Reinhard German

Prof. Dr.-Ing. Reinhard German

Head of Computer Science 7

Department of Computer Science
Chair of Computer Science 7 (Computer Networks and Communication Systems)

Room: Room 06.155
Martensstr. 3
91058 Erlangen

Secretary

Short Biography

Reinhard German received his diploma in computer science in 1991, the PhD degree in 1994, and the habilitation degree in 2000 from the Computer Science Department, Technical University of Berlin. Thereafter, he joined the Department of Computer Science at the University Erlangen-Nuremberg. First, he was an associate professor (system simulation), then he became a full professor in 2004
(computer networks and communication systems), and served as head of department and as dean of the faculty of engineering.
He is contact professor of INI.FAU, a research cooperation with the AUDI AG, conducts simulation projects at the
Energie Campus Nürnberg (EnCN) and is scientific representative for Connected Mobility in the Center Digitalization of Bavaria (ZD.B).
In 2019 he received an offer by Monash University, Melbourne, Australia, for a position as a Full Professor for “IT in Energy” and
is now a Adjunct Professor at Monash. His research interests include performance and dependability analysis of networked systems
based on numerical analysis, network calculus, discrete-event simulation, measurements, and testing.
Vehicular communications, smart energy systems, and healthcare constitute major application domains.

More Information

Publications

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Projects

  • National Research Data Infrastructure for Interdisciplinary Energy System Research

    (Third Party Funds Group – Overall project)

    Term: 2023-03-01 - 2028-02-28
    Funding source: Deutsche Forschungsgemeinschaft (DFG)
    Abstract

    The necessary transformation of energy systems towards net zero greenhouse gas emissions provides a plethora of new research challenges. New interconnections between different energy sectors, such as power, heat and mobility, increase the system's complexity. In this context, the digitalisation towards cyber-physical energy systems (CPES) alleviates change, and equally affects technical, social, and societal topics, as well as the mode of research in the CPES research community. Research efforts towards CPES heavily rely on modelling and (co-)simulation-based approaches. Tracking of models together with all data creates a complex software and data management challenge, which needs to be addressed in each research project. To this end, nfdi4energy covers the whole research and transfer cycle of projects in energy system research ranging from (1) identifying relevant competences for a project; (2) defining relevant scenarios and experimental setup; (3) integrating models and data; coupling tools and laboratories; (4) extracting results, facilitating public consultation; to (5) identifying research challenges for follow-up activities.

  • QUICOPTSAT

    (Third Party Funds Single)

    Term: 2022-12-01 - 2024-12-01
    Funding source: andere Förderorganisation
    Abstract

    The TCP performance over satellite communications has become a well-known problem, following significant experimentation with Internet services over satellite since the '90s. Several tailored TCP optimisations have been introduced (mainly implementing changes at the sender side, but also at the receiver side in some proposals). In parallel, given the challenge of installing tailored TCP versions directly in the end user system, a set of architectural extensions have been introduced culminating in the concept of a Performance Enhancing Proxy (PEP, RFC 3135), whereby a native end-to-end TCP connection is now commonly split into a series of multiple connection (a split TCP concept). This allows a tailored TCP to be deployed on the satellite link (i.e., between the satellite terminals and gateways to be optimised). Though largely used since the early 2000's, PEPs have always been unable to enhance non-TCP protocols or VPN connections traversing the satellite network segment. Application-layer compression and acceleration was also provided in some PEPs.

    Since 2000, there has been a continued effort to evolve the protocol stack for Internet web services, with several updates to the protocols for HTTP-based services. A design of HTTP by Google, known as SDPY, was standardised as HTTP/2. This provided significant improvements in download speed of satellite, but at the same time deployed application-layer encryption and compression – making application-layer acceleration dependent on using an authenticated proxy and impossible within a PEP.

    A more recent Google proposal (known as gQUIC) sought a transport other than TCP that uses a UDP substrate with transport encryption. This effort evolved in standardisation by the Internet Engineering Task Force (IETF) and was finally published as IETF QUIC (RFC 9000) in 2021. QUIC is specified for use with HTTP/3, a replacement for HTTP2/TCP. The main leap from classical HTTP services over TCP is in that QUIC uses encrypted datagram connections, with congestion control, flow control, NAT-rebinding and migration algorithms directly implemented within the QUIC protocol. Following standardisation, QUIC and HTTP/3 have been implemented and have been rapidly deployed to the Internet.

    Hence, the design rationale of QUIC intrinsically prevents using a classical PEP solution for the optimisation of performance over a satellite system.  Whilst the application-layer performance of HTTP/3 resembles or improves on that of HTTP/2, and the transport design has been shown to operate correctly over satellite with respect to initialisation, protocol timers, and other core functions, experiments have shown that performance of QUIC operated end-to-end over paths comprising a satellite network segment can be lower than offered by TCP using a PEP. This has motivated the scientific community and the satellite industry to think of alternative solutions for QUIC congestion control (CC) to accelerate with the QUIC performance degradation, which is still now at the early stages. QUIC has also been suggested for other applications.

    The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt), University of Aberdeen, and Friedrich-Alexander-Universität Erlangen-Nürnberg have built a consortium that is committed to thoroughly analyse the existing approaches and options to improve the performance of TCP over satellite network segment and apply the most appropriate concepts to QUIC congestion control mechanisms as well as understanding the implications of deploying the new approaches as a part of a secure end-to-end architecture. As a result, a novel algorithm will be defined and then verified against the relevant technical requirements. Finally, the resulting new QUIC specifications will be validated using real satellite trials in exemplar scenarios.

  • Simulation der Energieflüsse in der Metropolregion zur Verbebesserung der Entscheidungsfindung im Kontext der Energiewende

    (Third Party Funds Group – Sub project)

    Overall project: Klimapakt2030plus - Energiewende in der Metropolregion Nürnberg
    Term: 2022-12-01 - 2027-11-30
    Funding source: BMBF / Verbundprojekt

  • Adaptive Quality of Service Provisioning for an Efficient and Resilient Operation of Smart Distribution Grids

    (Third Party Funds Single)

    Term: 2022-07-01 - 2026-06-30
    Funding source: Deutsche Forschungsgemeinschaft (DFG)
    Abstract

    In transmission systems, a dedicated and high-performance communication infrastructure allows a parallel execution of communication-intensive functions and services. In the course of the expansion of renewable energies at lower voltage levels of the distribution networks and the shift of system responsibility to (operators of) these plants and systems, similar functions and services must also be implemented at the distribution network level in Smart Grids – so-called Smart Grid Services (SGSs).
    In this project, we will therefore conduct research on online reconfiguration methods based on a two-step QoS-provisioning approach: At a first level, discrete optimization is used to find an allocation of SGSs to available servers and allocation of flows to paths through the communication network based on a topological view of the compute, storage, and communication facilities. At a second level, Network Calculus is used to ensure analytically that all critical SGSs can meet their QoS requirements. The overall effect of the two-step approach will then be assessed by simulation.
    FAU will be mainly considering the networking and QoS aspects in this cooperation, while Oldenburg University will concentrate on the effects on the energy network and the reconfiguration of the Smart Grid Services.

