[MNRDR17]
Paul Müller, Bernhard Neumair, Helmut Reiser, and Gabi Dreo Rodosek. 10. DFN-Forum Kommunikationstechnologien. June 2017.
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Der DFN-Verein ist seit seiner Gründung dafür bekannt, neueste Netztechnologien und innovative netznahe Systeme anwendungsorientiert zu erforschen und einzusetzen, um damit die Leistungen für seine Mitglieder laufend zu erneuern und zu optimieren. Beispiele dafür sind die aktuelle Plattform des Wissenschaftsnetzes X-WiN und Dienstleistungen für Forschung und Lehre wie die DFN-PKI, DFN-AAI und föderierte Cloud-Dienste. Um diese Technologien einerseits selbst mit zu gestalten und andererseits frühzeitig die eigenen Forschungsergebnisse mit den Entwicklungen anderer Wissenschaftler abzugleichen, veranstaltet der DFN-Verein seit vielen Jahren wissenschaftliche Tagungen zu Netztechnologien. Mit den Zentren für Kommunikation und Informationsverarbeitung in Forschung und Lehre e.V. (ZKI) und der Gesellschaft für Informatik e.V. (GI) gibt es in diesem Bereich eine langjährige und fruchtbare Zusammenarbeit. Das DFN-Forum Kommunikationstechnologien „Verteilte Systeme im Wissenschaftsbereich“ im Jahr 2017 ist bereits die 10. Veranstaltung in dieser Reihe. Es setzt die Tradition der neun sehr erfolgreichen Vorgänger in Kaiserslautern, München, Konstanz, Bonn, Regensburg, Erlangen, Fulda, Lübeck und Rostock fort. Als Jubiläumsveranstaltung wird das diesjährige Forum vom DFN-Verein und der Freien Universität Berlin gemeinsam mit dem ZKI e.V. und der GI am 30. und 31. Mai am Sitz des DFN-Vereins in Berlin veranstaltet. Wie seine Vorgänger soll es eine Plattform zur Darstellung und Diskussion neuer Forschungs- und Entwicklungsergebnisse aus dem Bereich TK/IT darstellen. Das Forum dient dem Erfahrungsaustausch zwischen Wissenschaftlern und Praktikern aus Hochschulen, Großforschungseinrichtungen und Industrie. Aus den eingereichten Beiträgen konnte ein hochwertiges und aktuelles Programm zusammengestellt werden, das sich neben Fragen von Netzsicherheit und IT Service Management auch mit e-Infrastrukturen für Forschung, Lehre und Forschungsdatenmanagement befasst. Eingeladene Beiträge runden das Programm ab. So wird im Jubiläumsjahr der DFN-Verein über Herausforderungen und Perspektiven bei Entwicklung und Betrieb eines großen Forschungsnetzes berichten. Das auch dieses Jahr hochaktuelle Thema Sicherheit im Internet wird im Beitrag „DDoS 3.0: the day the internet stopped working“ beleuchtet. Abgerundet wird das Programm durch einen Beitrag zur Ausfallsicherheit moderner SW-gesteuerter Systeme aus industrieller Sicht. Wir möchten uns bei den Autoren für alle eingereichten Beiträge, beim Programmkomitee für die Auswahl der Beiträge und die Zusammenstellung des Programms, bei den Mitarbeiterinnen und Mitarbeitern der Geschäftsstelle des DFN-Vereins für die Organisation und beim Gastgeber für die Unterstützung des Forums sowie die Gastfreundschaft bedanken. Allen Teilnehmern wünschen wir für die Veranstaltung interessante Vorträge und fruchtbare Diskussionen.

[WSM17]
Sebastian Wüst, Dennis Schwerdel, and Paul Müller. Container-based virtualization technologies. June 2017.
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As a newer concept, in comparison to hypervisor technologies, container-based virtualization is a rather lightweight virtualization concept. By not emulating any hardware it has a much lower overhead with good isolation. The basic idea is to generate isolated containers which use the same kernel as the host system, instead of individual ones per virtual machine. Hence the virtualized applications or systems have to be compatible to the same kernel. Networking testbeds like ToMaTo can benefit from such technology, since it allows to run many virtual machines in parallel. In this paper, three representatives of Linux container-based virtualization technologies will be presented: OpenVZ, Linux-VServer and LXC. The main features and concepts of each technology will be discussed, followed by a comparison about performance, security, virtualization system integration and client software. At the end their value for ToMaTo will be rated.

[MS17]
Paul Müller and Dennis Schwerdel. A Novel Approach Towards Sustainable Testbeds: ToMaTo on CloudLab. June 2017.
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Although testbeds and experimental facilities are accepted as tools for research in the scope of distributed systems research, such as Future Internet Research, they lack sustainability; once established as a project, they must be maintained and renewed every few years. However, unfortunately, due to an absence of long-term funding for operating/maintenance and reinvestment, a lot of these are terminated just after the project is complete.

In this paper, we describe a software-defined testbed on demand; this is based on the Topology Management Tool (ToMaTo), a software environment which was developed within the G-Lab project. ToMaTo, initially designed to run on the G-Lab infrastructure, is now independent of the underlying infrastructure and can be deployed on any Cloud infrastructure on demand. We describe here the deployment of ToMaTo to the CloudLab infrastructure offered by the NSF-funded CloudLab project.

This approach offers a new method for sustainable testbeds where neither upfront investment nor the recurring and operating/maintenance costs for the infrastructure will burden the budgets of the projects.

[GSM17]
Tim Gerhard, Dennis Schwerdel, and Paul Müller. Providing Information Centricity in Today’s Internet via Software-Defined Networking and In-Network Processing. June 2017.
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The Internet is a successful network that connects people all over the world. However, it has some fundamental architectural problems which require application developers and service providers to spend a tremendous effort in combating these. Examples for these efforts are content delivery networks or mobile TCP. Thus, it can be said that the Internet is currently not fulfilling the requirements on the global network anymore. The Internet of the future, or its replacement, must solve these problems.

There are multiple clean-slate approaches for information-centric networking. However, they are inherently incompatible to the Internet or applications building on it.

This work presents a novel resource transport protocol that is optimized for detection by software-defined networks and may be re-routed to in-network processors. Furthermore, it is shown how this protocol can be used to support concepts of ICN even in today’s Internet. Moreover, the resource format that is used in this work is independent from the underlying network, resulting in possible reuse in other networks as well. Applications and protocols building on this resource format can thus easily be re-used in clean-slate networks like NDN.

[GSM16]
Tim Gerhard, Dennis Schwerdel, and Paul Müller. Discovering Resources in Federated Clouds with Millions of Nodes: The SwarmCloud Approach. November 2016.
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Cloud Computing offers a way to outsource IT infrastructure and thereby reduce costs, especially for SMEs. However, companies remain skeptical of using the clouds of foreign organizations because of privacy and security concerns. Due to lack of experience and a too high up-front investment, companies also restrain from setting up their own cloud. The SwarmCloud project aims at creating a swarm-like network of cloud blocks that can cooperate in a decentralized manner. Each block is a minimal cloud system that is easily affordable for small companies. The SwarmCloud network automatically connects several blocks to form a federated higherlevel cloud system. Scaling such a network to millions of blocks requires a novel decentralized approach to network coordination and resource discovery. This paper proposes and evaluates a scalable network structure for the SwarmCloud network that leverages peer-to-peer paradigms to build swarms of millions of blocks.

[MNRDR16]
Paul Müller, Bernhard Neumair, Helmut Reiser, and Gabi Dreo Rodosek. 9. DFN-Forum Kommunikationstechnologien. Gesellschaft für Informatik (GI), May 2016.
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Der DFN-Verein ist seit seiner Gründung dafür bekannt, neueste Netztechnologien und innovative netznahe Systeme anwendungsorientiert zu erforschen und einzusetzen, um damit die Leistungen für seine Mitglieder laufend zu erneuern und zu optimieren. Beispiele dafür sind die aktuelle Plattform des Wissenschaftsnetzes X-WiN und Dienstleistungen für Forschung und Lehre wie die DFN-PKI, DFN-AAI und föderierte Cloud- Dienste. Um diese Technologien einerseits selbst mit zu gestalten und andererseits frühzeitig die eigenen Forschungsergebnisse mit den Entwicklungen anderer Wissenschaftler abzugleichen, veranstaltet der DFN-Verein seit vielen Jahren wissenschaftliche Tagungen zu Netztechnologien. Mit den Zentren für Kommunikation und Informationsverarbeitung in Forschung und Lehre e.V. (ZKI) und der Gesellschaft für Informatik e.V. (GI) gibt es in diesem Bereich eine langjährige und fruchtbare Zusammenarbeit. Das 9. DFN-Forum Kommunikationstechnologien „Verteilte Systeme im Wissenschaftsbereich“ steht in dieser Tradition. Nach den sehr erfolgreichen Vorgängerveranstaltungen in Kaiserslautern, München, Konstanz, Bonn, Regensburg, Erlangen, Fulda und Lübeck wird die diesjährige Tagung vom DFN-Verein und der Universität Rostock gemeinsam mit dem ZKI e.V. und der GI am 31. Mai und 1. Juni 2016 in Rostock veranstaltet und soll eine Plattform zur Darstellung und Diskussion neuer Forschungs- und Entwicklungsergebnisse aus dem Bereich TK/IT darstellen. Das Forum dient dem Erfahrungsaustausch zwischen Wissenschaftlern und Praktikern aus Hochschulen, Großforschungseinrichtungen und Industrie. Aus den eingereichten Beiträgen konnte ein hochwertiges und aktuelles Programm zusammengestellt werden, das sich neben Fragen von Netztechnologien und ITInfrastrukturen auch mit Infrastrukturen für eResearch befasst. Traditionell ist auch die IT- und Netz-Sicherheit ein wichtiges Thema des Forums, das auch in diesem Jahr intensiv und breit behandelt wird. Eingeladene Beiträge runden das Programm ab. So wird der DFN globale Trends in der Kooperation zwischen Wissenschaftsnetzen präsentieren. Die Zentralstelle Cybercrime in Bayern wird aus der staatsanwaltschaftlichen Praxis der Verfolgung von Cybercrime berichten und eine Vertreterin des Bundesamtes für Bevölkerungsschutz und Katastrophenschutz wird Kritische Infrastrukturen und IT-Sicherheit beleuchten. Wir möchten uns bei den Autoren für alle eingereichten Beiträge, beim Programmkomitee für die Auswahl der Beiträge und die Zusammenstellung des Programms, bei den Mitarbeiterinnen und Mitarbeitern für die umfangreichen organisatorischen Arbeiten und beim Gastgeber für die Unterstützung des Forums sowie die Gastfreundschaft bedanken. Allen Teilnehmern wünschen wir für die Veranstaltung interessante Vorträge und fruchtbare Diskussionen.

[MSC16]
Paul Müller, Dennis Schwerdel, and Justin Cappos. ToMaTo a Virtual Research Environment for Large Scale Distributed Systems Research. January 2016.
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Networks and distributed systems are an important field of research. To enable experimental research in this field we propose a new tool ToMaTo (Topology Management Tool) which was developed to support research projects within the BMBF funded project G-Lab. It should support researchers from various branches of science who investigate distributed systems by providing a virtual environment for their research. Using various virtualization technologies, ToMaTo is able to provide realistic components that can run realworld software as well as lightweight components that can be used to analyze algorithms at large scale. This paper describes how an additional virtualization technology from the Seattle testbed has been added to ToMaTo to allow even larger experiments with distributed algorithms. Moreover the paper describes some concrete experiments that are carried out with ToMaTo.

