Aktuelle Trends in Verteilten und Kontextsensitiven Systemen

The IEEE 802.11be standard introduces Multi-Link Operation (MLO), which enables devices to operate concurrently over multiple channels, either within or across frequency bands. By distributing traffic over these parallel links, MLO reduces latency and congestion on any single channel while increasing total throughput. Consequently, MLO improves the reliability and efficiency of IEEE 802.11be networks.

Ziele der Seminararbeit:
• Explain the MLO technique in IEEE 802.11be
• A literature review on the real-world performance evaluation of MLO

The IEEE 802.11 standard uses Forward Error Correction (FEC) to enable receivers to identify and correct bit errors autonomously by embedding redundant parity information into the physical (PHY) layer. This mechanism increases robustness against channel impairments such as noise, interference, and multipath fading. Hence, FEC improves the reliability of links and the effective throughput in IEEE 802.11 networks.

Ziele der Seminararbeit:
• Why is FEC not used in IEEE 802.3?
• Explain the two different FEC techniques in IEEE 802.11
• What is the relationship between FCS and the Modulation and Coding Scheme (MCS)?
• Why is the Frame Check Sequence (FCS) still needed?

Accurate clock synchronization is essential in networks requiring time-critical data transfer, where even minimal clock deviations can lead to significant operational errors. Given that the internal clocks of network devices inherently drift apart over time, clock synchronization is indispensable for reliable and error-free operations.

In wired Ethernet networks, protocols like the Generalized Precision Time Protocol (gPTP), defined in the IEEE 802.1AS standard, are widely implemented. gPTP employs a master-slave architecture and hardware timestamping to achieve time synchronization with sub-microsecond accuracy. However, in emerging network domains – including converged 6G/TSN networks – further problems, such as variable link delays, arise. Thus, time synchronization in these fields is still under active research.

Ziele der Seminararbeit:
• Explain the mechanisms through which gPTP achieves precise time synchronization in traditional Ethernet-networks and how these mechanisms can be employed in converged 6G/TSN networks.

Efficient allocation of radio resources is critical in 5G networks, where diverse services such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC) must coexist. Network slicing enables multiple logical networks to share the same physical infrastructure while maintaining performance isolation. However, realizing slicing at the Radio Access Network (RAN) level introduces significant challenges, particularly in the allocation and scheduling of radio resources within the resource grid. Ensuring that different slices operate efficiently while minimizing interference and maximizing spectral efficiency is a key research problem.

The resource grid in 5G is a structured framework that defines how radio spectrum is divided into time-frequency units. In RAN slicing, each slice may require a different configuration in terms of bandwidth, latency, and reliability, necessitating dynamic partitioning of the resource grid. This involves defining slice-specific configurations at different protocol layers, such as adaptive scheduling at the Medium Access Control (MAC) layer and customized numerologies at the physical layer (PHY). Furthermore, ensuring isolation between slices while maintaining overall network efficiency requires sophisticated resource management strategies, including dynamic spectrum allocation and interference mitigation techniques.

Ziele der Seminararbeit:
• Examine how the resource grid in 5G is structured and allocated among different 5G slices with a possible focus on resource scheduling, isolation mechanisms and strategies for efficient spectrum utilization.

DECT NR+ is a non-cellular 5G technology standard that specializes on ultra-high reliability and ultra-low latency (>99.99% reliability at sub-millisecond latencies). This seminar topic aims to provide a technical introduction to the central DECT NR+ mechanisms that enable such guarantees.

[1] ETSI TS 103 636-1, DECT-2020 New Radio (NR); Part 1: Overview

Ziele der Seminararbeit:
• Motivate the usage of DECT NR+ compared to public/private 5G deployments.
• Provide a technical introduction to DECT NR+, including its physical layer and media access control (MAC) layer.
• Discuss potential applications and technical limitations of DECT NR+.

Software-Defined Networking (SDN) enables dynamic network management and network programmability by decoupling the network control and data plane. This is achieved through a network controller that can provide both low-level control (e.g., adding/removing a switch) and high-level control (e.g., load-balancing) over the network. While logically centralized, modern SDN controllers often follow an microservice-based design (e.g., Google's Orion [1]) that splits the controller independent modules for routing decisions.

