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Konferenzbeiträge | Technische Berichte | Studentische Arbeiten

Konferenzbeiträge

Maximilian Köstler und Florian Kauer. A Remote Interface for Live Interaction with OMNeT++ Simulations. In Proceedings of the 4th OMNeT++ Community Summit 2017, September 2017. Bremen, Germany.
@InProceedings{Telematik_OMNETPP_2017, author = {Maximilian Köstler and Florian Kauer}, title = {A Remote Interface for Live Interaction with OMNeT++ Simulations}, booktitle = {Proceedings of the 4th OMNeT++ Community Summit 2017}, number = {arXiv:1709.02822}, day = {07-08}, month = sep, year = 2017, location = {Bremen, Germany}, }
Abstract: Discrete event simulators, such as OMNeT++, provide fast and convenient methods for the assessment of algorithms and protocols, especially in the context of wired and wireless networks. Usually, simulation parameters such as topology and traffic patterns are predefined to observe the behaviour reproducibly. However, for learning about the dynamic behaviour of a system, a live interaction that allows changing parameters on the fly is very helpful. This is especially interesting for providing interactive demonstrations at conferences and fairs. In this paper, we present a remote interface to OMNeT++ simulations that can be used to control the simulations while visualising real-time data merged from multiple OMNeT++ instances. We explain the software architecture behind our framework and how it can be used to build demonstrations on the foundation of OMNeT++.
Florian Kauer, Florian Meyer und Volker Turau. A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants. In Proceedings of the 13th Workshop on Intelligent Solutions in Embedded Systems (WISES 2017), Juni 2017. Hamburg, Germany.
@InProceedings{Telematik_WISES_2017, author = {Florian Kauer and Florian Meyer and Volker Turau}, title = {A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants}, booktitle = {Proceedings of the 13th Workshop on Intelligent Solutions in Embedded Systems (WISES 2017)}, pages = , day = {12-13}, month = jun, year = 2017, location = {Hamburg, Germany}, }
Abstract: In cyber-physical systems, such as modern industrial plants, complex software is an essential part that enables cost-effective and flexible operation. However, this complexity increases the probability of problems that only reveal themselves after the deployment. This is even more important if security aspects are involved. Therefore, providing the possibility for software updates is an important building block in the design of industrial plants. This paper presents a holistic concept for software updates in an industrial plant with thousands of wirelessly connected embedded devices. Using wireless technology imposes additional difficulties in terms of data rate, packet size and reliability that have to be addressed in particular. The contribution also includes an analytical model to estimate the time until a new firmware is distributed. Evaluations carried out on hardware as well as in the OMNeT++ simulator demonstrate the applicability and scalability of the proposed approach.
Florian Kauer, Maximilian Köstler, Tobias Lübkert und Volker Turau. OpenDSME - A Portable Framework for Reliable Wireless Sensor and Actuator Networks (Demonstration). In Proceedings of the 3rd International Conference on Networked Systems (NetSys 2017), März 2017. Göttingen, Germany.
@InProceedings{Telematik_Netsys_2017, author = {Florian Kauer and Maximilian Köstler and Tobias Lübkert and Volker Turau}, title = {OpenDSME - A Portable Framework for Reliable Wireless Sensor and Actuator Networks (Demonstration)}, booktitle = {Proceedings of the 3rd International Conference on Networked Systems (NetSys 2017)}, day = {13-16}, month = mar, year = 2017, location = {Göttingen, Germany}, }
Abstract: The Deterministic and Synchronous Multi-Channel Extension (DSME) of the IEEE 802.15.4 standard provides a data link layer for time division multiple access in wireless mesh networks. The authors present openDSME, a portable implementation for hardware and simulators which promises reliable message transfer suitable for applications in demanding industrial environments. A demonstration has been developed to illustrate the performance of openDSME in a simulated network and to show its benefits over CSMA/CA.
Florian Kauer, Maximilian Köstler, Tobias Lübkert und Volker Turau. Formal Analysis and Verification of the IEEE 802.15.4 DSME Slot Allocation. In Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems, November 2016, pp. 140–147. Malta.
