Publications
Books | Journal Articles | Conference Contributions | Technical Reports
See also DBLP, Google Scholar, Computer Science Bibliographies, CiteSeer, and ACM.
Books
Volker Turau. Algorithmische Graphentheorie. Oldenbourg, München, Germany, 3rd edition, October 2009.
@Book{Telematik_Turau_2009_AGT,
author = {Volker Turau},
title = {Algorithmische Graphentheorie},
publisher = {Oldenbourg},
address = {München, Germany},
edition = {3rd},
month = oct,
year = 2009,
isbn = {978-3-486-59057-9},
}
Wilfried Elmenreich, Markus Kucera, Bernhard Rinner, Ralf Seepold and Volker Turau, editors. Challenges on Complexity and Connectivity in Embedded Systems. Hindawi, 2009.
@Book{Telematik_Turau_2009_EURASIP,
editor = {Wilfried Elmenreich and Markus Kucera and Bernhard Rinner and Ralf Seepold and Volker Turau},
title = {Challenges on Complexity and Connectivity in Embedded Systems},
series = {EURASIP Journal of Embedded Systems},
volume = {2009},
publisher = {Hindawi},
year = 2009,
issn = {1687-3955},
}
Volker Turau and Christoph Weyer, editors. Proceedings of the Third International Workshop on Intelligent Solutions in Embedded Systems (WISES'05). Hamburg University of Technology, Hamburg, Germany, May 2005.
@Book{Telematik_Turau_2005_WISES,
editor = {Volker Turau and Christoph Weyer},
title = {Proceedings of the Third International Workshop on Intelligent Solutions in Embedded Systems (WISES'05)},
publisher = {Hamburg University of Technology},
address = {Hamburg, Germany},
month = may,
year = 2005,
isbn = {3-902463-03-1},
}
Volker Turau. Web-basierte Anwendungen entwickeln in JSP 2. dpunkt.verlag, Heidelberg, Germany, November 2003.
@Book{Telematik_Turau_2003_JSP2,
author = {Volker Turau},
title = {Web-basierte Anwendungen entwickeln in JSP 2},
publisher = {dpunkt.verlag},
address = {Heidelberg, Germany},
month = nov,
year = 2003,
isbn = {3-89864-235-6},
}
Volker Turau, Krister Saleck and Marc Schmidt. Java Server Pages und J2EE (Unternehmensweite web-basierte Anwendungen). dpunkt.verlag, Heidelberg, Germany, June 2001.
@Book{Telematik_Turau_2001_J2EE,
author = {Volker Turau and Krister Saleck and Marc Schmidt},
title = {Java Server Pages und J2EE (Unternehmensweite web-basierte Anwendungen)},
publisher = {dpunkt.verlag},
address = {Heidelberg, Germany},
month = jun,
year = 2001,
isbn = {3-898-64112-0},
}
Journal Articles
Christian Renner and Volker Turau. Adaptive Energy-Harvest Profiling to Enhance Depletion-Safe Operation and Efficient Task Scheduling. Sustainable Computing: Informatics and Systems, 2(1):43–56, March 2012.
@Article{Telematik_RT_2012_AdaptiveSlotting,
author = {Christian Renner and Volker Turau},
title = {Adaptive Energy-Harvest Profiling to Enhance Depletion-Safe Operation and Efficient Task Scheduling},
pages = {43-56},
journal = {Sustainable Computing: Informatics and Systems},
volume = {2},
number = {1},
month = mar,
year = 2012,
issn = {2210-5379},
}
Abstract:
Forecasting the expected energy harvest enables small-sized energy-harvesting sensor nodes to schedule tasks or adapt the radio duty cycle. This ability ensures depletion-safe and efficient operation. Most energy sources exhibit cyclic patterns of intensity, e.g., the sun. These patterns show periods with unequal--low versus high and stable versus varying--energy production and heavily depend on a node's location as well as seasonal and environmental changes. Existing forecast algorithms do not exploit these patterns, but create and update forecasts at static and arbitrary points in time, the main knob being the number of updates per cycle. We present a method enabling sensor nodes to adapt to harvesting patterns at runtime. It is designed for seamlessly replacing the static scheme to improve the accuracy of a wide range of existing forecast algorithms. In our evaluation, we show that (i) the adaptive method traces the energy pattern in real-world deployments accurately, (ii) reacts to seasonal and environmental changes, (iii) increases forecast accuracy, and (iv) reduces the number of prediction updates. These achievements enhance depletion-safe operation and efficient task scheduling with fewer recalculations and adjustments of the duty cycle. They also facilitate the exchange of harvesting forecasts for collaborative node tasks, since less information has to be shared.
Arne Bosien, Volker Turau and Franco Zambonelli. Approaches to Fast Sequential Inventory and Path Following in RFID-enriched environments. International Journal of Radio Frequency Identification Technology and Applications, 4(1):28–48, 2012.
@Article{Telematik_BTZ_2012_RFID,
author = {Arne Bosien and Volker Turau and Franco Zambonelli},
title = {Approaches to Fast Sequential Inventory and Path Following in RFID-enriched environments},
pages = {28-48},
journal = {International Journal of Radio Frequency Identification Technology and Applications},
volume = {4},
number = {1},
year = 2012,
}
Abstract:
Although RFID is mostly used for ticketing, e-passports and supply chain management applications, the technology is also suitable for transponder based navigation systems. There it can be applied to leave a virtual trace on writeable RFID tags. These applications use RFID in a different way, because the tags are stationary and related to each other, since each tag of the path points to the following one. This offers the possibility to develop more efficient algorithms for their detection. In this paper, we suggest to store the identifying masks of subsequent tag IDs on the tags. The approach can easily be used with query-tree anti-collision methods. We examine the requirements for such an approach and describe a concrete algorithm, which is simulated and compared with different anti-collision algorithms.
Volker Turau. Efficient Transformation of Distance-2 Self-Stabilizing Algorithms. Journal of Parallel and Distributed Computing, 72(4):603–612, 2012.
@Article{Telematik_T_2012_JPDC,
author = {Volker Turau},
title = {Efficient Transformation of Distance-2 Self-Stabilizing Algorithms},
pages = {603-612},
journal = {Journal of Parallel and Distributed Computing},
volume = {72},
number = {4},
year = 2012,
issn = {0743-7315},
}
Sven Köhler and Volker Turau. Fault-containing self-stabilization in asynchronous systems with constant fault-gap. Distributed Computing, 25(3):207–224, 2012.
@Article{Telematik_KT_2011_DC,
author = {Sven Köhler and Volker Turau},
title = {Fault-containing self-stabilization in asynchronous systems with constant fault-gap},
pages = {207-224},
journal = {Distributed Computing},
volume = {25},
number = {3},
year = 2012,
issn = {0178-2770},
}
Volker Turau and Bernd Hauck. A new Analysis of a Self-Stabilizing Maximum Weight Matching Algorithm with Approximation Ratio 2. Theoretical Computer Science, 412(40):5527–5540, September 2011. Stabilization, Safety and Security.
@Article{Telematik_HT_2010_TCS_Matching,
author = {Volker Turau and Bernd Hauck},
title = {A new Analysis of a Self-Stabilizing Maximum Weight Matching Algorithm with Approximation Ratio 2},
pages = {5527-5540},
journal = {Theoretical Computer Science},
volume = {412},
number = {40},
month = sep,
year = 2011,
keywords = {Self-stabilizing algorithms, approximation algorithm, weighted matching, distributed algorithms},
issn = {0304-3975},
note = {Stabilization, Safety and Security},
}
Abstract:
The maximum weight matching problem is a fundamental problem in graph theory with a variety of important applications. Recently Manne and Mjelde presented the first self-stabilizing algorithm computing a 2-approximation of the optimal solution. They established that their algorithm stabilizes after O(2^n) (resp. O(3^n)) moves under a central (resp. distributed) scheduler. This paper contributes a new analysis improving these bounds considerably. In particular it is shown that the algorithm stabilizes after O(nm) moves under the central scheduler and that a modified version of the algorithm also stabilizes after O(nm) moves under the distributed scheduler. The paper presents a new proof technique based on graph reduction to analyze the complexity of self-stabilizing algorithms.
Volker Turau and Bernd Hauck. A fault-containing self-stabilizing (3 - 2/(Delta+1))-approximation algorithm for vertex cover in anonymous networks. Theoretical Computer Science, 412(33):4361–4371, 2011.
@Article{Telematik_HT_2011_TCSVC,
author = {Volker Turau and Bernd Hauck},
title = {A fault-containing self-stabilizing (3 - 2/(Delta+1))-approximation algorithm for vertex cover in anonymous networks},
pages = {4361-4371},
journal = {Theoretical Computer Science},
volume = {412},
number = {33},
year = 2011,
keywords = {Self-stabilizing algorithms, Fault tolerance, Distributed algorithms, Graph algorithms},
}
Abstract:
The non-computability of many distributed tasks in anonymous networks is well known. This paper presents a deterministic self-stabilizing algorithm to compute a 3 - (2 / (Delta+1))-approximation of a minimum vertex cover in anonymous networks. The algorithm operates under the distributed unfair scheduler, stabilizes after O(n+m) moves respectively O(Delta) rounds, and requires O(log n) storage per node. Recovery from a single fault is reached within a constant time and the contamination number is O(Delta). For trees the algorithm computes a 2-approximation of a minimum vertex cover.
Volker Turau. Self-Stabilizing Vertex Cover in Anonymous Networks with Optimal Approximation Ratio. Parallel Processing Letters, 20(2):173–186, 2010.
@Article{Telematik_T_2010_PPL,
author = {Volker Turau},
title = {Self-Stabilizing Vertex Cover in Anonymous Networks with Optimal Approximation Ratio},
pages = {173-186},
journal = {Parallel Processing Letters},
volume = {20},
number = {2},
year = 2010,
}
Matthias Witt and Volker Turau. Robust and Low-Communication Geographic Routing for Wireless Ad Hoc Networks. Wireless Communications and Mobile Computing, 10(4):486–510, 2010.
@Article{Telematik_TW_2009_GeographicRouting,
author = {Matthias Witt and Volker Turau},
title = {Robust and Low-Communication Geographic Routing for Wireless Ad Hoc Networks},
pages = {486-510},
journal = {Wireless Communications and Mobile Computing},
volume = {10},
number = {4},
year = 2010,
}
Volker Turau and Bernd Hauck. A Self-Stabilizing Algorithm for Constructing Weakly Connected Minimal Dominating Sets. Information Processing Letters, 109(14):763–767, 2009.
@Article{Telematik_HT_2009_WCMDS,
author = {Volker Turau and Bernd Hauck},
title = {A Self-Stabilizing Algorithm for Constructing Weakly Connected Minimal Dominating Sets},
pages = {763-767},
journal = {Information Processing Letters},
volume = {109},
number = {14},
year = 2009,
keywords = {Self-stabilizing algorithms, Fault tolerance, Distributed algorithms, Graph algorithms},
issn = {0020-0190},
}
Abstract:
This paper presents a new distributed self-stabilizing algorithm for the weakly connected minimal dominating set problem. It assumes a self-stabilizing algorithm to compute a breadth-first tree. Using an unfair distributed scheduler the algorithm stabilizes in at most O(nmA) moves, where A is the number of moves to construct a breadth-first tree. All previously known algorithms required an exponential number of moves.
Volker Turau and Christoph Weyer. Fault Tolerance in Wireless Sensor Networks through Self-Stabilization. International Journal of Communication Networks and Distributed Systems, 2(1):78–98, 2009.
@Article{Telematik_TW_2009_SelfStabilization,
author = {Volker Turau and Christoph Weyer},
title = {Fault Tolerance in Wireless Sensor Networks through Self-Stabilization},
pages = {78-98},
journal = {International Journal of Communication Networks and Distributed Systems},
volume = {2},
number = {1},
year = 2009,
}
Abstract:
Wireless sensor networks (WSNs) suffer from resource limitations, high failure rates and faults caused by the lossy nature of wireless communication. This can lead to situations, where nodes lose synchrony and programs reach arbitrary states. Traditional approaches to fault tolerance like fault masking or global resets are not feasible for WSNs. Applying the concepts of self-stabilisation to achieve fault tolerance is a promising concept. However, the majority of self-stabilising algorithms found in the literature is based on models not suitable for WSNs. This paper proposes a problem-independent transformation for algorithms that stabilise under the central daemon scheduler such that they meet the demands of a WSN. Furthermore, a comparison with transformers from the literature is made through a series of simulations. Finally, the proposed transformer is evaluated with a real sensor network in a field test.
Norbert Luttenberger, Stefan Fischer, Erik Mähle, Dirk Timmermann and Volker Turau. Multi-hybride Sensornetze. PIK - Praxis der Informationsverarbeitung und Kommunikation, 31(3):141–145, 2008.