  • Traffic Engineering for Resilient Quality of Service Requirements

    (Non-FAU Project)

    Term: since 2022-05-02
    Abstract

    Die Bundesanstalt für den Digitalfunk der Behörden und Organisationen mit Sicherheitsaufgaben (BDBOS) ist die Netzbetreiberin des Bundes. Unter anderem verantwortet sie die Netze des Bundes und entwickelt diese im Zuge der Digitalisierung weiter. Mit der Netzstrategie 2030 verfolgt die BDBOS u.a. das strategische Ziel, einen einheitlichen, zukunftsfähigen, resilienten und leistungsfähigen Informationsverbund der öffentlichen Verwaltung zu schaffen.
    In Kooperation mit der BDBOS und auf Basis einer externen Promotion soll dieses strategische Ziel wissenschaftlich untersucht und die daraus resultierenden Ergebnisse evaluiert werden. Das Ergebnis sollte ein resilientes und qualitätsgewährleistendes Modell/Framework sein (resilient QChain of a System – resQoSystem, ausgesprochen: rescue of a system), welches die Leistungsfähigkeit des Informationsverbundes öffentliche Verwaltung in den unterschiedlichsten Lagen sicherstellt und gewährleistet.

  • Simulation KI-unterstützter automobiler Szenarien und Protokoll-Optimierung

    (Third Party Funds Group – Sub project)

    Overall project: Optimierung der Konnektivität für automobile Anwendungen in hybriden Satelliten / terrestrischen 5G Netzwerken mittels künstlicher Intelligenz
    Term: 2022-02-01 - 2025-01-31
    Funding source: Bundesministerium für Wirtschaft und Technologie (BMWi)
    Abstract

    The cooperation between Airbus Defense and Space GmbH, Fraunhofer Institute for Integrated Circuits, Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg and ZF Friedrichshafen AG has the common goal of increasing the connectivity for automotive applications in hybrid satellite-terrestrial 5G networks using artificial intelligence.

    The FAU works primarily on concepts for the integration of automotive applications, the creation of a simulation model for the combination of vehicular and satellite communication, the integration of AI algorithms, the performance evaluation and optimization of quality-of-service related protocols, and supporting the implementation of a real-time demonstrator. Results shall be presented at scientific conferences and contribute to the standardization of 5G and future 6G networks.

  • New protocols for faster Internet via satellite

    (Third Party Funds Single)

    Term: 2021-10-01 - 2024-09-30
    Funding source: Bundesministerium für Wirtschaft und Technologie (BMWi)
    Abstract
    In the QUICSAT project, the cooperation between the Friedrich-Alexander University (FAU) Erlangen-Nürnberg and ND SatCom GmbH has the common goal of improving Internet protocols and applications for geostationary satellite connections.

    The potential of new technologies (AQM, ECN, BBR and especially QUIC) will be examined. The ultimate goal is that Internet via satellite should perform as good as terrestrial Internet connections.

    The high latency of geostationary satellites, the current architecture of Internet protocols and the constantly increasing complexity of Internet applications (especially websites) are the reason why the performance of Internet via satellite is sometimes worse than the performance of terrestrial Internet connections, even if the data rates are comparable. Newer Quality of Service (QoS) mechanisms are currently not used in satellite communication. With QUIC there is also the risk that the performance of satellite internet will decrease due to the non-applicability of Performance Enhancing Proxies.

    The project makes a contribution to protocol research, standardization and reference implementations.

  • MBPLE4Mobility - Continuous model-based product line development for control systems in vehicle technology

    (Third Party Funds Single)

    Term: 2021-07-01 - 2024-06-30
    Funding source: Bundesministerium für Wirtschaft und Technologie (BMWi)
    Abstract

    As part of a large consortium, the Chair of Computer Science 7 is involved in the project with the model-based system design of the vehicle communication systems under inclusion of variant diversity. For this purpose, on the one hand, an optimization for the configuration and resource design of the network architecture for different communication protocols and mechanisms is realized. On the other hand, safety analyses are performed using fault trees and extending them for product lines.

    Network calculus is used for the formal verification of the required real-time properties. Therefore, suitable approaches for the scheduling methods applied in the networking technologies (e.g. TAS, priority-based, CBS, etc.) have to be formulated.

    Model and code generators will be developed for automated and accelerated generation of the network optimizations. safety and real-time analyses. The results of these analyses are fed back into the modeling of the overall system.

  • Multi-sector coupled energy system modeling on a regional level

    (Third Party Funds Group – Overall project)

    Term: 2021-05-01 - 2024-04-30
    Funding source: Bundesministerium für Wirtschaft und Technologie (BMWi)
    URL: https://www.esm-regio.de
    Abstract
    Reducing primary energy use and greenhouse gases are central goals of the energy transition. However, switching from fossil to regenerative energy sources is not enough to achieve them. An overarching view and optimization of the different sectors of the energy system - electricity, gas, heat and transport - can significantly advance the further development of the energy system in Germany. Potential exists above all on a regional level.

    The goal of the ESM-Regio project - short for "Multisectoral Coupled Energy System Modeling on a regional level" - is to create a temporally high-resolution energy system model on a county level that takes into account the four sectors of electricity, gas, heat and transport as well as the required interface technologies. A key feature of the project is a cross-sector model logic. Suitable simulation methods enable a holistic analysis and optimization of the system operation under consideration of the four relevant sectors of the energy system.

  • Satellite Internet Performance Measurements

    (Non-FAU Project)

    Term: 2021-01-01 - 2021-04-30
    Funding source: andere Förderorganisation
    URL: https://www.cs7.tf.fau.de/forschung/quality-of-service/forschungsprojekte/sat-internet-performance/
    Abstract

    This work evaluates the performance of different applications over different Internet access technologies, with focus on Internet access via satellite.

    The following Internet access technologies have been selected:

    • Geostationary satellites (Konnect/Eutelsat, skyDSL/Eutelsat, Bigblu/Eutelsat, Novostream/Astra Connect)
    • Satellite megaconstellations in low Earth orbit (Starlink)
    • Terrestrial systems as reference (o2 DSL, Congstar LTE)

  • Heterogeneous vehicle networks for data transmission in the field

    (Third Party Funds Single)

    Term: 2020-04-01 - 2023-09-30
    Funding source: andere Förderorganisation
    Abstract
    Vehicles are evolving to a mobile data platform. Besides mobility as their main purpose, the demand for entertainment, connectivity and current software is increasing. Besides installing updates in the workshop there is already today a mobile communication module built into the car, by which map updates, traffic information and entertainment applications are run. Mobile communication however depends on existing network coverage and can be limited in certain areas. Additionally a fee has to be paid to the mobile network provider, which is usually dependent on the amount of used data traffic. In this project additional technologies are to be evaluated, that may enable effective communication in the future. Publicly available WLAN hotspots have a potential as they are often available in the road area and can mostly be used cost-effective. Additionally vehicles need similar information, for instance a map update, that has to be delivered to multiple cars in the field. Therefor direct communication between vehicles as in 5G offers the possibility to exchange information in the field and reduce the usage of mobile communication. The goal is to test the combination of different technologies to a complex, heterogeneous vehicle network and evaluate the applicability of opportunistic networks. At the same time, proposals for future standardization are to be developed. From a scientific point of view suitable coordination and routing mechanisms are vital as connection times are short, vehicles serve as temporary storage and source of information and effective usage of transmission paths is relevant.

