@inproceedings {INPROC-2005-98,
   author = {Abdelmajid Khelil and Jos{\'e} Pedro Marr{\'o}n and Kurt Rothermel},
   title = {{Contact-Based Mobility Metrics for Delay-Tolerant Ad Hoc Networking}},
   booktitle = {Proceedings of the 13th IEEE International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems: MASCOTS'05; Atlanta, Georgia, September, 2005},
   address = {Los Alamitos, California},
   publisher = {IEEE Conference Publishing Services},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {IEEE Computer Society Order Number},
   volume = {P2458},
   pages = {435--444},
   type = {Conference Paper},
   month = {September},
   year = {2005},
   isbn = {0-7695-2458-3},
   keywords = {MANET; Contact; encounter; delay-tolerant; mobility metrics},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols,
                   I.6.5 Model Development},
   contact = {Universit{\"a}t Stuttgart / IPVS, Universit{\"a}tsstr. 38 70569 Stuttgart, Germany, {khelil, marron, rothermel}@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Mobility plays a major role in mobile ad hoc networks (MANETs) since it
      stresses networking tasks such as routing on one hand but aids to increase the
      network capacity and to overcome network partitioning on the other hand. To
      benefit from node mobility, a new class of MANET protocols and applications are
      designed to be delay-tolerant and mobility-aided. For delay-tolerant
      mobility-aided networking mobility on a large time-scale is a key feature. So
      far, in MANETs, the mobility is investigated on a short time-scale. That is why
      we present novel mobility metrics that quantify a large time-scale mobility.
      Our approach is based on the pair-wise contacts between mobile nodes. We
      present a detailed statistical study of our novel metrics using the widely used
      random waypoint mobility model as an example. For the random waypoint model we
      introduce an analytical model, which allows protocol developers to analytically
      compute some of the designed metrics. In order to provide an easy access to
      these metrics in a network simulator, we provide a framework for ns-2.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-98&engl=1}
}

@inproceedings {INPROC-2005-97,
   author = {Abdelmajid Khelil and Jos{\'e} Pedro Marr{\'o}n and R{\"u}diger Dietrich and Kurt Rothermel},
   title = {{Evaluation of Partition-Aware MANET Protocols and Applications with ns-2}},
   booktitle = {Proceedings of the 2005 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS ’05), Philadelphia, PA, July 24–28, 2005},
   address = {Cherry Hill, NJ, USA},
   publisher = {Simulation Councils, Inc.},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {SIM Series},
   volume = {37(3)},
   pages = {435--444},
   type = {Conference Paper},
   month = {July},
   year = {2005},
   isbn = {1-56555-300-4},
   keywords = {MANET; Network Partitioning; Protocol Evaluation; ns-2; Hypergossiping},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols},
   contact = {Universit{\"a}t Stuttgart / IPVS, Universit{\"a}tsstr. 38 70569 Stuttgart, Germany, {khelil, marron, rothermel}@informatik.uni-stuttgart.de, ruediger.dietrich@gmx.net},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Mobile Ad Hoc Networks (MANET) are composed of mobile devices equipped with
      short range radio capabilities. Commu­nication is possible between devices
      located in each other's transmission range. Especially in sparse MANETs, node
      mo­bility leads to frequent network partitioning, which makes typical
      networking tasks much more difficult. Although we observe an increasing need
      for partitioning information, the widely used network simulator ns­2 does not
      support proto­col developers to easily evaluate their protocols concerning
      network partitioning.
      
      To simplify the evaluation of MANET partition­aware pro­tocols and applications
      in ns­2, we extend the simulator to provide partitioning information at the
      simulation time. De­velopers might be interested in using this information to
      eval­uate their partition­aware protocols and applications and to compare their
      performance to the optimal case.
      
      Hypergossiping is a partition­aware broadcast protocol for MANETs. Nodes
      rebroadcast messages upon joining the par­titions that have not yet received
      these messages. Hypergos­siping uses a heuristic to detect partition joins. We
      show the feasibility of our approach and the applicability of the parti­tioning
      information we provide for ns­2 users to compare the performance of our
      approach to the optimal case.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-97&engl=1}
}

@inproceedings {INPROC-2005-96,
   author = {Abdelmajid Khelil and Jos{\'e} Pedro Marr{\'o}n and Christian Becker and Kurt Rothermel},
   title = {{Hypergossiping: A Generalized Broadcast Strategy for Mobile Ad Hoc Networks}},
   booktitle = {Proceedings of Kommunikation in Verteilten Systemen 2005 (KiVS'05); Kaiserslautern, Germany, 2005},
   address = {Kaiserslautern},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {0--1},
   type = {Conference Paper},
   month = {February},
   year = {2005},
   keywords = {mobile ad hoc network (MANET); adaptive broadcast; network partitioning},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols},
   contact = {Universit{\"a}t Stuttgart / IPVS / VS Universit{\"a}tsstrasse 38, 70569 Stuttgart, Germany +49 711 7816 {251, 357, 228, 434} {khelil, marron, becker, rothermel}@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Broadcasting is a commonly used communication primitive needed by many
      applications and protocols in mobile ad hoc networks (MANETs). Unfortunately,
      most broadcast solutions are tailored to one class of MANETs with respect to
      node density and node mobility and are unlikely to operate well in other
      classes. In this paper, we introduce hypergossiping, a novel adaptive broadcast
      algorithm that combines two strategies. Hypergossiping uses adaptive gossiping
      to efficiently distribute messages within single network partitions and
      implements an efficient heuristic to distribute them across partitions.
      Simulation results in ns-2 show that hypergossiping operates well for a broad
      range of MANETs with respect to node densities and mobility levels.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-96&engl=1}
}

