This file was created by the TYPO3 extension bib --- Timezone: CEST Creation date: 2024-04-19 Creation time: 16-02-21 --- Number of references 39 article 2016-kunz-tomacs-horizon ACM Transactions on Modeling and Computer Simulation (TOMACS) 2016 1 26 2 12:1--12:26 The technical evolution of wireless communication technology and the need for accurately modeling these increasingly complex systems causes a steady growth in the complexity of simulation models. At the same time, multi-core systems have become the de facto standard hardware platform. Unfortunately, wireless systems pose a particular challenge for parallel execution due to a tight coupling of network entities in space and time. Moreover, model developers are often domain experts with no in-depth understanding of parallel and distributed simulation. In combination, both aspects severely limit the performance and the efficiency of existing parallelization techniques. We address these challenges by presenting parallel expanded event simulation, a novel modeling paradigm that extends discrete events with durations which span a period in simulated time. The resulting expanded events form the basis for a conservative synchronization scheme that considers overlapping expanded events eligible for parallel processing. We furthermore put these concepts into practice by implementing Horizon, a parallel expanded event simulation framework specifically tailored to the characteristics of multi-core systems. Our evaluation shows that Horizon achieves considerable speedups in synthetic as well as real-world simulation models and considerably outperforms the current state-of-the-art in distributed simulation. Parallel discrete event simulation, Multi-core Systems, Wireless Systems, Simulation Modeling Paradigm, Conservative Synchronization horizon ACM en 10.1145/2832909 1 GeorgKunz MirkoStoffers OlafLandsiedel KlausWehrle JamesGross article 2012-4-alizai-wild-ijdsn International Journal of Distributed Sensor Networks (IJDSN) 2012 4 2 wld fileadmin/papers/2012/2012-ijdsn-wld-alizai.pdf unpublished en 1550-1329 1 Muhammad HamadAlizai OlafLandsiedel KlausWehrle inproceedings 2011-ipsn-alizai-pad 2011 4 fileadmin/papers/2011/2011-ipsn-alizai-pad.pdf Online ACM

New York, NY, USA

Proceedings of the 10th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN 2011), Chicago, IL, USA Chicago, IL, USA en 978-1-60558-988-6 1 Muhammad HamadAlizai TobiasVaegs OlafLandsiedel StefanGötz Jó AgilaBitsch Link KlausWehrle inproceedings 2010-kunz-mascots-horizon 2010 8 18 172-181 The simulation models of wireless networks rapidly increase in complexity to accurately model wireless channel characteristics and the properties of advanced transmission technologies. Such detailed models typically lead to a high computational load per simulation event that accumulates to extensive simulation runtimes. Reducing runtimes through parallelization is challenging since it depends on detecting causally independent events that can execute concurrently. Most existing approaches base this detection on lookaheads derived from channel propagation latency or protocol characteristics. In wireless networks, these lookaheads are typically short, causing the potential for parallelization and the achievable speedup to remain small. This paper presents Horizon, which unlocks a substantial portion of a simulation model's workload for parallelization by going beyond the traditional lookahead. We show how to augment discrete events with durations to identify a much larger horizon of independent simulation events and efficiently schedule them on multi-core systems. Our evaluation shows that this approach can significantly cut down the runtime of simulations, in particular for complex and accurate models of wireless networks. horizon fileadmin/papers/2010/2010-kunz-mascots-horizon.pdf Online IEEE Computer Society