  • Reliability design of multi-sensor systems

    (Third Party Funds Single)

    Term: 2020-01-01 - 2022-12-31
    Funding source: andere Förderorganisation
    Abstract
    Modern driver assistance systems for self-driving cars often rely on data collected by different sensors to determine the necessary system decisions. To prevent system failures, different techniques can be used to enhance the reliability of such multi-sensor systems, e.g., aggregation, filtering, majority voting and other mechanisms for fault tolerance. As a consequence, erroneous sensing is rare but can be correlated in successive sensor readings (e.g., as error bursts) and also between sensors (e.g., in specific environmental conditions such as bad weather).

    For a reliable design, error probabilities of such multi-sensor systems must be determined. In the project an existing analytical model based on Markov chain as well as a simulation model should be extended. This includes the following aspects: extensions for several correlated sensors, integration of practically relevant sensor fusion algorithms, consideration of environmental conditions, adaption of structure and parametrization of the error model, extensions of the simulation for rare events and inclusion of code, validation of the model results based on available data, and realization as a software tool for the reliability design of multi-sensor systems.

    In this project, the preliminary work of the INI.FAU project is to be built and both the existing analytical model based on Markov chains and the simulation model for multi-sensor systems are to be expanded. The desired scientific knowledge consists in the further development of the analytical Markov model, which already takes into account bursts of errors of individual sensors and dependencies between two sensors, the expansion to more sensors, the consideration of further error prevention strategies and a tool implementation. Furthermore, knowledge of the use of rare event simulation is to be achieved in order to execute more detailed simulation models of multi-sensor systems in practical terms and thus to derive statistically reliable results. The simulation allows an even more realistic system simulation and a validation of the analytical modeling. A scientifically based methodology is developed to determine the reliability of multi-sensor systems.

  • Optimization of Multi-Access Edge Computing (MEC) for Network-Dependent Services

    (Non-FAU Project)

    Term: 2019-10-01 - 2024-12-31
    Abstract
    In the future, data exchange will no longer take place exclusively between the cloud (or a server in a data center) and a mobile device. Instead, communication between devices will be established directly on the basis of application relationships in order to realize immersive applications, automated driving or virtual reality. To this end, 5G and future network technologies are increasingly following the data-centric paradigm in their design, in which, among other things, the increasing relevance of direct device communication is taken into account. Another elementary development also contributes to this: Computing or information resources are no longer provided exclusively by cloud servers.
    Multi-Access Edge Computing (MEC) is part of current research and deals with the provision of resources on distributed edge nodes. For example, MEC instances can be located close to base stations to serve applications with special requirements, such as low latency, low-variance jitter, high bandwidth, or privacy requirements close to the end device. Over time, services will emerge whose components can be deployed literally anywhere and in a distributed manner - without the need to consider a mandatory hierarchical network topology. In addition to a cloud instance, a service can therefore also be operated on the edge instance in the vicinity, e.g. a mobile radio base station, a traffic control system or even a neighboring user equipment (UE). Multi-level MEC constellations are also possible. A homogeneous technology stack that extends cloud computing enables a data-centric architecture that can simultaneously accommodate stringent service requirements.
    The resulting architecture can be viewed from two perspectives. In terms of network communication, MEC resources are accessible via only a few links or hops. This geographical or topological proximity means that the links are not overloaded, which results in the aforementioned performance advantages. With regard to the services provided, a MEC orchestrator can dynamically adapt service deployments on compute nodes to the current situation and integrate resources into the topology or remove them, for example, to save energy. In addition to orchestration decisions, the movement of nodes also leads to a change in the network topology. In order to exploit the full potential of MEC and thus also to be able to operate services that rely on MEC resources, both perspectives must be combined in a meaningful way.
    In static environments, MEC resources can usually be planned well in advance. It becomes a challenge especially when the mentioned dynamic topology changes or mobility of UEs affect the overall system. One of the key questions that arises is: Can the communication requirements of MEC-dependent services, which are necessary for the smooth implementation of the service, be met at all times?
    The research project deals with the selection of the best MEC resources, for example from a UE point of view, as well as the, from a network point of view, best locations for orchestrators to provide the services. In particular, the focus is on the current network and topology situation in combination with the strict communication requirements of services that need MEC resources. Strategies and algorithms, for example based on graphs, are developed, implemented and evaluated. Verification takes place through system-level simulations and real-world deployment.

  • Performance Evaluation of Hardware-in-the-Loop Test Systems for Autonomous Driving Functions

    (Non-FAU Project)

    Term: since 2019-06-03

  • Decentralized Provision of Ancillary Services with Electric Vehicles

    (Third Party Funds Single)

    Term: 2019-04-01 - 2020-12-31
    Funding source: Bayerisches Staatsministerium für Bildung und Kultus, Wissenschaft und Kunst (ab 10/2013)
    URL: https://zentrum-digitalisierung.bayern/initiativen-fuer-die-wissenschaft/graduate-program/graduate-fellowships/
    Abstract

    As part ofthe Energy Transition, conventional power plants, which are currentlyresponsible for the stability of the electricity grid, are increasingly beingtaken off the grid. New concepts are necessary to ensure system stability in thefuture. Therefore, a model is developed to describe the flexibility of chargingprocesses of electric vehicles. Simulations are performed to investigate thecapability, reliability, limits and costs of ancillary services with electricvehicles such as reserve power and congestion management as well as combinationsof partly competing goals for various scenarios. A close cooperation partner isthe StartUp ChargingLedger, which brings concepts from simulation toapplication.

  • Time Management and Real-Time Capabilities of Parallel and Distributed Simulation for the Virtual Development and Validation of Automated Driving Functions

    (Third Party Funds Single)

    Term: 2018-10-01 - 2021-09-30
    Funding source: andere Förderorganisation
    Abstract
    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 simulation provides a starting point for coupling with real software or hardware components (SIL or HIL). Time management in the distributed simulation must ensure causality: if there are deviations in the assignment of simulation time to real-time in the components, causality violations can occur. One example is cooperative safety functions, where actions take place in a very fast sequence. Reasons for causality violations can be, for example, non-synchronized clocks or delays in message delivery. Another task of the time management is to ensure the reproducibility of the simulation results. Jitter in the execution time of individual components or during message transmission results in a non-determinism in the execution sequence, which can lead to a different simulation result.

  • Simulation and modeling based on collected real-world data

    (Non-FAU Project)

    Term: 2018-10-01 - 2021-09-30
    Abstract

     Die Funktionssicherheit von Fahrerassistenzsystemen sowie automatisierter und vernetzter Funktionen ist vom Automobilhersteller in jeder denkbaren Verkehrssituation sicherzustellen.  Im Entwicklungs- und Absicherungsprozess ist dazu eine erhebliche Zahl  von Verkehrssituationen, sog. Szenarien, abzuprüfen.  Dieser umfangreiche Prüfumfang lässt sich in Zukunft eigentlich nur noch durch den massiven Einsatz von Computersimulation sinnvoll bewältigen. Um in diesen Simulationen eine entsprechende Validität und Praxisrelevanz zu erzeugen, müssen Modelle des eigenen Fahrzeugs, der Strecken und –Umgebung sowie des umgebenden Verkehrs adäquat modelliert werden.