@inproceedings {INPROC-2005-85,
   author = {Arno Wacker and Mirko Knoll and Timo Heiber and Kurt Rothermel},
   title = {{A New Approach for Establishing Pairwise Keys for Securing Wireless Sensor Networks}},
   booktitle = {Proceedings of the Third International Conference on Embedded Networked Sensor Systems: ACM SenSys'05; San Diego, California, November 2-4, 2005},
   address = {San Diego},
   publisher = {ACM Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {27--38},
   type = {Conference Paper},
   month = {November},
   year = {2005},
   isbn = {1-59593-054-X},
   keywords = {Wireless Sensor Network Security, Key Establishment},
   language = {English},
   cr-category = {D.4.6 Operating Systems Security and Protection,
                   C.2.0 Computer-Communication Networks, General,
                   C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-85/INPROC-2005-85.pdf},
   contact = {Senden sie eine mail an arno.wacker@ipvs.uni-stuttgart.de oder arno@wacker-online.net},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Wireless sensor networks based on highly resource-constrained devices require
      symmetric cryptography in order to make them secure. Integral to this is the
      exchange of unique symmetric keys between two devices. In this paper, we
      propose a novel decentralized key exchange protocol that guarantees the
      confidentiality of a key exchange even if an attacker has compromised some of
      the devices in the network. A central objective of the protocol design was to
      minimize resource consumption on the individual devices. We evaluate the
      resource requirements of our protocol in terms of memory requirements, CPU
      usage and network traffic both through theoretical analysis and through
      simulations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-85&engl=1}
}

@inproceedings {INPROC-2005-73,
   author = {Marcus Handte and Christian Becker and Kurt Rothermel},
   title = {{Peer-based Automatic Configuration of Pervasive Applications}},
   booktitle = {Proceedings of the 2nd IEEE International Conference on Pervasive Services (ICPS 2005), Santorini, Greece, 11-14 July,2005},
   publisher = {-},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {249--260},
   type = {Conference Paper},
   month = {July},
   year = {2005},
   language = {German},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Pervasive computing envisions seamless support for user tasks through
      cooperating devices that are present in an environment. Fluctuating
      availability of devices, induced by mobility and failures, requires mechanisms
      and algorithms that allow applications to adapt to changing environmental
      conditions without user intervention. To ease the development of adaptive
      applications, we have proposed the peer-based component system PCOM. This
      system provides fundamental mechanisms to support the automated composition of
      applications at runtime. In this paper, we discuss the requirements on
      peer-based automatic configuration of pervasive applications and present an
      approach based on distributed constraint satisfaction. The resulting algorithm
      configures applications in the presence of strictly limited resources. To show
      the feasibility of the approach, we have integrated the algorithm into PCOM and
      provide an evaluation based on simulation and measurements.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-73&engl=1}
}

@inproceedings {INPROC-2005-72,
   author = {Marcus Handte and Gregor Schiele and Stephan Urbanski and Christian Becker},
   title = {{Adaptation Support for Stateful Components in PCOM}},
   booktitle = {Workshop on Software Architectures for Self-Organization: Beyond Ad-Hoc Networking at Pervasive 2005, M{\"u}nchen, Germany, 2005},
   publisher = {-},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1--5},
   type = {Conference Paper},
   month = {May},
   year = {2005},
   keywords = {Adaptation, Stateful Services},
   language = {German},
   cr-category = {D.2.7 Software Engineering Distribution, Maintenance, and Enhancement},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In ever-changing environments as they are envisioned in Pervasive Computing,
      applications have to adapt to changes in their execution environment.
      Reselection of services is a common technique for stateless services. This
      paper presents an approach that allows reselection of stateful services by
      combining checkpointing techniques and client-side request histories. An
      implementation that allows transparent service reselection is outlined and
      parameters for the automatic creation of checkpoints are discussed.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-72&engl=1}
}

@inproceedings {INPROC-2005-71,
   author = {Pedro Jos{\'e} Marr{\'o}n and Matthias Gauger and Andreas Lachenmann and Daniel Minder and Olga Saukh and Kurt Rothermel},
   title = {{Adaptive System Software Support for Cooperating Objects}},
   booktitle = {Proceedings of the Workshop on Smart Object Systems; Tokyo, Japan},
   publisher = {N/A},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {September},
   year = {2005},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols,
                   D.4.7 Operating Systems Organization and Design},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-71/INPROC-2005-71.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Efficient system software support is essential for cooperating object
      applications in order to cope with the complexity and heterogeneity of typical
      scenarios in this domain. In this paper, we argue that adaptation capabilities
      should be an integral part of such system software and present the TinyCubus
      framework as one possible solution that provides the features required of
      system software for cooperating objects.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-71&engl=1}
}

@inproceedings {INPROC-2005-70,
   author = {Daniel Minder and Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Kurt Rothermel},
   title = {{Experimental construction of a meeting model for smart office environments}},
   booktitle = {Proceedings of the First REALWSN 2005 Workshop on Real-World Wireless Sensor Networks, SICS Technical Report T2005:09},
   publisher = {N/A},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {June},
   year = {2005},
   keywords = {Wireless Sensor Network},
   language = {English},
   cr-category = {C.3 Special-Purpose and Application-Based Systems,
                   I.6.5 Model Development},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-70/INPROC-2005-70.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The simulation of mobile networks requires mobility models that reproduce the
      movement of nodes in a realistic way. Although many such models exist, they are
      not well suited for model office scenarios in which movements are mostly caused
      by people meeting in known locations to discuss some issues. We present first
      steps towards a meeting model for office environments which is based on the
      real world movement data gathered after performing a one-week sensor network
      deployment in our department. We describe details about the processing of the
      acquired data, the construction, and the execution of the movement model.
      Finally, we discuss some of the lessons learned throughout the experiment.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-70&engl=1}
}