[MNRDR15]
Paul Müller, Bernhard Neumair, Helmut Reiser, and Gabi Dreo Rodosek. 8. DFN-Forum Kommunikationstechnologien. Gesellschaft für Informatik (GI), June 2015.
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Der DFN-Verein ist seit seiner Gründung dafür bekannt, neueste Netztechnologien und innovative netznahe Systeme anwendungsorientiert zu erforschen und einzusetzen, um damit die Leistungen für seine Mitglieder laufend zu erneuern und zu optimieren. Beispiele dafür sind die aktuelle Plattform des Wissenschaftsnetzes X-WiN und Dienstleistungen für Forschung und Lehre wie die DFN-PKI und DFN-AAI. Um diese Technologien einerseits selbst mit zu gestalten und andererseits frühzeitig die eigenen Forschungsergebnisse mit den Entwicklungen anderer Wissenschaftler abzugleichen, veranstaltet der DFN-Verein seit vielen Jahren wissenschaftliche Tagungen zu Netztechnologien. Mit den Zentren für Kommunikation und Informationsverarbeitung in Forschung und Lehre e.V. (ZKI) und der Gesellschaft für Informatik e.V. (GI) gibt es in diesem Bereich eine langjährige und fruchtbare Zusammenarbeit.

[KGM14a]
Aneta Kabzeva, Joachim Götze, and Paul Müller. Service Network Modeling: A Generic Approach. In 4th International Workshop on Adaptive Services for the Future Internet (WAS4FI 2014), September 2014.
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With the broad adoption of service-orientation for the realization of business applications and their provisioning and usage over open cloud infrastructures, the topology of the resulting service networks is becoming extremely complex. Due to the composition of services for value-added business capabilities and the reusability of a service in multiple compositions, the execution of one service often depends on other services and changes in its provisioning can affect the health of large parts of the service network. The lack of insight on the relationships between the network components makes the management of the service network's health and change impact hard and error prone tasks. This paper proposes a service network modeling approach for capturing the topology of a service network at design time. The model is used to validate the health of the service network to ensure the operability of its services. At run time the model can be applied for analyzing the effects of evolutionary events such as service modification or withdrawal. Our major contributions are a generic and adaptable modeling structure and a classification of service network entities and relationships. The applicability of our approach is evaluated on an example service network scenario.

[KGM14b]
Aneta Kabzeva, Joachim Götze, and Paul Müller. Service Network Modeling Approaches: Overview, Classification, and Analysis. In 40th EUROMICRO Conference on Software Engineering and Advanced Applications, August 2014.
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The emergence of Software-as-a-Service solutions and their open provisioning on web-based service platforms has initiated the research on service networks in recent years. Being a complex and dynamic distributed system of service systems, the maintenance and evolution of a service network has called for the definition of new modeling approaches. A formal model, providing a description of the complex relationships emerging between the independent network participants in the context of applications composed of cross-domain services, can support evolutionary decisions in the network. However, the variety of stakeholder perspectives on a service network and the different abstraction layers of a service-oriented application make the specification of a generic service network model a challenging task. This paper provides an extensive overview of the current research on service network modeling. It classifies existing modeling approaches according to the level of abstraction of the models they produce, ranging from a business to a technical perspective. Further, it presents a comparative analysis of service network modeling approaches against a set of properties evaluating the integration of different stakeholder perspectives, the support for heterogeneous specifications, and the adaptability to analysis needs of their models.

[GFKM14]
Joachim Götze, Tino Fleuren, Aneta Kabzeva, and Paul Müller. Requirements-driven and Reflective Communication Middleware Using Feature Chains for Service-oriented Applications. In 40th EUROMICRO Conference on Software Engineering and Advanced Applications, August 2014.
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[JGR+14]
Sagar Jadhav, Tim Gerhard, Priya Rath, Sundeep Yadav, Syed Mhedi, Raj Shah, and Paul Müller. Seminar - Service-orientation in Communication and Applications. Technical report, University of Kaiserslautern, Germany, July 2014.
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Service-oriented architecture (SOA) is an architectural paradigm applied for the development of distributed systems. With the help of design principles like loose coupling and service contract it is possible to create a pool of application agnostic, reusable services. Via orchestration and choreography of such services, complex business processes can be modeled as workflows. The application of the SOA principles can improve the agility not only of applications but also of network infrastructures. They offer novel possibilities for the development of future network protocols.

[MNRDR14]
Paul Müller, Bernhard Neumair, Helmut Reiser, and Gabi Dreo Rodosek. 7. DFN-Forum Kommunikationstechnologien. In Gesellschaft für Informatik (GI), June 2014.
[ bib | dspace ]

Der DFN-Verein ist seit seiner Gründung dafür bekannt, neueste Netztechnologien und innovative netznahe Systeme einzusetzen und damit seine Leistungen für seine Mitglieder laufend zu erneuern und zu optimieren. Beispiele dafür sind die aktuelle Plattform des Wissenschaftsnetzes X-WiN und Dienstleistungen für Forschung und Lehre wie die DFN-PKI und DFN-AAI. Um diese Technologien einerseits selbst mit zu gestalten und andererseits frühzeitig die Forschungsergebnisse anderer Wissenschaftler kennenzulernen, veranstaltet der DFN-Verein seit vielen Jahren wissenschaftliche Tagungen zu Netztechnologien. Mit den Zentren für Kommunikation und Informationsverarbeitung in Forschung und Lehre e.V. (ZKI) und der Gesellschaft für Informatik e.V. (GI) gibt es in diesem Bereich eine langjährige und fruchtbare Zusammenarbeit.

[GSM14]
Tim Gerhard, Dennis Schwerdel, and Paul Müller. A Networkless Data Exchange and Control Mechanism for Virtual Testbed Devices. In Springer, May 2014.
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Virtualization has become a key component of network testbeds. However, transmitting data or commands to the test nodes is still either a complicated task or makes use of the nodes’ network interfaces, which may interfere with the experiment itself. This paper creates a model for the typical lifecycle of experiment nodes, and proposes a mechanism for networkless node control for virtual nodes in such a typical experiment lifecycle which has been implemented in an existing testbed environment.

[SHME14b]
James P.G. Sterbenz, David Hutchison, Paul Müller, and Chip Elliott. Special issue on Future Internet Testbeds – Part II. In Elsevier B.V., April 2014.
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These two special issues on Future Internet Testbeds (Volumes 61 and 63) focus on the design, building and use of contemporary testbeds on several continents. The overall topic is split across two volumes, the first primarily focused on the architecture, infrastructure, and deployment of the testbeds themselves, and the second broadly dealing with experiments and usage of these testbeds. Note that this division is not perfect, and many of the papers in these two issues cover both aspects.

[SHME14a]
James P.G. Sterbenz, David Hutchison, Paul Müller, and Chip Elliott. Special issue on Future Internet Testbeds – Part I. Elsevier B.V., March 2014.
[ bib | dspace ]

These two special issues on Future Internet Testbeds (Volumes 61 and 63) focus on the design, building and use of contemporary testbeds on several continents. The overall topic is split across two volumes, the first primarily focused on the architecture, infrastructure, and deployment of the testbeds themselves, and the second broadly dealing with experiments and usage of these testbeds. Note that this division is not perfect, and many of the papers in these two issues cover both aspects.

[SRZ+14]
Dennis Schwerdel, Bernd Reuther, Thomas Zinner, Paul Müller, and Phuoc Tran-Gia. Future Internet research and experimentation: The G-Lab approach. In Elsevier B.V., March 2014.
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The German Lab (G-Lab) project aims to investigate architectural concepts and technologies for a new inter-networking architecture as an integrated approach between theoretic and experimental studies. Thus G-Lab consists of two major fields of activities: research studies of future network components and the design and setup of experimental facilities. Both are controlled by the same community to ensure that the experimental facility meets the demands of the researchers. Researchers gain access to virtualized resources or may gain exclusive access to resources if necessary. We present the current setup of the experimental facility, describing the available hardware, management of the platform, the utilization of the PlanetLab software and the user management. Moreover, a new approach to setup and deploy virtual network topologies will be described.

[KSM14]
M. Rahamatullah Khondoker, Abbas Siddiqui, and Paul Müller. Realization of Service-Orientation Paradigm in Network Architectures. In River Publishers, March 2014.
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The implementation of communication protocols in the current Internet architecture is tightly-coupled which hinders the evolution of the Internet. This article describes how the principles of Service Oriented Architecture (SOA) can be employed to develop a flexible network architecture. The prototype of the concept has been developed and demonstrated in the EuroView 2012 workshop. We showed that the SOA paradigm can be applied to networks by utilizing the concepts of self-contained building blocks, dynamic protocol graphs (PGs) and functional composition (FC) methods. We demonstrated that both short-term flexibility (i.e., networks are adapted based on application requirements) and long-term flexibility (i.e., networks can be evolved) can be achieved by using the architecture.

[KGM13]
Aneta Kabzeva, Joachim Götze, and Paul Müller. Capturing and Analyzing Service Network Models. In ACM Press (iiWAS 2013), December 2013.
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The composition of services offered and consumed over the Internet results in complex environments comprising multiple service-based applications, referred to as Service Networks (SNs). Understanding the role of a service as part of an SN requires modeling techniques allowing to express and analyze its integration within the network. This paper presents a relationship-based framework for capturing and analyzing Service Network models. It uses business process specifi cations and service descriptions to generate an explicit cross-application relationship model. Based on prede fined structural rules, the framework validates the completeness of the model and informs on inconsistency issues.

[KGLM13]
Aneta Kabzeva, Joachim Götze, Thomas Lottermann, and Paul Müller. Service Relationships Management for Maintenance and Evolution of Service Networks. In The Eighth International Conference on Software Engineering Advances (ICSEA 2013), October 2013.
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The Service-Oriented Architecture (SOA) paradigm is broadly accepted for the realization of business capabilities. Hence, the maintenance and evolution of Service Networks (SN) as systems comprising multiple service-based applications is becoming a growing issue. The larger a service inventory grows and the more often services are reused, the more consequences a service change or fault can cause on related applications in the SN. While reducing the adaptation complexity of a single solution, the realization of business processes as service compositions introduces logical relations defined implicitly between the technically independent services. To preserve the consistency in the whole SN, maintenance and evolution processes have to consider all relations to the changing configuration item. We present a framework for collection, validation, and representation of service relationship information. Contributions of the proposed solution include a semi-automatic approach for relationship identification, a mechanism for completeness and consistency validation, and a tailormade representation of relations according to stakeholder needs.

[FGM13]
Tino Fleuren, Joachim Götze, and Paul Müller. Facilitating scientific workflow configuration with parameterized workflow skeletons. In Proceeding of 39rd Euromicro SEAA, September 2013.
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This paper describes an operator for configuring scientific workflows that facilitates the process of assigning workflow activities to cloud resources.

In general, modeling and configuring scientific workflows is complex and error-prone, because workflows are built of highly parallel patterns comprising huge numbers of tasks. Reusing tested patterns as building blocks avoids repeating errors. Workflow skeletons are parametrizable building blocks describing such patterns. Hence, scientists have a means to reuse validated parallel constructs for rapidly defining their in-silico experiments.