    Im Rahmen dieser Arbeit sollen Fahrsituationen, sogenannte Fahrszenarien, realer Versuchsfahrzeuge sensorisch erfasst und aufgezeichnet werden. Aus diesen Datenaufzeichnungen soll das aufgezeichnete Fahrszenario in einer Fahrsimulation nachgebildet und eine aktivierte automatisierte Fahrfunktion darin betrieben werden. Dadurch kann die Exaktheit des Simulationsmodells mit den aufgezeichneten Messdaten verglichen und validiert werden. Darüber hinaus werden so anspruchsvolle Fahrszenarien für einen Prüfkatalog gesammelt und das Fahrszenario kann mit vielen Variationen der zu simulierenden automatischen Fahrfunktion durchgespielt und verglichen werden.

    Aufbauend auf einem funktionierendem Verfahren der Szenariengenerierung aus Messdaten soll ein Verfahren für gezielte Datenanalyse relevanter Szenarien  aus Massendaten hinsichtlich Kategorien, Definitionen, Trajektorien zur Erzeugung von parametrierbarer Manöverklassen systematisch erarbeitet werden.

  • Engineering of next-generation Train Control and Management Systems (TCMS)

    (Third Party Funds Single)

    Term: 2018-10-01 - 2021-09-30
    Funding source: Siemens AG
    Abstract
    With the developing technologies and methods in the field of real-time communication and the constantly increasing amount of data to be transmitted, the railway industry has jumped on the bandwagon of modernizing its processes.

    In the field of railway applications, various manufacturers still provide different and mostly incompatible solutions.  These solutions are specified for a certain constellation of a train, but in most cases they are not able to offer the correct functionality if the constellation of the train changes.  In order to separate safety and time-critical areas from non-critical areas that e.g. offer services for passengers such as wireless LAN, separate networks with their own infrastructure must also be set up. That means more weight and costs for the train and its manufacturers.

    In the area of real-time communications, time-sensitive networking (TSN) has proven to be a possible solution to overcome the problems mentioned above.  It provides methods and mechanisms for Ethernet technology that enrich it with aspects of determinism and reliability.

    With Time-Sensitive Networks (TSN), the safety and time critical domains can be merged with non-critical areas, so that the safety and time critical domains can still be guaranteed sufficient reliability and determinism and the needs of passengers are satisfied.

    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.

  • Network Calculus for Time-Sensitive Networking

    (Own Funds)

    Term: since 2018-10-01
    Abstract
    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 summarized under the term Time-Sensitive Networking (TSN). Within the scope of this research project, the application of Network Calculus for TSN is now being investigated. Network Calculus (NC) is a system theory for deterministic performance evaluation. It uses mathematical methods to provide performance guarantees for communication systems. NC can help evaluate TSN's real-time properties, meet required latency limits, and provide insight into the optimal configuration of networks. It also enables buffer sizing and can evaluate existing or new scheduling algorithms.

  • Evaluation methodology for automated driving using function simulation

    (Non-FAU Project)

    Term: 2018-09-01 - 2021-08-31
    Abstract
    Die Funktionssicherheit von Fahrerassistenzsystemen sowie automatisierter und vernetzter Funktionen ist vom Automobilhersteller in jeder denkbaren Verkehrssituation sicherzustellen.  Im Entwicklungs- und Absicherungsprozess ist dazu eine erhebliche Zahl  von Verkehrssituationen, sog. Szenarien, abzuprüfen.  Dieser umfangreiche Prüfumfang lässt sich in Zukunft nur noch durch den massiven Einsatz von Computersimulation sinnvoll bewältigen. Um in diesen Simulationen eine entsprechende Validität und Praxisrelevanz zu erzeugen, müssen Modelle des eigenen Fahrzeugs, der Strecken und –Umgebung sowie des umgebenden Verkehrs adäquat modelliert werden.

    Im Rahmen dieser Arbeit soll eine Methodik zur Absicherung von Systemen und Funktionen des automatisierten und vernetzten Fahrens mittels Computersimulation auf virtuellen Streckenmodellen konzipiert und prototypisch entwickelt werden. Aspekte, die dabei Berücksichtigung finden sollen, sind Qualitätsanforderungen an das Streckenmodell hinsichtlich unterschiedlicher Sensor- und Reglerfunktionen, erforderliche Parameter/Dimensionen für die darzustellenden (Verkehrs-)Szenarien, Klassifizierung der Ähnlichkeit/Genauigkeit von digitalen Zwillingen (Simulation und Versuchsfahrzeug) oder auch eine Validierungssystematik für solch ein virtuelles Umfeldmodell.
    Aufbauend auf die Anforderungen an die Simulation und den Spezifikationen an das virtuelle Streckenmodell soll ein systematisches und belastbares Verfahren zur simulationsbasierten Absicherung von automatisierten Fahrfunktion erarbeitet werden.

  • Decentralized organization of future energy systems based on the combination of blockchains and the cellular concept

    (Third Party Funds Single)

    Term: 2018-01-01 - 2019-03-31
    Funding source: Bayerisches Staatsministerium für Bildung und Kultus, Wissenschaft und Kunst (ab 10/2013)
    Abstract

    The goal of the project is to develop an energy IT system in a decentralized and locally autonomous manner, which is able to integrate a scalable number of actors. By means of decentralization of system responsibility a stable energy system shall be empowered based on renewable energies and storages. 

    The solution approach is based on the combination of blockchain technology and the cellular concept. The smart IT infrastructure can be used to stabilize the electricity system on all levels e.g. by variable prices. Furthermore, virtual inertia, which can replace the decreasing number of rotating masses in the system, can be generated and congestion management can be automated by fostering a local balance between demand and supply.

  • Hybrid Co-Simulation Framework

    (Own Funds)

    Term: since 2017-11-01
    Abstract
    Simulation is a decent method to study, evaluate, and validate upcoming technologies and algorithms. In order to generate realistic results, it is necessary to overcome different challenges. One of these challenges is the computational feasibility of holistic simulation scenarios, especially when it comes to large-scale setups. These scenarios may model a whole city or even an entire country. Besides performance problems, adequate modeling of real world scenarios often requires the combination of multiple simulation tools from different domains. This combination often requires the connection of different modeling paradigms. Other challenges tasks are the time synchronization of the different simulation tools and the data exchange between them.
    To solve these problems, a hybrid co-simulation framework is developed in this project. The Framework uses an implementation of High Level Architecture (HLA, IEEE1516) as a middleware and enables the dynamic composition of a simulation setup that matches current requirements. The composition takes place in two dimensions. In a vertical dimension, multi-level support empowers the simulation at different levels of detail, corresponding to the demands regarding performance, available data, or posed questions. In a horizontal dimension, the coupling of tools from different domains is enabled. The focus on extendability makes it possible to add any needed tools at a later point in time to the framework.