@inproceedings {INPROC-2005-69,
   author = {Andreas Lachenmann and Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Kurt Rothermel},
   title = {{An Analysis of Cross-Layer Interactions in Sensor Network Applications}},
   booktitle = {Proceedings of the 2005 Intelligent Sensors, Sensor Networks \& Information Processing Conference},
   publisher = {IEEE},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {121--126},
   type = {Conference Paper},
   month = {December},
   year = {2005},
   isbn = {0-7803-9400-3},
   keywords = {wireless sensor networks; cross-layer interactions; data sharing; TinyXXL},
   language = {English},
   cr-category = {C.2.2 Network Protocols,
                   D.2.11 Software Engineering Software Architectures,
                   D.3.3 Programming Language Constructs and Features},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-69/INPROC-2005-69.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In the field of sensor networks cross-layer interactions are favored over
      strict layering of components and regarded as a way to provide the optimization
      capabilities required by sensor network applications. Despite their importance,
      developers tend to devise specific solutions for the application at hand,
      instead of designing more general primitives that can be used across
      applications. The contribution of this paper is twofold: We analyze several
      typical sensor network applications and provide a classification of the types
      of cross-layer interactions found in their code. Based on this classification,
      we propose TinyXXL, an extension to the nesC language that defines primitives
      for seamless cross-layer data exchange.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-69&engl=1}
}

@inproceedings {INPROC-2005-68,
   author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Olga Saukh and Kurt Rothermel},
   title = {{Generic Model and Architecture for Cooperating Objects in Sensor Network Environments}},
   booktitle = {Proceedings of the 12th International Conference on Telecommunications (ICT 2005)},
   publisher = {N/A},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {May},
   year = {2005},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-68/INPROC-2005-68.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The complexity and heterogeneity of cooperating object applications in
      ubiquitous environments or of applications in the sensor network domain require
      the use of generic models and architectures. These architectures should provide
      support for the following three key issues: flexible installation, management
      and reconfiguration of components in the system; optimization strategies whose
      implementation usually involves the proper management of cross-layer
      information; and proper adaptation techniques that allow for the
      self-configuration of nodes and components in the system with minimal human
      intervention. In this paper, we present one possible instance of such a generic
      model and architecture and show its applicability using Sustainable Bridges, a
      sensor network application that requires the analysis of complex sensor data to
      achieve its goal of effectively monitoring bridges for the detection of
      structural defects.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-68&engl=1}
}

@inproceedings {INPROC-2005-67,
   author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Kurt Rothermel},
   title = {{TinyCubus: A Flexible and Adaptive Cross-Layer Framework for Sensor Networks}},
   booktitle = {4. GI/ITG KuVS Fachgespr{\"a}ch ``Drahtlose Sensornetze'', Technical Report TR 481, Computer Science Department, ETH Zurich},
   publisher = {N/A},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {49--54},
   type = {Conference Paper},
   month = {March},
   year = {2005},
   language = {German},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-67/INPROC-2005-67.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {With the proliferation of sensor networks and sensor network applications
      during the last few years, the overall complexity of such systems is
      continuously increasing. Sensor networks are now heterogeneous in terms of
      their hardware characteristics and application requirements even within a
      single network. In addition, the requirements of current applications are
      expected to change over time. All of this makes developing, deploying, and
      optimizing sensor network applications an extremely difficult task. In the
      TinyCubus project we research a necessary infrastructure to support the
      complexity of such systems.
      
      TinyCubus consists of a data management framework, a cross-layer frame work,
      and a configuration engine. The data management framework allows the dynamic
      selection and adaptation of system and data management components. The
      cross-layer framework supports data sharing and other forms of interaction
      between components in order to achieve cross-layer optimizations. The
      configuration engine allows code to be distributed reliably and efficiently by
      taking into account the topology of sensors and their assigned functionality.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-67&engl=1}
}

@inproceedings {INPROC-2005-58,
   author = {Daniela Nicklas and Susanne B{\"u}rklen and Tobias Drosdol and Nicola H{\"o}nle},
   title = {{Benefits of Context Models in Smart Environments}},
   booktitle = {2. GI/ITG KuVS Fachgespr{\"a}ch Ortsbezogene Anwendungen und Dienste},
   editor = {J{\"o}rg Roth},
   address = {Hagen},
   publisher = {Fernuniversit{\"a}t Hagen},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   series = {Informatik Bericht},
   volume = {324},
   pages = {12--15},
   type = {Conference Paper},
   month = {June},
   year = {2005},
   keywords = {context models; smart environment; smart room; Nexus},
   language = {English},
   cr-category = {H.4 Information Systems Applications},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-58/INPROC-2005-58.pdf,
      http://dreamteam.fernuni-hagen.de/fg_lbs/meeting_2/meeting_2.html,
      http://www.nexus.uni-stuttgart.de},
   contact = {daniela.nicklas@informatik.uni-stuttgart.de susanne.buerklen@informatik.uni-stuttgart.de tobias.drosdol@informatik.uni-stuttgart.de nicola.hoenle@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Ongoing technologic advances drive the emergence of smart items, everyday
      objects with embedded microcomputers and communication capabilities. In a smart
      envi-ronment a multitude of such smart items exist to assist its users. In this
      paper, we will show how smart environments can benefit from the concepts of the
      Nexus platform, an open pervasive computing system that supports various kinds
      of context-aware applica-tions by providing a federated, potentially global
      context model.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-58&engl=1}
}

@inproceedings {INPROC-2005-37,
   author = {Illya Stepanov and Daniel Herrscher and Kurt Rothermel},
   title = {{On the Impact of Radio Propagation Models on MANET Simulation Results}},
   booktitle = {Proceedings of the 7th IFIP International Conference on Mobile and Wireless Communication Networks (MWCN 2005), Marrakech, Morocco, September 2005},
   publisher = {N/A},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {September},
   year = {2005},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.4 Performance of Systems,
                   I.6.3 Simulation and Modeling Applications},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-37/INPROC-2005-37.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Network simulation tools are frequently used to analyze performance of MANET
      protocols and applications. They commonly offer only simple radio propagation
      models that neglect obstacles of a propagation environment. In this paper, we
      integrate a more accurate radio propagation model into a simulation tool. The
      model is based on ray tracing and considers geographic data of the simulation
      area. We prove that the usage of a more precise propagation model changes
      simulated connection topologies considerably. Consequently, we obtain different
      performance evaluation results. To our best knowledge, no other study of MANETs
      has been performed so far with such a detailed radio propagation model. Hence,
      this paper also gives new insights on the realistic performance of MANETs in
      outdoor environments.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-37&engl=1}
}