Often, configurations of data parallel patterns are generated automatically. However, for many task parallel patterns each task needs to be configured manually. In frameworks like MapReduce, scientists have no control of how tasks are assigned to cloud resources. What is the strength of such patterns, may lead to unnecessary data transfers in other patterns.

Workflow Skeletons facilitate the configuration by providing an operator that accepts parameters; this allows for scalable configurations saving time and cost by allocating cloud resources just in time. In addition, this configuration operator helps to define configurations that avoid unnecessary data transfers.

[GFRM13]
Joachim Götze, Tino Fleuren, Bernd Reuther, and Paul Müller. A Model for Policy-based Automation of Usage Accounting across Multiple Cloud Infrastructures. In 39th EUROMICRO Conference on Software Engineering and Advanced Applications, September 2013.
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Cloud Computing provides flexible and dynamic provisioning of resources, services, and applications. As such, Cloud Computing is the ideal IT infrastructure for the ever changing workload of companies and service providers. Although, cloud providers offer functionality for usage accounting, this functionality is limited to their own requirements. Companies and service providers as cloud users have also a need for usage accounting, but with different requirements than the cloud providers. Additionally, cloud users are not limited to a single cloud, but make use of multiple cloud infrastructures and applications depending on their needs.

Cloud users require a usage accounting infrastructure not only capable of supporting billing as an accounting application, but capable of supporting all kinds of applications. For example applications like cost allocation or trend analysis. In order to be able to manage such a complex and adaptable usage accounting infrastructure, we present a policy-based management approach. Policies are used as a high-level description of the intended behavior of the infrastructure which are then utilized to derive configurations for the infrastructure services. Such a solution ensures the efficient management and administration of complex usage accounting infrastructures.

[Mül13b]
Paul Müller. Software Defined Networking: Bridging the gap between distributed-systems and networked-systems research. In Gesellschaft für Informatik (GI), June 2013.
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This contribution takes a quote from Einstein, We can't solve problems by using the same kind of thinking we used when we created them, to take a step back and try to have another viewpoint when thinking about a new internetworking architecture. The ongoing research will not be looked at from an application research point of view nor from a communication technology point of view, but from a software engineering perspective. This new way of thinking leads us to realize that the Internet is a largely distributed software system, and thus we propose to apply software-oriented methodologies to define a new internetworking architecture. These methodologies lead to a new, flexible architecture that allows for both evolutionary and clean-slate approaches. Moreover, this approach bridges the gap between application and distributed systems research, and networking research to have a more holistic view and avoid suboptimal solutions.

[MNRDR13]
Paul Müller, Bernhard Neumair, Helmut Reiser, and Gabi Dreo Rodosek. 6. DFN-Forum Kommunikationstechnologien. Gesellschaft für Informatik (GI), June 2013.
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[GKM13]
Daniel Günther, Nathan Kerr, and Paul Müller. A Method for Producing Requirement-Specific Protocol Graphs in a Flexible Network Architecture. April 2013.
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Future-Internet research tries to improve the Internet in various ways. Functional-block-based approaches use flexible network stacks called protocol graphs which are created from functional blocks which encapsulate network functionalities. This article presents a method for producing requirement-specific protocol graphs which organizes the problem domain into the separate concerns of modeling functional blocks with impact functions, using those impact functions to evaluate the impact of a protocol graph, searching through the set of possible protocol graphs to select those protocol graphs which fulfill the requirements, and then reducing that set of protocol graphs to the most suitable one. Algorithms for the impact evaluation, search and selection, and optimization methods along with their relations are presented. An example is also presented to further clarify and describe our approach.

[Mül13a]
Paul Müller. Software Defined Networking: A Position Statement. In European Commission, February 2013.
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In this contribution we take Einstein’s quote “We can't solve problems by using the same kind of thinking we used when we created them” to take a step back and try to have another viewpoint when we think about a new internetworking architecture. We don’t want to look to the ongoing research from a “communication technology” point of view but from a “software engineering” one. This new way of thinking leads us to the assumption the Internet is a “largely distributed software system” and thus we propose to apply software-oriented methodologies for the definition of a new internetworking architecture. This methodology leads us to a new flexible architecture that span from evolutionary to clean-slate approaches that allows incremental and reactive improvements as well as clean-slate approaches for a new internetworking architecture.

[Mül12b]
Paul Müller. Future internetworking research and innovation - A software-defined networking perspective. In Ebenezer House, Ryecroft, December 2012.
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[SKM12]
Abbas Siddiqui, M. Rahamatullah Khondoker, and Paul Müller. Template Based Composition for Requirements Based Network Stack. In IEEE, in the proceedings of the 2012 Australasian Telecommunication Networks and Applications Conference (ATNAC 2012), Brisbane, Australia, November 2012.
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The modularizing of the functionalities from a network stack and then to compose a desirable service on demand is relatively new in the network architecture however the modularizing is being practiced in the software engineering since few decades now. The composition of functionalities to achieve a desired result can be performed at various timephases(e.g. run-time, design-time, deployment-time), but it is not clear which phase is the most suitable one in terms of performance, complexity and flexibility. It is most likely that a single approach will not be appropriate in every circumstance. In this paper, an intermediate approach so called template based composition is proposed to find a compromise between complexity and flexibility.

[Mül12a]
Paul Müller. Future Internet - Ein internationales Projekt zur Föderation heterogener Cloudsysteme. In Deutsches Forschungsnetz, November 2012.
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Die Entwicklung des Internets in den letzten Jahren hat gezeigt, dass es immer schwieriger wird, neue Funktionalität zu integrieren, um Anforderungen seitens der Applikationen zu erfüllen und auf veränderte Rahmenbedingungen der Transporttechnologien zu reagieren. Insbesondere die Kernmechanismen (TCP/IP) sind nur schwer veränderbar. Daher wird seit einiger Zeit die Entwicklung einer neuen Architektur für ein zukünftiges Internet im Rahmen internationaler, europäischer und deutscher Projekte vorangetrieben. In diesem Beitrag wird ein, zwischen den Projekten GENI (USA) und G-Lab (Deutschland) durchgeführtes Projekt zur Föderation heterogener Cloudsysteme vorgestellt.

[BCM+12]
Andy Bavier, Yvonne Coady, Tony Mack, Chris Matthews, Joe Mambretti, Rick McGeer, Paul Müller, Alex Snoeren, and Marco Yuen. GENICloud and TransCloud. In ACM, September 2012.
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Abstract In this paper, we argue that federation of cloud systems requires a standard API for users to create, manage, and destroy virtual objects, and a standard naming scheme for virtual objects. We introduce an existing API for this purpose, the Slice-Based Federation Architecture, and demonstrate that it can be implemented on a number of existing cloud management systems. We introduce a simple naming scheme for virtual objects, and discuss its implementation.

[SM12b]
Abbas Siddiqui and Paul Müller. Tradeoffs in Selection and Composition Approaches for Future Internet Architectures. August 2012.
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A successful SC process generates a protocol graph, a protocol graph is a sequence of instructions which may require specialized engine to understand and execute it. Selection and composition of functionalities can be performed at different phases which varies from development time to on-the-fly (i.e. runtime). Three different approaches are briefly described below.

[GKM12c]
Daniel Günther, Nathan Kerr, and Paul Müller. A Multistep Process Model for Selecting and Composing Functional Blocks in a Future Internet Architecture. In Second International Workshop on Future Internet and Next Generation Networks (FINGNet-2012),, July 2012.
[ bib | dspace ]

Future Internet research activities try to increase the flexibility of the Internet. A well known approach in this area is to build protocol graphs by connecting functional blocks together. The protocol graph that should be used is the one most suitable to the application’s requirements. This paper presents a Multistep Process Model to find the most suitable protocol graph. We evaluate our proposed method by conceptual review in combination with a defined evaluation scenario using loss reduction.

[LNdM+12]
Gergö Lovasz, Florian Niedermeier, Hermann de Meer, Daniel Günther, Paul Müller, and Stefan Dambeck. Demonstration of the Ener-G Resource Allocation System. In 12th Würzburg Workshop on IP: ITG Workshop Visions of Future Generation Networks (EuroView2012), July 2012.
[ bib | dspace ]

[SM12a]
Abbas Siddiqui and Paul Müller. A Requirement-Based Socket API for a Transition to Future Internet Architectures. In Sixth International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing (IMIS-2012), July 2012.
[ bib | dspace ]

The existing application programming interface (API) between applications and the network architecture is one reason that it is hard to deploy novel protocols into the network architecture. Coupling between applications and underlying protocols makes it almost impossible to change one without changing the other. Coupling can be loosened or resolved by not involving applications in protocols implementation details but, only in functionality necessary to establish a communication. This way underlying network can deploy novel or updated implementations of a functionality without needing to change the applications. Using intermediate abstraction layers is an approach to break the dependency between applications and network protocols. One of the major goals in future internet architectures is to be flexible enough to adapt to application’s requirements. In this paper, a requirement-based API is presented as an abstraction layer to make applications independent of network mechanisms, which also helps in the transition to future internet architectures.

[GSS+12]
Daniel Günther, Dennis Schwerdel, Abbas Siddiqui, M. Rahamatullah Khondoker, Bernd Reuther, and Paul Müller. Selecting and Composing Requirement Aware Protocol Graphs with SONATE. In 12th Würzburg Workshop on IP: ITG Workshop Visions of Future Generation Networks (EuroView2012), July 2012.
[ bib | dspace ]

[KSRM12]
M. Rahamatullah Khondoker, Abbas Siddiqui, Bernd Reuther, and Paul Müller. Service Orientation Paradigm in Future Network Architectures. In Sixth International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing (IMIS-2012), July 2012.
[ bib | dspace ]

The Internet can not keep up with changing application requirements and new network technologies as its network architecture makes it hard to introduce new functionality because existing functionalities in the Architecture are inherently tightly coupled. This article describes how the principles of Service Oriented Architecture (SOA) can help to develop more flexible network architecture. We argue that the SOA paradigm can be applied to networks by utilizing the concepts of self-contained building blocks, dynamic protocol graphs and selection and composition methods. In order to make use of flexible networks, applications must be decoupled from the protocols they use. We give a brief overview, of how some of these concepts are already implemented, by presenting few approaches. Finally we describe some challenges of service oriented network architecture.

[GKM12f]
Daniel Günther, Nathan Kerr, and Paul Müller. A Strategic Search Method for Requirement-Aware Functional-Block Selection and Composition in a Flexible Network. In Journal of Digital Information Management, June 2012.
[ bib | dspace ]

Internet applications have reached such a high complexity that the network stack concept introduced decades ago is not suitable anymore. Future Internet research activities try to increase the flexibility of the Internet in order to allow the network to adapt to present and future requirements and applications. A well known approach is to build protocol graphs, which will be used instead of inflexible network stacks, by connecting functional blocks together. A functional block encapsulates a particular network function. The protocol graph that should be used is the one most suitable to the application’s requirements. To find the most suitable graph, all possible protocol graphs must be evaluated. However, the number of possible protocol graphs increases exponentially as the number of functional blocks increases. This article presents a method of modeling the protocol graph search space as a set of search trees and then using search strategies to manage the inherent complexity of the search process. We evaluate our proposed method by simulation.