@Article{Telematik_LFMTT_2008_MultiHybrideSensornetze,
author = {Norbert Luttenberger and Stefan Fischer and Erik Mähle and Dirk Timmermann and Volker Turau},
title = {Multi-hybride Sensornetze},
pages = {141-145},
journal = {PIK - Praxis der Informationsverarbeitung und Kommunikation},
volume = {31},
number = {3},
year = 2008,
}
Volker Turau. Linear Self-Stabilizing Algorithms for the Independent and Dominating Set Problems using an Unfair Distributed Scheduler. Information Processing Letters., 103(3):88–93, July 2007.
@Article{Telematik_TT_2007_Selfstabilizing,
author = {Volker Turau},
editor = {A. Tarlecki},
title = {Linear Self-Stabilizing Algorithms for the Independent and Dominating Set Problems using an Unfair Distributed Scheduler},
pages = {88-93},
journal = {Information Processing Letters.},
volume = {103},
number = {3},
month = jul,
year = 2007,
}
Abstract:
This paper presents distributed self-stabilizing algorithms for the maximal independent and the minimal dominating set problems. Using an unfair distributed scheduler the algorithms stabilizes in at most max{3n-5,2n} resp. 9n moves. All previously known algorithms required O(n2) moves.
Volker Turau, Christoph Weyer and Matthias Witt. Ein robustes Datenmonitoring-Verfahren für Sensornetzwerke. it - Information Technology, 47(2):63–69, April 2005.
@Article{Telematik_TWW_2005_Datenmonitoring,
author = {Volker Turau and Christoph Weyer and Matthias Witt},
editor = {Christian Becker and Pedro José Marrón},
title = {Ein robustes Datenmonitoring-Verfahren für Sensornetzwerke},
pages = {63-69},
journal = {it - Information Technology},
volume = {47},
number = {2},
month = apr,
year = 2005,
}
Abstract:
A new data monitoring method for wireless sensor networks is introduced. The method combines geographic hash tables with in-network aggregation. Queries are processed in regions, whose sensor nodes collect their values in nodes close to a determinated location within the region, where they can easily be requested from outside. The method is robust against node failures and movements and generates very little network traffic. This is confirmed by various simulations.
Weimin Chen and Volker Turau. On Regular Tree Embeddings. SIAM Journal on Computing, 29(1):288–301, 1999.
@Article{Telematik_Turau_1999_embeddings,
author = {Weimin Chen and Volker Turau},
title = {On Regular Tree Embeddings},
pages = {288-301},
journal = {SIAM Journal on Computing},
volume = {29},
number = {1},
year = 1999,
}
Volker Turau. Techniken zur Realisierung Web-basierter Anwendungen. Informatik Spektrum, 22(1):3–12, 1999.
@Article{Telematik_Turau_1999_webapps,
author = {Volker Turau},
title = {Techniken zur Realisierung Web-basierter Anwendungen},
pages = {3-12},
journal = {Informatik Spektrum},
volume = {22},
number = {1},
year = 1999,
}
Volker Turau. Web-Roboter - Das Aktuelle Schlagwort. Informatik Spektrum, 21(3):159–160, 1998.
@Article{Telematik_Turau_1998_web_roboter,
author = {Volker Turau},
title = {Web-Roboter - Das Aktuelle Schlagwort},
pages = {159-160},
journal = {Informatik Spektrum},
volume = {21},
number = {3},
year = 1998,
}
Volker Turau. What Practices Are Being Adopted on the Web?. IEEE Computer, 31(5):106–108, 1998.
@Article{Telematik_Turau_1998_web_practices,
author = {Volker Turau},
title = {What Practices Are Being Adopted on the Web?},
pages = {106-108},
journal = {IEEE Computer},
volume = {31},
number = {5},
year = 1998,
}
Volker Turau. The Fortune 500 Web. IEEE Computer, 31(11):119–120, 1998.
@Article{Telematik_Turau_1998_fortune500,
author = {Volker Turau},
title = {The Fortune 500 Web},
pages = {119-120},
journal = {IEEE Computer},
volume = {31},
number = {11},
year = 1998,
}
Weimin Chen and Volker Turau. Multiple-Dispatching Based on Automata. TAPOS, 1(1):41–59, 1995.
@Article{Telematik_Turau_1995_multi_dispatch,
author = {Weimin Chen and Volker Turau},
title = {Multiple-Dispatching Based on Automata},
pages = {41-59},
journal = {TAPOS},
volume = {1},
number = {1},
year = 1995,
}
Volker Turau and Horst Duchêne. Equality Testing for Complex Objects Based on Hashing. Data and Knowledge Engineering, 10:101–111, 1993.
@Article{Telematik_Turau_1993_equality_testing,
author = {Volker Turau and Horst Duchêne},
title = {Equality Testing for Complex Objects Based on Hashing},
pages = {101-111},
journal = {Data and Knowledge Engineering},
volume = {10},
year = 1993,
}
Erich J. Neuhold and Volker Turau. Database Research at IPSI. SIGMOD Record, 21(1):133–138, 1992.
@Article{Telematik_Turau_1992_database_research,
author = {Erich J. Neuhold and Volker Turau},
title = {Database Research at IPSI},
pages = {133-138},
journal = {SIGMOD Record},
volume = {21},
number = {1},
year = 1992,
}
Volker Turau. Fixed-Radius Near Neighbors Search. Information Processing Letters, 39(4):201–203, 1991.
@Article{Telematik_Turau_1991_fixed_radius_search,
author = {Volker Turau},
title = {Fixed-Radius Near Neighbors Search},
pages = {201-203},
journal = {Information Processing Letters},
volume = {39},
number = {4},
year = 1991,
}
Volker Turau. A model for a control and monitoring system for an autonomous mobile robot. Robotics and Autonomous Systems, 4(1):41–47, 1988.
@Article{Telematik_Turau_1988_monitoring_model,
author = {Volker Turau},
title = {A model for a control and monitoring system for an autonomous mobile robot},
pages = {41-47},
journal = {Robotics and Autonomous Systems},
volume = {4},
number = {1},
year = 1988,
}
Conference Contributions
Stefan Unterschütz and Volker Turau. Reliable Signaling an Emergency Shutdown in Large-Scale, Wireless Controlled Industrial Plants. In Proceedings of the 10th ACM International Symposium on Mobility Management and Wireless Access (MOBIWAC '12), November 2012. Paphos, Cyprus Island.
@InProceedings{Telematik_UT_2012_Shutdown,
author = {Stefan Unterschütz and Volker Turau},
title = {Reliable Signaling an Emergency Shutdown in Large-Scale, Wireless Controlled Industrial Plants},
booktitle = {Proceedings of the 10th ACM International Symposium on Mobility Management and Wireless Access (MOBIWAC '12)},
day = {21-22},
month = nov,
year = 2012,
location = {Paphos, Cyprus Island},
}
Helge Klimek, Björn Greßmann and Volker Turau. Protocols for Resource Constrained Infrastructure Networks. In Proceedings of the 10th ACM International Symposium on Mobility Management and Wireless Access (MobiWac '12), October 2012. Paphos, Cyprus.
@InProceedings{Telematik_MOBIWAC_2012_ProtocolsInfrastructureNetwork,
author = {Helge Klimek and Björn Greßmann and Volker Turau},
title = {Protocols for Resource Constrained Infrastructure Networks},
booktitle = {Proceedings of the 10th ACM International Symposium on Mobility Management and Wireless Access (MobiWac '12)},
day = {20-25},
month = oct,
year = 2012,
location = {Paphos, Cyprus},
}
Abstract:
This paper introduces two protocols for communication in infrastructure networks consisting of a central server, stationary basestations and mobile devices. Mobile devices use IEEE 802.15.4 to communicate with the basestations. Among other things, the proposed protocols differ in their location management and in the routing of downlink and uplink packets. Through extensive simulations the protocols are compared with the focus on latency and packet loss metrics. The strength of each protocol depends on the traffic pattern caused by an application. This paper concludes with a recommendation for the usage of each protocol.
Sven Köhler, Volker Turau and Gerhard Mentges. Self-stabilizing local k-placement of replicas with minimal variance. In Proceedings of the 14th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'12), Springer, October 2012, pp. 16–30. Toronto, Canada.
@InProceedings{Telematik_KT_SSS12,
author = {Sven Köhler and Volker Turau and Gerhard Mentges},
title = {Self-stabilizing local k-placement of replicas with minimal variance},
booktitle = {Proceedings of the 14th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'12)},
pages = {16-30},
series = {Lecture Notes in Computer Science},
volume = {7596},
publisher = {Springer},
day = {1-4},
month = oct,
year = 2012,
location = {Toronto, Canada},
}
Abstract:
Large scale distributed systems require replication of resources to amplify availability and to provide fault tolerance. The placement of replicated resources significantly impacts performance. This paper considers local k-placements: Each node of a network has to place k replicas of a resource among its direct neighbors. The load of a node in a given local k-placement is the number of replicas it stores. The local k-placement problem is to achieve a preferably homogeneous distribution of the loads. We present a novel self-stabilizing, distributed, asynchronous, scalable algorithm for the k-placement problem such that the standard deviation of the distribution of the loads assumes a local minimum.
Martin Ringwelski, Christian Renner, Andreas Reinhardt, Andreas Weigel and Volker Turau. The Hitchhiker's Guide to Choosing the Compression Algorithm for Your Smart Meter Data. In Proceedings of the IEEE International Energy Conference and Exhibition (EnergyCon'12), September 2012. Florence, Italy.
@InProceedings{Telematik_RRWRT_2012_CompressionGuide,
author = {Martin Ringwelski and Christian Renner and Andreas Reinhardt and Andreas Weigel and Volker Turau},
title = {The Hitchhiker's Guide to Choosing the Compression Algorithm for Your Smart Meter Data},
booktitle = {Proceedings of the IEEE International Energy Conference and Exhibition (EnergyCon'12)},
day = {9-12},
month = sep,
year = 2012,
location = {Florence, Italy},
}
Abstract:
Smart meters are increasingly penetrating the market, resulting in enormous data volumes to be communicated. In many cases, embedded devices collect the metering data and transmit them wirelessly to achieve cheap and facile deployment. Bandwidth is yet scarce and transmission occupies the spectrum. Smart meter data should hence be compressed prior to transmission. Here, solutions for personal computers are not applicable, as they are too resource-demanding. In this paper, we propose four lossless compression algorithms for smart meters. We analyze processing time and compression gains and compare the results with five off-the-shelf compression algorithms. We show that excellent compression gains can be achieved when investing a moderate amount of memory. A discussion of the suitability of the algorithms for different kinds of metering data is presented.
Christian Renner and Volker Turau. State-of-Charge Assessment for Supercap-Powered Sensor Nodes: Keep it Simple Stupid!. In Proceedings of the International Workshop on Algorithms and Concepts for Networked Sensing Systems Powered by Energy Harvesters (EnHaNSS'12), June 2012. Antwerp, Belgium.
@InProceedings{Telematik_RT_2012_CapModels,
author = {Christian Renner and Volker Turau},
title = {State-of-Charge Assessment for Supercap-Powered Sensor Nodes: Keep it Simple Stupid!},
booktitle = {Proceedings of the International Workshop on Algorithms and Concepts for Networked Sensing Systems Powered by Energy Harvesters (EnHaNSS'12)},
day = {11},
month = jun,
year = 2012,
location = {Antwerp, Belgium},
}
Abstract:
Electric double-layer capacitors, also known as supercaps, have several advantages over traditional energy buffers: They do not require complex charging circuits, offer virtually unlimited charge-discharge cycles, and generally enable easy state-of-charge assessment. A closer look yet reveals that leakage and internal reorganization effects hamper state-of-charge assessment by means of terminal voltage, particularly after a charging cycle. Sophisticated models capture this effect at the cost of an increased calculation and parameter-estimation complexity. As this is hardly feasible on low-power, low-resource sensor nodes, we evaluate the performance of simple models on a real energy-harvesting sensor node platform. We show that model errors are as low as 1-2% on average and never exceed 5% in our experiments, supporting that there is no need to employ more complex models on common sensor node platforms, equipped with unreliable ADC readings and uncertain consumption due to hardware variation in the same order of magnitude.
Christian Renner, Florian Meier and Volker Turau. Holistic Online Energy Assessment: Feasibility and Practical Application. In Proceedings of the 9th IEEE International Conference on Networked Sensing Systems (INSS'12), June 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.
Stefan Unterschütz and Volker Turau. Fail-Safe Over-The-Air Programming and Error Recovery in Wireless Networks. In Proceedings of the 10th Workshop on Intelligent Solutions in Embedded Systems (WISES'12), June 2012. Klagenfurt, Austria.