@inproceedings {INPROC-2005-31,
   author = {Frank D{\"u}rr and Christian Becker and Kurt Rothermel},
   title = {{Efficient Forwarding of Symbolically Addressed Geocast Messages}},
   booktitle = {Proceedings of the 14th International Conference on Computer Communications an Networks (ICCCN 2005); San Diego, CA, October 2005},
   publisher = {IEEE},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {77--85},
   type = {Conference Paper},
   month = {October},
   year = {2005},
   doi = {10.1109/ICCCN.2005.1523812},
   keywords = {Geocast, Multicast, Networking, Communication Network, Location-based Service},
   language = {English},
   cr-category = {C.2 Computer-Communication Networks},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-31/INPROC-2005-31.pdf,
      http://dx.doi.org/10.1109/ICCCN.2005.1523812},
   contact = {frank.duerr@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Geocast is used to send messages to all hosts located in a geographic area.
      This target area can be defined either by geometric figures like polygons or by
      symbolic addresses like city names or room numbers.
      
      Geographic routing algorithms, which forward messages based on geographic
      information, can be used to forward geocast messages. If routing of
      symbolically addressed messages is based on geometric coordinates, complex
      mappings between symbolic addresses and their geometric extent as well as
      complex geometric operations are required. Therefore, we propose a routing
      algorithm for symbolically addressed geocast messages that operates directly on
      a symbolic location model. This approach does not require any geometric
      information for message forwarding, and forwarding decisions can be realized
      efficiently by comparably simple operations.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-31&engl=1}
}

@inproceedings {INPROC-2005-26,
   author = {Steffen Maier and Daniel Herrscher and Kurt Rothermel},
   title = {{On Node Virtualization for Scalable Network Emulation}},
   booktitle = {Proceedings of the 2005 International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS ’05), Philadelphia, PA, July 24–28, 2005},
   publisher = {Simulation Councils, Inc.},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {917--928},
   type = {Conference Paper},
   month = {July},
   year = {2005},
   keywords = {software performance evaluation; network emulation; mobile ad hoc networks; scalability; virtual routing},
   language = {English},
   cr-category = {C.4 Performance of Systems,
                   D.4.4 Operating Systems Communications Management,
                   D.4.8 Operating Systems Performance,
                   I.6.3 Simulation and Modeling Applications},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-26/INPROC-2005-26.pdf,
      http://net.informatik.uni-stuttgart.de/},
   contact = {e-mail to Steffen Maier maier@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {During the development of network protocols and distributed applications, their
      performance has to be analyzed in appropriate environments. Network emulation
      testbeds provide a synthetic, configurable network environment for comparative
      performance measurements of real implementations. Realistic scenarios have to
      consider hundreds of communicating nodes. Common network emulation approaches
      limit the number of nodes in a scenario to the number of computers in an
      emulation testbed. To overcome this limitation, we introduce a virtual node
      concept for network emulation. The key problem for node virtualization is a
      transparent, yet efficient separation of node resources. In this paper, we
      provide a brief survey of candidate node virtualization approaches to
      facilitate scalable network emulation. Based on the gathered insights, we
      propose a lightweight virtualization solution to achieve maximum scalability
      and discuss the main points regarding its implementation. We present extensive
      evaluations that show the scalability and transparency of our approach in both
      a traditional wired infrastructure-based, and in a wireless ad hoc network
      emulation scenario. The measurements indicate that our solution can push the
      upper limit of emulation scenario sizes by a factor of 20 to 30. Given our
      emulation testbed consisting of 64 computers, this translates to possible
      scenario sizes of up to 1920 nodes.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-26&engl=1}
}

@inproceedings {INPROC-2005-21,
   author = {Martin Bauer and Kurt Rothermel},
   title = {{An Architecture for Observing PhysicalWorld Events}},
   booktitle = {Proceedings of the 11th International Conference on Parallel and Distributed Systems: ICPADS 2005; Fukuoka, Japan, July 20-22, 2005},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Conference Paper},
   month = {July},
   year = {2005},
   keywords = {distributed systems; event service; event service architecture; event observation; real-world events; world model; distributed world model},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   H.3.3 Information Search and Retrieval,
                   H.3.4 Information Storage and Retrieval Systems and Software},
   ee = {http://www.nexus.uni-stuttgart.de},
   contact = {Martin Bauer mabauer@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In this paper we investigate the observation of physical world events, i.e.
      events that occur in the physical world, and are observed through model data,
      part of which is collected by sensors. The physical world events of interest
      here are those that are suitable for proactively supporting mobile users. This
      means that they have to be on the same highabstraction level as perceived by
      the user. In a large-scale system as we envision it, the model data needed for
      the observation of these high-level physical world events may be distributed
      over multiple servers.
      
      We first present a requirement analysis. Then we propose an event service
      architecture that fulfills the requirements. Finally, we show the scalability
      of the approach through an evaluation based on a prototype implementation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-21&engl=1}
}

@inproceedings {INPROC-2005-15,
   author = {Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Daniel Minder and J{\"o}rg H{\"a}hner and Robert Sauter and Kurt Rothermel},
   title = {{TinyCubus: A Flexible and Adaptive Framework for Sensor Networks}},
   booktitle = {Proceedings of the Second European Workshop on Wireless Sensor Networks (EWSN 2005)},
   editor = {Erdal Cayirci and Sebnem Baydere and Paul Havinga},
   address = {Istanbul, Turkey},
   publisher = {IEEE},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {278--289},
   type = {Conference Paper},
   month = {January},
   year = {2005},
   isbn = {0-7803-8801-1},
   keywords = {sensor network; system architecture; adaptation; framework; code distribution; cross-layer},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols,
                   D.4.7 Operating Systems Organization and Design},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-15/INPROC-2005-15.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {With the proliferation of sensor networks and sensor network applications, the
      overall complexity of such systems is continuously increasing. Sensor networks
      are now heterogeneous in terms of their hardware characteristics and
      application requirements even within a single network. In addition, the
      requirements of currently supported applications are expected to change over
      time. All of this makes developing, deploying, and optimizing sensor network
      applications an extremely difficult task. In this paper, we present the
      architecture of TinyCubus, a flexible and adaptive cross-layer framework for
      TinyOS based sensor networks that aims at providing the necessary
      infrastructure to cope with the complexity of such systems. TinyCubus consists
      of a data management framework that selects and adapts both system and data
      management components, a cross-layer framework that enables optimizations
      through cross-layer interactions, and a configuration engine that installs
      components dynamically. Furthermore, we show the feasibility of our
      architecture by describing and evaluating a code distribution algorithm that
      uses application knowledge about the sensor topology in order to optimize its
      behavior.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-15&engl=1}
}

