@techreport{NavadeMaileGerman2023,
  type      = {Working Paper},
  author    = {Navade, Piyush and Maile, Lisa and German, Reinhard},
  title     = {Multiple DCLC Routing Algorithms for Ultra-Reliable and Time-Sensitive Applications},
  series = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  journal   = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  doi       = {10.25972/OPUS-32217},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322177},
  pages     = {4},
  year      = {2023},
  abstract  = {This paper discusses the problem of finding multiple shortest disjoint paths in modern communication networks, which is essential for ultra-reliable and time-sensitive applications. Dijkstra's algorithm has been a popular solution for the shortest path problem, but repetitive use of it to find multiple paths is not scalable. The Multiple Disjoint Path Algorithm (MDPAlg), published in 2021, proposes the use of a single full graph to construct multiple disjoint paths. This paper proposes modifications to the algorithm to include a delay constraint, which is important in time-sensitive applications. Different delay constraint least-cost routing algorithms are compared in a comprehensive manner to evaluate the benefits of the adapted MDPAlg algorithm. Fault tolerance, and thereby reliability, is ensured by generating multiple link-disjoint paths from source to destination.},
  language  = {en}
}
@techreport{FundaMarinGarciaGermanetal.2023,
  type      = {Working Paper},
  author    = {Funda, Christoph and Mar{\´i}n Garc{\´i}a, Pablo and German, Reinhard and Hielscher, Kai-Steffen},
  title     = {Online Algorithm for Arrival \& Service Curve Estimation},
  series = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  journal   = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  doi       = {10.25972/OPUS-32211},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322112},
  pages     = {5},
  year      = {2023},
  abstract  = {This paper presents a novel concept to extend state-of-the-art buffer monitoring with additional measures to estimate service-curves. The online algorithm for service-curve estimation replaces the state-of-the-art timestamp logging, as we expect it to overcome the main disadvantages of generating a huge amount of data and using a lot of CPU resources to store the data to a file during operation. We prove the accuracy of the online-algorithm offline with timestamp data and compare the derived bounds to the measured delay and backlog. We also do a proof-of- concept of the online-algorithm, implement it in LabVIEW and compare its performance to the timestamp logging by CPU load and data-size of the log-file. However, the implementation is still work-in-progress.},
  language  = {en}
}
@techreport{MartinoDeutschmannHielscheretal.2023,
  type      = {Working Paper},
  author    = {Martino, Luigi and Deutschmann, J{\"o}rg and Hielscher, Kai-Steffen and German, Reinhard},
  title     = {Towards a 5G Satellite Communication Framework for V2X},
  series = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  journal   = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  doi       = {10.25972/OPUS-32214},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322148},
  pages     = {5},
  year      = {2023},
  abstract  = {In recent years, satellite communication has been expanding its field of application in the world of computer networks. This paper aims to provide an overview of how a typical scenario involving 5G Non-Terrestrial Networks (NTNs) for vehicle to everything (V2X) applications is characterized. In particular, a first implementation of a system that integrates them together will be described. Such a framework will later be used to evaluate the performance of applications such as Vehicle Monitoring (VM), Remote Driving (RD), Voice Over IP (VoIP), and others. Different configuration scenarios such as Low Earth Orbit and Geostationary Orbit will be considered.},
  language  = {en}
}
@techreport{FundaKonheiserGermanetal.2023,
  type      = {Working Paper},
  author    = {Funda, Christoph and Konheiser, Tobias and German, Reinhard and Hielscher, Kai-Steffen},
  title     = {How to Model and Predict the Scalability of a Hardware-In-The-Loop Test Bench for Data Re-Injection?},
  series = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  journal   = {KuVS Fachgespr{\"a}ch - W{\"u}rzburg Workshop on Modeling, Analysis and Simulation of Next-Generation Communication Networks 2023 (WueWoWAS'23)},
  doi       = {10.25972/OPUS-32215},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322150},
  pages     = {4},
  year      = {2023},