Ziele der Seminararbeit:
• Investigate the design choices of the Orion architecture.
• Provide a technical introduction into consistency models [2] and their necessity when updating the network configuration at runtime.
• Provide an overview of recent approaches on formally verified high-availability control planes [3].

Subroutines encapsulate some computation and help to break down a large program into smaller parts. Coroutines imitate this property, but the lifetime of a coroutine is not tied to the control flow of the program. When a subroutine returns to the calling program, its control information and local variables are destroyed. In contrast, when a coroutine returns control to its caller, its execution is not finished and thus its state is preserved. Each time control reenters the coroutine, it resumes execution where its local control left off and data state is retained. Hence, coroutines are a form of retentive control.

Coroutines are especially well suited for the implementation of asynchronous or event-driven applications. With the use of coroutines, data or IO stalls can be hidden, improving parallelism at runtime and reducing programming complexity at build-time. For this reason, coroutines are experiencing a resurgence. Many popular languages have recently introduced native support for coroutines. Moreover, coroutine-based implementations of highly parallel applications are becoming more and more popular.

Ziele der Seminararbeit:
• Comprehensive review of relevant literature and case studies on the principles and mechanisms of coroutines, including synchronization primitives for coroutines, state and context switch mechanics for coroutines, and mechanisms for runtime optimization.

Utreexo offers a pathway to minimize Bitcoin’s Unspent Transaction Output (UTXO) set storage through the use of cryptographic accumulators. This enables the operation of lightweight, fully validating nodes using only a few kilobytes per node while maintaining network security and integrity.

Ziele der Seminararbeit:
• Explore the internal workings of Utreexo and its potential to improve scalability by examining the impact of Utreexo on node management, decentralization.
• Discuss the future prospects of blockchain technology and potential for participation in the Bitcoin network.

Federated Learning is a machine learning setting, where many clients train together without making the data itself accessible for the collaborators. This enables many institutions with smaller datasets to gain insights they couldn’t get with just their own data. Also, in privacy restricted areas like medical data Federated Learning could help.

With the evolving mobile communication technologies edge computing theory and techniques have been attracted an increasing interest of researchers and engineers around the world. Edge computing can help to accelerate content delivery and reduce network load, by communicating with near edge nodes instead of the cloud. This leads to new problems like task scheduling, data replication and data placement.

Ziele der Seminararbeit:
• Describe challenges for Federated Learning especially in edge networks.
• Explain how some Federated Learning approaches tackle these challenges.
• Compare the results of approaches that take these challenges into account with results of standard Federated Learning approaches.

With the evolving mobile communication technologies edge computing theory and techniques have been attracted an increasing interest of researchers and engineers around the world. Edge computing can help to accelerate content delivery and reduce network load, by communicating with near edge nodes instead of the cloud.

Artificial Intelligence (AI) is increasingly used to enhance the performance, scalability, and efficiency of edge computing environments. AI-driven techniques help in dynamic resource allocation, predictive maintenance and real-time workload distribution. By leveraging machine learning and deep learning models, edge networks can self-optimize, adapt to changing conditions, and reduce operational costs.

Ziele der Seminararbeit:
• Describe approaches which use AI to optimize edge computing environments.
• Discuss the benefits and limitations of AI-driven edge optimization.
• Examine the trade-offs between computational overhead and performance gains.

Smart home environments typically consist of devices from different manufacturers that must communicate and operate within a shared ecosystem. However, many existing smart home solutions rely on proprietary protocols and platforms, leading to fragmentation and limited interoperability between devices. To address this challenge, the Matter standard has been introduced as a unified application-layer protocol designed to enable reliable and secure communication across devices from different vendors. By providing a common framework for device discovery, communication, and control, Matter aims to simplify the development and integration of smart home technologies.