Los Alamitos, CA, USA

Proceedings of the 18th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS'10), Miami, FL, USA Miami, FL, USA 18th Annual Meeting of the IEEE/ACM International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS'10) August 17-19, 2010 en 978-0-7695-4197-6 1526-7539 10.1109/MASCOTS.2010.26 1 GeorgKunz OlafLandsiedel JamesGross StefanGötz FarshadNaghibi KlausWehrle inproceedings 2010-ipsn-sasnauskas-kleenet 2010 4 12 186--196 Complex interactions and the distributed nature of wireless sensor networks make automated testing and debugging before deployment a necessity. A main challenge is to detect bugs that occur due to non-deterministic events, such as node reboots or packet duplicates. Often, these events have the potential to drive a sensor network and its applications into corner-case situations, exhibiting bugs that are hard to detect using existing testing and debugging techniques. In this paper, we present KleeNet, a debugging environment that effectively discovers such bugs before deployment. KleeNet executes unmodified sensor network applications on symbolic input and automatically injects non-deterministic failures. As a result, KleeNet generates distributed execution paths at high-coverage, including low-probability corner-case situations. As a case study, we integrated KleeNet into the Contiki OS and show its effectiveness by detecting four insidious bugs in the uIP TCP/IP protocol stack. One of these bugs is critical and lead to refusal of further connections. automated protocol testing, experimentation, failure detection, wireless sensor networks kleenet fileadmin/papers/2010/2010-04-ipsn-sasnauskas-KleeNet.pdf Print ACM

New York, NY, USA

Proceedings of the 9th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN 2010), Stockholm, Sweden en 978-1-60558-988-6 http://doi.acm.org/10.1145/1791212.1791235 1 RaimondasSasnauskas OlafLandsiedel Muhammad HamadAlizai CarstenWeise StefanKowalewski KlausWehrle inproceedings 20104-IPSN-alizai-svr 2010 4 12 366-367 We present Statistical Vector Routing (SVR), a protocol that efficiently deals with communication link dynamics in wireless networks. It assigns virtual coordinates to nodes based on the statistical distribution of their distance from a small set of beacons. The distance metric predicts the current location of a node in its address distribution. Our initial results from a prototype implementation over real testbeds demonstrate the feasibility of SVR. wld https://www.comsys.rwth-aachen.de/fileadmin/papers/2010/2010-alizai-ipsn-pad.pdf http://portal.acm.org/citation.cfm?id=1791257 Print ACM

New York, NY, USA

Proceedings of the 9th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN 2010), Stockholm, Sweden Stockholm, Sweden 9th ACM/IEEE International Conference on Information Processing in Sensor Networks (IPSN 2010) April 12-16, 2010 en 978-1-60558-988-6 1 Muhammad HamadAlizai TobiasVaegs OlafLandsiedel RaimondasSasnauskas KlausWehrle incollection 2010-kunz-simtools-deployments 2010 4 83-97 Print Klaus Wehrle and Mesut Günes and James Gross Springer

Berlin, Germany

6 Modeling and Tools for Network Simulation en 978-3-642-12330-6 1 GeorgKunz OlafLandsiedel GeorgWittenburg inbook 2010-02-book-alizai-hardware-and-systems 2010 2 1 99-117 http://www.network-simulation.info/ http://www.amazon.com/Modeling-Tools-Network-Simulation-Wehrle/dp/3642123309 Print Springer LNCS Chapter 7 Modeling and Tools for Network Simulation EN 978-3-642-12330-6 Muhammad HamadAlizai LeiGao TorstenKempf OlafLandsiedel inproceedings 20105munawardynamictinyos 2010 1-6 Long-term deployments of sensor networks in physically inaccessible environments make remote re-programmability of sensor nodes a necessity. Ranging from full image replacement to virtual machines, a variety of mechanisms exist today to deploy new software or to fix bugs in deployed systems. However, TinyOS - the current state of the art sensor node operating system - is still limited to full image replacement as nodes execute a statically-linked system-image generated at compilation time. In this paper we introduce Dynamic TinyOS to enable the dynamic exchange of software components and thus incrementally update the operating system and its applications. The core idea is to preserve the modularity of TinyOS, i.e. its componentization, which is lost during the normal compilation process, and enable runtime composition of TinyOS components on the sensor node. The proposed solution integrates seamlessly into the system architecture of TinyOS: It does not require any changes to the programming model of TinyOS and existing components can be reused transparently. Our evaluation shows that Dynamic TinyOS incurs a low performance overhead while keeping a smaller - upto one third - memory footprint than other comparable solutions. fileadmin/papers/2010/2010-05-icc-munawar-DynamicTinyOS.pdf Online IEEE Proceedings of the IEEE International Conference on Communications (ICC), Cape Town, South Africa en 978-1-4244-6402-9 1550-3607 1 WaqaasMunawar Muhammad HamadAlizai OlafLandsiedel KlausWehrle inproceedings 2010-ARCS-alizai-promotingpower 2010 387-392 Accurate prediction of energy consumption early in the design process is essential to efficiently optimize algorithms and protocols. However, despite energy efficiency gathering significant attention in networking research, limited effort has been invested in providing requisite evaluation tools and models. Hence, developers demand powerful evaluation tools to assist them in comparing new communication paradigms in terms of energy efficiency, and minimizing the energy requirements of algorithms. In this paper, we argue for promoting energy to a first class metric in network simulations. We explore the challenges involved in modelling energy in network simulations and present a detailed analysis of different modelling techniques. Finally, we discuss their applicability in high-level network simulations. fileadmin/papers/2010/2010-2-ARCS-alizai-promoting-power.pdf Print VDE-VERLAG