@InProceedings{Telematik_MSWIM_Formal_DSME, author = {Florian Kauer and Maximilian Köstler and Tobias Lübkert and Volker Turau}, title = {Formal Analysis and Verification of the IEEE 802.15.4 DSME Slot Allocation}, booktitle = {Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems}, pages = {140-147}, month = nov, year = 2016, location = {Malta}, }
Abstract: Providing dependability is still a major issue for wireless mesh networks, which restrains their application in industrial contexts. The widespread CSMA/CA medium access can provide high throughput and low latency, but can not prevent packet loss due to collisions, especially in very large and dense networks. Time slotted medium access techniques together with a distributed slot management, as proposed by the Distributed Synchronous Multi-channel Extension (DSME) of the IEEE 802.15.4 standard, are promising to provide low packet loss, high scalability and bounded end-to-end delays. However, our implementation, openDSME, exposed some weaknesses. While the allocated slots allow for reliable data transmission, the slot management itself is conducted via CSMA/CA and is thus vulnerable to packet loss, eventually leading to an inconsistent slot allocation. This paper uses the UPPAAL framework for formal analysis and verification of the slot management process. The analysis identifies weaknesses of the slot allocation process under communication and node failures. However, it is shown that inconsistencies are eventually resolved and improvements to the procedure are proposed that reduce the negative impact of failed slot allocation procedures significantly.
Maximilian Köstler, Florian Kauer, Tobias Lübkert und Volker Turau. Towards an Open Source Implementation of the IEEE 802.15.4 DSME Link Layer. In Proceedings of the 15. GI/ITG KuVS Fachgespräch Sensornetze, University of Applied Sciences Augsburg, Dept. of Computer Science, September 2016. Augsburg, Germany.
@InProceedings{Telematik_FGSN_openDSME, author = {Maximilian Köstler and Florian Kauer and Tobias Lübkert and Volker Turau}, editor = {Juergen Scholz and Alexander von Bodisco}, title = {Towards an Open Source Implementation of the IEEE 802.15.4 DSME Link Layer}, booktitle = {Proceedings of the 15. GI/ITG KuVS Fachgespräch Sensornetze}, pages = , publisher = {University of Applied Sciences Augsburg, Dept. of Computer Science}, day = {22-23}, month = sep, year = 2016, location = {Augsburg, Germany}, }
Abstract: Reliable wireless solutions for large-scale automation are a major challenge today. The IEEE 802.15.4 standard forms the basis for many open and proprietary implementations. To reflect current state-of-the-art techniques, the IEEE has amended standard 802.15.4 with new MAC-layers such as TSCH, which resembles WirelessHART, and the Deterministic and Synchronous Multi-Channel Extension (DSME). This paper introduces openDSME, our implementation of IEEE 802.15.4 DSME. DSME aims at preventing packet collisions through slot reservation in networks where conventional CSMA/CA is not reliable enough. In this document, we will outline core features of DSME and openDSME, and present details of our implementation. Additionally, current research efforts on connected topics will be highlighted.
Florian Meier. Ph.D. Forum Abstract: Scalable Wireless Networks for Industrial Control Systems with Time and Reliability Constraints. In Proceedings of the 15th ACM/IEEE Conference on Information Processing in Sensor Networks, April 2016. Vienna, Austria.
@InProceedings{Telematik_IPSN_Meier_PhD_Forum, author = {Florian Meier}, title = {Ph.D. Forum Abstract: Scalable Wireless Networks for Industrial Control Systems with Time and Reliability Constraints}, booktitle = {Proceedings of the 15th ACM/IEEE Conference on Information Processing in Sensor Networks}, pages = , day = {11}, month = apr, year = 2016, location = {Vienna, Austria}, }
Abstract: Using wireless communication instead of laying cables promises high cost savings in many applications. Motivated by the intended deployment of wireless networks in solar tower power plants with up to hundreds of thousands of possible clients, this research shall explore the limits of large-scale wireless networks. Apart from the pure number of supported clients, maintaining reliability and time-bounded communication is a key requirement for such industrial control systems.
Florian Meier und Volker Turau. An Analytical Model for Fast and Verifiable Assessment of Large Scale Wireless Mesh Networks. In Proceedings of the Design of Reliable Communication Networks (DRCN), März 2015, pp. 185–190. Kansas City, MO, USA.
@InProceedings{Telematik_DRCN_Model, author = {Florian Meier and Volker Turau}, title = {An Analytical Model for Fast and Verifiable Assessment of Large Scale Wireless Mesh Networks}, booktitle = {Proceedings of the Design of Reliable Communication Networks (DRCN)}, pages = {185-190}, month = mar, year = 2015, location = {Kansas City, MO, USA}, }
Abstract: Ensuring reliability is a key requirement for using wireless mesh networks in industrial applications. Analytical models provide a valuable support in the design of reliable networks, especially for large scale applications, where simulations do not provide the required scalability. This paper proposes an analytical model for multi-hop IEEE 802.15.4 networks that incorporates significant improvements compared to previous models. Comparisons of the model with simulations using the MiXiM framework for OMNeT++ exhibit a very good compliance. The analytical model is therefore adequate for assessment of very large wireless mesh networks. Additionally, the model yields new insights into the characteristics of IEEE 802.15.4 networks, regarding the impact of acknowledgment collisions and the influence of hidden nodes on retransmissions.