[AKGM12]
Senol Arikan, Aneta Kabzeva, Joachim Götze, and Paul Müller. A Generic Testing Framework for the Internet of Services. In The Seventh International Conference on Internet and Web Applications and Services - ICIW2012, May 2012.
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A widespread approach of the design and development of heterogeneous distributed software systems is the use of an interacting group of services. This approach uses the concepts of Service-oriented architectures to realize a dynamic adaptive communication system among service provider, service consumer and service broker. Today, the Internet, as the largest heterogeneous distributed software system, uses the ideas of service orientation more and more, thus it is extended to the Internet of Services. In the Internet of Services, autonomous services can be deployed by different service providers on service platforms; thereby they are available via the Internet for a large number of service consumers. Service providers can change their service implementation at any time without notifying the service’s consumers; therefore, no guarantees can be made about the adherence of these services to the specification the consumers expect. In order to ensure the compliance of the services to their specifications and provide a certain level of quality assurance for service consumers and platform providers, a service platform needs to provide comprehensive testing mechanisms which support the quality needs of all actors on the platform. In this paper, we propose a generic testing framework which can be used during design and run-time for the automated verification of distributed services.

[GKM12a]
Daniel Günther, Nathan Kerr, and Paul Müller. Auswahl von Netzwerktransportangeboten in einer Future-Internet-Architektur basierend auf funktionalen Blöcken. In Gesellschaft für Informatik (GI), May 2012.
[ bib | dspace ]

Verschiedene Ansätze im Forschungsfeld Future Internet beschäftigen sich mit der Problemstellung, die Flexibilität des Internets zu erhöhen. Um dieses Ziel zu erreichen, wurden bisher verschiedene Entwicklungsstufen durchlaufen. Ein verbreiteter Ansatz in diesem Forschungsfeld ist der flexible Zusammenbau von Netzwerkprotokollgraphen durch die Verbindung einzelner funktionaler Blöcke. Diese Methode erlaubt es, den Kommunikationsanforderungen der Anwendung mithilfe eines hierzu erstellten Netzwerktransportangebotes zu entsprechen. Aufgrund der hierdurch erreichten Flexibilität ist es möglich, dass mehrere Funktionskompositionen die gestellten Anforderungen – in unterschiedlicher Angebotsausprägung – erfüllen. Notwendig ist es nun, ein Angebot für die Kommunikation auszuwählen. Problematisch ist hierbei allerdings die Entscheidung, welches Angebot in Form eines Netzwerktransportangebotes verwendet werden soll. Unterschiedliche Optimierungskriterien erhöhen zusätzlich die Komplexität dieser Problemstellung. Der vorliegende Beitrag präsentiert eine Methode zur Auswahl eines geeigneten Angebotes basierend auf einem multikriteriellen Entscheidungsverfahren. Die dargestellte Vorgehensweise wird durch Simulation mehrerer Testfälle, Komplexitätsbetrachtung sowie Diskussion evaluiert.

[MNRDR12]
Paul Müller, Bernhard Neumair, Helmut Reiser, and Gabi Dreo Rodosek. 5. DFN-Forum Kommunikationstechnologien. Gesellschaft für Informatik (GI), May 2012.
[ bib | dspace ]

[GKM12d]
Daniel Günther, Nathan Kerr, and Paul Müller. A Requirement Aware Method to Reduce Complexity in Selecting and Composing Functional-block-based Protocol Graphs. In The Fourth International Conference on Networked Digital Technologies (NDT’2012), April 2012.
[ bib | dspace ]

Future Internet research activities try to increase the flexibility of the Internet. A well known approach is to build protocol graphs by connecting functional blocks together. The protocol graph that should be used is the one most suitable to the application’s requirements. To find the most suitable graph, all possible protocol graphs must be evaluated. However, the number of possible protocol graphs increases exponentially as the number of functional blocks increases. This paper presents a method of representing the protocol graph search space as a set of search trees and then uses forward pruning to reduce the number of protocol graphs evaluated. We evaluate our proposed method by simulation.

[GKM12e]
Daniel Günther, Nathan Kerr, and Paul Müller. A Simulation Model for Evaluating the Impact of Communication Services in a Functional-block-based Network Protocol Graph. In 15th Communications and Networking Simposium (CNS'12) at SpringSim'12, March 2012.
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A flexible Future Internet Architecture based on functional blocks will allow the use of different mechanisms to fulfill emerging communication requirements. With this freedom of choice, we can make use of application requirements and system constraints to choose the best Protocol Graph. Each available block impacts the quality of the Protocol Graph. How then can the given requirements and constraints be used to determine which block to use? In this paper we present a simulation model to evaluate the impact of network communication services to decide if a block or a set of blocks composed into a protocol graph is able to fulfill the given application requirements and system constraints. The results gained by simulating our presented model show that it is possible to select an appropriate mechanism by matching the application requirements with given offers.

[Mea12]
Paul Müller and et all. Future Internet Design Principles. In European Commission - Information Society and Media, January 2012.
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The EC Future Internet Architecture (FIArch) Experts Reference Group (ERG) focuses on a few key architectural issues, contributing to an EC research roadmap towards a Future Internet Architecture. It is composed of repr esentatives of the most relevant FP7 research projects in relation to Future Internet architectures and renowned experts from industry and academy covering in a complementarily way all areas related to the Future Internet Architecture.

[GKM12b]
Daniel Günther, Nathan Kerr, and Paul Müller. A Model to Select and Compose Functional Block Based Protocol Graphs. In 7th GI/ITG KuVS Workshop on Future Internet, January 2012.
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Future Internet research looks to increase the flexibility of the Internet architecture. A well known approach uses functional composition to build protocol graphs from a pool of functional blocks which implement the mechanisms needed to create a network stack. This talk will present the Multistep Process Model (MPM) approach to create requirement aware protocol graphs.

[SM12c]
Abbas Siddiqui and Paul Müller. Tradeoffs in Selection and Composition Approaches for Future Internet Architectures. In 7th GI/ITG KuVS Workshop on Future Internet, January 2012.
[ bib | dspace ]

A successful SC process generates a protocol graph, a protocol graph is a sequence of instructions which may require specialized engine to understand and execute it. Selection and composition of functionalities can be performed at different phases which varies from development time to on-the-fly (i.e. runtime). Three different approaches are briefly described below.

[TDG+11]
Hong-Linh Truong, Schahram Dustdar, Joachim Götze, Tino Fleuren, Paul Müller, Michaël Mrissa, Chirine Ghedira, and Salah-Eddine Tbahriti. Exchanging Data Agreements in the DaaS Model. In The 2011 IEEE Asia-Pacific Services Computing Conference, Jeju, Korea. IEEE, December 2011.
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Rich types of data offered by data as a service (DaaS) in the cloud are typically associated with different and complex data concerns that DaaS service providers, data providers and data consumers must carefully examine and agree with before passing and utilizing data. Unlike service agreements, data agreements, reflecting conditions established on the basis of data concerns, between relevant stakeholders have got little attention. However, as data concerns are complex and contextual, given the trend of mixing data sources by automated techniques, such as data mashup, data agreements must be associated with data discovery, retrieval and utilization. Unfortunately, exchanging data agreements so far has not been automated and incorporated into service and data discovery and composition. In this paper, we analyze possible steps and propose interactions among data consumers, DaaS service providers and data providers in exchanging data agreements. Based on that, we present a novel service for composing, managing, analyzing data agreements for DaaS in cloud environments and data marketplaces.

[KVM11]
M. Rahamatullah Khondoker, Eric Veith, and Paul Müller. A Description Language for Communication Services of Future Network Architectures. In Network of Future (NoF), Paris, France, November 2011.
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For selecting and composing communication services to create a networking stack in a flexible future network architecture, service descriptions are required. In this paper, we propose a language for describing communication services. The language has been implemented by using the Resource Description Framework (RDF) and evaluated by describing a set of dependencies and a complete service. Irrespective of the selection and composition methods at design time, deployment time and runtime, the language can be used any place where a networking service description is required.

[GVM11a]
Daniel Günther, Eric MSP Veith, and Paul Müller. Extracting Decision Criteria by Modeling Retransmission and Forward Error Correction in a Future Internet Architecture. In Proceedings of the Work in Progress Session held in connection with the 37th Euromicro Conference on Software Engineering and Advanced Applications (SEAA2011), September 2011.
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[FGM11]
Tino Fleuren, Joachim Götze, and Paul Müller. Workflow Skeletons: Increasing Scalability of Scientific Workflows by Combining Orchestration and Choreography. In 9th IEEE European Conference on Web Services (ECOWS), September 2011.
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Dataflow modeling is the natural way of composing scientific workflows, because they often comprise numerous data transformation steps applying massive parallelism. However, modeling control flow within dataflow is often achieved at the expense of clarity and comprehensibility. This paper describes scientific workflows maintaining the robustness of centralized control (using orchestration) by modeling control flow, while at the same time integrating sub-workflows that are modeled by workflow skeletons (using choreography) describing dataflow. Following the concept of algorithmic skeletons, we define workflow skeletons as re-usable parallel constructs describing dataflow connections between proxies representing services. Proxies are able to communicate with each other allowing for efficient coupling between parallel tasks and avoiding of unnecessary data transfers. Skeletons increase scalability on demand by accepting the number of parallel tasks. The primary contributions are a formal model describing workflow skeletons and a script language ”Workflow Skeleton Language” (WorkSKEL). Furthermore, this paper demonstrates the definition of selected workflow patterns like pipeline and farm in WorkSKEL.

[GFRM11]
Joachim Götze, Tino Fleuren, Bernd Reuther, and Paul Müller. Extensible and Scalable Usage Accounting in Service-oriented Infrastructures based on a Generic Usage Record Format. In 6th Workshop on Enhanced Web Service Technologies (WEWST), September 2011.
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Service orientation is a successful architecture paradigm used within different application scenarios. Some of these scenar- ios are high performance computing (grid computing), the Internet of services, and cloud computing. Usage accounting is a topic currently covered prevalent for computing services and networking resources, but a generic approach comprising arbitrary services does not exist. Such an approach to usage accounting can provide a benefit for the platform provider by taking into account all kinds of services and applications. It is not only possible to create a financially- independent service platform, but also to take advantage of applications like cost allocation and trend analysis of service utilization. The main contributions of the solution for usage accounting proposed here are: a generic usage record format able to support accounting information of any kind of service in a future-proof manner as well as a scalable accounting infrastructure easily adaptable to the specific requirements of the application domain.

[SKM+11]
Abbas Siddiqui, Michael Kleis, Julius Müller, Paul Müller, and Thomas Magedanz. Application and Network Services Composition with the Help of Mediation. In 11th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2011), August 2011.
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The G-Lab DEEP cross-layer FC architecture leads to a two-layer functional composition architecture. Services (e.g. web services, encoding service) are composed at service layer and network services at network layer. Scope of services at network and service layer is not limited as any kind of service could be implemented at any of both layers but it is important to take in to consideration where specific service would be most optimized and efficient. This separation is still valuable because an application designer should not know and compose the network functional blocks by himself but explicitly state the abstract requirements of an application, e.g. encryption and QoS (maximum delay, maximum loss). Nevertheless, there should be a feedback of the network if requirements can be met or not, thus service level can react by realizing e.g. encryption on service level, using another media encoding, or by selecting a different content source. For this purpose we propose in this paper a cross layer mediator that negotiates and exchange information between the two layers .