Berlin, Germany

Proceedings of the Workshop on Energy Aware Systems and Methods, in conjunction with GI/ITG ARCS 2010 Hannover, Feb. 21-23 en 978-3-8007-3222-7 1 Muhammad HamadAlizai GeorgKunz OlafLandsiedel KlausWehrle phdthesis 2010-landsiedel-phd 2010 RWTH Aachen University OlafLandsiedel inproceedings 2009-sensys-alizai-burstytraffic 2009 11 71-84 wld fileadmin/papers/2009/2009-alizai-sensys-bre.pdf ACM

New York, NY, USA

Proceeding of 7th ACM Conference on Embedded Networked Sensor Systems (Sensys 09), Berkeley, CA, USA Berkley, California Sensys 09 November 2009 en 978-1-60558-519-2 1 Muhammad HamadAlizai OlafLandsiedel Jó AgilaBitsch Link StefanGötz KlausWehrle inproceedings 2009-kunz-mascots-horizon 2009 9 21 575-577 This paper presents Horizon, an extension to network simulation that enables the efficient and detailed simulation of wireless networks. Our contributions are two-fold as Horizon provides i) an API for accurately modeling processing time of discrete event simulation models by augmenting events with time spans and ii) a lightweight parallelization scheme that utilizes timing information to guide the parallel execution of simulations on multi-core computers. In this paper we primarily focus on the latter. horizon fileadmin/papers/2009/2009-kunz-mascots-horizon.pdf Poster Online IEEE Computer Society

Los Alamitos, CA, USA

Proceedings of the 17th Annual Meeting of the IEEE International Symposium on Modelling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS'09), London, UK London, Great Britain 17th Annual Meeting of the IEEE International Symposium on Modelling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS'09) September 21-32, 2009 en 978-1-4244-4926-2 1526-7539 10.1109/MASCOT.2009.5366710 1 GeorgKunz OlafLandsiedel KlausWehrle techreport 200908munawarfgsndynamictinyos 2009 9 9-12 fileadmin/papers/2009/2009-08-munawar-fgsn-dynamic-tinyos.pdf http://doku.b.tu-harburg.de/volltexte/2009/581/pdf/proceedings.pdf Print Technical University Hamburg

Technical University Hamburg

Proceedings of the 8th GI/ITG KuVS Fachgespräch "Wireless Sensor Networks", Hamburg, Germany Technical University Hamburg en WaqaasMunawar OlafLandsiedel Muhammad HamadAlizai KlausWehrle techreport 200908alizaifgsnburstyrouting 2009 9 63-66 Accurate estimation of link quality is the key to enable efficient routing in wireless sensor networks. Current link estimators focus mainly on identifying long-term stable links for routing, leaving out a potentiality large set of intermediate links offering significant routing progress. Fine-grained analysis of link qualities reveals that such intermediate links are bursty, i.e., stable in the short term. In this paper, we use short-term estimation of wireless links to accurately identify short-term stable periods of transmission on bursty links. Our approach allows a routing protocol to forward packets over bursty links if they offer better routing progress than long-term stable links. We integrate a Short Term Link Estimator and its associated routing strategy with a standard routing protocol for sensor networks. Our evaluation reveals an average of 22% reduction in the overall transmissions when routing over long-range bursty links. Our approach is not tied to any special routing protocol and integrates seamlessly with existing routing protocols and link estimators. wld fileadmin/papers/2009/2009-08-alizai-fgsn-bursty-routing.pdf doku.b.tu-harburg.de/volltexte/2009/581/pdf/proceedings.pdf Print Technical University Hamburg