Andreas Pfahl, Michael Randt, Florian Meier, Martin Zaschke, C.P.W. Geurts und Michael Buselmeier. A Holistic Approach for Low Cost Heliostat Fields. In Proceedings of the SolarPACES 2014, September 2014. Beijing, China.
@InProceedings{Telematik_SolarPACES_HolisticHeliostatFields, author = {Andreas Pfahl and Michael Randt and Florian Meier and Martin Zaschke and C.P.W. Geurts and Michael Buselmeier}, title = {A Holistic Approach for Low Cost Heliostat Fields}, booktitle = {Proceedings of the SolarPACES 2014}, month = sep, year = 2014, location = {Beijing, China}, }
Abstract: The AutoR-project takes a holistic approach to reduce the cost of heliostat fields: Wireless control and energy supply enables to use smaller heliostats which need less steel per mirror area (but usually have high wiring cost). A low cost but high efficient drive system is chosen which reduces energy consumption to a minimum amount and leads to low cost for PV cell and energy storage. The usual boundary layer wind tunnels tests for heliostats are proven regarding energy spectra to avoid oversizing of steel structure and drives or failures because of underestimations of the loads. The concepts for wireless control and energy supply, the wind tunnel investigations and the first rim drive heliostat prototype are presented.
Shrirang Abhyankar, Jed Brown, Matthew Knepley, Florian Meier und Barry Smith. Poster Abstract: Abstractions for Expressing Network Problems in PETSc. In SIAM Workshop on Network Science, Juli 2014. Chicago, US.
@InProceedings{SIAM_PETSc, author = {Shrirang Abhyankar and Jed Brown and Matthew Knepley and Florian Meier and Barry Smith}, title = {Poster Abstract: Abstractions for Expressing Network Problems in PETSc}, booktitle = {SIAM Workshop on Network Science}, month = jul, year = 2014, location = {Chicago, US}, }
Abstract: Developing scalable software for large-scale applications, particularly for networks and circuits, is challenging due to the underlying unstructured and irregular geometry of the problem. We present a programming framework recently added to the PETSc library to easily express network problems, and thereby reduce the application development time. A brief overview of the framework is presented and two application examples, one from power grid and the other from radio networks, are discussed.
Florian Meier, Marco Fink und Udo Zölzer. The JamBerry - A Stand-Alone Device for Networked Music Performance Based on the Raspberry Pi. In Proceedings of the Linux Audio Conference (LAC'14), Mai 2014. Karlsruhe, Germany.
@InProceedings{LAC_JamBerry, author = {Florian Meier and Marco Fink and Udo Zölzer}, title = {The JamBerry - A Stand-Alone Device for Networked Music Performance Based on the Raspberry Pi}, booktitle = {Proceedings of the Linux Audio Conference (LAC'14)}, month = may, year = 2014, location = {Karlsruhe, Germany}, }
Abstract: Today's public Internet availability and capabilities allow manifold applications in the field of multimedia that were not possible a few years ago. One emerging application is the so-called Networked Music Performance, standing for the online, low-latency interaction of musicians. This work proposes a stand-alone device for that specific purpose and is based on a Raspberry Pi running a Linux-based operating system.
Christian Renner, Florian Meier und Volker Turau. Holistic Online Energy Assessment: Feasibility and Practical Application. In Proceedings of the 9th IEEE International Conference on Networked Sensing Systems (INSS'12), Juni 2012. Antwerp, Belgium. Best Student Paper Award.
@InProceedings{Telematik_RT_2012_HolisticEnergyAssessment, author = {Christian Renner and Florian Meier and Volker Turau}, title = {Holistic Online Energy Assessment: Feasibility and Practical Application}, booktitle = {Proceedings of the 9th IEEE International Conference on Networked Sensing Systems (INSS'12)}, day = {11-14}, month = jun, year = 2012, location = {Antwerp, Belgium}, note = {Best Student Paper Award}, }
Abstract: Combining energy harvesting with energy-aware scheduling enables perpetually operating sensor networks. The practical realization of this goal yet requires reliable and precise holistic online energy assessment. While the building blocks--assessing residual energy, predicting energy intake, and tracing energy consumption--have been studied in detail, the analysis of their interaction on a real platform has been neglected. This paper answers the question, whether these techniques can be easily joined to give a precise and correct picture of a sensor node's energetic state and behavior. For this purpose, we model the energy flow of a prototype energy-harvesting sensor node and evaluate the joint performance of state-of-the-art energy assessment based on a field test. We verify the system model and show the feasibility of holistic energy assessment, which tolerates small configuration errors, achievable with a combination of generic configuration and online calibration. We also analyze the feasibility of forecasting a node's future energetic state, and find that the presented method gives sufficient results for uniformly distributed consumption profiles.