@InProceedings{Telematik_UT_2012_OTAP,
author = {Stefan Unterschütz and Volker Turau},
title = {Fail-Safe Over-The-Air Programming and Error Recovery in Wireless Networks},
booktitle = {Proceedings of the 10th Workshop on Intelligent Solutions in Embedded Systems (WISES'12)},
day = {5-6},
month = jun,
year = 2012,
location = {Klagenfurt, Austria},
}
Stefan Unterschütz, Andreas Weigel and Volker Turau. Cross-Platform Protocol Development Based on OMNeT++. In Proceedings of the 5th International Workshop on OMNeT++ (OMNeT++'12), March 2012. Desenzano, Italy.
@InProceedings{Telematik_UWT_2012_CometOS,
author = {Stefan Unterschütz and Andreas Weigel and Volker Turau},
title = {Cross-Platform Protocol Development Based on OMNeT++},
booktitle = {Proceedings of the 5th International Workshop on OMNeT++ (OMNeT++'12)},
day = {23},
month = mar,
year = 2012,
location = {Desenzano, Italy},
}
Christian Renner, Florian Meier and 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), March 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 and Volker Turau. Poster Abstract: Energy Assessment in Praxis. In Adjunct Proceedings of the 9th European Conference on Wireless Sensor Networks (EWSN'12), February 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.
Stefan Unterschütz, Christian Renner and Volker Turau. Opportunistic, Receiver-Initiated Data-Collection Protocol. In Proceedings of the 9th European Conference on Wireless Sensor Networks (EWSN'12), February 2012. Trento, Italy.
@InProceedings{Telematik_URT_2012_Orinoco,
author = {Stefan Unterschütz and Christian Renner and Volker Turau},
title = {Opportunistic, Receiver-Initiated Data-Collection Protocol},
booktitle = {Proceedings of the 9th European Conference on Wireless Sensor Networks (EWSN'12)},
day = {15-17},
month = feb,
year = 2012,
location = {Trento, Italy},
}
Abstract:
This paper presents and evaluates ORiNoCo, a novel data-collection and event-reporting protocol for sensor networks. ORiNoCo is built upon the asynchronous duty-cycle protocol RI-MAC and breaks with the tradition of exchanging extensive neighborhood information, a cornerstone of many competing collection protocols and one of their major source of communication overhead and energy expenditure. The merit of this venture is an opportunistic, energy-efficient, latency-reducing, and self-stabilizing protocol. ORiNoCo comes at virtually no extra costs in terms of memory demand and communication overhead compared to RI-MAC. We derive theoretical boundaries for the improvements in radio efficiency, latency, and energy-consumption. ORiNoCo is verified with these findings via simulation and compared with CTP. ORiNoCo achieves lower energy-consumption while reducing end-to-end delays.
Sven Köhler and Volker Turau. Space-efficient fault-containment in dynamic networks. In Proceedings of the 13th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'11), Springer, October 2011, pp. 311–325. Grenoble, France.
@InProceedings{Telematik_KT_SSS11,
author = {Sven Köhler and Volker Turau},
title = {Space-efficient fault-containment in dynamic networks},
booktitle = {Proceedings of the 13th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'11)},
pages = {311-325},
series = {Lecture Notes in Computer Science},
volume = {6976},
publisher = {Springer},
day = {10-12},
month = oct,
year = 2011,
location = {Grenoble, France},
}
Abstract:
Bounding the impact of transient small-scale faults by self-stabilizing protocols has been pursued with independent objectives: Optimizing the system's reaction upon topological changes (e.g. super-stabilization), and reducing system recovery time from memory corruptions (e.g. fault-containment). Even though transformations adding either super-stabilization or fault-containment to existing protocols exists, none of them preserves the other. This paper makes a first attempt to combine both objectives. We provide a transformation adding fault-containment to silent self-stabilizing protocols while simultaneously preserving the property of self-stabilization and the protocol's behavior in face of topological changes. In particular, the protocol's response to a topology change remains unchanged even if a memory corruption occurs in parallel to the topology change. The presented transformation increases the memory footprint only by a factor of 4 and adds O(1) bits per edge. All previously known transformations for fault-containing self-stabilization increase the memory footprint by a factor of 2m/n.
Jürgen Jessen, Marcus Venzke and Volker Turau. Design Considerations for a Universal Smart Energy Module for Energy Harvesting in Wireless Sensor Networks. In Proceedings of the Ninth Workshop on Intelligent Solutions in Embedded Systems (WISES 2011), July 2011, pp. 35–40. Regensburg, Germany.
@InProceedings{Telematik_JVT_SmartSupply,
author = {Jürgen Jessen and Marcus Venzke and Volker Turau},
title = {Design Considerations for a Universal Smart Energy Module for Energy Harvesting in Wireless Sensor Networks},
booktitle = {Proceedings of the Ninth Workshop on Intelligent Solutions in Embedded Systems (WISES 2011)},
pages = {35-40},
day = {07-08},
month = jul,
year = 2011,
location = {Regensburg, Germany},
}
Abstract:
This paper presents the design of a universal energy module for nodes in wireless sensor networks. It supports a wide range of energy harvesters and energy storage systems. The focus is on the efficient conversion and storage of energy and to provide a smart platform for higher level energy management functions. The module provides maximum power point tracking and supports hybrid harvesters.
Stefan Unterschütz and Volker Turau. Construction of Connected Dominating Sets in Large-Scale MANETs Exploiting Self-Stabilization. In Proceedings of the 5th International Workshop on Localized Algorithms and Protocols for Wireless Sensor Networks (LOCALGOS'11), June 2011. Barcelona, Spain.
@InProceedings{Telematik_UT_2011_CDS,
author = {Stefan Unterschütz and Volker Turau},
title = {Construction of Connected Dominating Sets in Large-Scale MANETs Exploiting Self-Stabilization},
booktitle = {Proceedings of the 5th International Workshop on Localized Algorithms and Protocols for Wireless Sensor Networks (LOCALGOS'11)},
day = {29},
month = jun,
year = 2011,
location = {Barcelona, Spain},
}
Björn Greßmann, Helge Klimek and Volker Turau. Intelligent Passenger Flows in Airport Terminals Using a Digital Boarding Assistance. In Proceedings of the 8th International Workshop on Intelligent Transportation (WIT2011), March 2011. Hamburg, Germany.
@InProceedings{WIT2011C10,
author = {Björn Greßmann and Helge Klimek and Volker Turau},
title = {Intelligent Passenger Flows in Airport Terminals Using a Digital Boarding Assistance},
booktitle = {Proceedings of the 8th International Workshop on Intelligent Transportation (WIT2011)},
day = {22-23},
month = mar,
year = 2011,
location = {Hamburg, Germany},
}
Abstract:
In this paper we present a Digital Boarding Assistance (DigiBa) system for passengers in airport terminals. By providing navigation, notification and information services, passengers are enabled to move efficiently through the terminal. Based on functional requirements of such a system, the paper presents a prototype implementation on an embedded mobile device with restricted resources. Challenges concerning channel access in dense networks and indoor navigation on a device with limited hardware capabilities are outlined.
Holger Machens and Volker Turau. Avoiding Publication and Privatization Problems on Software Transactional Memory. In 17th GI/ITG Conference on Communication in Distributed Systems (KiVS 2011), Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik, February 2011, pp. 97–108. Kiel, Germany.
@InProceedings{Telematik_MT_2011_KIVS,
author = {Holger Machens and Volker Turau},
title = {Avoiding Publication and Privatization Problems on Software Transactional Memory},
booktitle = {17th GI/ITG Conference on Communication in Distributed Systems (KiVS 2011)},
pages = {97-108},
series = {OpenAccess Series in Informatics (OASIcs)},
volume = {17},
publisher = {Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},
day = {25},
month = feb,
year = 2011,
location = {Kiel, Germany},
}
Abstract:
This paper presents a new approach to exclude problems arising from dynamically switching between protected concurrent and unprotected single-threaded use of shared data when using software transactional memory in OO languages such as Java. The approach is based on a simple but effective programming model separating transactions from non-transactional operation. It prevents the application programmer from errors but does not force the software transactional memory library to observe non-transactional access and thereby preserves modularity of the software. A prototypical toolchain for validation and source code instrumentation was implemented as a proof of concept.
Christian Renner, Sebastian Ernst, Christoph Weyer and Volker Turau. Prediction Accuracy of Link-Quality Estimators. In Proceedings of the 8th European Conference on Wireless Sensor Networks (EWSN'11), February 2011. Bonn, Germany. Acceptance rate 20%.
@InProceedings{Telematik_REWT_HoPS,
author = {Christian Renner and Sebastian Ernst and Christoph Weyer and Volker Turau},
title = {Prediction Accuracy of Link-Quality Estimators},
booktitle = {Proceedings of the 8th European Conference on Wireless Sensor Networks (EWSN'11)},
day = {23-25},
month = feb,
year = 2011,
location = {Bonn, Germany},
note = {Acceptance rate 20%},
}
Abstract:
The accuracy of link-quality estimators (LQE) is mission-critical in many application scenarios in wireless sensor networks (WSN), since the link-quality metric is used for routing decisions or neighborhood formation. Link-quality estimation must offer validity for different timescales. Existing LQEs describe and approximate the current quality in a single value only. This method leads to a limited accuracy and expressiveness about the presumed future behavior of a link. The LQE developed in this paper incorporates four quality metrics that give a holistic assessment of the link and its dynamic behavior; therefore, this research is an important step to achieving a higher prediction accuracy including knowledge about the short- and long-term behavior.
Sven Köhler and Volker Turau. A new Technique for proving Self-Stabilization under the Distributed Scheduler. In Proceedings of the 12th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'10), Springer, September 2010, pp. 65–79. New York, NY, USA.
@InProceedings{Telematik_KT_ProofTechnique,
author = {Sven Köhler and Volker Turau},
title = {A new Technique for proving Self-Stabilization under the Distributed Scheduler},
booktitle = {Proceedings of the 12th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'10)},
pages = {65-79},
series = {Lecture Notes in Computer Science},
volume = {6366},
publisher = {Springer},
day = {20-22},
month = sep,
year = 2010,
location = {New York, NY, USA},
}
Abstract:
Proving stabilization of a complex algorithm under the distributed scheduler is a non-trivial task. This paper introduces a new method which allows to extend proofs for the central scheduler to the distributed scheduler. The practicability of the method is shown by applying it to two existing algorithms, for which stabilization under the distributed scheduler was an open problem.
Sven Köhler and Volker Turau. Fault-containing self-stabilization in asynchronous systems with constant fault-gap. In Proceedings of the 30th IEEE International Conference on Distributed Computing Systems (ICDCS'10), IEEE Computer Society, June 2010, pp. 418–427. Genoa, Italy.
@InProceedings{Telematik_KT_FaultContain,
author = {Sven Köhler and Volker Turau},
title = {Fault-containing self-stabilization in asynchronous systems with constant fault-gap},
booktitle = {Proceedings of the 30th IEEE International Conference on Distributed Computing Systems (ICDCS'10)},
pages = {418-427},
publisher = {IEEE Computer Society},
day = {21-25},
month = jun,
year = 2010,
location = {Genoa, Italy},
}
Abstract:
This paper presents a new transformation which adds fault-containment properties to any silent self-stabilizing protocol. The transformation features a constant slow-down factor and the fault-gap – that is the minimal time between two containable faults – is constant. The transformation scales well to arbitrarily large systems and avoids global synchronization.
Christian Renner, Volker Turau and Christoph Weyer. Performance of Energy-Efficient TDMA Schemes in Data-Gathering Scenarios with Periodic Sources. In Proceedings of the 7th IEEE International Conference on Networked Sensing Systems (INSS'10), June 2010. Kassel, Germany. Acceptance rate 22%.
@InProceedings{Telematik_RTW_EnergyEfficientTDMA,
author = {Christian Renner and Volker Turau and Christoph Weyer},
title = {Performance of Energy-Efficient TDMA Schemes in Data-Gathering Scenarios with Periodic Sources},
booktitle = {Proceedings of the 7th IEEE International Conference on Networked Sensing Systems (INSS'10)},
day = {15-18},
month = jun,
year = 2010,
location = {Kassel, Germany},
note = {Acceptance rate 22%},
}
Abstract:
Energy-efficient transportation of periodical sensor readings towards a single sink in wireless sensor networks is a challenging task. In general, two data-gathering strategies exist: on-demand and bulk data forwarding. For both strategies, cross-layer techniques are a promising approach, where TDMA is tailored to the underlying routing tree. Therefore, different TDMA schemes are compared regarding achievable throughput, packet delay, and energy-efficiency for various sampling rates and scenarios. Existing schemes perform well in dedicated topologies only. The new and simple TDMA scheme presented in this paper outperforms its predecessors in all scenarios under consideration. These findings are substantiated by both theoretical analysis and extensive simulation.
Björn Greßmann, Helge Klimek and Volker Turau. Towards Ubiquitous Indoor Location Based Services and Indoor Navigation. In Proceedings of the 7th IEEE Workshop on Positioning Navigation and Communication (WPNC2010), March 2010. Dresden, Germany.
