The collaborative research project 6G-ANNA develops concepts for the 6G radio access network (RAN) architecture and technology components. Previous RAN generations have become inherently more complex and reach their limits in handling foreseen future traffic demands with their diverse characteristics in an efficient manner, e.g., for the use-case of mobile eXtended Reality (XR) on a massive scale. One main objective of 6G is to regain both operational and energy efficiency, i.e., by simplification and automation. To achieve this, in this paper a flexible 6G RAN functional architecture and protocol stack as well as implementation and deployment options are described. We outline how performance is optimized by distributed Multiple Input Multiple Output (MIMO) and distributed Carrier Aggregation (CA), and furthermore, how adaptiveness and scalability is enabled by Cloud RAN and service orchestration. Finally, the proposed zero-trust framework mitigates security risks in the described 6G RAN architecture.

The 6th generation of wireless mobile networks is emerging as a paradigm shifting successor to unifying the experience across the physical, digital, and human worlds, pushing boundaries on performance in capacity, throughput, latency, scalability, flexibility, and reliability, while prominently addressing new major factors, including sustainability, security and privacy, as well as digital inclusion. Many research institutions and initiatives worldwide have started investigations to make 6G a reality by approximately 2030. In Germany, federal funding from the German Ministry of Education and Research (BMBF) supports a large-scale 6G initiative, with its lighthouse project, called 6G-ANNA. The core aim of this project is to develop the key aspects of a holistic, sustainable, secure, and resilient 6G system design that will simplify and improve the interaction between humans, digital assets, and the physical environment. This paper shares the vision of the project’s main technical working areas and advances, spanning topics from radio access, integration of multiple networks, as well as automation and simplification in networking to new applications and testbed scenarios, including real-time digital twins and extended reality. The industrial impact and relevance of standardization makes 6G-ANNA uniquely positioned to lead and realize the vision of next-generation wireless mobile network technologies, systems, and applications.

Industry 4.0, a subset of the fourth industrial revolution, derives industrial automation for manufacturing sectors by setting targets and mechanisms for industrial data exchange. 5G system is considered as a communication platform that provides flexibility and wireless connectivity to support industrial automation. However, several issues are to be addressed in order for 5G NR to enable industrial automation, such as, efficient multiplexing between industrial flows i.e. maintaining QoS for critical traffic while enhancing efficiency for other traffic. In this paper, we present our view on how to solve several relevant issues, from medium access control (MAC) layer perspective. The main advantage of our solutions is that it requires very low complexity resulting in minimal changes to existing standardization specification.

The fifth generation (5G) of mobile networks is envisioned to support new applications having demanding requirements, such as low latency and high reliability, which is the focus of this article along with enhanced traditional mobile broadband and massive sensing. Different approaches have already been proposed to achieve low latency while guaranteeing high reliability. However, the challenge of efficient resource utilization remains. In this article, concepts for a flexible and low-latency-enabling mobile network architecture are presented, along with strategies for staying efficient. The work is put in perspective with respect to ongoing standardization activities. Finally, future visions for network management architectures and 5G's impact on economic aspects are discussed.

5G is currently being standardized and addresses, among other things, new URLLC services. These are characterized by the need to support reliable communication, where successful data transmission can be guaranteed within low latency bounds, like 1 ms, at a low failure rate. This article describes the functionality of both the NR and LTE radio interfaces to provide URLLC services. Achievable latency bounds are evaluated, and the expected spectral efficiency is demonstrated. It is shown that both NR and LTE can fulfill the ITU 5G requirements on URLLC; however, this comes at the cost of reduced spectral efficiency compared to mobile broadband services without latency or reliability constraints. Still, the impact on the overall network performance is expected to be moderate.

Integrating different radio access technologies (RATs) is one effective method to meet the demand to provide ever increasing data rates to the users. For integrating LTE and WLAN in particular, the purpose is to enhance the operators control of when the UE uses WLAN. Another aim, in addition to better network control on which RAT is used, is the possible data aggregation which enables simultaneous utilization of both resources. In this paper, we present LTE-WLAN Aggregation (LWA) as specified in 3GPP and compare it to the LTE-WLAN Radio Level Integration with IPsec tunnel (LWIP), also specified in 3GPP. In addition, we provide simulation results comparing the schemes in an example scenario.

Industrial automation applications generally have stringent communication requirements in terms of low latency and high reliability. Existing wireless technologies operating in the unlicensed spectrum are unable to fulfill these requirements owing to the regulatory constraints for coexistence and spectrum sharing. In this paper, we (i) comprehensively analyze and classify the typical industrial automation applications based on their latency and reliability requirements, (ii) investigate the performance of LTE and its latency reduction and reliability enhancements, and (iii) identify which classes of industrial automation applications can be satisfied by using LTE and its enhancements. Our detailed system level simulation results indicate that LTE (release 14 and beyond) is able to satisfy the requirements for some of the identified industrial automation use-cases such as machine tools, production lines, and logistics.

Future 5G wireless systems aim to support new use-cases and requirements. For instance, critical machine type communication and enhanced mobile broadband drive the requirement of ultra-low latency. The evolution of LTE has already achieved enhancements to peak data rate and spectral efficiency. The focus, however, has shifted to reduce the LTE radio latency in order to strengthen its role in the 5G ecosystem. In this paper, we evaluate LTE Release 14 and Release 15 lowlatency features. These features, which are currently being standardized, comprise improvements to physical layer and medium access. We show how their reduction of LTE's round trip time can significantly improve the end-user performance of latency-depended applications.

This paper investigates how suitable TV White Space (TVWS) is for use by cellular networks. Unlike in licensed bands, transmit power in TVWS is limited and considerable interference from TV towers exists. This suggests that evaluating TVWS only in terms of available bandwidth can be misleading, since performance of wireless networks in TVWS is likely lower than in the same amount of dedicated spectrum. We quantify TVWS at the example of Germany, using the European methodology developed in CEPT ECC SE 43. In the second step, we determine the performance of a cellular network operating in TVWS using a calibrated multi-cell and multi-user system level simulation tool. This way we also consider interference between TVWS users, which in previous TVWS studies has not been investigated in detail. Not all locally available TV channels are equally useful. We thus compare different channel selection algorithms a TVWS operator could apply to select from the set of available TVWS channels. We found that while the available spectrum for TVWS usage is in theory quite high, its actual utility strongly depends on the channel selection method and the requirements it is based on. Due to the high interference from TV towers, cellular networks based on frequency re-use one (like LTE) have difficulties finding channels that allow good performance at the cell edge. The inner part of a cell can however considerably benefit from TVWS. This indicates that for cellular networks TVWS is primarily suitable for traffic offloading and spotty coverage rather than for building large contiguous coverage networks.