Technical University Hamburg

Proceedings of the 8th GI/ITG KuVS Fachgespräch "Wireless Sensor Networks", Hamburg, Germany en 1 Muhammad HamadAlizai OlafLandsiedel Jó AgilaBitsch Link StefanGötz KlausWehrle inproceedings 2009-landsiedel-visa-vipe 2009 8 17 45--52 Although the diversity of platforms for network experimentation is a boon to the development of protocols and distributed systems, it is challenging to exploit its benefits. Implementing or adapting the systems under test for such heterogeneous environments as network simulators, network emulators, testbeds, and end systems is immensely time and work intensive. In this paper, we present VIPE, a unified virtual platform for network experimentation, that slashes the porting effort. It allows to smoothly evolve a single implementation of a distributed system or protocol from its design up into its deployment by leveraging any form of network experimentation tool available. deployment, network experimentation, resource virtualization, simulation fileadmin/papers/2009/2009-landsiedel-visa-vipe.pdf Print ACM Press

New York, NY, USA

Proceedings of the 1st ACM SIGCOMM Workshop on Virtualized Infastructure Systems and Architectures, Barcelona, Spain Barcelona, Spain 1st ACM SIGCOMM Workshop on Virtualized Infastructure Systems and Architectures August 17, 2009 en 978-1-60558-595-6 10.1145/1592648.1592657 1 OlafLandsiedel GeorgKunz StefanGötz KlausWehrle poster 2009-kunz-nsdi-profab 2009 4 22 fileadmin/papers/2009/2009-kunz-nsdi-protocolFactory.pdf Poster Online USENIX Association

Berkeley, CA, USA

6th USENIX Symposium on Networked Systems Design and Implementation (NSDI'09) en 1 GeorgKunz OlafLandsiedel StefanGötz KlausWehrle article 2009AlizaiPIKtimingenergy PIK Journal, Special Issue on Energy Aware Systems 2009 2 32 2 127-132 fileadmin/papers/2009/2009-2-alizai-modeling-energy.pdf Print en 0930-5157 1 Muhammad HamadAlizai OlafLandsiedel KlausWehrle techreport 2008-fgsn-alizai-stle 2008 7 27-30 wld fileadmin/papers/2008/2008-08-alizai-fgsn-stle.pdf ftp://ftp.inf.fu-berlin.de/pub/reports/tr-b-08-12.pdf Print Fachbereich Mathematik und Informatik

Berlin, Germany

Proceedings of the 7th GI/ITG Workshop on Wireless Sensor Networks FGSN 08 September 2010 en 1 Muhammad HamadAlizai OlafLandsiedel KlausWehrle AlexanderBecher inproceedings 2008-becher-hotemnets-linkestimation 2008 6 3 1--5 Commonly, routing in sensor networks is limited to longterm stable links. Unstable links, although often promising to be of large routing progress, are not considered for packet forwarding as link estimators typically cannot handle their dynamics. In this paper we introduce short-term link estimation to capture link dynamics at a high resolution in time and to identify when these render a link temporarily reliable or unreliable. We identify such dynamics based on packet overhearing, predict short-term availability and unavailability, and adapt neighbor tables, thereby enlarging the set of links useable by any routing algorithm. Additionally, we show that short-term link estimation integrates seamlessly into today's sensor network link estimators and routing protocols. wld fileadmin/papers/2008/2008-becher-hotemnets-linkestimation.pdf Online ACM Press