@InProceedings{WPNC10,
author = {Björn Greßmann and Helge Klimek and Volker Turau},
title = {Towards Ubiquitous Indoor Location Based Services and Indoor Navigation},
booktitle = {Proceedings of the 7th IEEE Workshop on Positioning Navigation and Communication (WPNC2010)},
day = {11-12},
month = mar,
year = 2010,
location = {Dresden, Germany},
}
Abstract:
Outdoor navigation services have become ubiquitously available due to small handheld devices such as GPS enabled mobile phones or dedicated mobile navigation systems. Two main drivers were necessary in order to provide widespread location based services: Acquiring positioning information with a certain degree of precision and widespread (mobile) access to computer networks to use the position information with a large information basis such as the Internet. Envisioned is a future, where indoor navigation and location based services are used as naturally as outdoor location based services are now. To achieve this long term vision where users seamlessly navigate for example from work desk to departure gate at the airport and use location based services on the way, various challenges have to be solved. In this paper, these challenges and open issues are discussed. The paper proposes an architecture which abstracts from different mobile devices and localization technologies. Additionally, it sketches the use of indoor topology information to increase the accuracy of indoor localization. These two presented concepts form a basis for a transition period until standards for ubiquitous indoor location based services have emerged.
Christian Renner and Volker Turau. CapLibrate: Self-Calibration of an Energy Harvesting Power Supply with Supercapacitors. In Proceedings of the GI/ITG Workshop on Energy-aware Systems and Methods, February 2010. Hannover, Germany.
@InProceedings{Telematik_RT_2010_CapLibrate,
author = {Christian Renner and Volker Turau},
title = {CapLibrate: Self-Calibration of an Energy Harvesting Power Supply with Supercapacitors},
booktitle = {Proceedings of the GI/ITG Workshop on Energy-aware Systems and Methods},
day = {22-23},
month = feb,
year = 2010,
location = {Hannover, Germany},
}
Abstract:
Achieving perpetual and self-sustaining operation of wireless sensor nodes is an important topic of current research in the field of energy harvesting. Closely related to this is the employment of energy budgeting, i.e., effective utilization of available and future energy resources without pushing a node towards the hazard of energy depletion. Therefore, reliable prediction of node lifetime in context of the available energy within a given time is required. This in turn requires self-calibration of the sensor nodes and their energy harvesting supply. In this paper, we explore and assess models for a supercapacitor-based harvesting supply. The parameters of the models are discussed and determined, so that fast, reliable, and energy-efficient calibration becomes possible. Moreover, measurement results for a specific hardware platform are discussed and a roadmap for a self-calibration algorithm is presented.
Volker Turau and Bernd Hauck. A Self-Stabilizing Approximation Algorithm for Vertex Cover in Anonymous Networks. In Proceedings of the 11th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'09), Springer, November 2009, pp. 341–353. Lyon, France.
@InProceedings{Telematik_HT_2009_VC,
author = {Volker Turau and Bernd Hauck},
title = {A Self-Stabilizing Approximation Algorithm for Vertex Cover in Anonymous Networks},
booktitle = {Proceedings of the 11th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS'09)},
pages = {341-353},
series = {Lecture Notes in Computer Science},
volume = {5873},
publisher = {Springer},
day = {3-6},
month = nov,
year = 2009,
location = {Lyon, France},
}
Abstract:
This paper presents a deterministic self-stabilizing algorithm that computes a 3-approximation vertex cover in anonymous networks. It reaches a legal state after O(n+m) moves or 2n + 1 rounds respectively and recovers from a single fault within a constant containment time. The contamination number is 2 Delta + 1. An enhanced version of this algorithm achieves a 2-approximation on trees.
Christian Renner, Jürgen Jessen and Volker Turau. Poster: Energy Estimation for Harvesting Supplies with Supercaps. In Proceedings of the Workshop on Self-Organizing Wireless Sensor and Communication Networks, October 2009. Hamburg, Germany.
@InProceedings{Telematik_RJT_2009_EnergyEstimation,
author = {Christian Renner and Jürgen Jessen and Volker Turau},
title = {Poster: Energy Estimation for Harvesting Supplies with Supercaps},
booktitle = {Proceedings of the Workshop on Self-Organizing Wireless Sensor and Communication Networks},
day = {8-9},
month = oct,
year = 2009,
location = {Hamburg, Germany},
}
Arne Bosien and Volker Turau. RFID for Mobile Applications. In Proceedings of the Workshop on Self-Organizing Wireless Sensor and Communication Networks, October 2009, pp. 27–33. Hamburg, Germany.
@InProceedings{Telematik_SOMSED_2009_MOBILE_RFID,
author = {Arne Bosien and Volker Turau},
title = {RFID for Mobile Applications},
booktitle = {Proceedings of the Workshop on Self-Organizing Wireless Sensor and Communication Networks},
pages = {27-33},
day = {8-9},
month = oct,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
The availability of fast anti-collision algorithms is crucial for most RFID applications. This paper aims to evaluate these algorithms for applications in which it is not intended to identify the entirety of moving objects but to detect as much tags as needed to allow orientation. The navigation of Automated Guided Vehicles (AGV) by distributed landmarks is an example which clarifies the discriminative requirements compared to supply chain tasks. For the former purpose redundant information can be gained from different tags. This requires the detection of an application dependent percentage of all tags. Because AGVs are moving, the detection and read and write operations have to be close together and very fast, since repetitive communication is not always possible.
Christoph Weyer, Volker Turau, Andreas Lagemann and Jörg Nolte. Programming Wireless Sensor Networks in a Self-Stabilizing Style. In Proceedings of the Third International Conference on Sensor Technologies and Applications (SENSORCOMM'09), June 2009. Athens, Greece.
@InProceedings{Telematik_WLT_2009_SelfWISE,
author = {Christoph Weyer and Volker Turau and Andreas Lagemann and Jörg Nolte},
title = {Programming Wireless Sensor Networks in a Self-Stabilizing Style},
booktitle = {Proceedings of the Third International Conference on Sensor Technologies and Applications (SENSORCOMM'09)},
day = {18-23},
month = jun,
year = 2009,
location = {Athens, Greece},
}
Abstract:
Wireless Sensor Networks (WSNs) operate in an unstable environment and thus are subject to arbitrary transient faults. Self-stabilization is a promising technique to add tolerance against transient faults in a self-contained non-masking way. A core factor for the applicability of a given self-stabilizing algorithm is its convergence time. This paper analyses the average stabilization time of three algorithms commonly regarded as central building blocks for WSNs. The analysis is accomplished with SelfWISE, a framework providing programming abstractions for selfstabilizing algorithms. The performed analysis considers the target models as well as network size and density. This demonstrates the usability of SelfWISE for evaluating selfstabilizing algorithms under a wide range of models.
Christoph Weyer, Christian Renner, Volker Turau and Hannes Frey. TinyAID: Automated Instrumentation and Evaluation Support for TinyOS. In Proceedings of the Second International Workshop on Sensor Network Engineering (IWSNE'09), June 2009. Marina del Rey, CA, USA.
@InProceedings{Telematik_WRTF_2009_TinyAID,
author = {Christoph Weyer and Christian Renner and Volker Turau and Hannes Frey},
title = {TinyAID: Automated Instrumentation and Evaluation Support for TinyOS},
booktitle = {Proceedings of the Second International Workshop on Sensor Network Engineering (IWSNE'09)},
day = {10},
month = jun,
year = 2009,
location = {Marina del Rey, CA, USA},
}
Abstract:
TinyAID is a tool that supports automated instrumentation and evaluation of TinyOS-based distributed applications. Two types of instrumentations are provided: logging of call chains and message flows within the network. TinyAID assists the debugging process by post evaluation of the logged data. A main benefit is the visualization component for representing traces in their spatial and temporal order. The instrumentation and evaluation concepts are evaluated in two case studies: the SelfWISE framework and a selection of routing algorithms. Due to the automated process of TinyAID the evaluation could be performed without a deeper knowledge of the implementations under test. In the first case TinyAID revealed a weakness in the TOSSIM random number generator. The second case demonstrates the power of TinyAID to visualize the quality of protocols in a unified manner, without any manual changes to the specific source code.
Marcus Venzke, Mikko Jania and Volker Turau. VoIP over WLAN: Replacing Professional Mobile Radio on Airports. In Proceedings of the Second International Workshop on Aircraft System Technologies (AST'09), March 2009. Hamburg, Germany.
@InProceedings{Telematik_VJT_2009_VoIP,
author = {Marcus Venzke and Mikko Jania and Volker Turau},
title = {VoIP over WLAN: Replacing Professional Mobile Radio on Airports},
booktitle = {Proceedings of the Second International Workshop on Aircraft System Technologies (AST'09)},
day = {26-27},
month = mar,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
This paper proposes and analyses the idea of replacing professional mobile radio for airport ground handlers by VoIP systems based on WLAN. The proposed communication scheme is adjusted to business processes at airports. It provides push-to-talk unicast and group messages (determined by business tasks or location) with priorities, encrypted transmission, and mailboxes. The resulting architecture and proof-of-concept prototype consists of a server and software clients reusing already installed hardware and WLAN infrastructure, and uses peer-to-peer RDP voice streams. Bandwidth considerations estimate a maximum of 72 concurrent streams per access point on WLAN for IEEE 802.11g (54 Mbit/s) and 13 streams for IEEE 802.11b (11 Mbit/s), enhanced with a factor 3 to 5 if IEEE 802.11e is used as quality of service support.
Christoph Weyer and Volker Turau. SelfWISE: A Framework for Developing Self-Stabilizing Algorithms. In Proceedings of the 16th ITG/GI - Fachtagung Kommunikation in Verteilten Systemen (KiVS'09), March 2009, pp. 67–78. Kassel, Germany.
@InProceedings{Telematik_TW_2009_SelfWISE,
author = {Christoph Weyer and Volker Turau},
title = {SelfWISE: A Framework for Developing Self-Stabilizing Algorithms},
booktitle = {Proceedings of the 16th ITG/GI - Fachtagung Kommunikation in Verteilten Systemen (KiVS'09)},
pages = {67-78},
day = {2-6},
month = mar,
year = 2009,
location = {Kassel, Germany},
}
Abstract:
This paper introduces SelfWISE, a framework for enabling wireless sensor networks to be programmed in a self-stabilizing manner. The framework eases the formal specification of algorithms by abstracting from low-level details such as wireless channel and hardwarespecific characteristics. SelfWISE consists of a language for expressing self-stabilizing algorithms, a runtime environment for simulating algorithms in wireless sensor networks, and supporting tools. The hereby applied transformation of formally described algorithms into the simulation environment preserves the self-stabilizing properties. Development, evaluation, and debugging of self-stabilizing algorithms is considerably facilitated by utilizing SelfWISE.
Volker Turau, Christoph Weyer and Christian Renner. Efficient Slot Assignment for the Many-to-One Routing Pattern in Sensor Networks. In Proceedings of the First International Workshop on Sensor Network Engineering (IWSNE'08), June 2008. Santorini Island, Greece.
@InProceedings{Telematik_TWR_2008_SlotAssignmentManyOne,
author = {Volker Turau and Christoph Weyer and Christian Renner},
title = {Efficient Slot Assignment for the Many-to-One Routing Pattern in Sensor Networks},
booktitle = {Proceedings of the First International Workshop on Sensor Network Engineering (IWSNE'08)},
day = {11},
month = jun,
year = 2008,
location = {Santorini Island, Greece},
}
Abstract:
In this paper an efficient TDMA slot assignment for the many-to-one routing pattern in wireless sensor networks is presented and analyzed. This assignment scheme is based on a simple to implement heuristic, named spatial path-based reuse (SPR). By considering several metrics, the superiority of this heuristic with respect to energy consumption and runtime compared to proposals found in the literature is demonstrated.
Arne Bosien, Marcus Venzke and Volker Turau. A rewritable RFID environment for AGV navigation. In Proceedings of the 5th International Workshop on Intelligent Transportation (WIT'08), March 2008, pp. 87–92. Hamburg, Germany.
@InProceedings{Telematik_BVT_2008_AVG_RFID_Environment,
author = {Arne Bosien and Marcus Venzke and Volker Turau},
title = {A rewritable RFID environment for AGV navigation},
booktitle = {Proceedings of the 5th International Workshop on Intelligent Transportation (WIT'08)},
pages = {87-92},
day = {18-19},
month = mar,
year = 2008,
location = {Hamburg, Germany},
}
Abstract:
The paper analyses potentials, challenges, and applications of using rewritable, stationary RFID tags for marking routes for autonomous vehicles in manufacturing environments. This approach promises to be flexible, robust, and inexpensive. Two algorithms are proposed also considering additional sensors.
Volker Turau and Christoph Weyer. TDMA-Schemes for Tree-Routing in Data Intensive Wireless Sensor Networks. In Proceedings of the First International Workshop on Protocols and Algorithms for Reliable and Data Intensive Sensor Networks (PARIS'07), October 2007. Pisa, Italy.