  • Simulation and Modelling of various 5G-Mechanisms within the context of connected mobility

    (Own Funds)

    Term: 2017-10-01 - 2022-08-31
    Abstract

    The networking of vehicles with other road users or the infrastructure (Vehicle-to-Everything (V2X)) is one of the key technologies for autonomous driving and smart cities. The WLAN standard IEEE 802.11p developed for this purpose has already been the focus of research for a decade. So far, however, this communication technology has not been able to establish itself as a communication standard in the automotive industry. One possible reason for this is the non-existent stationary infrastructure (base stations at the roadside or at traffic lights), which would require high investments.

    Many automobile manufacturers are therefore focusing their research on the latest generation of mobile radio technologies. The required infrastructure is available nationwide due to other mobile phone subscribers. LTE has already adopted specifications for direct communication between vehicles and communication via a base station. The latest mobile radio generation (5G), which is to be introduced from 2020, takes into account application cases and criteria for V2X communication right from the start. For 5G, the virtualization of mobile radio components via network slicing in conjunction with SDN and NFV will play a decisive role in maintaining quality of service parameters compared to LTE and WLAN.

    For the simulation of V2X communication scenarios via WLAN IEEE 802.11p the Veins framework developed at the chair has been used in numerous studies. In order to evaluate comparisons between WLAN and mobile radio by simulation, a further development of Veins with the mobile radio technologies LTE/5G is of great interest. The focus here is in particular on questions of Quality of Service (QoS) and the planned V2X application cases. In the context of this doctoral thesis the Veins framework is extended to the 5G technology. The focus here is on mechanisms of the lower network layers and the planned network slicing and Quality of Service (QoS) approaches.

  • Modeling and Simulation of Three-Dimensional Vehicular Ad Hoc Networks

    (Own Funds)

    Term: 2017-10-01 - 2022-09-30
    Abstract
    The possibilities and challenges of vehicle-to-everything communication (V2X communication) have been being researched for several years already. A popular means allowing for sufficient flexibility in the investigations whilst maintaining a relatively high level of detail is the simulation of such networks, which must take both the traffic as well as communication aspects into account. The simulation framework Veins developed at the chair has already proven to be a successful tool.
    A limitation of current V2X simulation frameworks is the assumption of a quasi-two-dimensional environment. The various influences of terrain shape, other road participants or communication across multiple road levels usually remain unconsidered. However, due to the mentioned aspects, many real-world traffic scenarios and thus vehicular networks exhibit a three-dimensional character, which is why it must be assumed that they can be analyzed only limitedly with current simulators.
    In this project, we seek to investigate whether the above-mentioned assumption holds true. For this purpose, conventional packet-based V2X simulation has to be extended accordingly in order to be able to simulate such scenarios at large scale. This also requires the implementation of new channel models that can realistically depict the three-dimensional character of complex scenarios with limited computational effort. To ensure correct results the new simulation models should be validated with the help of appropriate field tests. Furthermore, the computational effort of complex simulation scenarios is to be reduced by means of suitable techniques and possibly AI methods.

  • Multi Battery Systems - Hybrid and New Storage Simulation Tool

    (Third Party Funds Single)

    Term: 2017-05-01 - 2020-04-30
    Funding source: Siemens AG
    Abstract
    With the expansion of highly fluctuating renewables, the introduction of electric vehicles or securing the sufficient energy coverage of portable electronic devices electrochemical battery systems of each kind and dimensioning gain greater significance in various fields of everyday life. To assure cost- and time-efficient analysis for system design and project planning the usage of powerful models simulating the behavior of these battery systems is inevitable. In the project “Multi Battery Systems – Hybrid and New Storage Simulation Tool” in the context of FAU Campus – Future Energy Systems (FES) the Chair of Computer Science 7 (Computer Networks and Communication Systems) conceives detailed simulation models of several electrochemical battery storage systems. The project, which is realized in cooperation with Siemens AG Erlangen, aims to depict besides current storage technologies – like lithium-ion-batteries and lead-batteries – systems which thus far lack widespread application as well, like redox-flow-batteries or thermal batteries. In this manner, the designed models also extend the modular model-library of the software i7-AnyEnergy in order to enable more sophisticated analysis in distinct storage scenarios.

  • Transparent Multichannel IPv6

    (Third Party Funds Single)

    Term: 2017-04-01 - 2020-12-31
    Funding source: Bundesministerium für Wirtschaft und Technologie (BMWi)
    Abstract
    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 links. An illustrative example is the combination of a rural DSL connection with low data rate/low latency and a satellite connection with high data rate but high latency, which results in a user’s internet access with high data rate and low latency providing a better Quality of Experience (QoE).

    Satellite-based internet access from different operators is provided by our project partners in order to experience realistic satellite communication environment and test potential solutions. The outdoor unit (parabolic antenna) is mounted on the roof of the Wolfgang-Händler-Hochhaus.

  • Communication in energy information networks

    (Own Funds)

    Term: since 2017-04-01
    Abstract
    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 over large areas and time critical.
    The object of this research project is the replacement of proprietary solutions by a programmable communication network with standard components. These enable economical operation and high compatibility, individual requirements are fulfilled by software. The overarching goal is to make optimal use of the infrastructure of the energy and communication networks and to minimize over-provisioning.

  • Pal-Grid: A Comprehensive Simulation Framework for the Palestinian Power Grid

    (Third Party Funds Single)

    Term: 2017-03-01 - 2019-02-28
    Funding source: Bundesministerium für Bildung und Forschung (BMBF)
    Abstract

    The aim of this project is to develop a comprehensive simulation framework for the Palestinian electric power network system with a focus on a specific area. The simulation framework should be able to capture the different aspects of the future energy supply.

    The project will provide two levels of abstraction. The first simulation level will be very abstract and it helps the authorities, and especially the energy regulatory authority to take decisions to boost the penetration of renewable energy resources (RES) and improve the Palestinian power grid. Thus, the most important political, economic and technical characteristics and interactions will be addressed. This level of abstraction will provide the essential tools to compare and evaluate different scenarios to enhance of the Palestinian power grid for long planning horizons. The second model will be particularly characterized by a detailed modeling of the different components of a power system. Therefore, the power grid as well as the communication network will be addressed in this model. This will enable exploring ICT-enabled power grid application, i.e., the emerging smart grid applications.

  • SP1-1 Aufwertung von Niedertemperaturwärme mit reversiblen HP-ORC-Systemen

    (Third Party Funds Group – Sub project)

    Overall project: Energy Campus Nuremberg
    Term: 2017-01-01 - 2021-12-31
    Funding source: Bayerisches Staatsministerium für Bildung und Kultus, Wissenschaft und Kunst (ab 10/2013)
    URL: https://www.evt.tf.fau.de/forschung/forschungsschwerpunkte/2nd-generation-fuels/energie-campus-nuernberg-teilprojekt-grosse-spei
    Abstract

    The Energy Campus Nuremberg deals with energy technology of the future. The partners work on all relevant topics to make energy supply more flexible and sustainable. In the part addressing the long-time storage of energy the Chair of Energy Processing works on a new, innovative concept for methanation.

