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Quality-of-Service

Quality-of-Service

Quality of service parameters like goodput, packet loss, latency, and jitter are not only responsible for the quality of experience of communication systems. In many fields of application, fulfilling the QoS requirements is also essential for a safe and reliable performance of the offered services. Industrial communication and communication between electronic control units in vehicles are examples for critical applications. In both systems, messages need to arrive within given time bounds so that the system can react to events in the required time frame.

In our quality-of-service research group we evaluate relevant quality of service metrics of communication systems. For this purpose, we apply measurements, modeling, simulation, mathematical analysis, Network Calculus, and optimization. We also design communication systems and protocols that can fulfill given quality of service parameters.

Current fields of application are communication systems in rail vehicles, smart grids, time synchronization for the development of vehicular control units, modern Ethernet standards (TSN), and satellite-based Internet communication.

Projects

Network calculus (NC) is a system theory for deterministic performance
evaluation. It uses mathematical methods to provide performance
guarantees for communication systems. It can be applied in the
design phase of future systems as well as the analysis of existing
systems. In real-time systems, the timeliness of events plays an
important role. Therefore, the classical performance evaluation based on
stochastic methods that result in (stochastic) expectation values, i.e.
mean values, has to…

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The electrical energy network is in a state of change due to the digitization and integration of decentralized energy sources. Pervasive and interconnected sensors and actuators are creating complex virtual control systems.
Based on an efficient communication network, innovative services and applications can provide an ecological, economical, stable and high-quality energy supply. A particular challenge are the diverse requirements and traffic patterns of applications that may be distributed…

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Distributed simulations are often used to improve performance or to couple different simulators. This coupling is very important for the simulation of autonomous driving functions, because reusable simulation components can be created for the closer and wider environment of the vehicle, for the ego and other vehicles, for sensor technology, for procedures in the control units, for vehicle dynamics and for similar aspects and can be executed together in a simulation. Furthermore, such a distributed…

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This research project deals with the application of quality of service guarantees in Time-Sensitive Networking, in particular using Network Calculus. Real-time systems are increasingly required in industry, e.g. the automotive, automation or entertainment industries. Classical Ethernet, however, does not guarantee real-time performance, which leads the Time-Sensitive Networking Task Group (IEEE 802.1) to develop standards for real-time data transmission over Ethernet networks. These standards are…

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Satellite communication is a way to provide broadband internet access all over the world. However, with geostationary satellites the propagation delay leads to very high delays in the magnitude of several hundred milliseconds. In order to improve the interactivity and responsiveness of communication systems, utilizing a second communication link can be highly beneficial.

The Transparent Multichannel IPv6 (TMC-IPv6) Project aims to combine the advantages of multiple heterogeneous communication…

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The aim of this research project is to test the suitability of TSN in the railway sector.  The primary goal of the project is to analyse whether the requirements of safety and time-critical applications can be met with respect to deterministic network communication and bounded latencies and at the same time to prove that the fulfilment of the requirements of critical applications does not lead to a significant impairment of non-critical applications.

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Publications of this research group