New York, NY, USA

Proceedings of Fifth Workshop on Embedded Networked Sensors (Hot EmNets'08), Charlottesville, VA, USA Chalottesville, USA Fifth Workshop on Embedded Networked Sensors (Hot EmNets'08) June 2-3, 2008 en 978-1-60558-209-2 1 AlexanderBecher OlafLandsiedel GeorgKunz KlausWehrle inproceedings 200804landsiedelIPSN08TimingMatters 2008 344-354 The rising complexity of data processing algorithms in sensor networks combined with their severely limited computing power necessitates an in-depth understanding of their temporal behavior. However, today only cycle accurate emulation and test-beds provide a detailed and accurate insight into the temporal behavior of sensor networks. In this paper we introduce fine grained, automated instrumentation of simulation models with cycle counts derived from sensor nodes and application binaries to provide detailed timing information. The presented approach bridges the gap between scalable but abstracting simulation and cycle accurate emulation for sensor network evaluation. By mapping device-specific code with simulation models, we can derive the time and duration a certain code line takes to get executed on a sensor node. Hence, eliminating the need to use expensive instruction-level emulators with limited speed and restricted scalability. Furthermore, the proposed design is not bound to a specific hardware platform, a major advantage compared to existing emulators. Our evaluation shows that the proposed technique achieves a timing accuracy of 99% compared to emulation while adding only a small overhead. Concluding, it combines essential properties like accuracy, speed and scalability on a single simulation platform. fileadmin/papers/2008/2008-04-IPSN-2008-landsiedel-Timing-Matters.pdf Print IEEE Computer Society

Washington, DC, USA

Proceedings of the 7th ACM International Conference on Information Processing in Sensor Networks (IPSN 2008), St. Louis, MO, USA en 978-0-7695-3157-1 1 OlafLandsiedel Muhammad HamadAlizai KlausWehrle techreport 2007-fgsn-alizai-timetossim 2007 7 fileadmin/papers/2008/2007-07-fgsn-alizai-accurate-timing.pdf https://www.ds-group.info/events/fgsn07/fgsn07proc.pdf Print RWTH Aachen

Aachen, Germany

Proceedings of the 6th GI/ITG KuVS Workshop on Wireless Sensor Networks (FGSN 07) RWTH Aachen Aachen, Germany FGSN 07 July 2007 en Muhammad HamadAlizai OlafLandsiedel KlausWehrle article LandsiedelEtAl2007 Special Issue on Peer-to-Peer of the it - Information Technology Journal 2007 49 5 298-303 Mobile ad-hoc networks and distributed hash tables share key characteristics in terms of self organization, decentralization, redundancy requirements, and limited infrastructure. However, node mobility and the continually changing physical topology pose a special challenge to scalability and the design of a DHT for mobile ad-hoc networks. In this paper, we show that with some local knowledge we can build a scalable and mobile structured peer-to-peer network, called Mobile Hash Table (MHT). Furthermore, we discuss practical challenges such as Churn, load balacing and security of the Mobile Hash Table. A special focus is put on the differences and new challenges that the use of a DHT in a mobile environment poses. http://it-Information-Technology.de Print Oldenbourg Verlag