@InProceedings{Telematik_TW_2007_TDMASchemesTreeRouting,
author = {Volker Turau and Christoph Weyer},
title = {TDMA-Schemes for Tree-Routing in Data Intensive Wireless Sensor Networks},
booktitle = {Proceedings of the First International Workshop on Protocols and Algorithms for Reliable and Data Intensive Sensor Networks (PARIS'07)},
day = {8},
month = oct,
year = 2007,
location = {Pisa, Italy},
}
Abstract:
A particular class of data intensive wireless sensor networks are those networks where sensors periodically measure data with high rates. The focus of this work is on the efficient transport of high volumes of sampled data through a multi-hop network with limited resources using a routing tree. This paper analyzes TDMA schemes for this purpose with respect to buffer usage and energy consumption. In particular, it is shown, that classical TDMA schemes are not optimal for tree-routing in data-intensive sensor networks.
Jens Ove Lauf, Dieter Gollmann and Volker Turau. MASC - Monitoring and Security of Containers. In Proceedings of the 37th Jahrestagung der Gesellschaft für Informatik e.V. (INFORMATIK'07), Workshop Container Security, September 2007, pp. 5–10. Bremen, Germany.
@InProceedings{LGT_2007_MASC,
author = {Jens Ove Lauf and Dieter Gollmann and Volker Turau},
title = {MASC - Monitoring and Security of Containers},
booktitle = {Proceedings of the 37th Jahrestagung der Gesellschaft für Informatik e.V. (INFORMATIK'07), Workshop Container Security},
pages = {5-10},
day = {24-27},
month = sep,
year = 2007,
location = {Bremen, Germany},
}
Volker Turau and Christoph Weyer. Long-term Reliable Data Gathering Using Wireless Sensor Networks. In Proceedings of the Fourth International Conference on Networked Sensing Systems (INSS'07), June 2007, pp. 252–259. Braunschweig, Germany.
@InProceedings{Telematik_LVMHTM_2007_Long-termReliableDataGathering,
author = {Volker Turau and Christoph Weyer},
title = {Long-term Reliable Data Gathering Using Wireless Sensor Networks},
booktitle = {Proceedings of the Fourth International Conference on Networked Sensing Systems (INSS'07)},
pages = {252-259},
day = {6-8},
month = jun,
year = 2007,
location = {Braunschweig, Germany},
}
Abstract:
This paper presents the design of a long-term reliable data gathering service for many-to-one communication in wireless sensor networks: all nodes send periodically delaytolerant data to a single node. The service operates reliably despite strict resource constraints, poor link qualities, and frequent disconnects. This paper presents a novel protocol for gathering periodically measured data including a solution for the wearleveling problem of the EEPROM. Furthermore, theoretical limits of this approach based on available bandwidth and local memory are provided. Finally, preliminary results of an implementation of the service are presented. In particular a detailed analysis of the energy consumption during the different phases of this experiment is provided.
Volker Turau and Christoph Weyer. Scheduling Transmission of Bulk Data in Sensor Networks using a Dynamic TDMA Protocol. In Proceedings of the International Workshop on Data Intensive Sensor Networks (DISN'07), May 2007, pp. 321–325. Mannheim, Germany.
@InProceedings{Telematik_TW_2007_SchedulingBulkData,
author = {Volker Turau and Christoph Weyer},
title = {Scheduling Transmission of Bulk Data in Sensor Networks using a Dynamic TDMA Protocol},
booktitle = {Proceedings of the International Workshop on Data Intensive Sensor Networks (DISN'07)},
pages = {321-325},
day = {1},
month = may,
year = 2007,
location = {Mannheim, Germany},
}
Abstract:
Sensor networks are increasingly used for applications in which sensors periodically measure data with high sampling rates. The reliable transport of high volumes of sampled data through a multi-hop network with limited resources requires sophisticated algorithms. This paper presents a novel protocol for this task that uses minimal energy, provides high throughput, and requires only small amounts of additional buffer. The protocol is based on a dynamic TDMA scheme and is robust against omission failures.
Steffen Loth, Marcus Venzke, Dietmar Möller, Axel Husfeldt, Volker Turau and Christoph Meier. Car Management on Aprons (CARMA) - Developing Integrated Solutions for Vehicle Management at Mid-Size Airports. In Proceedings of the First International Workshop on Aircraft System Technologies (AST'07), March 2007, pp. 257–266. Hamburg, Germany.
@InProceedings{Telematik_LVMHTM_2007_CARMA,
author = {Steffen Loth and Marcus Venzke and Dietmar Möller and Axel Husfeldt and Volker Turau and Christoph Meier},
title = {Car Management on Aprons (CARMA) - Developing Integrated Solutions for Vehicle Management at Mid-Size Airports},
booktitle = {Proceedings of the First International Workshop on Aircraft System Technologies (AST'07)},
pages = {257-266},
day = {29-30},
month = mar,
year = 2007,
location = {Hamburg, Germany},
}
Abstract:
The paper investigates the development of systems for vehicle management on airport aprons, using current A-SMGCS experiences, with a focus on fleet management and turn around processes of mid-size airports. An architecture is proposed that is derived from A-SMGCS, reducing cost by only supporting cooperative targets and off-the-shelf hardware. Available candidate technologies for implementing the architecture_s components are discussed, pointing out criteria for selection. Systems for vehicle management on aprons are important, because the continuous reductions of aircraft turn-around times increase the pressure on airports and ground handling companies to optimize infrastructure and resources.
N. I. Damm, Dietrich Fahrenholtz and Volker Turau. On Fluctuation Resilience of Second Generation Distributed Hash Tables. In Proceedings of the 15th ITG/GI - Fachtagung Kommunikation in verteilten Systemen (KiVS'07), February 2007, pp. 105–110. Bern, Switzerland.
@InProceedings{Telematik_DFT_2007_FluctuationResilience,
author = {N. I. Damm and Dietrich Fahrenholtz and Volker Turau},
title = {On Fluctuation Resilience of Second Generation Distributed Hash Tables},
booktitle = {Proceedings of the 15th ITG/GI - Fachtagung Kommunikation in verteilten Systemen (KiVS'07)},
pages = {105-110},
month = feb,
year = 2007,
location = {Bern, Switzerland},
}
Abstract:
Every Peer-to-Peer system destined for wide-spread use has to face the challenges imposed by peer population dynamics, which result from peers joining and leaving the system at their own discretion. So any Distributed Hash Table (DHT) design must take precautions against this peer population fluctuation (aka. churn) to sustain efficient lookup performance. Although important, an analysis of the influence of fluctuation on the performance of second generation DHTs in a unified attempt has not been done yet. An existing performance versus cost analysis by Li et al. aims at finding optimal parameters for DHTs being evaluated. However, their analysis focuses on one fluctuation scenario only. In this paper, we analyse second generation DHTs covering a wide range of topologies in a simulation framework under different fluctuation rates and evaluate their performance. Overall Kademlia attains the best lookup performance but its bandwidth consumption goes up significantly when increasing fluctuation rate. With a limited bandwidth budget and high fluctuation rate, Kelips lookup performance is the best among all examined DHTs.
Dietrich Fahrenholtz, Volker Turau and Andreas Wombacher. On Optimal Replication Group Splits in P2P Data Stores Based on the Hypercube. In Proceedings of the 15th ITG/GI - Fachtagung Kommunikation in Verteilten Systemen (KiVS'07), February 2007, pp. 155–162. Bern, Switzerland.
@InProceedings{Telematik_FTW_2007_ReplicationGroupHypercube,
author = {Dietrich Fahrenholtz and Volker Turau and Andreas Wombacher},
title = {On Optimal Replication Group Splits in P2P Data Stores Based on the Hypercube},
booktitle = {Proceedings of the 15th ITG/GI - Fachtagung Kommunikation in Verteilten Systemen (KiVS'07)},
pages = {155-162},
month = feb,
year = 2007,
location = {Bern, Switzerland},
}
Abstract:
P2P data stores excel if availability of inserted data items must be guaranteed. Their inherent mechanisms to counter peer population dynamics make them suitable for a wide range of application domains. This paper presents and analyzes the split maintenance operation of our P2P data store. The operation aims at reorganizing replication groups in case operation of them becomes suboptimal. To this end, we present a formal cost model that peers use to compute optimal points when to run performance optimizing maintenance. Finally, we present experimental results that validate our cost model by simulating various network conditions.
Volker Turau and Christoph Weyer. Randomized Self-stabilizing Algorithms for Wireless Sensor Networks. In Proceedings of the First International Workshop on Self-Organizing Systems (IWSOS'06), September 2006, pp. 74–89. Passau, Germany.
@InProceedings{Telematik_TW_2006_RandomizedSelfStabilizing,
author = {Volker Turau and Christoph Weyer},
title = {Randomized Self-stabilizing Algorithms for Wireless Sensor Networks},
booktitle = {Proceedings of the First International Workshop on Self-Organizing Systems (IWSOS'06)},
pages = {74-89},
day = {18-20},
month = sep,
year = 2006,
location = {Passau, Germany},
}
Abstract:
Wireless sensor networks (WSNs) pose challenges not present in classical distributed systems: resource limitations, high failure rates, and ad hoc deployment. The lossy nature of wireless communication can lead to situations, where nodes lose synchrony and programs reach arbitrary states. Traditional approaches to fault tolerance like replication or global resets are not feasible. In this work, the concept of self-stabilization is applied to WSNs. The majority of self-stabilizing algorithms found in the literature is based on models not suitable for WSNs: shared memory model, central daemon scheduler, unique processor identifiers, and atomicity. This paper proposes problem-independent transformations for algorithms that stabilize under the central daemon scheduler such that they meet the demands of a WSN. The transformed algorithms use randomization and are probabilistically self-stabilizing. This work allows to utilize many known self-stabilizing algorithms in WSNs. The proposed transformations are evaluated using simulations and a real WSN.
Matthias Witt and Volker Turau. The Impact of Location Errors on Geographic Routing in Sensor Networks. In Proceedings of the Second International Conference on Wireless and Mobile Communications (ICWMC'06), July 2006, pp. 76. Bucharest, Romania.
@InProceedings{Telematik_WT_2006_LocationErrorRouting,
author = {Matthias Witt and Volker Turau},
title = {The Impact of Location Errors on Geographic Routing in Sensor Networks},
booktitle = {Proceedings of the Second International Conference on Wireless and Mobile Communications (ICWMC'06)},
pages = 76,
day = {29-31},
month = jul,
year = 2006,
location = {Bucharest, Romania},
}
Abstract:
Geographic routing in wireless sensor networks is based on the prerequisite that every node has information about its current position, for instance via GPS or some localization algorithm. This location information has a certain degree of inaccuracy in real deployments. The majority of geographic routing algorithms, however, has been designed for nodes with exact position information. We show that location errors yield bad performance or even complete failures. Two elaborated geographic routing algorithms for sensor networks, GPSR and BGR, are evaluated with the nodes having inaccurate location information, varying the standard deviation of the position error between zero and the transmission range. Simulation studies show a vast decrease of the packet delivery ratio. To enhance both algorithms, fixes for them are presented to improve the delivery ratio and to save energy in case of location errors.
Volker Turau, Matthias Witt and Marcus Venzke. Field Trials with Wireless Sensor Networks: Issues and Remedies. In Proceedings of the Second International Conference on Wireless and Mobile Communications (ICWMC'06), July 2006, pp. 86. Bucharest, Romania.
@InProceedings{Telematik_TWV_2006_FieldTrialsWSN,
author = {Volker Turau and Matthias Witt and Marcus Venzke},
title = {Field Trials with Wireless Sensor Networks: Issues and Remedies},
booktitle = {Proceedings of the Second International Conference on Wireless and Mobile Communications (ICWMC'06)},
pages = 86,
day = {29-31},
month = jul,
year = 2006,
location = {Bucharest, Romania},
}
Abstract:
Extensive field trials are essential to evaluate protocols and algorithms for wireless sensor networks. The high costs of such trials demand for a systematic approach. This paper discusses the issues of setting up a field trial such as packaging, logging, and deployment. Details about a concrete field trial to evaluate a topology discovery algorithm are presented.
Volker Turau. Computing Bridges, Articulations, and 2-Connected Components in Wireless Sensor Networks. In Proceedings of the Second International Workshop on Algorithmic Aspects of Wireless Sensor Networks (ALGOSENSORS'06), July 2006, pp. 164–175. Venice, Italy.