@inproceedings {INPROC-2005-14,
   author = {Dominique Dudkowski and Tobias Drosdol and Pedro Jos{\'e} Marr{\'o}n},
   title = {{Towards Scalable and Efficient Processing of Probabilistic Spatial Queries in Mobile Ad Hoc and Sensor Networks}},
   booktitle = {Mobile Datenbanken: heute, morgen und in 20 Jahren. 8. Workshop des GI-Arbeitskreises ``Mobile Datenbanken und Informationssysteme''},
   editor = {Birgitta K{\"o}nig-Ries and Michael Klein},
   address = {Karlsruhe},
   publisher = {-},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   pages = {75--84},
   type = {Conference Paper},
   month = {February},
   year = {2005},
   keywords = {Mobile Ad Hoc Networks; MANETs; MANET; Sensor Networks; WSNs; WSN; Wireless Sensor Networks; Mobile Networks; Queries; Probabilistic Queries; Spatial Queries},
   language = {English},
   cr-category = {C.2.4 Distributed Systems},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-14/INPROC-2005-14.pdf},
   contact = {Senden Sie eine E-Mail an dudkowski@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {With the proliferation of sensor technology and advances in wireless
      communication, gathering, processing, and querying context information in
      mobile ad hoc and sensor networks becomes attractive and feasible. To support
      context-aware applications in such networks, efficient processing techniques
      for frequently used functionality, such as query and event management, are
      highly beneficial. In this paper, we discuss the challenges in efficient
      processing of spatial queries in mobile ad hoc and sensor networks. These
      comprise advanced query semantics based on inaccurate position information,
      efficient protocols and algorithms for data storage and query resolution,
      scalability with respect to network size, and support for mobile network nodes.
      We outline our concepts for solving these issues and show how they can be
      implemented in a suitable software architecture. Using current evaluation
      results, we show that our prototype implementation fulfills the stated
      challenges.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-14&engl=1}
}

@inproceedings {INPROC-2005-12,
   author = {Timo Heiber and Pedro Jose Marron},
   title = {{Exploring the Relationship between Context and Privacy}},
   booktitle = {Privacy, Security and Trust within the Context of Pervasive Computing},
   editor = {Philip Robinson and Harald Vogt and Waleed Wagealla},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {The Kluwer International Series in Engineering and Computer Science},
   volume = {780},
   type = {Conference Paper},
   month = {January},
   year = {2005},
   isbn = {0-387-23461-6},
   language = {English},
   cr-category = {H.2.8 Database Applications,
                   K.6.5 Security and Protection},
   contact = {timo.heiber@informatik.uni-stuttgart.de pedro.marron@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Privacy is universally regarded as an important consideration for pervasive
      computing environments. This is especially true when considering context-aware
      systems, because of the fact that context often contains personal information.
      Moreover, an adversary who takes the semantics of the context information into
      account can potentially infer knowledge beyond the information represented in
      the actual context data. In this paper, we describe a generic framework to
      model privacy in context-aware systems and discuss possible inferences based on
      the context of ID, location and time.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-12&engl=1}
}

@inproceedings {INPROC-2005-11,
   author = {Michael Kinateder and Ernesto Baschny and Kurt Rothermel},
   title = {{Towards a Generic Trust Model}},
   booktitle = {Proceedings of the Third International Conference on Trust Management: iTrust'05; Rocquencourt, France, May 23-26, 2005},
   publisher = {Springer-Verlag},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   series = {Lecture Notes in Computer Science},
   volume = {3477},
   pages = {177--192},
   type = {Conference Paper},
   month = {May},
   year = {2005},
   isbn = {3-540-26042-0},
   keywords = {Vertrauen, Reputation, Vertrauensmodell, Vertrauensaktualisierung, trust, reputation, trust model, trust-update},
   language = {English},
   cr-category = {I.6.5 Model Development,
                   I.2.6 Artificial Intelligence Learning,
                   J.4 Social and Behavioral Sciences,
                   K.4.4 Electronic Commerce},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-11/INPROC-2005-11.pdf,
      http://unitec.informatik.uni-stuttgart.de},
   contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Research in the area of trust and reputation systems has put a lot of effort in
      developing various trust models and associated trust update algorithms that
      support users or their agents with different behavioral profiles. While each
      work on its own is particularly well suited for a certain user group, it is
      crucial for users employing different trust representations to have a common
      understanding about the meaning of a given trust statement.
      
      The contributions of this paper are three-fold: Firstly we present the UniTEC
      generic trust model that provides a common trust representation for the class
      of trust update algorithms based on experiences. Secondly, we show how several
      well-known representative trust-update algorithms can easily be plugged into
      the UniTEC system, how the mappings between the generic trust model and the
      algorithm-specific trust models are performed, and most importantly, how our
      abstraction from algorithm-specific details in the generic trust model enables
      users using different algorithms to interact with each other and to exchange
      trust statements. Thirdly we present the results of our comparative evaluation
      of various trust update algorithms under a selection of test scenarios.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-11&engl=1}
}