  abstract  = {This paper describes a novel application of an empirical network calculus model based on measurements of a hardware-in-the-loop (HIL) test system. The aim is to predict the performance of a HIL test bench for open-loop re-injection in the context of scalability. HIL test benches are distributed computer systems including software, hardware, and networking devices. They are used to validate complex technical systems, but have not yet been system under study themselves. Our approach is to use measurements from the HIL system to create an empirical model for arrival and service curves. We predict the performance and design the previously unknown parameters of the HIL simulator with network calculus (NC), namely the buffer sizes and the minimum needed pre-buffer time for the playback buffer. We furthermore show, that it is possible to estimate the CPU load from arrival and service-curves based on the utilization theorem, and hence estimate the scalability of the HIL system in the context of the number of sensor streams.},
  language  = {en}
}
@techreport{DeutschmannHielscherGerman2022,
  type      = {Working Paper},
  author    = {Deutschmann, J{\"o}rg and Hielscher, Kai-Steffen and German, Reinhard},
  title     = {Next-Generation Satellite Communication Networks},
  series = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  journal   = {W{\"u}rzburg Workshop on Next-Generation Communication Networks (WueWoWas'22)},
  doi       = {10.25972/OPUS-28073},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-280732},
  pages     = {4},
  year      = {2022},
  abstract  = {This paper gives an overview of our recent activities in the field of satellite communication networks, including an introduction to geostationary satellite systems and Low Earth Orbit megaconstellations. To mitigate the high latencies of geostationary satellite networks, TCP-splitting Performance Enhancing Proxies are deployed. However, these cannot be applied in the case of encrypted transport headers as it is the case for VPNs or QUIC. We summarize performance evaluation results from multiple measurement campaigns. In a recently concluded project, multipath communication was used to combine the advantages of very heterogeneous communication paths: low data rate, low latency (e.g., DSL light) and high data rate, high latency (e.g., geostationary satellite).},
  subject      = {Datennetz},
  language  = {en}
}
@article{SchlundGermanPruckner2022,
  author    = {Schlund, Jonas and German, Reinhard and Pruckner, Marco},
  title     = {Synergy of unidirectional and bidirectional smart charging of electric vehicles for frequency containment reserve power provision},
  series = {World Electric Vehicle Journal},
  volume    = {13},
  journal   = {World Electric Vehicle Journal},
  number    = {9},
  issn      = {2032-6653},
  doi       = {10.3390/wevj13090168},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288324},
  year      = {2022},
  abstract  = {Besides the integration of renewable energies, electric vehicles pose an additional challenge to modern power grids. However, electric vehicles can also be a flexibility source and contribute to the power system stability. Today, the power system still heavily relies on conventional technologies to stay stable. In order to operate a future power system based on renewable energies only, we need to understand the flexibility potential of assets such as electric vehicles and become able to use their flexibility. In this paper, we analyzed how vast amounts of coordinated charging processes can be used to provide frequency containment reserve power, one of the most important ancillary services for system stability. Therefore, we used an extensive simulation model of a virtual power plant of millions of electric vehicles. The model considers not only technical components but also the stochastic behavior of electric vehicle drivers based on real data. Our results show that, in 2030, electric vehicles have the potential to serve the whole frequency containment reserve power market in Germany. We differentiate between using unidirectional and bidirectional chargers. Bidirectional chargers have a larger potential but also result in unwanted battery degradation. Unidirectional chargers are more constrained in terms of flexibility, but do not lead to additional battery degradation. We conclude that using a mix of both can combine the advantages of both worlds. Thereby, average private cars can provide the service without any notable additional battery degradation and achieve yearly earnings between EUR 200 and EUR 500, depending on the volatile market prices. Commercial vehicles have an even higher potential, as the results increase with vehicle utilization and consumption.},
  language  = {en}
}