both in terms of KPIs that must be supported, and in terms of their requirements on an ultra-dense computational infrastructure, to support the required degree of computational offloading. Thus, academia and industry have shifted their attention to the investigation of a new generation of Smart Networks capable of supporting such performance. The first results of these studies show that 6G networks will deliver efficiency clearly superior to 5G and satisfy evolving services and applications, making them a key enabler for the intelligent digital society of 2030. Several breakthrough ideas have been already proposed for 6G like joint communication and sensing, cell-free, Radio Intelligent Surfaces, complete cloud continuum etc.
Key participants from 4 5G-PPP projects (MonB5G, MARSAL, REINDEER, HEXA-X) have joined forces to pursue the federation of their efforts in the 6G-BRICKS experimentation facility, leveraging on a mature set of experimentation tools from the 5GMediaHUB 5G-PPP project. 6G-BRICKS will be the first open 6G experimentation platform that combines cell-free, Open-Air Interface (OAI) and RIS, while adopting the proven principles of softwarisation, Open Interfaces (O-RAN), and Open-Source software stacks, putting future expansion and evolvability at its core. However, experience from previous 5G-PPP efforts has shown that the enormous complexity of the standards and software stacks makes evolvability and scaling-out efforts extremely challenging, requiring interdisciplinary efforts and big investments in integration.
This is where 6G-BRICKS steps in, bringing together specialists on breakthrough 6G technologies, such as cell-free networking, distributed processing and Reconfigurable Intelligent Surfaces (RIS), and adopting principles of modularity and softwarisation to deliver the first truly modular end-to-end 6G experimentation platform in Europe. 6G-BRICKS will structure the various architecture tiers around the concept of “LEGO Bricks”, delivering self contained testbed nodes that can be reused across testbed infrastructures. This significantly lowers the barrier of entry to an end-to-end experimentation platform for specialists to bring their breakthrough technologies for validation and experimentation.
6G-BRICKS will adopt the trend of Software-Defined Infrastructures (SDI) and Software Networks that replace “black boxes” (e.g., physical network functions, such as firewalls) with their softwarised equivalents. This trend will be extended to the RAN via the O-RAN initiative, aiming to evolve O-RAN elements in the 6G era via the integration of breakthrough technologies. To this end, 6G-BRICKS will deliver the first open and programmable O-RAN Radio Unit (RU) for 6G networks, termed the OpenRU, based on an NI USRP-based platform. Moreover, 6G-BRICKS will integrate the RIS concept into the OAI. In addition, 6G-BRICKS will deliver breakthrough experimentation tools, going well beyond the current Testing as a Service (TaaS) capabilities of current initiatives, and allowing experiments also on devices via O-RAN compliant xAPPs. Thus, the 6G-BRICKS experimentation facility aims to serve a dual role, both as a playground for testing advanced vertical applications and for validation testing and showcasing of the clear benefits and capabilities of 6G breakthrough technologies and devices. Moreover, it will deliver and test new architecture principles, with multi-tenancy, disaggregated Operations Support Systems (OSS) and Deep Edge integration at the forefront.
6G-BRICKS aims to offer a trusted, agile and evolvable 6G experimentation facility, federating two experimentation platforms in Belgium (KUL) and France (EUR) from previous 5G-PPP initiatives under a Core Site (ISI/ATH) acting as the facility entry point, and offering Public Cloud and experimentation services. The Facility will be accessible by third-party consortiums, vertical application owners, as well as experimenters from the vertical and component industry. The facility will showcase a disaggregated Management Plane and Operations Support System, to support extendibility, evolvability, and multi-tenancy, going well beyond centralized Cross-Domain Service Orchestrators (CDSOs) and OSS/BSS systems typically supported in 5G-PPP experimentation platforms. The 6G experimentation facility architecture is shown in Figure 1.
More specifically, the 6G-BRICKS facility will include the following architectural tiers:
The Core Tier acts as the entry point to the experimentation facility, offering Public Cloud services to the 6G Sites. Mature frontend elements and experimentation engines will be leveraged and deployed at the Core Site from the 5GMediaHUB project, delivering DevOps Driven Testing as a Service functionality which allows test cases and validation testing workflows to be authored via standard DevOps tools. A unique testing tool based on Near-RT RIC will also be delivered for the first time, giving experimenters access to low-level RRM and RAN slicing capabilities via standardized xApps. Moreover, the Core Site will offer Business Support System (BSS) services to the 6GBRICKS facility, allowing vertical application owners to upload their applications and Business Intents (SLOs).
A disaggregated Management Plane, which consists of a set of Domain Manager Orchestrators (DMOs) for each Cloud, Edge, and Network orchestration domain. The DMO layer, deployed at each facility site, acts as a unified controllability framework aiming to provide the ability to enforce and propagate state-to-action mappings, automatically generating service objectives based on the SLOs (or business intents) submitted at the Business Layer. These actions are subsequently implemented by the infrastructure domain (e.g., RAN controller, SDN, VIM, etc.). Explainable AI mechanisms are leveraged for policy translation and unification. This breakthrough explainable architecture design supports end-to-end slicing, provides explainable feedback to experimenters for potential SLA breaches and facilitates a loose coupling with the Business Layer, avoiding bottlenecks.
6G Experimentation Platforms layer, where breakthrough 6G technologies are integrated into reusable, self-contained modules with O-RAN interfaces to ensure the openness and reusability of the developed components. At the KUL site, a Distributed Cell-Free RAN is delivered, leveraging on the MARSAL baseline work and an O-RAN stack from ISRD. The EUR site builds on the 5G-EVE facility and the EUR OpenAirInterface O-RAN stack, which will be integrated with a RIS platform from the RISE-6G project. In both sites, UE Farms will be deployed, i.e., a managed constellation of UE devices to be offered to experimenters, supporting virtualization and service placement at the device level, termed the Deep Edge. The UE farm may include (i) 5G enabled remotely controlled smartphone devices or (ii) similarly spaced clusters of Single Board Computers (e.g. Raspberry PIs) and IoT devices.