[SKV+11]
Dennis Schwerdel, M. Rahamatullah Khondoker, Eric MSP Veith, Bernd Reuther, and Paul Müller. Requirements Based Automatic Service Composition: A Demonstration. In 11th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2011), August 2011.
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The current Internet architecture was designed decades ago. Back then the main goals of the architecture were stability, performance and of course its functionality. Current trends, e.g. mobile devices, cloud computing, energy efficiency pose new requirements that the current Internet architecture cannot fulfill. Rather than building new functionality on top of the Internet or adding more complexity to it by introducing even more conditional functionality the Future Internet should have a smarter way to deal with diverse requirements and environmental constraints. Future network architectures must be flexible both long-term and a short-term in order to evolve and adapt to changing application requirements and new transport technologies (fixed and/or mobile) with different capabilities, and should enable evolutionary changes of the network itself. Thereby long-term flexibility can be seen as the capability of a system to evolve with updated protocols and network capabilities. Short-term flexibility is understood as the capability of a system to adapt itself and react to network conditions and an application requirements [1]. The Service-Oriented Network Architecture [2] (SONATE) tries to handle these requirements and constraints by using concepts of modularity and service-orientation. As such, services are central elements of SONATE: A service reflects the effects of an activity rather than the algorithms and data structures that implement it. Thus, a service can be provided using different algorithms. A building block is a functional block that implements one distinct networking functionality. Examples for building blocks are retransmission mechanisms, data encryption algorithms, and monitoring functionality. Each building block usually has several effects like increasing the end-to-end delay or reducing the maximum payload size in addition to its main function. All the effects of a building block form the service which the building block provides. Since a service does not define the mechanism that is needed to provide it, several building blocks can provide the same service and are thus exchangeable. The services of multiple building blocks might be needed to provide the service which the application requested.

[KSS+11]
Michael Kleis, Abbas Siddiqui, Irfan Simsek, Martin Becke, Dirk Hoffstadt, Alexander Marold, Christian Henke, Julius Müller, Cristian Varas, Thomas Magedanz, Paul Müller, and Erwin Rathgeb. Cross-Layer Security and Functional Composition for a Future Internet. In 11th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2011), August 2011.
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In this paper we describe a demonstrator developed within the G-Lab DEEP project combining Cross-Layer Security and FC principles. The use case we address is the protection of VoIP domains against Registration Hijacking attacks. In the demonstration, is shown how Cross-Layer Security combined with Network and Application Level FC principles can be used in a flexible way to detect, trace back and mitigate such attacks. The combination of Cross-Layer and FC principles allows to assign the resources of network components in a fine-grained and controlled way. Measurement probes for detection and trace back as well as filter modules can be instantiated on demand for selected flows. The whole process is controlled based on predefined FC templates. The prototype has been developed on a G-Lab Testbed.

[SKR+11]
Abbas Siddiqui, M. Rahamatullah Khondoker, Bernd Reuther, Paul Müller, Christian Henke, and Helge Backhaus. Functional Composition and its Challenges. In The First International Workshop on Future Internet and Next Generation Networks (FIGNet-2011), Seoul, South Korea, July 2011.
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Functional composition is an approach for a flexible network architecture which enables a customized combination of functionality with respect to application requirements. Functional composition overcomes the inflexibility of the current Internet architecture and facilitates the management of functionality within the network. Several projects have addressed this topic with different aspects, in this paper several main challenges of network functional composition are identified and discussed.

[SPM11a]
Dennis Schwerdel, Matthias Priebe, and Paul Müller. ChordNet: A Chord-based self-organizing super-peer network. In 7th EURO-NF CONFERENCE ON NEXT GENERATION INTERNET, June 2011.
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Chord has proved to be a robust and efficient selforganizing structured Peer-to-Peer overlay. In this paper, we show that with the addition of super-peers, bidirectional communications, and two novel routing improvements, Chord can safely operate in environments with firewall-protected peers at a considerably reduced end-to-end message delay. Our concept, ChordNet, is suitable for high-traffic applications including video streaming supporting broadcast, multicast and highvolume point-to-point communications created automatically on demand. We demonstrate by means of simulation that ChordNet is superior to related approaches including bidirectional Chord.

[SGK+11]
Dennis Schwerdel, Daniel Günther, M. Rahamatullah Khondoker, Bernd Reuther, and Paul Müller. A building block interaction model for flexible future internet architectures. In 7th EURO-NF CONFERENCE ON NEXT GENERATION INTERNET, June 2011.
[ bib | dspace ]

Today’s Internet has a static architecture that makes introducing new functionality a complex and costly task, so the Internet can not keep pace with rising demands and new network capabilities. Therefore, evolvability and flexibility are the keys to a future Internet architecture. In this paper we propose a building block interaction model that can be used to build highly flexible and evolvable network architectures. The paper also explains how the interaction model can be used as a basis for automatic protocol selection and composition.

[GVM11b]
Daniel Günther, Eric MSP Veith, and Paul Müller. A Way to Identify Decision Criteria for Selecting Different Mechanisms wich Provide reliable Transmission in a Future Internet Architecture. In 7th EURO-NF CONFERENCE ON NEXT GENERATION INTERNET (NGI 2011), June 2011.
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In the current rather rigid communication model on the Internet, the functional composition of available algorithms is dictated by the ISO/OSI stack model. A flexible architecture, as often discussed in the Future Internet research area, will be able to support the desire to dynamically choose certain mechanisms based on the requirements of a particular application at both design time and run time. Such a dynamic composition of algorithms needs not only a flexible architecture to combine methods, but also decision criteria to enable the automatic selection from a pool of mechanisms. We present a way to extrapolate the decision criteria with a simulated experimental environment. We will describe how our scenario is able to support an evaluation that will lead to the identification of the required decision criteria.

[MNDR11]
Paul Müller, Bernhard Neumair, and Gabi Dreo Rodosek. 4. DFN-Forum Kommunikationstechnologien. Gesellschaft für Informatik (GI), June 2011.
[ bib | dspace ]

Das 4. DFN-Forum Kommunikationstechnologien „Verteilte Systeme im Wissenschaftsbereich“ steht in einer guten Tradition. Nach den sehr er-folgreichen Vorgängerveranstaltungen in Kaiserslautern, München und Konstanz wird die diesjährige Tagung vom DFN-Verein und der Univer-sität Bonn gemeinsam mit dem ZKI e.V. und der GI am 20. und 21. Juni 2011 in Bonn veranstaltet und soll eine Plattform zur Darstellung und Diskussion neuer Forschungs- und Entwicklungsergebnisse aus dem Be-reich TK/IT darstellen. Das Forum dient dem Erfahrungsaustausch zwi-schen Wissenschaftlern und Praktikern aus Hochschulen, Großfor-schungseinrichtungen und Industrie.

[TMDT11]
Kurt Tutschku, Paul Müller, and Frédéric Dang Tran. Network Virtualisation: Concepts and Performance Aspects. Inderscience Enterprises Ltd., May 2011.
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Guest Editor of the Special Issue

[GSKM11]
Daniel Günther, Michel Steichen, Nathan Kerr, and Paul Müller. Evaluating Network Simulators as Extensions of Real Network Testbeds. In 14th Communications and Networking Symposium (CNS'2011) at SpringSim'11, April 2011.
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Network testbeds are limited and often hard to configure. One method of overcoming these limitations is to use network simulators for extending a testbed. This paper aims to find out which network simulator is best able to extend a network testbed. Simulators are compared by their ability to provide a proposed environment in a network testbed. Both objective and subjective criteria are used in the comparison. The evaluated simulators are the well-known tools ns-3 and OMNeT++.

[SHG+11]
Dennis Schwerdel, David Hock, Daniel Günther, Bernd Reuther, Phuoc Tran-Gia, and Paul Müller. ToMaTo - a network experimentation tool. In 7th International Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities (TridentCom 2011), April 2011.
[ bib | dspace ]

Networks are an important field of research in information technology and experimental facilities are key instruments to enable practical research in this area. In the context of the German-Lab project, the topology management tool “ToMaTo” has been developed to be used as experimental facility software. This paper describes the features and the design of ToMaTo and evaluates it by identifying common experiment types and matching their requirements to the properties of ToMaTo.

[SKRM11]
Dennis Schwerdel, M. Rahamatullah Khondoker, Bernd Reuther, and Paul Müller. Self-organizing future network architectures, February 2011.
[ bib | dspace ]

The Internet has aged and outgrown its original purpose, today it has a lot of problems. In theory, most of these problems could be solved by modifying existing protocols, introducing new protocols or changing protocol interaction. The real problem of the current Internet architecture is that it offers no practical way to introduce changes into a deployed network. The available protocols and their functionality and interaction cannot be changed easily, because most changes require a global synchronization that is nearly impossible due to the size of the Internet. A future Internet architecture needs mechanisms to support protocol evolution: New protocols or improved versions of existing protocols should be easy to introduce and to automatically be used for communication. Self-organization in network stacks can help to solve this problem.

[FM11]
Tino Fleuren and Paul Müller. Zhao,P. & Di, L. (Eds.), IGI Global, chapter Geospatial Service Composition in Grid Environments (In Geospatial Web Services: Advances in Information Interoperability ). Zhao,P. & Di, L. (Eds.), IGI Global, January 2011.
[ bib | dspace ]

The composition of geospatial services (like OGC Web services) allows defining powerful geospatial simulations. In order to benefit from the compute power, parallel execution capabilities, and data management possibilities of a Grid environment (like OGSA), the workflow designer has to meet several challenges including heterogeneous service technologies (like WSRF or REST) large amounts of geospatial data, parallel execution, and instable Grid resources. The workflow management system enacting these workflows has to support parallelism in an efficient way; it must avoid becoming a bottleneck, which is often the case with classic centralized workflow engines, where all data has to pass through the engines. This chapter presents a workflow enactment system that maintains the robustness of centralized control (using service orchestration), but is enhanced by distributed components called proxy services that can communicate with each other to allow for efficient coupling between parallel tasks and avoiding of unnecessary data transfers (using service choreography).

[SPM11b]
Dennis Schwerdel, Matthias Priebe, and Paul Müller. A distributed algorithm to estimate node counts in self-organizing ring topologies. In IEEE Consumer Communications and Networking Conference 2011, January 2011.
[ bib | dspace ]

Ring topologies are peer to peer network structures that organize the nodes in a ring. Each node knows its direct neighbors and a few other nodes but has no global view of the network. In such a network it is complicated to measure or estimate the number of participating nodes. We provide a lightweight, distributed algorithm to estimate the size of the node population. We also show how correct the estimates are with simulations.

[GFSM10]
Joachim Götze, Tino Fleuren, Simon Schwantzer, and Paul Müller. License4Grid: Adopting DRM for Licensed Content in Grid Environments. In 8th IEEE European Conference on Web Services, December 2010.
[ bib | dspace ]

Processing of licensed content with automatic compliance checking of the license terms is currently not supported in Grid environments. However, applications processing large amounts of data is a topic recently gaining more and more attention. The use of high performance computing capabilities, e.g., provided by Grid environments, is an obvious choice to speed up the processing time.