    This new concept is optimized for dynamic operation in power-to-gas applications and is experimentally demonstrated.

  • Hybrid Simulation of Smart Energy Systems

    (Own Funds)

    Term: since 2017-01-01
    Abstract
    The expansion of renewable energy sources and the growing share of decentralized and highly fluctuating energy producers pose complex challenges for modern energy systems. Storage systems such as CHP systems with heat storage, pure electricity storage, or other technologies also play a decisive role. Furthermore, communication between producers, consumers, and storage as well as the intelligent control of electricity producers and consumers is crucial for the stability and efficiency of the energy system.

    The aim of the project is the development of methods and tools for the comprehensive analysis of the increasingly renewable energy-based energy industry at the level of individual houses and smart grids. As part of the project, the simulation framework i7-AnyEnergy is being developed, which enables the rapid development of hybrid simulation models of networked intelligent energy systems. For this purpose, methods such as discrete event simulation (e.g., for consumer, weather, and control models) and system dynamics models (e.g., for energy and cost flows) are combined in a simulation model. The simulation framework i7-AnyEnergy provides basic components for the energy consumption (electrical and thermal), for energy production (eg gas heating, combined heat and power with fuel cells), for renewable energy (photovoltaic), for energy storage (batteries, chemical storage such as based on LOHC), as well as for the control. These components are used to create house models that can be coupled to smart grid models with a common weather model and a communication Network.

  • Dynamic Simulation of Energy Flows and Storage of Waste Heat from Data Centers and of the Integration of Large Storage Systems in Local Heating Networks

    (Third Party Funds Group – Sub project)

    Overall project: Energie Campus Nürnberg 2
    Term: 2017-01-01 - 2019-12-31
    Funding source: Bayerische Staatsministerien
    Abstract
    The share of electricity from photovoltaics in the electricity mix in Germany has been greatly expanded in recent years. In the near future, electricity generation from renewable energies and thus also solar generated electricity will continue to increase. At high solar radiation, this already leads to a local oversupply in the power grid, while the photovoltaic at night naturally can not contribute to the power supply. Ensuring the nightly base load at night is therefore largely ensured by fossil production from coal and lignite with corresponding CO2 emissions.

    By using base load storage systems with low-temperature storage, the use of polluting thermal power plants should be reduced. During the day, heat from geothermal energy or industrial processes is upgraded with excess electricity from photovoltaics using heat pumps (HP) and stored in a low-temperature storage system. To generate nocturnal base load power, this heat energy is then removed from the storage via an Organic Rankine Cycle (ORC) process.

    The aim of the project is the dynamic simulation of energy flows in HP-ORC heat storages that are integrated into the energy system and use excess heat and power. With the simulation models, the dimensioning and suitable operating modes for the economic operation of low-temperature storage systems should be investigated.

  • Combined Optimization, Simulation and Grid Analysis of the German Electrical Power System in an European Context

    (Third Party Funds Group – Overall project)

    Term: 2016-10-01 - 2019-09-30
    Funding source: Bundesministerium für Wirtschaft und Technologie (BMWi)
    Abstract
    Germany decided to reorganize its energy supply system in a sustainable way by initiating the energy transition (Energiewende). One of its main targets is to be one of the most environmentally friendly and energy-conserving economies worldwide with competitive energy prices at the same time. This requires the support of all-embarrassing analytical systems, which take into account the technical, market and regulatory framework at once. Existing energy system analysis models often neglect or simplify the modeling of the electrical grid, which motivated the preliminary multidisciplinary work of the chairs of the FAU Erlangen-Nürnberg in the recent years.

    A holistic system-oriented modeling approach for the electrical power supply system in Germany was initially developed with a focus on Bavaria. The model of the German electrical power supply system includes the transmission grid, conventional power plants and feed-in from renewables concerning the current market mechanisms in Germany. With the developed model it is possible to derive statements about grid and storage expansion or the development of CO2 emissions for the federal state Bavaria. The overall model includes sub-models for optimization (determination of cost-optimal expansion scenarios), for simulation (stochastic simulation of different scenarios with high temporal resolution and technical detail) and grid analysis (quasi-stationary AC load flow calculations) for checking the required grid planning criteria and stable system operation.

    Within the research project KOSiNeK funded by the Federal Ministry for Economic Affairs and Energy (BMWi) we now extend the existing holistic system-oriented modeling approach for the German electric energy system to derive statements about the future development of the system within the European context. This includes both the evaluation of net expansion scenarios and the simulation and analysis of regulatory frameworks. In order to cope with the increasing complexity of the problem, new approaches from the fields of mathematics, computer sciences and net analysis are necessary, which includes aggregation and decomposition techniques, hierarchical multipoint model approaches as well as probabilistic methods to determine the probability of occurrence of certain conditions. This leads to models of high complexity. To take this into account, the approaches from mathematics, computer science and grid analysis will also be coupled iteratively. This enables displaying technical and economic aspects with regard to the control of power plants in a very detailed manner as well as considering grid-regulations in order to guarantee a safe electrical power supply. In addition, it is possible to examine energy markets in an European context including their regulatory framework. The flexible and component-based model construction allows the influence of new market mechanisms such as dividing Germany into price zones or changing market conditions or funding mechanisms with a detailed, agent-based market model. For the integrated power grid analysis, the continental European transmission grid is integrated by network equivalents. A novel probabilistic approach will also be developed to evaluate the grid expansion scenarios.

    The project KOSiNeK (project number 03ET4035) is funded by the 6th energy research program of the German Federal Ministry for Economic Affairs and Energy (BMWi).

  • Modeling and Analysis of Complex Systems

    (Own Funds)

    Term: since 2016-01-01
    Abstract
    Today's computer technology supports researchers and scientists in developing their complex ideas and innovative technologies. The use of such new ideas and technologies in an increasingly complex overall technical and ecological system will be examined in this project. These can be production systems, transport systems, computer networks, smart grids, or even a combination of such systems.

    The modeling and analysis of such complex systems is supported by powerful data structures and algorithms, which enable the use of common PCs for the calculations. For example, data structures such as Multi-Valued Decision Diagrams (MDDs), analytical methods from queuing theory, hybrid simulation, Mixed-Integer Linear Programming (MILP), and combinations tailored to the system are used.

  • Koordinierte Kleinspeicher im Verteilnetz der N-ERGIE Aktiengesellschaft (SWARM)

    (Third Party Funds Single)

    Term: 2015-01-01 - 2017-12-31
    Funding source: Industrie
    Abstract
    Im Rahmen des Kooperationsprojektes SWARM der N-ERGIE AG und dem Energie Campus Nürnberg (EnCN) beschäftigt sich unter anderem der Lehrstuhl für Informatik 7 (Rechnernetze und Kommunikationssysteme) mit den Fragestellungen, unter welchen Bedingungen Privathaushalte in innovative Stromspeicher investieren, wie sich diese Speicher auf die Stabilität des Stromnetzes auswirken und welchen ökonomischen Nutzen sie aus Sicht des Netzbetreibers bzw. der Privathaushalte schaffen.