@inproceedings {INPROC-2005-08,
   author = {Illya Stepanov and Pedro Jose Marron and Kurt Rothermel},
   title = {{Mobility Modeling of Outdoor Scenarios for MANETs}},
   booktitle = {Proceedings of the 38th Annual Simulation Symposium (ANSS 38), San Diego, USA, April 2005},
   publisher = {N/A},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   type = {Conference Paper},
   month = {April},
   year = {2005},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.4 Performance of Systems,
                   I.6.3 Simulation and Modeling Applications},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-08/INPROC-2005-08.pdf},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Mobility of users significantly impacts performance of a mobile ad-hoc network.
      Most existing simulation tools offer only a few random mobility models, which
      poorly reflect user movements in outdoor scenarios. For example, they do not
      consider restrictions of a spatial environment. In this paper, we describe a
      comprehensive and extensible approach to model mobility of users in outdoor
      scenarios. It reflects the main factors that influence user movement: spatial
      environments, user travel decisions, and user movement dynamics. We identify
      model parameters and show how to set them for concrete scenarios. We provide a
      simulation environment implementing our approach. For concrete scenarios, the
      environment supports automatic derivation of some parameters from user position
      traces.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-08&engl=1}
}

@inproceedings {INPROC-2005-07,
   author = {Susanne B{\"u}rklen and Pedro Jos{\'e} Marr{\'o}n and Serena Fritsch and Kurt Rothermel},
   title = {{User Centric Walk: An Integrated Approach for Modeling the Browsing Behavior of Users on the Web}},
   booktitle = {Proceedings of the 38th IEEE Annual Simulation Symposium (ANSS'05), San Diego, CA, USA},
   editor = {IEEE Computer Society Press},
   address = {San Diego, CA, USA},
   publisher = {IEEE Computer Society Press},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Conference Paper},
   month = {April},
   year = {2005},
   keywords = {Browsing behavior model; heavy tailed distribution},
   language = {English},
   cr-category = {G.3 Probability and Statistics,
                   I.6 Simulation and Modeling,
                   H.1 Models and Principles},
   contact = {Contact: buerklen@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {The performance evaluation of Web applications usually requires the utilization
      of sequences of user requests for determined Web pages. These sequences can be
      obtained, for example, by applying empirical methods (recording the real
      sequence of requests), or by applying a formal model for generating synthetic
      results. In this paper, we present our Web Browsing Model and the User Centric
      Walk algorithm as its implementation. By taking into account the hyperlink
      structure as well as the different user behavior on the Web, this algorithm
      allows us to generate accurate synthetic data that can be used instead of
      empirically obtained requests. As another contribution of this paper we have
      shown, based on empirical data, that the probability of choosing some hyperlink
      from a given page as well as the probability a user leaves a page without
      following a hyperlink is best characterized by a power-law. Moreover, we show
      the flexibility and applicability of our model by performing the required
      correlations to empirical data, which validate our approach.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-07&engl=1}
}

@inproceedings {INPROC-2005-05,
   author = {Uwe-Philipp K{\"a}ppeler and Georg Kindermann and Daniela Nicklas and Nicola H{\"o}nle and Dominique Dudkowski},
   title = {{Shared Dynamic Context Models: Benefits for Advanced Sensor Data Fusion for Autonomous Robots}},
   booktitle = {Proceedings of Artificial Intelligence and Applications 2005; Innsbruck, Austria, February, 14-16, 2005},
   publisher = {IASTED},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Conference Paper},
   month = {February},
   year = {2005},
   keywords = {Autonomous; Robots; Sensor; Fusion; Nexus; Context; Sensorfusion},
   language = {English},
   cr-category = {H.3.3 Information Search and Retrieval,
                   I.2.9 Robotics},
   contact = {kaeppeler@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems},
   abstract = {Information provided by a shared dynamic context model offers new possibilities
      in the realm of autonomous robots. The availability of external context
      information can be used by a robot to extend and to validate the locally
      acquired knowledge about its dynamic environment. A lot of helpful context
      information is already available in digital form and its quantity will increase
      rapidly, according to the vision of ubiquitous computing.
      
      In this paper we present the Nexus Platform capable of managing a global
      dynamic context model that can be addressed and accessed in an easy and uniform
      way by all kinds of context-aware applications (like robots). Advantages for an
      autonomous wheelchair robot using the Nexus Platform are depicted within an
      airport scenario. We further present a framework for a sensor fusion agent,
      able to perform multi-sensor data fusion with selective attention control,
      concerning the current situation of the environment.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-05&engl=1}
}

@inproceedings {INPROC-2005-03,
   author = {Matthias Grossmann and Martin Bauer and Nicola H{\"o}nle and Uwe-Philipp K{\"a}ppeler and Daniela Nicklas and Thomas Schwarz},
   title = {{Efficiently Managing Context Information for Large-scale Scenarios}},
   booktitle = {Proceedings of the 3rd IEEE Conference on Pervasive Computing and Communications: PerCom2005; Kauai Island, Hawaii, March 8-12, 2005},
   publisher = {IEEE Computer Society},
   institution = {University of Stuttgart : Collaborative Research Center SFB 627 (Nexus: World Models for Mobile Context-Based Systems), Germany},
   type = {Conference Paper},
   month = {March},
   year = {2005},
   language = {English},
   cr-category = {H.3.0 Information Storage and Retrieval General,
                   H.3.4 Information Storage and Retrieval Systems and Software},
   ee = {http://www.nexus.uni-stuttgart.de},
   contact = {matthias.grossmann@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Applications of Parallel and Distributed Systems;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Image Understanding;
                  University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In this paper, we address the data management aspect of large-scale pervasive
      computing systems. We aim at building an infrastructure that simultaneously
      supports many kinds of context-aware applications, ranging from room level up
      to nation level. This allembracing approach gives rise to synergetic benefits
      like data reuse and sensor sharing. We identify major classes of context data
      and detail on their characteristics relevant for efficiently managing large
      amounts of it. Based on that, we argue that for large-scale systems it is
      beneficial to have special-purpose servers that are optimized for managing a
      certain class of context data. In the Nexus project we have implemented five
      servers for different classes of context data and a very flexible federation
      middleware integrating all these servers. For each of them, we highlight in
      which way the requirements of the targeted class of data are tackled and
      discuss our experiences.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-03&engl=1}
}