Currently, most of the input data required in such Grid applications is freely accessible by standard Grid technology. However, many upcoming applications for Grid Computing require data provided under a specific license, also leading to license violations on a regular basis, because license compliance can currently not be validated. Data under a specific license is often retrieved from outside the Grid over individual portals directly from a content provider or distributor. Beside the additional efforts for user and security management, such external distribution approaches prevent an association between the license information and the content.

In this work, the internal distribution approach for licensed content in Grid environments (License4Grid) is designed, maintaining the association between the license information and the corresponding data. The design respects the requirements emerging from handling either unprotected and protected content and makes use of the user and security mechanisms provided by common Grid technologies in order to fit into the environment homogeneously.

[KRS+10]
M. Rahamatullah Khondoker, Bernd Reuther, Dennis Schwerdel, Abbas Siddiqui, and Paul Müller. Describing and Selecting Communication Services in a Service Oriented Network Architecture. Proceedings of the ITU-T Kaleidoscope event, Pune, India, 13-15 Dec 2010, December 2010.
[ bib | dspace ]

Today networks offer communication services ranging from a rather simple and unsecure one to secure and reliable data transmission for communicating on the network. In the future, it is expected that networks will offer a large number of different communication services. With so many services available, determining which service to select and use becomes much more difficult. Here we propose a description schema including an ontology for describing communication services. For service selection a decision making process called Analytic Hierarchy Process (AHP) is utilized which is specially adapted and extended for automatic processing.

[KHM10]
Michael Koch, Markus Hillenbrand, and Paul Müller. A Monitoring Framework for the Venice Service Grid. In 36rd Euromicro SEAA conference, September 2010.
[ bib | dspace ]

The maintenance of a highly distributed and open system (where services can be deployed and undeployed at any point in time) needs a highly adaptive and robust monitoring system. Only with such a system, the administrators and service providers are able to react fast and precisely. In the Paper, the intended monitoring system, its requirements and a first architecture are explained.

[LNS+10]
Gergö Lovász, Florian Niedermeier, Michel Steichen, Bernd Reuther, Hermann de Meer, and Paul Müller. Ener-G: A Generic Approach for Modeling Energy Consumption. In 10th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2010), August 2010.
[ bib | dspace ]

[SHG+10]
Abbas Siddiqui, Christian Henke, Daniel Günther, Paul Müller, and Thomas Magedanz. Mediation between Service and Network Composition. In 10th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2010), August 2010.
[ bib | dspace ]

Some mediation techniques have been proposed by different researchers e.g. Protocol Negotiation , Dynamic and adaptive service brokering ) or within different scope (e.g. among web-services). We propose to use a mediation approach for negotiation between service and network layer in a functional composition approach which increases the flexibility of the architecture because it provides feedback from the both layers and enables adaptation of the network based on the application and vice versa.

[BCH+10b]
Martin Becke, Konrad Campowsky, Christian Henke, Dirk Hoffstadt, Julius Müller, Carsten Schmoll, Abbas Siddiqui, Irfan Simsek, Thomas Magedanz, Paul Müller, Erwin Rathgeb, and Tanja Zseby. A Demonstrator for Cross-Layer Composition. In 10th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2010), August 2010.
[ bib | dspace ]

Services of all-IP networks today are expecting the best-effort packet transport paradigm of the underlying access network to which the mobile and fixed devices are connected to. Thereby applications are not able to indicate their requirements on the connection for the delivery of their data flows. The project G-Lab DEEP presents a Future Internet architecture based on the cross-layer composition concept in which the network is composed according to application specific requirements. Functional composition is used to selects and composes functionalities on the network data path, suitable for the demanded application level requirements.

[KRM10]
M. Rahamatullah Khondoker, Bernd Reuther, and Paul Müller. Selecting Communication Services in a Service Oriented Network Architecture. 10th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2010), August 2010.
[ bib | dspace ]

Today networks offer few communication services provided by their associated protocols for communicating on the network. In the future, it is expected that networks will offer a large number of different communication services. With so many services available, determining which service to select and use will become much more difficult. Here we propose a description schema including an ontology for describing and selecting communication services. For service selection a human decision making process called Analytic Hierarchy Process (AHP) is utilized which is specially adapted and extended for automatic processing.

[KNMS10]
Aneta Kabzeva, Michael Niemann, Paul Müller, and Ralf Steinmetz. Applying TOGAF to Define and Govern a Service-oriented Architecture in a Large-scale Research Project, August 2010.
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The Service-oriented Architecture paradigm has become a widely adopted solution for enterprise application landscapes. SOA promises system integration improvement, business and IT alignment, applications reusability, and fast adaptability to changing requirements. Yet, the advantages that SOA offers lead to its main management challenges. An SOA consists not only of services. Business requirements, processes, models, rules, policies, and different stakeholders play also an important role. To manage this increased complexity and heterogeneity in SOA landscapes enterprises apply architecture frameworks and governance approaches. An essential enabler for SOA Governance is the traceable documentation of the service-oriented application landscape. This paper shows how the TOGAF Architecture Development Method was applied in a large-scale SOA-based research project to support the governance proposes in the context of a service marketplace. Supplementary templates were defined to guide the description of services, data models, and architectural components. Some of the models and decisions proposed by TOGAF were shifted to other phases to fit the innovative nature of research projects.

[BCH+10a]
Martin Becke, Konrad Campowsky, Christian Henke, Dirk Hoffstadt, Julius Müller, Carsten Schmoll, Abbas Siddiqui, Thomas Magedanz, Paul Müller, Erwin Rathgeb, and Tanja Zseby. Addressing Security in a Cross-Layer Composition Architecture. In 10th Würzburg Workshop on IP: Joint ITG and Euro-NF Workshop Visions of Future Generation Networks (EuroView2010), August 2010.
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Clean slate Future Internet approaches are triggered by the realization that there are challenges arising in the current Internet design that may hinder the deployment and development of future applications. New and elevated demands in terms of security, QoS, mobility support, privacy, sustainability and scalability have challenged the assumptions of the Internet's early days. The Internet has become complex and ossified, and is proving too inflexible to integrate new functionality. Further cyberspace tussles between users, intellectual property right holders, government, over-the top service providers (e.g. youtube) and Internet Service Providers hinder new functionalities to be deployed in the network.

[AHM10]
Senol Arikan, Markus Hillenbrand, and Paul Müller. A Runtime Testing Framework for Web Services. In 36rd Euromicro SEAA conference, August 2010.
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With Venice, Web services are deployed on the Internet by different providers, the functional adherence of the Web services implementation to the underlying specification cannot be guaranteed, e.g. providers can change the implementation of a Web services at any time without notifying their customers. To be able to test the compliance of these services with their specification, Venice provides a sophisticated runtime testing framework.

[SFB+10]
Dietmar Siepmann, Tino Fleuren, Stephan Braune, Matthew Smith, and Paul Müller. LimA – kommerzielles Programm zur Simulation von Lärm-Immission im Grid. In Strobl, J., Blaschke, T. & Griesebner, G. (Hrsg.): Angewandte Geoinformatik 2010, Wichmann, Heidelberg,, July 2010.
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Aufwändige Rechnungen zur Lärm-Immission rechtfertigen den Einsatz von Techniken des Grid-Computing. In diesem Beitrag wird die kommerzielle Software LimA zur Simulation von Lärm-Immission vorgestellt, die im Rahmen des Geodateninfrastruktur- (GDI-) Grid-Projekts Grid-fähig gemacht wurde. Grid-fähig bedeutet, eine Version der Software läuft als Bestandteil eines Grid-Workflows auf leistungsstarken Compute-Ressourcen des Grid. Kommerzielle Software muss im Grid besonders sorgfältig vor unberechtigter Nutzung geschützt werden.

[HSZ+10]
Christian Henke, Carsten Schmoll, Tanja Zseby, Abbas Siddiqui, Paul Müller, Thomas Magedanz, and Erwin Rathgeb. Scenarios for a Future Internet based on Cross-Layer Functional Composition. In 5th GI/ITG KuVS Fachgespräch Future Internet, Stuttgart, May 2010.
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Functional composition is an approach of a future Internet architecture that decomposes the network stack in functional blocks that can be dynamically composed upon connection request. This decomposition resembles the idea of web and telecommunication service in the SOA world. In this paper we will present an architecture to integrate functional blocks from different domains and describe different communication scenarios that demonstrate the advantages and flexibility of such an approach.

[MNDR10]
Paul Müller, Bernhard Neumair, and Gabi Dreo Rodosek. 3. DFN-Forum Kommunikationstechnologien. Gesellschaft Für Informatik (GI), May 2010.
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[SRLM10]
Michel Steichen, Bernd Reuther, Gergö Lovasz, and Paul Müller. Methods and Approaches for Energy Saving considered in the Ener-G project, April 2010.
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[KM10]
M. Rahamatullah Khondoker and Paul Müller. Comparing Ontology Development Tools Based on an Online Survey. In World Congress on Engineering 2010 (WCE 2010), London, UK, March 2010.
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Finding an appropriate tool to develop ontology is the first step towards ontology development. A lot of ontology development tools are available in the market, however, some are free and some are commercial. Which tools are mostly used by users? Are there any drawbacks using the tools? And if any, then what? The answers of these questions are highlighted in this paper. These topics are investigated and discussed based on the findings of an online survey concerned with current process of ontology development, the users of the tools, and their domain of working

[HKFM10]
Dirk Henrici, Aneta Kabzeva, Tino Fleuren, and Paul Müller. INTECH, chapter Data Storage in RFID Systems, Radio Frequency Identification Fundamentals and Applications Bringing Research to Practice. INTECH, February 2010.
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This book chapter discusses different design possibilities for data storage in RFID systems and their impact on the quality factors of the resulting system. As will be shown, many characteristics of the systems are influenced. The design decision on the data storage in an RFID system is therewith of great importance. The decision should thus be taken with care considering all relevant aspects.

[FM10]
Stefan Fischer and Paul Müller. Experimentalforschung für das Future Internet - deutsche und europäische Initiativen. In Springer Verlag, February 2010.
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Experimentelle Forschung gewinnt in der Informatik zunehmend an Bedeutung. Besonders im Zuge der Entwicklung des Future Internet wird klar erkennbar, dass Analyse und Simulation allein nicht genügen, sondern neue Mechanismen nur hinreichend gut entwickelt werden können, wenn sie auch im späteren Einsatzfeld, sozusagen ,,im wirklichen Leben“, getestet werden. Dieser Artikel beschreibt mit G-Lab und FIRE zwei umfangreiche Programme zur Einrichtung und Nutzung von Experimentalplattformen für das Future Internet.

[GSFM10]
Joachim Götze, Simon Schwantzer, Tino Fleuren, and Paul Müller. Distribution of Licensed Content in Grid Environments. In Proceedings of the Work in Progress Session of Software Engineering and Advanced Application (SEAA), 2010.
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Some applications require that licensed content is made available in a Grid environment. Currently, such content is either provided manually or with a kind of distribution technology that cannot be integrated directly into a Grid application. In order to improve such Grid applications, the licensed content should be directly accessible from within a Grid environment. With current Grid technology, compliance with the license cannot be guaranteed, because of the missing link between license information and content. In order to make licensed content directly available in a Grid environment, several problems have to be resolved. Content providers have to recognize the need to provide their content using technology that can be easily integrated into a Grid environment. But even more important is the enhancement of the current Grid environments with the ability to maintain and work with licensed content.

