The dynamics of Low Earth Orbit (LEO) constellations introduce frequent and unpredictable Line-of-Sight (LoS) interruptions that challenge conventional handover procedures in Non-Terrestrial Networks (NTNs). Previous analytical work has established that, once the residual LoS interval becomes shorter than the end-to-end control-plane delay, network-assisted preparation loses feasibility and the decision logic must shift toward the terminal. Building on this premise, this paper introduces a learning-based reactive handover model representing a UE-centric continuity mechanism under LoS-limited conditions. The proposed framework employs a lightweight Q-learning agent that selects target satellites based on locally observable indicators such as relative elevation and received signal level. Within a deterministic geometric environment, the agent converges toward stable switching behaviour and reproduces the qualitative trade-offs predicted by the analytical model of reactive continuity. The achieved 25-30% alignment improvement over a geometry-only baseline demonstrates that even simplified reinforcement learning can capture timing dependencies essential to NTN handover robustness. While not intended as a deployment result, the study provides a reproducible benchmark and a methodological foundation for future deep- or federated-learning extensions operating within realistic NTN channel and protocol constraints.

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Fraunhofer FOKUS' Open6GCore is the first practical implementation of a 6G core network. It challenges the traditional view of network functions as rigidly connected components, by embracing a highly modular software-driven approach that offers significant adaptability and reduced complexity. The flexibility of Open6GCore allows dynamic adaptation to requirements, whether as a 5G core network, simplified microservices, microcore, or a distributed large-scale core network. By implementing 3GPP standards with modern IT methodologies, Open6GCore achieves scalability and resilience and simplifies the addition of experimental features. Thus, it is particularly well-suited for research environments, facilitating rapid prototyping and seamless integration of new functionalities. Initial functional validation demonstrates successful deployment, interoperability with 5G User Equipment and Radio Access Networks, and efficient core network operations. These results demonstrate Open6GCore's readiness as a platform for 5G and 6G testbeds, trials, and innovation. This paper highlights the architecture, development, validation, and integration techniques of Open6GCore, offering insight into its role as a foundational platform for next-generation networks.

To enable seamless 5G service continuity for mobile ground users traversing infrastructure-limited or obstructed regions, the integration of Non-Terrestrial Networks based on Low Earth Orbit satellite constellations is being actively pursued. However, the mobility dynamics of ground terminals frequently result in sudden Line-of-Sight loss, which undermines the feasibility of conventional handover preparation involving context transfer, synchronization, and identity continuity. Without pre-coordination, such transitions lead to uplink blindness, session interruption, and degraded performance. This paper addresses the handover problem under Non-Terrestrial Network-specific constraints by (i) defining a structured taxonomy of service continuity mechanisms suited for impaired Line-of-Sight conditions, (ii) introducing an analytical model that captures handover delay, authentication feasibility, and buffer dimensioning under varying visibility regimes, and (iii) quantitatively evaluating these mechanisms in a high-mobility highway scenario. The results underline that while context mirroring ensures superior continuity under full coordination, handover with reactive preparation emerges as the most practical and resilient fallback under constrained Non-Terrestrial-Networks conditions.

The arrival of mega-constellations with inter-satellite links marks a major shift in space communication, evolving toward large-scale networking systems. This spurred significant interest in creating new routing mechanisms designed to tackle the unique challenges of space-based networks, characterized by predictable but high-latency and predictably changing links. This paper proposes a Software Defined Networks (SDN)-based routing solution for mega-constellations, designed to significantly cut routing convergence time and reduce processing demands on space nodes. It relies on a centralized terrestrial controller that asynchronously computes routing information and deploys it to space nodes prior to its usage. These nodes are equipped with lightweight semantic routing capabilities that allows them to autonomously determine optimal routing based on their current network status. As any SDN solution, the design is flexible enough to accommodate various routing optimizations available in the literature, facilitating their practical implementation. The paper provides a detailed description of the proposed solution, assesses its feasibility using an example routing algorithm, and compares it with existing routing approaches, highlighting its strong potential for real-world commercial system application.

In 5th Generation networks, the User Plane Function forwards the data of the different users in the Radio Access Networks to the destination networks. To improve the throughput of this component, we used the software acceleration technique eXpress Data Path (XDP) in previous work to shift the processing of GTP-U tunnel connections in the kernel. The developed solution for an XDP Receive Side Scaling (RSS) in the uplink direction distributes the encapsulated traffic across the CPUs, but the measured throughput was significantly lower than in the downlink direction. In this work, we investigate the impact of multiple connections in the downlink direction with RSS by Network Interface Card (NIC). For leveraging this NIC feature in the uplink direction, we propose a sender-side source port variation in combination with XDP enhancements. In RFC2544 frame loss tests, we evaluate the performance with an increasing number of GTP-U tunnels.

The benefits of the currently evolving IEEE Time-Sensitive Networking (TSN) standard have already been globally recognized. Whereas the application of TSN in a LAN is currently widely and globally tested, TSN in a Metropolitan Area Network (MAN) has not been a major focus until now. The possible benefits of utilizing co-located Edge Clouds in order to support multiple urban production sites with industrial realtime applications open a wide range of new business models. Therefore, we have analyzed the feasibility of transparently using PROFINET over TSN via a Dense Wavelength Division Multiplex (DWDM) link, where a machine park is controlled remotely by an Edge-based virtual Programmable Logic Controller (vPLC). As a result, we are able to setup a TSN connection over a MAN with a one-way delay of about 156.5 J.μs and a jitter of about 12 ns. This work can be extended to allow for dynamically provisioned TSN flows and multi-path Frame Replication and Elimination (FRER) for distributed hard real-time machine control and adoption to Ultra-Reliable Low-Latency Communication (URLLC) 5G campus networks.