    Übergeordnetes Ziel der Untersuchungen ist es, Erkenntnisse über vernetzte Speicher zu gewinnen und zu vertiefen.Das von der Caterva GmbH entwickelte Energiespeichersystem (ESS) mit einer Gesamtleistung von 20 kW und einer Bruttokapazität von 21 kWh richtet sich an Privathaushalte, die deutlich mehr als die durchschnittlich üblichen 30 Prozent ihres selbst erzeugten PV-Stroms nutzen möchten, da das ESS eine hohe Deckung des individuellen Strombedarfs aus Eigenerzeugung ermöglicht.

    Die Innovation des Systems liegt jedoch in seiner zweiten Funktion: Die Energiespeichersysteme können sich zu einem virtuellen Großspeicher vernetzen, der am Primärregelleistungsmarkt teilnimmt und damit eine Stabilisierungsfunktion im Stromnetz übernimmt. Der virtuelle Großspeicher speichert Strom bei einem Überangebot im Netz und speist umgekehrt bei Strombedarf in das Netz ein.Der Lehrstuhl für Informatik 7 (Rechnernetze und Kommunikationssysteme) entwickelt ein Simulationsmodell eines Kleinspeicher-Verbunds. Ziel des Modells ist es, die technischen Auswirkungen der Speicher auf die Netze zu ermitteln, sowie den ökonomischen Nutzen sowohl für die beteiligten Privathaushalte als auch für das gesamte Energiesystem zu identifizieren.

  • Formal verification and validation of test methods for complex vehicle safety systems in virtual environments

    (Third Party Funds Single)

    Term: 2014-08-01 - 2017-08-01
    Funding source: Industrie
    Abstract
    Integral safety functions provide a significant contribution to the protection of occupants and other road users by interconnecting active and passive safety and assistance systems. During the development of these complex, interrelated functions particular interest is taken into hedging against system failures and unwanted behavior. Malfunctions, e.g., an unwananted braking intervention at high speeds, can have a dramatic effect and therefore have to be appropriatly considered during the development, especially in the selection of test stations, system and functional requirements and for scheduling the test runs. However, ever shorter development cycles and increasing functional scopes increase the time pressure on all test stations. A development cycle involves modeling a system and specifying its test-model and generating code for its validation on both the development computer as well as on the target processor. The essential requirement to the validation is that it must be as realistic as possible, so that the system behavior can be examined in interaction with other control devices of a vehicle. For this purpose, a HiL simulator is used, which emulates the control units and the sensors and actuators of a vehicle, so that the validation can be carried out in a virtual environment. It is a framework be created, that verifies and validates test methods for complex vehicle safety systems in virtual environments.

  • RTG 1773: Heterogeneous Image Systems

    (Third Party Funds Group – Overall project)

    Term: 2012-10-01 - 2017-03-31
    Funding source: DFG / Graduiertenkolleg (GRK)
    Abstract

    Systeme zur Verarbeitung, Erzeugung und übertragung digitaler Bilder (Bildsysteme) unterliegen sehr oft harten Anforderungen an Rechenleistung, Latenz, Durchsatz und Kosten. Typische Beispiele sind die medi-zinische Bildverarbeitung, Computerspiele oder die Videokompression in Camcordern. Um diese Anforde-rungen zu erfüllen, werden oft dedizierte Hardware-Beschleuniger eingesetzt als auch Grafikprozessoren (GPUs) oder digitale Signalprozessoren (DSPs). Die entstehenden Bildsysteme sind in zweierlei Hinsicht heterogen. Zum einen ist innerhalb eines Systems die Berechnung auf mehrere verschiedenartige Kompo-nenten verteilt, zum anderen gibt es eine große, heterogene Menge an Architekturen, auf denen unter-schiedliche Bildanwendungen laufen können und sollen. Beide Arten von Heterogenität führen nun zu sehr interessanten und wichtigen Forschungsfragestellungen, die in dem Graduiertenkolleg erforscht werden sollen. Dies betrifft im Wesentlichen drei Bereiche: dedizierte Hardware-Architekturen für Bildsysteme, Werkzeuge und Methoden für die Programmierung heterogener Bildsysteme, sowie Anwendungen und Algorithmen für heterogene Bildsysteme. Bildsysteme haben in Forschung und Praxis eine große Bedeutung. Ihre Planung, Entwicklung und Reali-sierung erfordert themenübergreifendes und interdisziplinäres Wissen zu Soft- und Hardware, Methoden- und Werkzeugentwurf, sowie zur Algorithmenentwicklung. Das Thema eignet sich daher hervorragend für ein Graduiertenkolleg, gerade am Standort Erlangen. Die Doktoranden des Kollegs erhalten in ihrem Studi-enprogramm eine breit gefächerte Ausbildung, die anschließend in der Dissertation in speziellen Problem-stellungen vertieft wird. Postdoktoranden mit größerem fachlichen überblick bilden eine fachliche Klammer. Sie qualifizieren sich interdisziplinär, sammeln aber vor allem auch Lehrerfahrung. Die bereits bestehende tiefe Verankerung der Thematik in der Lehre ermöglicht die Einbeziehung begabter Studenten in das For-schungsprogramm. Schließlich bietet Erlangen ein industrielles Umfeld, das durch eine direkte Beteiligung am Graduiertenkolleg wichtige Impulse für die Forschung liefern wird, aber auch von neuen Ideen aus dem Graduiertenkolleg sowie hochqualifizierten Absolventen profitieren wird.

  • Hybrid Simulation of Intelligent Energy Systems

    (Third Party Funds Group – Sub project)

    Overall project: Energie Campus Nürnberg
    Term: 2011-10-01 - 2016-12-31
    Funding source: Bayerische Staatsministerien
    Abstract
    Development of the simulation framework i7-AnyEnergy for networked smart energy systems. For this framework methods such as discrete event simulation (e.g. for demand, weather and control models) and System Dynamics models (e.g. for energy and cost flows) are combined in one simulation model. It provides pre-built components from which more complex energy system models can be constructed in a flexible way. From the basic components for the energy demand (electrical and thermal), for energy conversion (e.g. gas heating, combined heat and power with fuel cells), for renewable energy (photovoltaics), for energy storage (batteries, chemical storages), as well as for the control, house models can be constructed and coupled to larger systems with a common weather model and communication Network.

  • ProHTA – Prospective Health Technology Assessment

    (Third Party Funds Group – Sub project)

    Overall project: Spitzencluster Medical Valley, Verbund Horizontale Innovationen
    Term: 2011-01-01 - 2015-03-31
    Funding source: BMBF / Spitzencluster
    Abstract

     

    The purpose of the "Prospective Health Technology Assessment Medical Valley EMN" (ProHTA) project is to set up a scientific service platform to assess innovative health technologies before they are launched on the market. ProHTA describes 1) The effect of new technologies and products on the quality and cost of healthcare; 2) Efficiency potential within the healthcare chain which can be leveraged with the aid of new technologies and products. Medical engineering is characterized by a high pace of innovation. It is therefore important for companies to understand in the early phase of the innovation process just what effect the introduction of technological innovations will have on the healthcare process, and what implications there are for the health system as a whole. ProHTA will pool and formalize knowledge on stakeholders, processes, effects and payments that is required for the prospective assessment and will also create simulation tools as a basis for more far-reaching analyses. By means of integration between technology and processes in modeled scenarios, it will be possible to show and assess the resulting effects on the individual stakeholders in the health system in terms of cost and benefit. Conclusions can then be reached regarding, for example, further development of innovations and the need for regulative adjustment (e.g. gaps in healthcare provision, payment situation, incentive mechanism) of the framework conditions in the health system.