[FGDM10]
Tino Fleuren, Joachim Götze, Voichita Droanca, and Paul Müller. Improving Data Management of Orchestrated Web Services. In Proceeedings of the Work in Progress Session of Software Engineering and Advanced Applications, 2010.
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The use of computational power and huge amounts of data to experiment and to solve problems is getting more and more important. A common approach to implement these experiments is scientific workflows, which are a kind of service-oriented workflows. These workflows define the orchestration of services, and workflow engines control their execution. Workflows are described by documents in a workflow language, e.g. Business Process Execution Language (BPEL). Scientific workflows describe simulations of complex experiments that use huge amounts of data, and result in long-running computations. In order to reduce the computation time, massively parallel execution is used. Scientists carry out many experiments and change the parameters frequently in order to compare the results. In this case, there is a rapid workflow alteration for each experiment. Additionally, the reuse of existing services implemented using different service technologies in order to create new workflows, i.e., experiments, at a faster rate is desired. An example of an application that can be realized by workflows is geospatial simulation. This kind of simulation tries to solve geographic problems by collecting, managing and representing geographically referenced information [3].

[SGH+10]
Dennis Schwerdel, Daniel Günther, Robert Henjes, Bernd Reuther, and Paul Müller. German-Lab Experimental Facility. In Future Internet - FIS 2010, 2010.
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The G-Lab project aims to investigate concepts and technologies for future networks in a practical manner. Thus G-Lab consists of two major fields of activities: research studies of future network components and the design and setup of experimental facilities. Both is controlled by the same community to ensure, that the experimental facility fits to the demand of researchers. Researchers gain access to virtualized resources or may gain exclusive access to resource if necessary. We present the current setup of the experimental facility, describing the available hardware, management of the platform, the utilization of the Planet-Lab software and the user management.

[KHR+09]
Aneta Kabzeva, Markus Hillenbrand, Nicolas Repp, Paul Müller, and Ralf Steinmetz. An Approach to Architecture-centric Design andManagement in Large Heterogeneous Research Projects. In MDD, SOA und IT-Management (MSI 2009), 06-07 October 2009, Oldenburg, October 2009.
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Architecture-centric software development is a standard in the realisation of industrial software intensive systems. Software architecture is normally defined before the design and implementation of the concrete system components and serves as a guideline during the whole development lifecycle. However, standard architecture-centric development approaches cannot be applied in heterogeneous research projects by implication. The large number of involved partners and the innovative nature implicate much information coordination and many architecture consistency challenges. This paper addresses all challenging aspects with an iterative architecture-centric design and management approach. The approach is based on the experience collected during the architecture design and management process in the research project THESEUS TEXO which is used here as example for the practicability of the offered method.

[WBS+09]
Brian Worden, Claudia Baltes, Inga Scheler, Paul Müller, and Hans Hagen. Accounting system for heterogeneous IP-networks (IPNA) implemented at Kaiserslautern University. In Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, Germany, September 2009.
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This paper describes an accounting system (IPNA) for heterogenous IP-networks with arbitrary topologies implemented at the university of Kaiserslautern. The produced data volume per unit is numerated. The collected data is stored in a database and offers different analysis possibilities. The results can be visualized and adapted to the usersrequirements.

The main effort was to build a data traffc quota system for single units as well as groups of devices that also report exceeded quotas. The system itself only observes the network traffc. Interfaces offer tools to interact with the network. The IPNA consists of a back-end for the data-acquisition and -preparation and a front-end for conffguration and visualization tasks including quality control.

[GRM+09]
Joachim Götze, Bernd Reuther, Paul Müller, Marc Seifert, Sebastian Breuers, Viktor Achter, and Ulrich Lan. SuGI - Portal and Training Systems for Grid Middlewares. In 35th Euromicro – SEAA 27-29. 08. 2009, Patras, Greece, August 2009.
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Grid computing is a research and development topic, currently getting much attention. As a result, new ideas as well as research and project results are being produced at a very high rate. Therefore, it is di cult for resource providers and researchers in this area to keep track of the development. Resource providers and researchers, new to the topic of Grid computing, have to overcome a huge inhibition threshold before work in this area can be started. The SuGI project is aiming to support providers and researchers with two approaches. First, the SuGI portal presents videos, documents, and links regarding many topics in the area of Grid computing for newcomers as well as for experts. Second, the training systems for Grid middlewares created by the SuGI project can help beginners to do their first steps without a complex installation process, while experts can easily try out di erent configurations without interfering with their productive systems.

[SRMH09]
Dennis Schwerdel, Bernd Reuther, Paul Müller, and Robert Henjes. Operation and Sustainability Concepts of the G-Lab Experimental Facility. August 2009.
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The goal of the G-Lab project is not limited to explore theoretical possibilities and novel ideas but also to use experimental approaches to verify the derived results while using the experimental facility. To investigate the functional aspects of novel Internet architecture approaches (e.g. routing, addressing, control, & management aspects) and their interaction with each other is such an intricate task which could not be validated only by analytical research and methods. In this part of the G-Lab project an experimental facility is built, on which new and innovative distributed simulation and emulation procedures are developed to verify proposed ideas in the entire G-Lab project.

[KHMS09]
Aneta Kabzeva, Markus Hillenbrand, Paul Müller, and Ralf Steinmetz. Towards an Architecture for the Internet of Services. In 35th Euromicro SEAA conference, 27-29 August 2009, Patras, Greece, August 2009.
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[SDS+09]
Dennis Schwerdel, Zornitsa Dimitrova, Abbas Siddiqui, Bernd Reuther, and Paul Müller. Composition of Self Descriptive Protocols for Future Network Architectures. In EuroMicro 2009, 27-29 August, Patras, Greece, August 2009.
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The network protocols we use today have been introduced decades ago. Since then the whole Internet came to existence and with it a single protocol stack: TCP/IP. What was a good solution back then, is no longer appropriate to fulfill the emerging demands of applications. Newer protocols have been created as solutions for the problems, but replacing TCP/IP requires a complicated deployment and migration phase. The problems with the current Internet architecture and its fixed structure have triggered a discussion on a Future Internet architecture. We propose a way to dynamically select and compose protocols based on principles of service oriented architectures. The goal is a network architecture where new protocols could be easily added and are automatically and transparently used by applications. In this paper we present a way to describe protocols and their effects and dependencies between them. We also present a method to select and compose protocols.

[SPMM09]
Dennis Schwerdel, Matthias Priebe, Paul Müller, and Peter Merz. ChordNet:Protocol Specification and Analysis. Technical report, University of Kaiserslautern, Germany, August 2009.
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Peer to peer overlay networks o er a new way of communication. These networks do not need a central component like a server and scale well with the number of participants. Peerto- peer networks can connect millions of nodes e ciently while client-server solutions would need huge investments in server architecture. With a peer-to-peer overlay the costs of the infrastructure is fairly distributed among all peers. ChordNet aims to be a state-of-the-art peer-to-peer overlay that e ciently connects even large numbers of nodes. Another design principle for the ChordNet protocol is to be platformindependent and easy to implement. ChordNet is application neutral. That means that ChordNet simply delivers messages between nodes and manages the network. It does not de ne what kind of payload the messages contain. It is possible to have nodes running di erent applications inside the same network. ChordNet is based on ChordNet but seeks to x some of the shortcomings of Chord. It uses a 2-tier architecture with super-peer/edge-peer distinction that allows peers with rewalls/NAT1. ChordNet improves Chord routing e ciency and deals with special problems that arise when Chord is used as a general peer-to-peer network. Also ChordNet introduces a latency-based routing method for Chord networks. The long-term goal of ChordNet is to have a large-scale ChordNet overlay network in the Internet which is open for all nodes and applications which speak the ChordNet protocol. With this speci cation implementers should be able to create software that uses the Chord- Net protocol.

[RSSM09]
Bernd Reuther, Abbas Siddiqui, Dennis Schwerdel, and Paul Müller. An Approach Towards a Flexible Network Architecture. In Euroview 2009, Würzburg, July 2009.
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The development of the Internet during the last years has shown that it is difficult to integrate new functionality. Especially the core mechanisms (TCP/IP) are hard to change. This is not a problem of a specific protocol, but of the architecture itself. We consider that tight coupling between several functionalities is the main hindrance for introducing new functionality. To overcome these problems we propose a new flexible network architecture.

[SHM09b]
Simon Schwantzer, Dirk Henrici, and Paul Müller. Learning in Dynamic Synchronous Information Spaces. In 2nd International eLBa Science Conference, June 2009.
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Working in unmoderated small groups is a common approach to explore complex fields of knowledge. This form of collaboration is based on the tight conjunction of communication, cooperation, and coordination. Taking a look at the portfolio of environments for distributed learning, most of them are trying to realize synchronous collaboration just with communication tools. The aim of this work is the design of a dynamic information space for synchronous cooperation and coordination. Based on this model, an environment is created that fulfils the requirements to enable members of a small group working together efficiently via computer networks.

[ABS+09]
Viktor Achter, Sebastian Breuers, Marc Seifert, Ulrich Lang, Joachim Götze, Bernd Reuther, and Paul Müller. Developing a Sustainable Educational Portal for the D-Grid Community. June 2009.
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Within the last years, several technologies have been developed to help building e-learning portals. Most of them follow approaches that deliver a vast amount of functionalities, suitable for class-like learning. The SuGI project, as part of the D-Grid (funded by the BMBF), targets on delivering a highly scalable and sustainable learning solution to provide materials (e.g. learning modules, training systems, webcasts, tutorials, etc.) containing knowledge about Grid computing to the D-Grid community. In this article, the process of the development of an e-learning portal focused on the requirements of this special user group is described. Furthermore, it deals with the conceptual and technical design of an e-learning portal, addressing the special needs of heterogeneous target groups. The main focus lies on the quality management of the software development process, Web templates for uploading new contents, the rich search and filter functionalities which will be described from a conceptual as well as a technical point of view. Specifically, it points out best practices as well as concepts to provide a sustainable solution to a relatively unknown and highly heterogeneous community.

[KHM09]
Michael Koch, Markus Hillenbrand, and Paul Müller. A Generic Database Web Service for the Venice Service Grid. In The IEEE 23rd International Conference on Advanced Information Networking and Applications (AINA-09), May 2009.
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This work describes a generic database service for the lightweight Venice Service Grid, which has been developed at the University of Kaiserslautern, Germany. By using Web services any SQL query can be processed and the corresponding result sets are sent back as strongly typed XML documents. The accurately defined interface allows an easy-to-use, platform and programming language independent access to all applications of a service federation. Transactions, prepared statements and parallel transfers of split result sets are supported, too. Because of a JDBC-like programming interface, the service can be used intuitively and existing software components can be quickly adjusted to the new system.

[RSS+09]
Bernd Reuther, Dennis Schwerdel, Abbas Siddiqui, Zornitsa Dimitrova, and Paul Müller. A Protocol Framework for a Service-OrientedFuture Internet Architecture. In GI/ITG KuVS Fachgespräch Future Internet, Munich, May 2009.
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The current Internet architecture has some problems that could not be foreseen when it was invented, decades ago. A big problem is that the architecture itself cannot be changed in an evolutionary way. To overcome these problems we propose a novel architecture that solves all current problems and allows for further evolutionary development.