Ziele der Seminararbeit:
• Comprehensive review of relevant technical documentation and research literature on the design and functionality of the Matter smart home standard.
• Describe the architecture of Matter, including its interaction with underlying network technologies such as IP-based communication, as well as its mechanisms for device discovery, commissioning, and secure communication. Give particular attention to how Matter enables interoperability between devices and ecosystems from different manufacturers.
• Explain how Matter-based systems operate in practice.
• Discuss the advantages and limitations of Matter systems in terms of interoperability, scalability, security, and its usability in smart home environments.

As the number of connected devices in smart homes continues to grow, communication technologies must support reliable, scalable, and energy-efficient networking. Mesh networking protocols are particularly well suited for this because they allow devices to relay messages through intermediate nodes, thereby extending network coverage and improving resilience. Thread is a relatively recent networking protocol designed for IoT applications that builds upon IPv6. It aims to provide secure and robust mesh communication for smart home devices.

Ziele der Seminararbeit:
• Comprehensive review of technical documentation and relevant research literature on the design and operation of the Thread networking protocol.
• Describe the different roles of devices in a Thread network, including routers, router-eligible devices, and end devices and explain how the devices collaborate to form a self-healing mesh network.
• Explain how Thread enables reliable communication in distributed IoT systems. Place particular emphasis on the mechanisms used for device discovery, network formation, and message routing between nodes.
• Discuss the advantages and limitations of Thread compared to other mesh networking technologies.

Traditionally, requirements engineering has a tendency to create use cases and elicit functional and non-functional requirements with limited user involvement. Often, developers act as representatives for users. Sometimes users’ attitudes are integrated through a small number of interviews. In many cases, this involvement is sufficient, especially when it comes to functional requirements.

However, more and more software systems are being developed where the benefit for users is not directly apparent or where the large number and heterogeneity of users does not allow for a straightforward requirements elicitation. To deal with such complex requirements engineering tasks, an interdisciplinary approach has been suggested, specifically building on findings from psychology and sociology.

Ziele der Seminararbeit:
• Give an overview of research on integrating users’ feedback into the requirements engineering process using interdisciplinary methods.
• Create a topology of software system problems and corresponding requirements engineering methods.

By tracking users’ eye movements while they are performing their daily tasks, their identity can be continuously verified in the background. This provides an additional layer of security without disrupting the user’s current task. However, the reliability of the authentication strongly depends on contextual factors, including multisource ambient lighting, head movements, and the quality (accuracy, sampling rate) of the eye tracking device. While authentication has reached robustness when using high-quality commercial eye trackers, its application in the wild with less powerful devices or even using web cameras remains uncertain.

Ziele der Seminararbeit:
• Comprehensive review of studies that compare how the performance of gaze-based authentication varies based on the used eye tracking device, ambient conditions, and other contextual factors.
• Extraction of factors that have the highest impact on the authentication performance.
• Discussion of the implications that the identified performance differences have on gaze feature extraction methods and authentication algorithms.

Traditional railway signaling relies on centralized control, but more flexible, self-adaptive architectures hold the potential to improve reliability and compliance with schedules. The MAPE-K framework enables self-adaptation by assigning the tasks of Monitoring, Analysis, Planning, and Execution to distinct components. A range of architectural patterns with varying degrees of decentralization and physical distribution of the MAPE components are currently deployed in volatile mobile scenarios, such as coordinated robot fleets and vehicular platooning.

Ziele der Seminararbeit:
• Comprehensive overview of scientific literature on MAPE patterns in mobile scenarios, focusing on the spectrum of decentralization and distribution.
• Discuss how varying degrees of distribution—ranging from localized MAPE loops on individual units to hierarchical structures—address the trade-offs between local autonomy and global system stability.
• Identify adaptation actions that are performed in the reviewed scenarios

As the automotive industry transitions toward Cooperative, Connected, and Automated Mobility, Vehicle-to-Everything (V2X) communication has emerged as a critical enabler. V2X describes a highly dynamic distributed system where vehicles, infrastructure, and vulnerable road users communicate to enable advanced functionalities like intersection assistance.