Christian Renner, Florian Meier und Volker Turau. Policies for Predictive Energy Management with Supercapacitors. In Proceedings of the 8th IEEE International Workshop on Sensor Networks and Systems for Pervasive Computing (PerSeNS'12), März 2012. Lugano, Switzerland.
@InProceedings{Telematik_RT_2012_Epol, author = {Christian Renner and Florian Meier and Volker Turau}, title = {Policies for Predictive Energy Management with Supercapacitors}, booktitle = {Proceedings of the 8th IEEE International Workshop on Sensor Networks and Systems for Pervasive Computing (PerSeNS'12)}, day = {19-23}, month = mar, year = 2012, location = {Lugano, Switzerland}, }
Abstract: This paper presents an algorithm to dynamically determine the maximum supported uniform demand for energy of sensor nodes powered by energy harvesters using supercapacitors as energy buffers. Knowledge about the maximum uniform consumption is required to adapt the sensor node's duty cycle or task schedule to achieve uniform, utility-maximizing, and depletion-safe operation. Our algorithm makes use of a supercapacitors' relationship between state-of-charge and voltage, is particularly designed to handle the non-linear system model, and is lightweight enough to run on low-power sensor node hardware. We define three energy policies, evaluate their performance using a real-world solar-harvesting trace, and analyze the influence of the supercapacitor's capacity and errors of the energy forecast.
Christian Renner, Florian Meier und Volker Turau. Poster Abstract: Energy Assessment in Praxis. In Adjunct Proceedings of the 9th European Conference on Wireless Sensor Networks (EWSN'12), Februar 2012. Trento, Italy.
@InProceedings{Telematik_RT_2012_EnergyAssessment, author = {Christian Renner and Florian Meier and Volker Turau}, title = {Poster Abstract: Energy Assessment in Praxis}, booktitle = {Adjunct Proceedings of the 9th European Conference on Wireless Sensor Networks (EWSN'12)}, day = {15-17}, month = feb, year = 2012, location = {Trento, Italy}, }
Abstract: Combining energy harvesting with energy-aware scheduling enables perpetually operating sensor networks. Practical realization yet requires precise holistic online energy assessment. The building blocks are available, but the analysis of their interaction has been neglected. To close the gap, we evaluate the joint performance of energy assessment components. Our experiments substantiate that holistic energy assessment is feasible and that small configuration errors are tolerable.

Technische Berichte

Florian Meier und Volker Turau. Analytical Model for IEEE 802.15.4 Multi-Hop Networks with Improved Handling of Acknowledgements and Retransmissions. Technical Report arXiv:1501.07594, arXiv.org e-prints, Januar 2015.
@TechReport{Telematik_ARXIV_Multihop_Networks, author = {Florian Meier and Volker Turau}, title = {Analytical Model for IEEE 802.15.4 Multi-Hop Networks with Improved Handling of Acknowledgements and Retransmissions}, number = {arXiv:1501.07594}, institution = {arXiv.org e-prints}, month = jan, year = 2015, }
Abstract: The IEEE 802.15.4 standard allows for the deployment of cost-effective and energy-efficient multi-hop networks. This document features an in-depth presentation of an analytical model for assessing the performance of such networks. It considers a generic, static topology with Poisson distributed data-collection as well as data-dissemination traffic. The unslotted CSMA/CA MAC layer of IEEE 802.15.4 is closely modeled as well as an enhanced model of the neighborhood allows for consideration of collisions of packets including interferences with acknowledgements. The hidden node problem is taken into account as well as a formerly disregarded effect of repeated collisions of retransmissions. The model has been shown to be suitable to estimate the capacity of large-scale multi-hop networks.

Studentische Arbeiten

Florian Meier. Low-Latency Audio over IP on Embedded Systems. Master's Thesis, Department of Signal Processing and Communications, Helmut Schmidt University, Hamburg, Germany, Oktober 2013.
@MastersThesis{Meier_2013_MasterThesis, author = {Florian Meier}, type = {Master's Thesis}, title = {Low-Latency Audio over IP on Embedded Systems}, school = {Department of Signal Processing and Communications, Helmut Schmidt University}, address = {Hamburg, Germany}, month = oct, year = 2013, }
Florian Meier. Energy-Aware and Prediction-Based Scheduling for Energy-Harvesting Sensor Nodes. Bachelor's Thesis, Hamburg University of Technology, Hamburg, Germany, September 2011.
@MastersThesis{Meier_2011_BachelorThesis, author = {Florian Meier}, type = {Bachelor's Thesis}, title = {Energy-Aware and Prediction-Based Scheduling for Energy-Harvesting Sensor Nodes}, school = {Hamburg University of Technology}, address = {Hamburg, Germany}, month = sep, year = 2011, }