@InProceedings{Telematik_TURAU_2006_ComputingBridgesUA,
author = {Volker Turau},
title = {Computing Bridges, Articulations, and 2-Connected Components in Wireless Sensor Networks},
booktitle = {Proceedings of the Second International Workshop on Algorithmic Aspects of Wireless Sensor Networks (ALGOSENSORS'06)},
pages = {164-175},
day = {15},
month = jul,
year = 2006,
location = {Venice, Italy},
}
Abstract:
This paper presents a simple distributed algorithm to determine the bridges, articulation points, and 2-connected components in asynchronous networks with an at least once message delivery semantics in time O(n) using O(lg n)-length messages. The algorithm does not assume a FIFO rule for message delivery. Previously known algorithms either use longer messages or need more time. The algorithm meets the requirements of wireless senor networks and can be applied in several areas relevant to this field such as topology control, clustering, localization and virtual backbone calculations.
Dietrich Fahrenholtz and Volker Turau. Improving Churn Resistance of P2P Data Stores Based on the Hypercube. In Proceedings of the the 5th International Symposium on Parallel and Distributed Computing (ISPDC'06), July 2006, pp. 263–270. Timisoara, Romania.
@InProceedings{Telematik_FT_2006_ImprovingChurnResistance,
author = {Dietrich Fahrenholtz and Volker Turau},
title = {Improving Churn Resistance of P2P Data Stores Based on the Hypercube},
booktitle = {Proceedings of the the 5th International Symposium on Parallel and Distributed Computing (ISPDC'06)},
pages = {263-270},
day = {6-9},
month = jul,
year = 2006,
location = {Timisoara, Romania},
}
Abstract:
P2P data stores as opposed to pure P2P networks display their special strength if availability of inserted data items must be guaranteed. Their inherent mech- anisms to counter peer population fluctuation, where peers continuously join or leave the network, make P2P data stores suitable for a wide range of application do- mains. This paper examines one of their maintenance operations called fusion. It reorganizes parts of our P2P data store in case the peer population shrinks so much that data availability is threatened. We present a formal cost model that is used to estimate the optimal point when a fusion is to be invoked. Finally, the paper presents experimental results showing our cost model is valid by simulating various network conditions.
Marcus Venzke, Peng Kong and Volker Turau. A Generic Java Interface for Vertical Integration of Wireless Sensor Networks. In Proceedings of the Fourth Workshop on Intelligent Solutions in Embedded Systems (WISES'06), June 2006. Vienna, Austria.
@InProceedings{Telematik_VKT_2006_VerticalIntegrationSensorNet,
author = {Marcus Venzke and Peng Kong and Volker Turau},
title = {A Generic Java Interface for Vertical Integration of Wireless Sensor Networks},
booktitle = {Proceedings of the Fourth Workshop on Intelligent Solutions in Embedded Systems (WISES'06)},
day = {30},
month = jun,
year = 2006,
location = {Vienna, Austria},
}
Abstract:
The paper presents a generic, high-level Java interface for the vertical integration of wireless sensor networks. The intuitive interfaces are implemented in a framework that is easy to use. The classes of the framework can be extended to meet the requirements of a wide range of applications. In particular, the framework supports sending packets to and receiving packets from nodes of the sensor network. Packet types are represented as Java classes generated from meta-data based on XML Schema. This approach fosters short development cycles and provides the productivity needed in vertical integration applications. The ScatterWeb platform is used as a sample platform for sensor networks.
Volker Turau, Matthias Witt and Christoph Weyer. Analysis of a Real Multi-hop Sensor Network Deployment: The Heathland Experiment. In Proceedings of the Third International Conference on Networked Sensing Systems (INSS'06), June 2006, pp. 6–13. Chicago, Illinois, USA.
@InProceedings{Telematik_TWW_2006_HeathlandDeployment,
author = {Volker Turau and Matthias Witt and Christoph Weyer},
title = {Analysis of a Real Multi-hop Sensor Network Deployment: The Heathland Experiment},
booktitle = {Proceedings of the Third International Conference on Networked Sensing Systems (INSS'06)},
pages = {6-13},
month = jun,
year = 2006,
location = {Chicago, Illinois, USA},
}
Abstract:
This paper reports on the results and experience gained during a real-world deployment of a sensor network based on the ESB platform in the heathlands of Northern Germany. The goal of the experiment was to gain a deeper insight into the problems of real deployments as opposed to simulated networks. The focus of the experiment was on the long- and short-term reliability of radio links, estimation of link qualities, the influence of the link quality on multi-hop routing, and on neighborhood exploration.
Volker Turau, Christian Renner, Marcus Venzke, Sebastian Waschik, Christoph Weyer and Matthias Witt. The Heathland Experiment: Results And Experiences. In Proceedings of the Workshop on Real-World Wireless Sensor Networks (REALWSN'05), June 2005. Stockholm, Sweden.
@InProceedings{Telematik_TRVWWW_2005_Heathland,
author = {Volker Turau and Christian Renner and Marcus Venzke and Sebastian Waschik and Christoph Weyer and Matthias Witt},
title = {The Heathland Experiment: Results And Experiences},
booktitle = {Proceedings of the Workshop on Real-World Wireless Sensor Networks (REALWSN'05)},
day = {20-21},
month = jun,
year = 2005,
location = {Stockholm, Sweden},
}
Abstract:
This paper reports on the experience gained during a real-world deployment of a sensor network based on the ESB platform in the heathlands of Northern Germany. The goal of the experiment was to gain a deeper insight into the problems of real deployments as opposed to simulated networks. The focus of this report is on the quality of radio links and the influence of the link quality on multi-hop routing.
Volker Turau, Dietrich Fahrenholtz and Marcus Venzke. Online Assessment for University Admission: Goals, Problems, and Experience. In Proceedings of the 9th International Computer Assisted Assessment Conference (CAA'05), June 2005, pp. 457–467. Loughborough, UK.
@InProceedings{Telematik_TFV_2005_OnlineAssessment,
author = {Volker Turau and Dietrich Fahrenholtz and Marcus Venzke},
title = {Online Assessment for University Admission: Goals, Problems, and Experience},
booktitle = {Proceedings of the 9th International Computer Assisted Assessment Conference (CAA'05)},
pages = {457-467},
day = {5-6},
month = jun,
year = 2005,
location = {Loughborough, UK},
}
Abstract:
This paper reports on the experience gained during the implementation and operation of an online assessment system for recruitment of engineering and computer science students. We identified problems that have to be solved to make online assessment a worthwhile building block of university admission. The presented work includes techniques for evaluating and monitoring online assessment processes.
Matthias Witt and Volker Turau. BGR: Blind Geographic Routing for Sensor Networks. In Proceedings of the Third Workshop on Intelligent Solutions in Embedded Systems (WISES'05), May 2005, pp. 51–61. Hamburg, Germany.
@InProceedings{Telematik_WT_2005_BGR,
author = {Matthias Witt and Volker Turau},
title = {BGR: Blind Geographic Routing for Sensor Networks},
booktitle = {Proceedings of the Third Workshop on Intelligent Solutions in Embedded Systems (WISES'05)},
pages = {51-61},
day = {20},
month = may,
year = 2005,
location = {Hamburg, Germany},
}
Abstract:
This paper introduces BGR, a new beacon-less geographic routing algorithm for wireless sensor networks. Data packets are forwarded toward the destination, and nodes which hear the packet compete for becoming the next hop. A recovery strategy is provided for the case of empty forwarding areas. The main innovation is a strategy to avoid simultaneous forwarding situations, which would otherwise cause packet failures. It is confirmed by simulation that BGR sends very few packets and is reliable in fields with sufficiently high node density. Furthermore, BGR is compared with similar algorithms after developing a general framework for beacon-less algorithms with an integrative terminology. Different kinds of forwarding areas are compared.
Marcus Venzke, Christoph Weyer and Volker Turau. Application Specific vs. Standard Web Service Interfaces for the Vertical Integration of Fieldbus Systems. In Proceedings of the Third Workshop on Intelligent Solutions in Embedded Systems (WISES'05), May 2005, pp. 153–162. Hamburg, Germany.
@InProceedings{Telematik_VWT_2005_WebService,
author = {Marcus Venzke and Christoph Weyer and Volker Turau},
title = {Application Specific vs. Standard Web Service Interfaces for the Vertical Integration of Fieldbus Systems},
booktitle = {Proceedings of the Third Workshop on Intelligent Solutions in Embedded Systems (WISES'05)},
pages = {153-162},
day = {20},
month = may,
year = 2005,
location = {Hamburg, Germany},
}
Abstract:
The paper compares two approaches for developing Web service interfaces for the vertical integration of TTP/A fieldbus systems. High-level abstractions are provided by application specific interfaces, generated from metadata describing fieldbus systems. In contrast standardised interfaces such as OPC XML DA only allow lower levels of abstractions. But these enable accessing the fieldbus system from a broad range of standard clients, while high-level abstractions reflecting the application programmer's view on the system facilitate the development of more specific clients and workflows.
Volker Turau and Christoph Weyer. Location-aware In-Network Monitoring in Wireless Sensor Networks. In Proceedings of the 34th Jahrestagung der Gesellschaft für Informatik e.V. (INFORMATIK'04), Volume 2, Workshop Sensor Networks, September 2004, pp. 355–359. Ulm, Germany.
@InProceedings{Telematik_TW_2004_InNetworkMonitoring,
author = {Volker Turau and Christoph Weyer},
title = {Location-aware In-Network Monitoring in Wireless Sensor Networks},
booktitle = {Proceedings of the 34th Jahrestagung der Gesellschaft für Informatik e.V. (INFORMATIK'04), Volume 2, Workshop Sensor Networks},
pages = {355-359},
day = {20-24},
month = sep,
year = 2004,
location = {Ulm, Germany},
}
Abstract:
This paper presents a data-centric and location-aware procedure to perform in-network evaluation of queries in sensor networks. The algorithm is a hybrid of geographic hash tables and in-network aggregation. It increases data availability and accounts for topology changes and generates mostly local network traffic.
Dietrich Fahrenholtz and Volker Turau. A Tree-based DHT Approach to Scalable Weakly Consistent Data Management. In Proceedings of the First International Workshop on P2P Data Management, Security and Trust (PDMST'04), IEEE Computer Society Press, August 2004, pp. 991–998. Zaragoza, Spain.
@InProceedings{Telematik_FT_2004_TreebasedDHT,
author = {Dietrich Fahrenholtz and Volker Turau},
title = {A Tree-based DHT Approach to Scalable Weakly Consistent Data Management},
booktitle = {Proceedings of the First International Workshop on P2P Data Management, Security and Trust (PDMST'04)},
pages = {991-998},
publisher = {IEEE Computer Society Press},
month = aug,
year = 2004,
location = {Zaragoza, Spain},
}
Volker Turau, Marcus Venzke, Christoph Weyer and Yesenia Vigil. Vertical Integration of TTP/A Fielbus Systems Using Web Services. In Proceedings of the First International Conference on Informatics in Control, Automation and Robotics (ICINCO'04), August 2004, pp. 390–393. Setubal, Portugal.
@InProceedings{Telematik_TVW_2004_VerticalIntegration,
author = {Volker Turau and Marcus Venzke and Christoph Weyer and Yesenia Vigil},
title = {Vertical Integration of TTP/A Fielbus Systems Using Web Services},
booktitle = {Proceedings of the First International Conference on Informatics in Control, Automation and Robotics (ICINCO'04)},
pages = {390-393},
month = aug,
year = 2004,
location = {Setubal, Portugal},
}
Abstract:
This paper presents a generic technique to expose data and control of fieldbus systems to applications located at the level of operational management. To provide a high degree of interoperability between the operational level and different fieldbus systems we utilize standardized techniques such as XML, HTTP, and Web services which can be deployed independently of the platform. The proposed service is based on the interface file system for TTP/A smart transducers. The defined interface provides high level abstractions appropriate for the integration into business applications and considers the latency introduced by the internet protocols.
Volker Turau, Marcus Venzke and Christoph Weyer. A Web Service for TTP/A Fieldbus Systems based on Meta-Data. In Proceedings of the Second Workshop on Intelligent Solutions in Embedded Systems (WISES'04), June 2004, pp. 159–168. Graz, Austria.
@InProceedings{Telematik_TVW_2004_MetaData,
author = {Volker Turau and Marcus Venzke and Christoph Weyer},
title = {A Web Service for TTP/A Fieldbus Systems based on Meta-Data},
booktitle = {Proceedings of the Second Workshop on Intelligent Solutions in Embedded Systems (WISES'04)},
pages = {159-168},
month = jun,
year = 2004,
location = {Graz, Austria},
}
Abstract:
This paper is concerned with the vertical integration of fieldbus systems. It presents a generic technique to expose data and control of fieldbus systems in a semantically rich way to applications located at the level of operational management. To provide a high degree of interoperability between the operational level and different fieldbus systems we utilize standardized techniques such as XML, HTTP, and Web services which can be deployed independently of the platform. The proposed service is based on the interface file system for TTP/A smart transducers. The defined interface provides high level abstractions appropriate for the integration into business applications and considers the latency introduced by the internet protocols. The operations of the service are automatically generated from meta-data descriptions of the smart transducers and their combination into larger clusters.