However, the safety-critical nature of these distributed functions poses a massive challenge for verification and validation. Testing V2X systems is non-trivial due to the sheer infinite number of traffic scenarios and the non-deterministic behavior of wireless communication channels (e.g., C-V2X or ITS-G5). A multitude of methodologies have therefore emerged to ensure the reliability of V2X functions.

Ziele der Seminararbeit:
• Communication Technologies & Standards: Analyze the underlying physical and networking layers (e.g., ITS-G5 vs. C-V2X). How is seamless communication realized in a decentralized topology and what standards govern these protocols?
• Simulation Testing: Evaluate the current simulation landscape. What frameworks (e.g., OMNeT++, SUMO, CARLA) allow for the co-simulation of network traffic and vehicle physics to validate distributed V2X components?
• Real-World Deployment & Field Trials: Review prominent pilot projects and testbeds. What are the lessons learned from large-scale real-world deployments regarding signal interference, latency bounds, and system scalability?

Connected Automated Vehicles (CAV) combine automated driving functions with network connectivity (Vehicle-to-Everything, V2X) to leverage off-board information for safer and more efficient transportation. While manufacturers largely rely on proprietary software stacks, open-source software for automated driving has matured considerably in recent years. A prominent example is Autoware, a comprehensive open software stack for automated driving. It leverages the Robot Operating System 2 (ROS2) as a communication middleware, which allows for seamless integration with other projects, such as the open-source autonomous driving simulator CARLA. Furthermore, both Autoware and CARLA support functionality related to Vehicle-to-Everything (V2X) communication, often facilitated through specific open-source plugins.

But how do these underlying frameworks operate, and how are they actively applied in current research? What capabilities do they offer researchers investigating cooperative driving?

Ziele der Seminararbeit:
• Technical Foundations: How does ROS2 enable communication, and what makes it suitable for automated driving?
• Existing Software: What are the existing research approaches and software solutions that leverage Autoware as a foundation to investigate CAV and V2X?
• Simulators: How are simulators like CARLA integrated with Autoware to test and validate V2X functionalities? Give an overview of the capabilities for V2X communication of the simulator.

Vehicle-to-Everything (V2X) communication promises tremendous opportunities for future mobility. It enables vehicles (cars, buses, trucks, etc.) to exchange information directly with their surroundings—including other traffic, infrastructure, and vulnerable road users like pedestrians. As the crucial backbone of Intelligent Transport Systems (ITS), this connectivity enhances everyday efficiency and paves the way for fully automated driving through use cases like non-line-of-sight sensing and cooperative maneuvers.

While the underlying technologies and communication protocols (like those standardized by ETSI) have been available for years, widespread market adoption remains limited. Manufacturers like Volkswagen have begun integrating selected V2X features into their vehicles, but a recent interview study identified regulatory hurdles as a primary reason stalling broader deployment.

Ziele der Seminararbeit:
• Provide a brief overview of existing V2X standards and protocols.
• Identify and describe regulatory conditions, contrasting developments across multiple markets.
• Analyze the broader reasons for the current lack of widespread market adoption of V2X functionality.

The Robot Operating System 2 (ROS 2) has established itself as the de facto standard for developing complex robotic applications. As robots evolve from isolated machines to highly interconnected, distributed systems – involving numerous sensors, actuators, and processing units – the need for robust, real-time communication between these components is paramount.

At its core, ROS 2 functions as a powerful middleware layer that sits between the host operating system and the robotic application code. By leveraging the industry-standard Data Distribution Service (DDS), ROS 2 abstracts underlying hardware and network complexities, providing a modular, secure, and highly scalable communication framework. Understanding how this middleware routes data and manages node-to-node connectivity is crucial for designing reliable robotic systems that require deterministic, low-latency data exchange.

Ziele der Seminararbeit:
• Provide an architectural overview of ROS 2 and its underlying integration with the Data Distribution Service (DDS).
• Analyze the core middleware communication paradigms, including Publish/Subscribe, Client/Service, and Actions.
• Evaluate the role of Quality of Service (QoS) profiles in managing real-time data constraints, network reliability, and distributed system performance.