  • Requirements oriented testing with Markov chain usage models in the automotive domain

    (Third Party Funds Single)

    Term: 2008-11-01 - 2011-10-31
    Funding source: Industrie
    Abstract
    As a result of the integration of increasingly elaborate and distributed functionality in modern automobiles the amount of installed electronic and software continuously grows. The associated growth in system complexity makes it inevitable that the test methods used for verification and validation keep pace with this development. Nowadays the test routine in industry usually requires each test case to be crafted manually by a test designer. The test case execution itself and test result evaluation usually are performed in an automated manner. This procedure has many drawbacks, as the crafting of single test cases is apparently awkward and error-prone and it is impractical to calculate test management criteria such as test coverage. Within this project a method is developed that overcomes these drawbacks. Markov chain usage models (MCUM) constitute the central role within this project. MCUMs are employed to describe the possible usage of the System-under-test and to derive test cases from them. On the one hand the integration of MCUMs makes it possible to develop methods to integrate test requirements formally, as to improve traceability. On the other hand they provide the basis to incorporate algorithms or strategies that allow the generation of test cases fitting to various test requirements in the automotive domain. These comprise e.g. different coverage criteria under usage or system oriented aspects. Moreover established methods exist that allow the calculation of dependability measures based on results obtained from test cases automatically generated from MCUMs. Also the test planning can be supported by indicators that are derived during the test process. The project aims for developing a method to describe test requirements formally by building a model. This model allows the derivation of test suites considering various testing aims and constraints. The tools themselves should form a part of the ITF (Integrated Testing Framework) and the process extend the current one described by EXAM and employed within the Volkswagen AG.

  • WinPEPSY-QNS - Performance Evaluation and Prediction System for Queueing Networks

    (Own Funds)

    Term: 2004-11-01 - 2005-12-31
    Abstract
    In cooperation with Chair 4 (Distributed Systems and Operating Systems), the queueing network analysis tool WinPEPSY-QNS (Windows Performance Evaluation and Prediction System for Queuing Networks) is being developed. The analytical methods used include, among others, the mean value analysis (MVA) and the method of Marie. For validation and analysis of non-product form networks, a simulation component will be integrated into WinPEPSY-QNS. In addition, the Jackson method is being used to analyze open product form networks and a decomposition method for open non-product form networks. Of particular note is the possibility to present the results in a tabular or graphic form in a very clear manner and to easily carry out extensive experiments for a given queueing network.

    The analysis methods for queueing networks with general distributions developed in the project Analysis Methods for Non-Markovian Models are to be integrated into WinPEPSY-QNS. They allow the approximative analysis of non-product form networks based on the method of supplementary variables or modeling by phase-type distributions and avoid the problem of state space explosion. Therefore, queueing systems with any distribution of service times and inter-arrival times can be analyzed. Emphasis should be placed on heavy-tailed distributions and the deterministic distribution. Thus, it should be possible to investigate the influence of methods and systems for the protection of privacy, authentication, guarantee of integrity as well as the anonymization on the performance (throughput and delay) through queueing systems.

  • Analysis Methods for Non-Markovian Models

    (Own Funds)

    Term: 2001-11-01 - 2004-10-30
    Abstract
    Traditional approaches to solve non-Markovian models use phase-type expansions, apply the method of supplementary variables or construct an embedded Markov chain. All three approaches have also been investigated in the context of queuing networks and stochastic Petri nets. The phase-type expansion approach suffers from the enlargement of the state space, whereas the method of supplementary variables and the embedded Markov chain construction require basically that non-exponentially timed activities are not concurrent. If they are concurrent this will result in multidimensional differential equations that are hard to solve. To avoid these problems more efficient techniques for the performance evaluation of computer networks like web servers or networks of embedded systems have to be developed. In such systems activity durations with large variances (file transfers) as well as deterministic durations (security aspects) arise.

    We have created two new approaches to approximately evaluate the performance models of these systems; the first one is based on the method of supplementary variables and the second one deals with phase-type expansions. We are currently enhancing these approaches and it is planned to combine them for the solution of large non-Markovian models.
    In cooperation with department 4 (Distributed Systems and Operating Systems) the tool WinPEPSY for performance evaluation and prediction of queueing systems was developed. It contains well known analysis methods for open and closed product form and non-product form networks (mean value analysis, Jackson-method, decomposition methods, simulation) and the new state-based analysis methods are integrated.
    In a cooperation with the Telecommunications Laboratory, Communications, Electronics and Information Engineering Division of the National Technical University of Athens simulation models for embedded network processors have been developed. The goal is to enhance the above mentioned methods, so that even performance measures for these large models can be derived.

Teaching

Winter Term 2023/24

Kommunikationssysteme (KS)

Simulation and Modeling 1 (SaM 1)

Modellierungs-AG

Seminar Communication Systems

Colloquium

Summer Term 2023

Quality of Service in Communications (QoSiC)

Simulation and Modeling 2 (SaM 2)

Rechnerkommunikation (RK)

Modellierungs-AG

Colloquium

Winter Term 2022/23

Kommunikationssysteme (KS)

Simulation and Modeling 1 (SaM 1)

Modellierungs-AG

Seminar Communication Systems

Colloquium

Summer Term 2022

Quality of Service in Communications (QoSiC)

Simulation and Modeling 2 (SaM 2)

Rechnerkommunikation (RK)

Modellierungs-AG

Colloquium

Winter Term 2021/22

Kommunikationssysteme (KS)

Simulation and Modeling 1 (SaM 1)

Modellierungs-AG

Seminar: Communication Systems

Colloquium

Summer Term 2021

Quality of Service in Communications (QoSiC)

Simulation and Modeling 2 (SaM 2)

Rechnerkommunikation (RK)

Modellierungs-AG

Colloquium

Winter Term 2020/21

Kommunikationssysteme (KS)

Simulation and Modeling 1 (SaM 1)

Modellierungs-AG

Seminar: Communication Systems (Multipath Communication)

Colloquium

Summer Term 2020

Quality of Service in Communications (QoSiC)

Simulation and Modeling 2 (SaM 2)

Rechnerkommunikation (RK)

Modellierungs-AG

Winter Term 2019/20

Kommunikationssysteme (KS)

Simulation and Modeling 1 (SaM 1)

Modellierungs-AG

Seminar: Rechnernetze und Kommunikationssysteme

Seminar: Kommunikationssysteme

Summer Term 2019

no Teaching

Winter Term 2018/19

Communication Systems (KS)

Simulation and Modeling 1 (SaM 1)

Seminar: Machine Learning for Computer Networking

Summer Term 2018

Dienstgüte von Kommunikationssystemen (DKS)

Simulation and Modeling 2 (SaM 2)

Rechnerkommunikation (RK)