Munich, Germany

en 1611-2776 1 OlafLandsiedel TobiasHeer KlausWehrle inbook 2007landsiedelwsnalgpseudo 2007 203-213 http://www.springer.com/computer/communications/book/978-3-540-74990-5 Dorothea Wagner, Roger Wattenhofer Springer Lecture Notes in Computer Science, Theoretical Computer Science and General Issues 11 Algorithms for Sensor and Ad-Hoc Networks OlafLandsiedel conference 200711Globecom2007Landsiedelmultipathonionrouting 2007 Although recent years provided many protocols for anonymous routing in overlay networks, they commonly rely on the same communication paradigm: Onion Routing. In Onion Routing a static tunnel through an overlay network is build via layered encryption. All traffic exchanged by its end points is relayed through this tunnel.In contrast, this paper introduces dynamic multipath Onion Routing to extend the static Onion Routing paradigm. This approach allows each packet exchanged between two end points to travel along a different path. To provide anonymity the first half of this path is selected by the sender and the second half by the receiver of the packet. The results are manifold: First, dynamic multipath Onion Routing increases the resilience against threats, especially pattern and timing based analysis attacks. Second, the dynamic paths reduce the impact of misbehaving and overloaded relays. Finally, inspired by Internet routing, the forwarding nodes do not need to maintain any state about ongoing flows and so reduce the complexity of the router. In this paper, we describe the design of our dynamic Multipath Onion Router (MORE) for peer-to-peer overlay networks, and evaluate its performance. Furthermore, we integrate address virtualization to abstract from Internet addresses and provide transparent support for IP applications. Thus, no application-level gateways, proxies or modifications of applications are required to sanitize protocols from network level information. Acting as an IP-datagram service, our scheme provides a substrate for anonymous communication to a wide range of applications using TCP and UDP. IEEE Global Communication Conference (GlobeCom), Washington D.C. OlafLandsiedel AlexisPimenidis KlausWehrle HeikoNiedermayer GeorgCarle inproceedings 200706juriFGSN07platform 2007

Aachen, Germany

Proceedings of 6th GI/ITG KuVS Fachgespräch "Wireless Sensor Networks" JuriSaragazki OlafLandsiedel KlausWehrle inproceedings 200707SchmidtFGSN07composition 2007

Aachen, Germany

Proceedings of 6th GI/ITG KuVS Fachgespräch "Wireless Sensor Networks", Aachen StefanSchmitz OlafLandsiedel KlausWehrle inproceedings 200606LandsiedelRatWatch 2006 6 19 1 1--2 In an attempt to employ sensor network technology for animal observation, in particular of wild rats, we identified several restrictive shortcomings in existing sensor network research, which we discuss in this paper. (Poster and Abstract) RatPack fileadmin/papers/2006/2006-06-Landsiedel-RatWatch.pdf http://www.sics.se/realwsn06/program.html Online Pedro José Marron and Thiemo Voigt SICS

Uppsala, Sweden

ACM Workshop on Real-World Wireless Sensor Networks (RealWSN) in conjunction with ACM MobiSys, Uppsala, Sweden ACM Uppsala, Sweden ACM Workshop on Real-World Wireless Sensor Networks, REALWSN'06 June 19, 2006 en 1 OlafLandsiedel Jó AgilaBitsch Link KlausWehrle JohannesThiele HanspeterMallot inproceedings 200602LandsiedelEWSNModularSN 2006 2 13 507 22 -- 23 In this paper we present our ongoing work on modular communication protocols for sensor networks. Their modularity allows recomposing a protocol dynamically at runtime and adapting it to the changing needs of a sensor network. Compared to existing work, our componentization is fine grained and protocol independent, enabling a high degree of component reusability. (Poster and Abstract) fileadmin/papers/2006/2006-02-Landsiedel-EWSN-ModularSN.pdf ftp://ftp.inf.ethz.ch/pub/publications/tech-reports/5xx/507.pdf Technical Report Online Kay Römer and Holger Karl and Friedemann Matterns Department of Computer Science, ETH Zurich