@inproceedings {INPROC-2005-01,
   author = {Michael Kinateder and Ralf Terdic and Kurt Rothermel},
   title = {{Strong Pseudonymous Communication for Peer-to-Peer Reputation Systems}},
   booktitle = {Proceedings of the 20th Annual ACM Symposium on Applied Computing: SAC'05; Santa Fe, New Mexico, March 13-17, 2005},
   publisher = {ACM Press},
   institution = {University of Stuttgart, Faculty of Computer Science, Electrical Engineering, and Information Technology, Germany},
   pages = {1570--1576},
   type = {Conference Paper},
   month = {March},
   year = {2005},
   isbn = {1-58113-964-0},
   keywords = {privacy, anonymous communication, pseudonyms, extended destination routing, Chaum mixes, mix-cascade, onion routing, distributed hash table, Chord},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   E.3 Data Encryption,
                   K.4 Computers and Society},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/INPROC-2005-01/INPROC-2005-01.pdf,
      http://unitec.informatik.uni-stuttgart.de/},
   contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In this paper we present a unique approach to enable untraceable communication
      between pseudonyms. In contrast to the related work, our approach provides
      strong sender and recipient anonymity most notably by eliminating the need to
      know of each other's address.
      
      We use a variation of Chaum mixes to achieve unlinkability between sender and
      recipient and introduce a concept called extended destination routing (EDR)
      which relies on routing headers constructed in multiple layers of encryption
      and published in a distributed hash table (DHT). When a sender intends to
      communicate, it contacts the DHT and requests the recipient's routing header,
      which is then extended and used for routing the message via a mix cascade to
      this recipient.
      
      This work was performed in the context of the UniTEC reputation system and
      describes the functionality of its anonymous communication layer, which is
      completely independent of the other UniTEC layers. Although trust and
      reputation systems in general are typical application areas for our
      contribution, the presented concepts are easily applicable not only to other
      reputation systems but also other application areas. We have implemented a
      prototype of UniTEC and present the first results from an ongoing evaluation in
      our network emulation testbed.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=INPROC-2005-01&engl=1}
}

@article {ART-2005-19,
   author = {Christian Becker and Frank D{\"u}rr},
   title = {{On Location Models for Ubiquitous Computing}},
   journal = {Personal and Ubiquitous Computing},
   publisher = {Springer-Verlag},
   volume = {9},
   number = {1},
   pages = {20--31},
   type = {Article in Journal},
   month = {January},
   year = {2005},
   keywords = {Location Model; Umgebungsmodell, Ubiquitous Computing; Context-aware Computing; Location-based Services},
   language = {English},
   cr-category = {H.0 Information Systems General},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2005-19/ART-2005-19.pdf,
      http://www.springerlink.com/content/7qjyl3g9hly15ky2/},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Common queries regarding information processing in ubiquitous computing are
      based on the location of physical objects. No matter if the next printer, next
      restaurant, or friend is searched for, a notion of distances between objects is
      required. A search for all objects in a certain geographic area requires the
      possibility to define spatial ranges and spatial inclusion of locations. In
      this paper we discuss general properties of symbolic and geometric coordinates.
      Based on that, we present an overview of existing location models allowing for
      position, range, and nearest neighbor queries. The location models are
      classified according to their suitability with respect to the query processing
      and the involved modeling effort along with other requirements. Besides an
      overview of existing location models and approaches the classification of
      location models with respect to application requirements can assist developers
      in their design decisions.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-19&engl=1}
}

@article {ART-2005-08,
   author = {Marcus Handte and Christian Becker and Kurt Rothermel},
   title = {{Peer-based Automatic Configuration of Pervasive Applications}},
   journal = {Journal of Pervasive Computing and Communications},
   publisher = {Troubadour Publishing},
   volume = {1},
   number = {4},
   pages = {251--264},
   type = {Article in Journal},
   month = {December},
   year = {2005},
   language = {English},
   cr-category = {C.2 Computer-Communication Networks,
                   D.2 Software Engineering,
                   D.3 Programming Languages},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {Pervasive Computing envisions seamless support for user tasks through
      cooperating devices that are present in an environment. Fluctuating
      availability of devices, induced by mobility and failures, requires mechanisms
      and algorithms that allow applications to adapt to their ever-changing
      execution environments without user intervention. To ease the development of
      adaptive applications, Becker et al. [3] have proposed the peer-based component
      system PCOM. This system provides fundamental mechanisms to support the
      automated composition of applications at runtime. In this article, we discuss
      the requirements on algorithms that enable automatic configuration of pervasive
      applications. Furthermore, we show how finding a configuration can be
      interpreted as Distributed Constraint Satisfaction Problem. Based on this, we
      present an algorithm that is capable of finding an application configuration in
      the presence of strictly limited resources. To show the feasibility of this
      algorithm, we present an evaluation based on simulations and real-world
      measurements and we compare the results with a simple greedy approximation.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-08&engl=1}
}

@article {ART-2005-06,
   author = {Pedro Jos{\'e} Marr{\'o}n and Andreas Lachenmann and Daniel Minder and Matthias Gauger and Olga Saukh and Kurt Rothermel},
   title = {{Management and configuration issues for sensor networks}},
   journal = {International Journal of Network Management},
   publisher = {John Wiley \& Sons, Inc.},
   volume = {15},
   number = {4},
   pages = {235--253},
   type = {Article in Journal},
   month = {July},
   year = {2005},
   isbn = {1099-1190},
   keywords = {wireless sensor network; self-organization; code distribution},
   language = {English},
   cr-category = {C.2.3 Network Operations,
                   C.2.1 Network Architecture and Design},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2005-06/ART-2005-06.pdf,
      http://www.interscience.wiley.com},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In this paper, we define three of the key issues that need to be solved in
      order to provide efficient management and configuration of applications and
      system software in sensor networks: the distribution and management of roles
      within the network, efficient code distribution algorithms, and efficient
      on-the-fly code update algorithms for sensor networks. The first issue is
      motivated by the increasing heterogeneity of sensor network applications and
      their need for more complex (nonhomogeneous) network topologies and structures.
      The second one is motivated by the intrinsic energy constraint issues and, in
      general, the resource limitation of sensor networks. Finally, the third one is
      needed due to the nature of monitoring applications and optimization needs from
      applications that should be able to efficiently incorporate code updates so
      that the network can adapt to its surroundings on the fly. In this paper we
      present related work and some results for each of these issues as we have dealt
      with them within the TinyCubus project.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-06&engl=1}
}