Volker Turau. Die Rolle von Web-Services im Middleware Spektrum. In Proceedings of the 26th European Congress Fair of Technical Communications (ONLINE'03), September 2003. Düsseldorf, Germany.
@InProceedings{Telematik_Turau_2003_WebServices,
author = {Volker Turau},
title = {Die Rolle von Web-Services im Middleware Spektrum},
booktitle = {Proceedings of the 26th European Congress Fair of Technical Communications (ONLINE'03)},
month = sep,
year = 2003,
location = {Düsseldorf, Germany},
}
Volker Turau. HTTPExplorer: Exploring the Hypertext Transfer Protocol. In Proceedings of the 8th Annual Conference Innovation and Technology in Computer Science Education (ITiCSE'03), July 2003. Thessaloniki, Greece.
@InProceedings{Telematik_Turau_2003_HTTPExplorer,
author = {Volker Turau},
title = {HTTPExplorer: Exploring the Hypertext Transfer Protocol},
booktitle = {Proceedings of the 8th Annual Conference Innovation and Technology in Computer Science Education (ITiCSE'03)},
month = jul,
year = 2003,
location = {Thessaloniki, Greece},
}
Volker Turau. A Caching System for Web Content Generated from XML Sources Using XSLT. In Proceedings of the OOIS 2002 Workshops on Advances in Object-Oriented Information Systems, Springer, September 2002, pp. 197–206. Montpellier, France.
@InProceedings{Telematik_Turau_2002_XSLTCache,
author = {Volker Turau},
title = {A Caching System for Web Content Generated from XML Sources Using XSLT},
booktitle = {Proceedings of the OOIS 2002 Workshops on Advances in Object-Oriented Information Systems},
pages = {197-206},
series = {Lecture Notes in Computer Science},
volume = {2426},
publisher = {Springer},
month = sep,
year = 2002,
location = {Montpellier, France},
}
Volker Turau. A framework for automatic generation of web-based data entry applications based on XML. In Proceedings of the 2002 ACM Symposium on Applied Computing, ACM, March 2002, pp. 1121–1126. Madrid, Spain.
@InProceedings{Telematik_Turau_2002_framework,
author = {Volker Turau},
title = {A framework for automatic generation of web-based data entry applications based on XML},
booktitle = {Proceedings of the 2002 ACM Symposium on Applied Computing},
pages = {1121-1126},
publisher = {ACM},
month = mar,
year = 2002,
location = {Madrid, Spain},
}
Albert Banchs, Wolfgang Effelsberg, Christian F. Tschudin and Volker Turau. Multicasting Multimedia Streams with Active Networks. In Proceedings of the 23rd Annual Conference on Local Computer Networks, October 1998, pp. 150–159. Lowell, MA , USA.
@InProceedings{Telematik_Turau_1998_multicast,
author = {Albert Banchs and Wolfgang Effelsberg and Christian F. Tschudin and Volker Turau},
title = {Multicasting Multimedia Streams with Active Networks},
booktitle = {Proceedings of the 23rd Annual Conference on Local Computer Networks},
pages = {150-159},
month = oct,
year = 1998,
location = {Lowell, MA , USA},
}
Weimin Chen and Volker Turau. An Optimized Implementation for VML Based on Pattern Matching and Dynamic Programming. In Proceedings of the 3rd International Conference on Information and Knowledge Management, ACM, December 1994, pp. 88–96. Gaithersburg, MD, USA.
@InProceedings{Telematik_Turau_1994_vml,
author = {Weimin Chen and Volker Turau},
title = {An Optimized Implementation for VML Based on Pattern Matching and Dynamic Programming},
booktitle = {Proceedings of the 3rd International Conference on Information and Knowledge Management},
pages = {88-96},
publisher = {ACM},
month = dec,
year = 1994,
location = {Gaithersburg, MD, USA},
}
Weimin Chen, Volker Turau and Wolfgang Klaas. Efficient Dynamic Look-Up Strategy for Multi-Methods. In Proceedings of the 8th European Conference on Object-Oriented Programming, Springer, July 1994, pp. 408–431. Bologna, Italy.
@InProceedings{Telematik_Turau_1994_efficient_lookup,
author = {Weimin Chen and Volker Turau and Wolfgang Klaas},
title = {Efficient Dynamic Look-Up Strategy for Multi-Methods},
booktitle = {Proceedings of the 8th European Conference on Object-Oriented Programming},
pages = {408-431},
series = {Lecture Notes in Computer Science},
volume = {821},
publisher = {Springer},
month = jul,
year = 1994,
location = {Bologna, Italy},
}
Volker Turau and Weimin Chen. GLB-Closures in Directed Acyclic Graphs and Their Applications. In Proceedings of the 20th International Workshop on Graph-Theoretic Concepts in Computer Science, Springer, June 1994, pp. 121–129. Herrsching, Germany.
@InProceedings{Telematik_Turau_1994_glb_closures,
author = {Volker Turau and Weimin Chen},
title = {GLB-Closures in Directed Acyclic Graphs and Their Applications},
booktitle = {Proceedings of the 20th International Workshop on Graph-Theoretic Concepts in Computer Science},
pages = {121-129},
series = {Lecture Notes in Computer Science},
volume = {903},
publisher = {Springer},
month = jun,
year = 1994,
location = {Herrsching, Germany},
}
Erich J. Neuhold, James Geller, Yehoshua Perl and Volker Turau. A Theoretical Underlying Dual Model for Knowledge-Based Systems. In Proceedings of the 1st International Conference on Systems Integration, IEEE Computer Society, April 1990, pp. 96–103. Morristown, NJ, USA.
@InProceedings{Telematik_Turau_1990_dual_model,
author = {Erich J. Neuhold and James Geller and Yehoshua Perl and Volker Turau},
title = {A Theoretical Underlying Dual Model for Knowledge-Based Systems},
booktitle = {Proceedings of the 1st International Conference on Systems Integration},
pages = {96-103},
publisher = {IEEE Computer Society},
month = apr,
year = 1990,
location = {Morristown, NJ, USA},
}
Horst Duschêne, Manfred Kaul and Volker Turau. VODAK Kernel Data Model. In Proceedings of the 2nd International Workshop on Object-Oriented Database Systems, Springer, September 1988, pp. 242–261. Bad Münster, Germany.
@InProceedings{Telematik_Turau_1988_vodak,
author = {Horst Duschêne and Manfred Kaul and Volker Turau},
title = {VODAK Kernel Data Model},
booktitle = {Proceedings of the 2nd International Workshop on Object-Oriented Database Systems},
pages = {242-261},
series = {Lecture Notes in Computer Science},
volume = {334},
publisher = {Springer},
month = sep,
year = 1988,
location = {Bad Münster, Germany},
}
Technical Reports
Stefan Lohs, Gerry Siegemund, Jörg Nolte and Volker Turau. Mission Statement: ToleranceZone A Self-Stabilizing Middleware for Wireless Sensor Netzworks. In Proceedings of the 11th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'12), September 2012. Darmstadt, Germany. To be published.
@InProceedings{Telematik_LSNT_2012_TZone_Mission,
author = {Stefan Lohs and Gerry Siegemund and Jörg Nolte and Volker Turau},
title = {Mission Statement: ToleranceZone A Self-Stabilizing Middleware for Wireless Sensor Netzworks},
booktitle = {Proceedings of the 11th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'12)},
day = {13-14},
month = sep,
year = 2012,
location = {Darmstadt, Germany},
}
Abstract:
Wireless sensor networks (WSN) can be used in a wide range of monitoring and controlling applications. These networks consist of nodes with sparse resources, which makes application implementation challenging. Therefore, many mid- dleware systems were developed in the last decade. Furthermore, unattended and long-living deployments of WSNs need fault-tolerant software architectures. The goal of the TOLERANCEZONE project is to design a self-stabilizing middleware, which supports the development of autonomously recovering and highly fault-tolerant WSN applications.
Stefan Unterschütz and Volker Turau. A Hybrid Testbed for a Seamless Combination of Wireless Sensor Networks and OMNeT++ Simulations. In Proceedings of the 11th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'12), September 2012. Darmstadt, Germany.
@InProceedings{Telematik_UT_2012_Testbed,
author = {Stefan Unterschütz and Volker Turau},
title = {A Hybrid Testbed for a Seamless Combination of Wireless Sensor Networks and OMNeT++ Simulations},
booktitle = {Proceedings of the 11th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'12)},
day = {13-14},
month = sep,
year = 2012,
location = {Darmstadt, Germany},
}
Helge Klimek, Björn Greßmann and Volker Turau. Report on Protocols for Resource Constrained Infrastructure Networks. Technical Report urn:nbn:de:gbv:830-tubdok-11642, Hamburg University of Technology, Hamburg, Germany, July 2012.
@TechReport{Klimek_Gressmann_Protocols-TechReport,
author = {Helge Klimek and Björn Greßmann and Volker Turau},
title = {Report on Protocols for Resource Constrained Infrastructure Networks},
number = {urn:nbn:de:gbv:830-tubdok-11642},
institution = {Hamburg University of Technology},
address = {Hamburg, Germany},
month = jul,
year = 2012,
}
Abstract:
This report introduces three protocols for communication in infrastructure networks consisting of a central server, stationary basestations and mobile devices. Mobile devices use IEEE 802.15.4 to communicate with the basestations. Among other things, the proposed protocols differ in their location management and in the routing of downlink and uplink packets. Through extensive simulations the protocols are compared with the focus on latency and packet loss metrics. The strength of each protocol depends on the traffic pattern caused by an application. The report concludes with a recommendation for the usage of each protocol.
Stefan Unterschütz and Volker Turau. Self-Stabilizing MAC Protocols for Large-Scale, Heavy Loaded Sensor Networks under Consideration of Hidden Nodes. Technical Report urn:nbn:de:gbv:830-tubdok-11639, Hamburg University of Technology, Hamburg, Germany, July 2012.
@TechReport{Unterschuetz_MAC-TechReport,
author = {Stefan Unterschütz and Volker Turau},
title = {Self-Stabilizing MAC Protocols for Large-Scale, Heavy Loaded Sensor Networks under Consideration of Hidden Nodes},
number = {urn:nbn:de:gbv:830-tubdok-11639},
institution = {Hamburg University of Technology},
address = {Hamburg, Germany},
month = jul,
year = 2012,
}
Abstract:
In large-scale, heavy loaded sensor networks the hidden node problem significantly restricts the attainable throughput. This paper examines this issue and depicts why most TDMA as well as dedicated hy- brid MAC protocols are still negatively affected by this phenomenon. The concept of probabilistic self-stabilization is adopted to provide a framework for implementable reservation MAC protocols that avoid packet loss caused by signal interferences even under high load. These protocols base upon two main primitives: continuity in channel access, allowing predictability, and acknowledgments, permitting to discover packet loss. The designed TDMA and CSMA protocols are able to cope with the hidden node problem and with topology changes and achieve a high throughput in a steady state. The protocols are simulated and compared with IEEE’s 802.15.4 unslotted CSMA/CA protocol.
Christian Renner, Stefan Unterschütz and Volker Turau. Power Management for Wireless Sensor Networks Based on Energy Budgets. Technical Report urn:nbn:de:gbv:830-tubdok-11065, Hamburg University of Technology, Hamburg, Germany, July 2011.
@TechReport{Renner_Unterschuetz_PowerManagement-TechReport,
author = {Christian Renner and Stefan Unterschütz and Volker Turau},
title = {Power Management for Wireless Sensor Networks Based on Energy Budgets},
number = {urn:nbn:de:gbv:830-tubdok-11065},
institution = {Hamburg University of Technology},
address = {Hamburg, Germany},
month = jul,
year = 2011,
}
Abstract:
This paper proposes and assesses analytical tools for large-scale monitoring applications with wireless sensor networks powered by energy-harvesting supplies. We introduce the concept of an energy budget, the amount of energy available to a sensor node for a given period of time. The presented tools can be utilized to realize distributed algorithms that determine a schedule to perform the monitoring task and the inherent communication. Scheduling is based on the energy budgets of the nodes or on latency requirements. In this context, we derive theoretical results for the energy consumption of the individual nodes plus the latency of event-reporting. These results are verified by simulations and a real testbed implementation.
Helge Klimek, Björn Greßmann and Volker Turau. Indoor Navigation and Location Based Services Scenario for Airports. Technical Report urn:nbn:de:gbv:830-tubdok-10856, Hamburg University of Technology, Hamburg, Germany, February 2011.