Zurich, Switzerland

Technical Report ETH Zurich / Dept. of Computer Science European Workshop on Wireless Sensor Networks (EWSN 2006), Zurich Switzerland EWSN Zurich, Switzerland 3rd European Workshop on Wireless Sensor Networks (EWSN 2006) February 13-15, 2006 en 1 OlafLandsiedel Jó AgilaBitsch Link KatharinaDenkinger KlausWehrle conference 200607landsiedelfgsnmodular 2006 In an attempt to employ sensor network technology for animal observation, in particular of wild rats, we identified several restrictive shortcomings in existing sensor network research. In this paper, we present modular and flexible communication protocols as an efficient substrate to address these shortcomings. Their modularity allows recomposing a protocol dynamically at runtime and adapting it to the changing needs of a deployed sensor network. 5th GI/ITG KuVS Fachgespräch "Wireless Sensor Networks", Stuttgart, Germany OlafLandsiedel KlausWehrle conference 200607landsiedelngimodels 2006 In this talk we discuss the increasing need for flexible and modular simulation models and our ongoing work in this area. Although a huge number of simulation models are available today, these models do not interoperate and cannot be easily combined to form a full protocol simulation stack. Visions of Future Generation Networks, Würzburg, Germany OlafLandsiedel LeoPetrak KlausWehrle inproceedings 200608landsiedelp2p06scalablemobility 2006 203-209 For the use in the Internet domain, distributed hash tables (DHTs) have proven to be an efficient and scalable approach to distributed content storage and access. In this paper, we explore how DHTs and mobile ad-hoc networks (MANETs) fit together. We argue that both share key characteristics in terms of self organization, decentralization, redundancy requirements, and limited infrastructure. However, node mobility and the continually changing physical topology pose a special challenge to scalability and the design of a DHT for mobile ad-hoc networks. In this paper, we show that with some local knowledge we can build a scalable and mobile structured peer-to-peer network, called Mobile Hash Table (MHT). Furthermore, we argue that with little global knowledge, such as a map of the city or whatever area the nodes move in, one can even further improve the scalability and reduce DHT maintenance overhead significantly, allowing MHT to scale up to several ten thousands of nodes. https://www.comsys.rwth-aachen.de/fileadmin/papers/2006/2006-landsiedel-p2p-mobility.pdf print IEEE

Washington, DC, USA

print Proceedings of the Sixth IEEE International Conference on Peer-to-Peer Computing (P2P'06), Cambridge, UK IEEE Cambridge, UK Sixth IEEE International Conference on Peer-to-Peer Computing (P2P'06) 2006-09-06 en 0-7695-2679-9 10.1109/P2P.2006.46 1 OlafLandsiedel StefanGötz KlausWehrle inproceedings landsiedel2005anonymous 2005 3 Although research provides anonymous Internet communication schemes, anonymous IP-services received only limited attention. In this paper we present SARA (Anonymous Overlay Routing Providing Sender And Receiver Anonymity), which enables sender, receiver and relationship anonymity using layered encryption and distributed traffic mixes, similar to a Chaumian Mix. Via IP-datagram service and address virtualization it is fully transparent to applications. Organized as structured Peer-To-Peer system, SARA is highly scalable and fault tolerant. In SARA each communication partner randomly selects a number of nodes from the overlay and concatenates them to an anonymous communication path. The sender selects the head of the path, the receiver builds the tail and publishes this information in the overlay network using an anonymous ID. Via this ID the sender retrieves the tail nodes of the path and concatenates both path section. Layered encryption hides the identities of the sender, receiver and the intermediate nodes. 5. Würzburger "Workshop IP Netzmanagement, IP Netzplanung und Optimierung" Würzburg, Germany 5. Würzburger "Workshop IP Netzmanagement, IP Netzplanung und Optimierung" March 2005 OlafLandsiedel SimonRieche HeikoNiedermayer KlausWehrle GeorgCarle article 200504landsiedelpikenergy Special Issue on Sensor Networks, PIK Journal 2005 28 2 Simulation is the de-facto standard tool for the evaluation of distributed and communication systems like sensor networks. Most simulation efforts focus on protocol- and algorithm-level issues, thus depending on the right choice and configuration of models. However, as such models commonly neglect time dependent issues, many research challenges, like energy consumption and radio channel utilization still remain. In this article we present two new tools to model and analyze sensor networks: Avrora, a fast and accurate sensor network simulator, and AEON, a novel tool built on top of Avrora, to evaluate the energy consumption and to accurately predict the lifetime of sensor networks. Avrora is a highly scalable instruction-level simulator for sensor network programs. It simulates the execution of the program down to the level of individual clock cycles, a time quantum of about 135 ns. By incorporating state of the art simulation techniques, including an efficiently maintained event queue, fast-forward through sleep-time, and parallel simulation, it can simulate entire networks of nodes in real time. AEON's energy model is based on Avrora and makes use of the cycle accurate execution of sensor node applications for precise energy measurements. Due to limited energy resources, power consumption is a crucial characteristic of sensor networks. AEON uses accurate measurements of node current draw and the execution of real code to enable accurate prediction of the actual power consumption of sensor nodes. Consequently, it prevents erroneous assumptions on node and network lifetime. Moreover, our detailed energy model allows to compare different low power and energy aware approaches in terms of energy efficiency. Thus, it enables a highly precise estimation of the overall lifetime of a sensor network. OlafLandsiedel KlausWehrle Ben LTitzer JensPalsberg conference 200509petraksoftcommobility 2005 Proceedings of the 2005 Conference on Software for Communication Systems and Computer Networks LeoPetrak OlafLandsiedel KlausWehrle conference 200509landsiedelp2ptdht 2005 In this paper, we introduce topology-based distributed hash tables (T-DHT) as an infrastructure for data-centric storage, information processing, and routing in ad hoc and sensor networks. T-DHTs do not rely on location information and work even in the presence of voids in the network. Using a virtual coordinate system, we construct a distributed hash table which is strongly oriented to the underlying network topology. Thus, adjacent areas in the hash table commonly have a direct link in the network. Routing in the T-DHT guarantees reachability and introduces low hop-overhead compared with the shortest path. Proceedings of Fifth International IEEE Conference on Peer-to-Peer-Computing, Konstanz, Germany OlafLandsiedel KatharinaLehmann KlausWehrle inproceedings 200503landsiedelfgsnaeon 2005 481 72-76 Power consumption is a crucial characteristic of sensor networks and their applications, as sensor nodes are commonly battery driven. Although recent research focuses strongly on energy aware applications and operating systems, power consumption is still a limiting factor. Once sensor nodes are deployed, it is challenging and sometimes even impossible to change batteries. As a result, erroneous lifetime prediction causes high costs and may render a sensor network useless, before its purpose is fulfilled. In this paper we present AEON, a novel evaluation tool to quantitatively predict power consumption of sensor nodes and whole sensor networks. Our energy model, based on measurements of node current draw and the execution of real code, enables accurate prediction of the actual power consumption of sensor nodes. Consequently, preventing erroneous assumptions on node and network lifetime. Moreover, our detailed energy model allows to compare different low power and energy aware approaches in terms of energy efficiency.