@article {ART-2005-05,
   author = {Pedro Jos{\'e} Marr{\'o}n and Daniel Minder and Andreas Lachenmann and Kurt Rothermel},
   title = {{TinyCubus: An Adaptive Cross-Layer Framework for Sensor Networks}},
   journal = {it - Information Technology},
   publisher = {Oldenbourg Verlag},
   volume = {47},
   number = {2},
   pages = {87--97},
   type = {Article in Journal},
   month = {April},
   year = {2005},
   isbn = {1611-2776},
   keywords = {wireless sensor network; system architecture; adaptation; framework; code distribution; cross-layer},
   language = {English},
   cr-category = {C.2.1 Network Architecture and Design,
                   C.2.2 Network Protocols,
                   D.4.7 Operating Systems Organization and Design},
   ee = {ftp://ftp.informatik.uni-stuttgart.de/pub/library/ncstrl.ustuttgart_fi/ART-2005-05/ART-2005-05.pdf,
      http://www.it-inftech.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {With the proliferation of sensor networks and sensor network applications, the
      overall complexity of such systems is continuously increasing. Sensor networks
      are now heterogeneous in terms of their hardware characteristics and
      application requirements even within a single network. In addition, the
      requirements of currently supported applications are expected to change over
      time. All of this makes developing, deploying, and optimizing sensor network
      applications an extremely difficult task. In this paper, we present the
      architecture of TinyCubus, a flexible and adaptive cross-layer framework for
      TinyOS-based sensor networks that aims at providing the necessary
      infrastructure to cope with the complexity of such systems. TinyCubus consists
      of a cross-layer framework that enables optimizations through cross-layer
      interactions, a configuration engine that distributes components efficiently by
      considering the roles of the sensor nodes and provides support to install
      components dynamically, and a data management framework that selects and adapts
      both system and data management components. Finally, relevant research
      challenges associated with the development of each framework are identified and
      discussed in the paper.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-05&engl=1}
}

@article {ART-2005-03,
   author = {Audun J{\o}sang and Elizabeth Gray and Michael Kinateder},
   title = {{Simplification and Analysis of Transitive Trust Networks}},
   journal = {Web Intelligence and Agent Systems: An International Journal},
   address = {Amsterdam, The Netherlands},
   publisher = {IOS Press},
   pages = {1--1},
   type = {Article in Journal},
   month = {September},
   year = {2005},
   issn = {1570-1263},
   keywords = {trust, reputation, transitive, transitivity, trust-graph, trust-chains},
   language = {English},
   cr-category = {J.4 Social and Behavioral Sciences,
                   C.2.4 Distributed Systems,
                   H.3.5 Online Information Services},
   ee = {http://unitec.informatik.uni-stuttgart.de},
   contact = {Michael Kinateder Kinateder@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {When transacting and interacting through open computer networks, traditional
      methods used in the physical world for establishing trust can no longer be
      used. Creating virtual network substitutes with which people, organisations and
      software agents can derive trust in other parties requires computerised
      analysis of the underlying trust networks. This article describes an approach
      to trust network analysis using subjective logic (TNA-SL), that consists of the
      three following elements. Firstly it uses a concise notation with which trust
      transitivity and parallel combination of trust paths can be expressed. Secondly
      it defnes a method for simplifying complex trust networks so that they can be
      expressed in this concise form. Finally it allows trust measures to be
      expressed as beliefs, so that derived trust can be automatically and securely
      computed with subjective logic. We compare our approach with trust derivation
      algorithms that are based on normalisation such as PageRank and EigenTrust. We
      also provide a numerical example to illustrates how TNA-SL can be applied.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-03&engl=1}
}

@article {ART-2005-02,
   author = {Michael Kinateder and Ralf Terdic and Kurt Rothermel},
   title = {{Trusting Pseudonyms – Anonymous Communication in Peer-to-Peer Reputation Systems}},
   journal = {International Journal for Infonomics},
   publisher = {e-Centre for Infonomics},
   pages = {1--1},
   type = {Article in Journal},
   month = {September},
   year = {2005},
   isbn = {ISSN 1742-4720},
   keywords = {privacy, anonymous communication, pseudonyms, extended destination routing, Chaum mixes, mix-cascade, onion routing, distributed hash table, Chord},
   language = {English},
   cr-category = {C.2.4 Distributed Systems,
                   E.3 Data Encryption,
                   K.4 Computers and Society},
   ee = {http://unitec.informatik.uni-stuttgart.de/,
      http://www.i-journal.org.uk/Special-issues/Special-Issues.htm},
   contact = {Michael Kinateder kinateder@informatik.uni-stuttgart.de},
   department = {University of Stuttgart, Institute of Parallel and Distributed Systems, Distributed Systems},
   abstract = {In this paper we present a novel approach to enable untraceable communication
      between pseudonyms. Our work provides strong sender and recipient anonymity by
      eliminating the need to know of each other’s address.
      
      We use a variation of Chaum mixes to achieve unlinkability between sender and
      recipient and introduce a concept called extended destination routing (EDR)
      which relies on routing headers constructed in multiple layers of encryption
      and published in a distributed hash table (DHT). In order to communicate, a
      sender requests from the DHT the recipient’s routing header, which is extended
      and used for routing the message via a mix cascade to this recipient.
      
      This work was performed in the context of the UniTEC reputation system and
      describes the functionality of its anonymous communication layer, which is
      completely independent of the other UniTEC layers. Although trust and
      reputation systems in general are typical application areas for our
      contribution, the presented concepts are suitable for various other application
      areas as well. We have implemented a prototype of UniTEC and present results
      from an ongoing evaluation in our network emulation testbed.},
   url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2005-02&engl=1}
}