@TechReport{Telematik-Klick_Gressmann_Turau-INLBS-TechReport,
author = {Helge Klimek and Björn Greßmann and Volker Turau},
title = {Indoor Navigation and Location Based Services Scenario for Airports},
number = {urn:nbn:de:gbv:830-tubdok-10856},
institution = {Hamburg University of Technology},
address = {Hamburg, Germany},
month = feb,
year = 2011,
}
Abstract:
This report describes usage scenarios of the architecture for indoor navigation and location based services (INLBS) developed in the Airport2030 project. The expandable architecture offers a framework and predefined services with a runtime environment and aims at enabling ubiquitous INLBS in any building with the users’ mobile device. The architecture consists of a mobile user platform (MUP) installed on mobile devices and a stationary facility platform (SFP) which is running on backend servers. For communication between MUP and SFP a communication and positioning infrastructure (CPI) is used. The SFP abstracts from different mobile hardware and communication and ranging technologies for ease of development. A runtime environment contains the service container which invokes life cycle functionality of the different services. Applications which are accessed from the MUP are developed using the services in the service container.
Jürgen Jessen, Marcus Venzke and Volker Turau. Smart Energy Module for Wireless Sensor Nodes. In Proceedings of the 9th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'10), September 2010, pp. 9–12. Würzburg, Germany.
@InProceedings{Telematik_JVT_SmartEnergyModule,
author = {Jürgen Jessen and Marcus Venzke and Volker Turau},
title = {Smart Energy Module for Wireless Sensor Nodes},
booktitle = {Proceedings of the 9th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'10)},
pages = {9-12},
day = {16-17},
month = sep,
year = 2010,
location = {Würzburg, Germany},
}
Abstract:
This paper presents the design of a universal energy module for wireless sensor nodes, which supports a wide range of energy harvesters and energy storages. The focus is on the efficient conversion and storage of energy and to provide hardware support for higher level management functions. The module facilitates maximum power point tracking to improve the harvester efficiency. By supporting hybrid harvesters, the module can make better use of the time-dependent availability of environmental energy sources.
Sebastian Ernst, Christian Renner, Christoph Weyer and Volker Turau. Holistic Packet Statistics for Neighborhood Management in Sensor Networks. In Proceedings of the 9th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'10), September 2010, pp. 17–20. Würzburg, Germany.
@InProceedings{Telematik_ERWT_HoPS,
author = {Sebastian Ernst and Christian Renner and Christoph Weyer and Volker Turau},
title = {Holistic Packet Statistics for Neighborhood Management in Sensor Networks},
booktitle = {Proceedings of the 9th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'10)},
pages = {17-20},
day = {16-17},
month = sep,
year = 2010,
location = {Würzburg, Germany},
}
Abstract:
Knowledge of neighboring nodes is a fundamental requirement of many algorithms in the field of wireless sensor networks. The neighborhood relation of nodes is defined by their ability to communicate directly and not by their proximity. Due to the temporal changes of the wireless channel, link qualities must be continuously estimated. In this paper a new approach based on holistic packet statistics is presented. Unlike existing estimation techniques it forswears from squeezing a link's characteristics into a single value. The benefit of this approach is substantiated by an evaluation utilizing real-world and synthetic data.
Andreas Lagemann, Jörg Nolte, Christoph Weyer and Volker Turau. Mission Statement: Applying Self-Stabilization to Wireless Sensor Networks. In Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09), August 2009, pp. 47–49. Hamburg, Germany.
@InProceedings{Telematik_LNWT_2009_SelfWISE,
author = {Andreas Lagemann and Jörg Nolte and Christoph Weyer and Volker Turau},
title = {Mission Statement: Applying Self-Stabilization to Wireless Sensor Networks},
booktitle = {Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09)},
pages = {47-49},
day = {13-14},
month = aug,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
Long living and unattended deployments of wireless sensor networks requires fault-tolerant solutions. Self-stabilizing algorithms are providing these properties in an elegant and verifiable way. Recently, a lot of research has been performed to determine appropriate means to apply these promising technique to wireless sensor networks. In this paper the current state of the art in this field is given. Additionally, three major challenges are presented for achieving self-stabilizing sensor networks.
Christoph Weyer, Christian Renner, Volker Turau and Hannes Frey. A Roadmap for Hardware and Software Support for Developing Energy-Efficient Sensor Networks. In Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09), August 2009, pp. 67–70. Hamburg, Germany.
@InProceedings{Telematik_WRTF_2009_Roadmap,
author = {Christoph Weyer and Christian Renner and Volker Turau and Hannes Frey},
title = {A Roadmap for Hardware and Software Support for Developing Energy-Efficient Sensor Networks},
booktitle = {Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09)},
pages = {67-70},
day = {13-14},
month = aug,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
Support for developing energy-efficient applications for wireless sensor networks is still scarce. In this paper a roadmap of a combined hardware and software approach is presented. The main idea is to collect state information and trace energy consumption of an application running in a testbed of real sensor nodes.
Torsten Stremlau, Christoph Weyer and Volker Turau. tinyMoBot: A Platform for Mobile Sensor Networks. In Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09), August 2009, pp. 43–44. Hamburg, Germany.
@InProceedings{Telematik_SW_2009_LEGO,
author = {Torsten Stremlau and Christoph Weyer and Volker Turau},
title = {tinyMoBot: A Platform for Mobile Sensor Networks},
booktitle = {Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09)},
pages = {43-44},
day = {13-14},
month = aug,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
In many application scenarios of wireless sensor networks parts or the whole network consist of mobile sensor nodes. Currently, no common platform is available. This paper describes a project that has developed a mobile sensor node, based on standard components: a Crossbow IRIS mote and LEGO MINDSTORMS NXT components, i.e., motors and sensors.
Lars Niemann, Marcus Venzke, Christian Renner and Volker Turau. Clock Synchronization of TinyOS-based Sensor Networks with DCF77. In Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09), August 2009, pp. 45–46. Hamburg, Germany.
@InProceedings{Telematik_NVRT_2009_DCF77,
author = {Lars Niemann and Marcus Venzke and Christian Renner and Volker Turau},
title = {Clock Synchronization of TinyOS-based Sensor Networks with DCF77},
booktitle = {Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09)},
pages = {45-46},
day = {13-14},
month = aug,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
The paper presents an approach of applying DCF77 time radio signals to provide a clock with global time in sensor networks based on TinyOS. Some nodes containing DCF77 receiver hardware reliably decode time signals even if these are distorted to some extent. The clock with global time is provided by compensating clock drift. Time is distributed in the network with a protocol generating timestamps on the MAC layer.
Christian Renner, Jürgen Jessen and Volker Turau. Lifetime Prediction for Supercapacitor-powered Wireless Sensor Nodes. In Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09), August 2009, pp. 55–58. Hamburg, Germany.
@InProceedings{Telematik_RJT_2009_Supercap,
author = {Christian Renner and Jürgen Jessen and Volker Turau},
title = {Lifetime Prediction for Supercapacitor-powered Wireless Sensor Nodes},
booktitle = {Proceedings of the 8th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'09)},
pages = {55-58},
day = {13-14},
month = aug,
year = 2009,
location = {Hamburg, Germany},
}
Abstract:
Energy-aware task scheduling is a novel research direction for wireless sensor networks. It depends on accurate models for lifetime prediction. In other terms, nodes must be aware of present and future energy resources. This paper addresses the first step towards reaching this goal: It explores discharging-characteristics of supercapacitors, discusses analytical discharging-models for lifetime prediction, and evaluates these models by comparing them with real discharging curves.
Christoph Weyer, Stefan Unterschütz and Volker Turau. Connectivity-aware Neighborhood Management Protocol in Wireless Sensor Networks. In Proceedings of the 7th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'08), September 2008. Berlin, Germany.
@InProceedings{Telematik_WUT_2008_Mahalle,
author = {Christoph Weyer and Stefan Unterschütz and Volker Turau},
title = {Connectivity-aware Neighborhood Management Protocol in Wireless Sensor Networks},
booktitle = {Proceedings of the 7th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'08)},
day = {25-26},
month = sep,
year = 2008,
location = {Berlin, Germany},
}
Abstract:
Neighborhood relations are changing over time in wireless sensor networks due to different hardware or environmental effects. These effects and memory limitations require a balanced neighborhood management to ensure agility, stability, symmetry, and connectivity. The proposed neighborhood management protocol Mahalle is optimized with regard to these four criteria. Agility and stability are achieved by ALE, a new adaptive link estimator.
Matthias Witt and Volker Turau. Geographic Routing in 3D. In Proceedings of the 6th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'07), July 2007, pp. 75–78. Aachen, Germany.
@InProceedings{Telematik_WT_2007_3DRouting,
author = {Matthias Witt and Volker Turau},
title = {Geographic Routing in 3D},
booktitle = {Proceedings of the 6th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'07)},
pages = {75-78},
day = {16-17},
month = jul,
year = 2007,
location = {Aachen, Germany},
}
Abstract:
Existing geographic routing algorithms assume a two-dimensional topology. Dedicated wireless sensor network scenarios demand for algorithms that operate in three-dimensional environments. This paper discusses issues which arise when making the step from 2D to 3D. Simulation studies show that 3D routing is less efficient than its 2D counterpart when comparing topologies with the same average node degree.
Matthias Witt and Volker Turau. Delivery Semantics for Geographic Routing. In Proceedings of the 5th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'06), July 2006. Stuttgart, Germany.
@InProceedings{Telematik_WT_2006_DeliverySemantics,
author = {Matthias Witt and Volker Turau},
title = {Delivery Semantics for Geographic Routing},
booktitle = {Proceedings of the 5th GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'06)},
day = {17-18},
month = jul,
year = 2006,
location = {Stuttgart, Germany},
}
Abstract:
Geographic routing algorithms use locations rather than node addresses as destinations. But since it is not always guaranteed that there is indeed a node exactly at the destination location, there must exist a description which nodes shall be allowed to consume a message. In some cases, the message must not be consumed by a node at another location (e. g., if the sink is the destination), whereas in other cases, nodes in the vicinity may also consume it. This has to be chosen by the application, so the routing protocol should support different delivery semantics. Another question is if only one node may consume the message, or if multiple destination nodes are allowed. This paper proposes three orthogonal delivery parameters: closeness, multiplicity, and accept-outside.
Dietrich Fahrenholtz, Andreas Wombacher and Volker Turau. Performance of Lookup Operations in a Hypercube-based P2P Data Store : Theoretical Model and Performance Evaluation. Technical Report Report No. TR-2005-12-01, URN: urn:nbn:de:gbv:830-opus-1057, Hamburg University of Technology, Hamburg, Germany, December 2005.
@TechReport{Telematik_FWT_2005_LookupHypercube,
author = {Dietrich Fahrenholtz and Andreas Wombacher and Volker Turau},
title = {Performance of Lookup Operations in a Hypercube-based P2P Data Store : Theoretical Model and Performance Evaluation},
number = {Report No. TR-2005-12-01, URN: urn:nbn:de:gbv:830-opus-1057},
institution = {Hamburg University of Technology},
address = {Hamburg, Germany},
month = dec,
year = 2005,
}
Abstract:
One way for Peer-to-Peer data stores to achieve high data availability is to replicate their data. This is necessary to counter the effects of peer population dynamics also known as churn. A consequence of churn is that locating a data item may require a peer to resend search messages thus introducing additional communication. A formal model of this communication pertaining to data item lookups is introduced and evaluated using simulation in this paper. Results hold true for hypercube-based P2P data stores.
Matthias Witt, Christoph Weyer and Volker Turau. Monitoring Energy Consumption In Wireless Sensor Networks. In Proceedings oth the Fourth GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'05), March 2005. Zürich, Switzerland.
@InProceedings{Telematik_WWT_2005_Monitoring,
author = {Matthias Witt and Christoph Weyer and Volker Turau},
title = {Monitoring Energy Consumption In Wireless Sensor Networks},
booktitle = {Proceedings oth the Fourth GI/ITG KuVS Fachgespräch "Drahtlose Sensornetze" (FGSN'05)},
month = mar,
year = 2005,
location = {Zürich, Switzerland},
}
Abstract:
This note introduces an approach to monitor the consumption of energy in wireless sensor networks based on video streams composed from sequences of temperature maps. It is used to compare and evaluate beacon-less geographic routing algorithms.
Dietrich Fahrenholtz and Volker Turau. Fluctuation in Peer-to-Peer Networks: Mitigating Its Effect on DHT Performance. Technical Report Report arXiv:cs.NI/0406027 v1, arXiv.org e-Print archive, Cornell University, June 2004.
@TechReport{Telematik_FT_2004_P2PFluctuation,
author = {Dietrich Fahrenholtz and Volker Turau},
title = {Fluctuation in Peer-to-Peer Networks: Mitigating Its Effect on DHT Performance},
number = {Report arXiv:cs.NI/0406027 v1},
institution = {arXiv.org e-Print archive},
address = {Cornell University},
month = jun,
year = 2004,
}
Abstract:
Due to the transient nature of peers, any Peer-to-Peer network is in peril to falling apart if peers do not receive routing table updates periodically. To this end, maintenance, which affects every peer, ensures connectedness and sustained data operation performance. However, a high rate of change in peer population usually incurs lots of network maintenance messages and can severely degrade overall performance. We discuss three methods how to tackle and mitigate the effect of peer fluctuation on a tree-based distributed hash table.