Zürich, CH

Proceedings of the 4th GI/ITG KuVS Fachgespräch "Wireless Sensor Networks", Techical Report No. 481 OlafLandsiedel KlausWehrle SimonRieche StefanGötz LeoPetrak inproceedings 200410riechehotp2preliability 2004 10 108-113 Peer-to-Peer (P2P) systems are very useful for managing large amounts of widely distributed data. For this purpose Distributed Hash Tables (DHT) offer a highly scalable and self-organizing paradigm for efficient distribution and retrieval of data. Thereby a common assumption of P2P-Systems is, that the participating nodes are unreliable and may fail at any time. Since many of research goes into the design of DHT lookup services, these systems aim to provide a stable global addressing structure. But to storage data reliable in a DHT only few techniques were already developed. However since data has to be stored persistent in the network, it should be retrieved anytime, even if nodes fail. In this work we discuss possibilities to store data fault tolerant in a structured Peer-to-Peer system. Print Proceedings of HOT-P2P '04: Hot Topics in Peer-to-Peer Computing at 12th Annual Meeting of the IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (MASCOTS) Volendam, Netherlands HOT-P2P '04: Hot Topics in Peer-to-Peer Computing at 12th Annual Meeting of the IEEE International Symposium on Modeling, Analysis, and Simulation of Computer Oct. 2004 en 1 SimonRieche KlausWehrle OlafLandsiedel StefanGötz LeoPetrak inproceedings 200410wehrlefgpcintegriertekonstruktionsmethode 2004

Stuttgart, Germany

Proceedings of the GI/ITG KuVS Fachgespräch Systemsoftware für Pervasive Computing KlausWehrle OlafLandsiedel SimonRieche StefanGötz LeoPetrak