[MNDR09]
Paul Müller, Bernhard Neumair, and Gabi Dreo Rodosek. 2. DFN-Forum Kommunikationstechnologien. Gesellschaft Für Informatik (GI), May 2009.
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[ASL+09]
Viktor Achter, Marc Seifert, Ulrich Lang, Joachim Götze, Bernd Reuther, and Paul Müller. Nachhaltigkeitsstrategien bei der Entwicklung eines Lernportals im D-Grid. April 2009.
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In dem Projekt SuGI (Sustainable Grid Infrastructures, gefördert durch das BMBF) wird unter anderem ein Lernportal entwickelt, welches auf die besonderen An- forderungen des D-Grids ausgerichtet ist. In diesem Umfeld spielen die heterogenen Communities, sowie die Nachhaltigkeit der Prozesse und der erstellten Produkte eine zentrale Rolle. Darunter fallen unter anderem die zum Teil sehr unterschiedlichen Vorkenntnisse von Anwendern und Grid-Experten, sowie die ressourcenschonende Bereitstellung und Archivierung von Inhalten und Erkenntnissen aus dem Gridumfeld oder die unterschiedlichen Zielsetzungen zwischen Rechenzentren von KMUs und solchen von etablierten Forschungsinstitutionen. Dieser Beitrag beschreibt die Konzeption und das Vorgehen bei der Entstehung des D-Grid Lernportals. Hierbei wurde der Entwicklungsprozess auf die speziellen Anforderungen von Lernportalen ausgerichtet, welche vor allem in der Dynamik der Inhalte und den komplexen Bedürfnissen der heterogenen Grid-Communities sowie den vielfältigen Formen des Lernens liegen. Dazu wurde ein evolutionäres Vorgehensmodell gewählt, wobei mehrere Generationen in einem durch Feedback unterstützten, rekursiven wie auch iterativen Prozess entstehen. Abschließend werden Ergebnisse der aktuellen Evaluierung des Lernportals präsentiert.

[SHM09a]
Simon Schwantzer, Dirk Henrici, and Paul Müller. Design of a Synchronous Collaborative Learning Environment. In 1st International Conference on Computer Supported Education, March 2009.
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In complex fields of knowledge, working in unmoderated small groups is a common approach for creating knowledge out of given information. Taking a look at the portfolio of learning environments, only a few systems provide the necessary functionality for synchronous collaboration. In most of them, synchronicity is reduced to communication. The aim of this work is the design of a synchronous collaboration environment which fulfills the requirements to enable members of a small group working together efficiently via computer networks. Based on the three elements communication, cooperation and coordination, a concept for an appropriate groupware is created and a flexible model defined. A sample environment called ”SLE” is developed to demonstrate the applicability.

[SHM09c]
Michel Steichen, Dirk Henrici, and Paul Müller. Messen und Schalten im Rechenzentrum: Kostengünstige Sensorknoten mit sicherer Anbindung an offene Netze. March 2009.
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Die in Rechenzentren eingesetzten vernetzten Sensorknoten zum Messen und Schalten sind heute in den meisten Fällen unabhängige und kostspielige Endgeräte. Intention dieses Beitrages ist es, ein verbessertes Konzept für solche Sensorknoten vorzustellen. Dabei handelt es sich keinesfalls um eine Nachimplementierung bestehender Lösungen. Vielmehr wurden in dieser Arbeit die Schwächen aktueller Lösungen und Lösungsvorschläge analysiert und darauf basierend eine neue, generische Architektur entworfen und prototypisch implementiert, die auch in anderen Bereichen, wie z.B. dem Assisted Living, einsetzbar ist. Berücksichtigte Anforderungen sind unter anderem Anschaffungskosten, Energieverbrauch im Betrieb, Benutzerfreundlichkeit, Skalierbarkeit, Sicherheit, Zuverlässigkeit und Flexibilität. Um all diese Anforderungen erfüllen zu können, wurden die Aufgaben der Sensorknoten in ein Modell aus mehreren Schichten aufgeteilt.

[HKM09]
Dirk Henrici, Aneta Kabzeva, and Paul Müller. chapter Development and Implementation of RFID Technology - RFID System Architecture Reconsidered. March 2009.
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In this book chapter, an overview of the security and privacy goals and the main concepts for reaching them is provided and evaluation criteria for RFID systems are given. Afterwards, the current RFID system architecture and the general direction of RFID security and privacy research are outlined and the practical deficiencies illustrated. As incremental improvements and extensions lack to provide satisfactory solutions, finally considerations on how a completely new RFID architecture might look like are performed.

[HFM09]
Dirk Henrici, Tino Fleuren, and Paul Müller. RFID-Technologie: Verbesserung des Datenschutzes durch Nutzung des technischen Gestaltungsspielraums. In 16. DFN Workshop Sicherheit in vernetzten Systemen, DFN CERT, 2009.
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RFID-Transponder dienen primär der eindeutigen Identifikation von Objekten, z.B. von Waren, Behältern oder Dokumenten. Weitergehend möchte man den Objekten eine Vielzahl von Daten zuordnen, die das Objekt beschreiben, seine Historie dokumentieren oder es in den Kontext anderer Objekte stellen. In diesem Beitrag wird dargestellt, welche technischen Gestaltungsspielräume es zur Speicherung derartiger Daten gibt und welche Auswirkungen bezüglich Kosten, Flexibilität und Datenschutz die Wahl des Speicherortes hat. Dadurch soll erreicht werden, dass diesbezügliche Designentscheidungen nicht unüberlegt oder mit einseitiger Sichtweise getroffen werden. Dieser Beitrag bezieht sich nur auf Transponder, die als reiner Datenspeicher genutzt werden. Transponder mit Prozessor, kryptographischer Hardware oder Sensoren bedürfen zum Teil einer gesonderten Betrachtung.

[FM09]
Tino Fleuren and Paul Müller. RFID und Datenschutz - Noch wird nicht auf derselben Wellenlänge gefunkt. In SecuMedia Verlags-GmbH, 2009.
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Zur RFID-Technologie verspricht die Industrie Verbesserungen der Dienstleistungen wie zum Beispiel schnellere Kassiervorgänge oder vereinfachte Zutrittskontrolle zu Gebäuden. Gleichzeitig warnen RFID-Kritiker vor Sicherheitsmängeln und vor dem Verlust der Privatsphäre - vor allem angesichts der Menge an Daten, die in Zukunft zu den unterschiedlichsten Zwecken eingesetzt werden könnten. Noch stehen sich Befürworter und Gegner unversöhnlich gegenüber - doch neue Architekturen könnten dies ändern.

[HGM08]
Markus Hillenbrand, Joachim Götze, and Paul Müller. Contract-first Service Development within the Venice Service Grid. In ACM Press (iiWAS 2008, Linz), November 2008.
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Virtualisation and abstraction are the keys to an open, flexible and dependable service deployment on the Internet. The Venice Service Grid is a framework that provides a set of services and an abstraction layer supporting the development and deployment of services. As part of its abstraction layer, the Venice Service Grid contains a service compiler that creates the necessary files and code constructs needed during the life-cycle of a Venice service. This paper describes the Venice Service Compiler that shifts the technology-dependant WSDL file creation from the design phase to the implementation phase and discusses the compiler’s benefits to developing services for the Venice Service Grid.

[GMM08]
Joachim Götze, Jochen Müller, and Paul Müller. Iterative Service Orchestration based on Dependability Attributes. Technical report, University of Kaiserslautern, Germany, September 2008.
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In a service-oriented architecture (SOA), the orchestration of services to new services and complex workflows is a common approach. Because the complexity and capabil- ity of the orchestrated services are increased, it is important to maintain and ensure the dependability attributes, e.g. availability and reliability, in such an environment. Today, most approaches focus on the needs during the creation of a single application, but the Internet became a commodity for end users during the last years and more services are available every day. While the range of available services is growing, the end users are helpless electing a service providing the quality of service they expect. Therefore, a straightforward approach is needed allowing the creation and modification of orchestrated services by end users with respect to dependability attributes.

[FM08]
Tino Fleuren and Paul Müller. BPEL Workflows Combining Standard OGCWeb Services and Grid-enabled OGC Web Services. In Proceedings of the 34th Euromicro Conference on Software Engineering and Advanced Applications, Parma, Italy, September 2008.
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When designing a Grid workflow, it might be necessary to integrate different kinds of services. In an ideal scenario all services are Grid-enabled. But real workflows often consist of Grid-enabled and non Grid-enabled services.

One reason is that Grid-enabling services can be costly. Therefore it is favorable to solely Grid-enable the compute-intensive and time-consuming applications. Additionally, workflows should be allowed to include Grid jobs that execute legacy applications.

Another reason is that very often, third parties charge fees for accessing their services. Hence, it is impossible to convert such a third party service into a service that can be integrated into a Grid environment at all.

This paper discusses problems of designing a workflow that consists of all these different kinds of services. The geospatial domain is exemplarily used to demonstrate difficulties that workflow designer have to overcome, i.e. constructing a geospatial workflow by using combinations of conventional Web services (XML-based), standard OGC Web services and Grid-enabled OGC Web services (WSRF-based).

The concept of a workflow engine capable of enacting these workflows is presented and an implementation based on the ActiveBPEL engine is proposed.

[MNDR08]
Paul Müller, Bernhard Neumair, and Gabi Dreo Rodosek. 1. DFN-Forum Kommunikationstechnologien. Gesellschaft Für Informatik (GI), May 2008.
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[ALRM08]
Viktor Achter, Ulrich Lang, Bernd Reuther, and Paul Müller. SuGI - Einsatz von Grid in mittleren und kleineren Rechenzentren. In GI-Edition Lecture Nodes in Informatics, May 2008.
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Die Kernaufgabe von SuGI besteht darin, Grid in die Fläche zu tragen und in der Fläche nutzbar zu machen. SuGI ist somit auf die Vielzahl kleinerer und mittlerer Rechenzentren von Hochschulen und Unternehmen ausgerichtet, die Grid-Technologien bisher nur in geringem Maße eingeführt haben. Im Verlauf des Projekts werden die im D-Grid-Projekt erlangten Erkenntnisse sowie D-Grid relevante Inhalte in geeigneter Weise den kleinen und mittleren Rechenzentren und der Unternehmens-IT von KMUs zugänglich gemacht. Um dies zu erreichen bietet SuGI einen Katalog von Maßnahmen, insbesondere Schulungen sowie externe Veranstaltungen in Form von online abrufbaren Inhalten, die der breiten Grid-Gemeinde zur Verfügung gestellt werden. Hierbei wird ein Fokus auf gut skalierende Methoden des E-Learnings gelegt, um mit hoch qualitativen Schulungsunterlagen eine möglichst breite Masse zu erreichen. Untermauert werden die Schulungen durch Probesysteme, an denen die neu erlangten Kenntnisse vertieft werden können.

[HdWM08b]
Dirk Henrici, Patric de Waha, and Paul Müller. Bridging the Gap Between Pervasive Devices and Global Networks (long version). Technical report, University of Kaiserslautern, Germany, March 2008.
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For the future, it is envisioned that an incredibly high number of inexpensive pervasive devices surrounds us. These devices are networked so that they can exchange data with their environment. Already today we have global networks like the Internet, and there are already many attempts to connect sensors and actuators to these networks. However, there are a variety of problems like security, scalability, reliability, as well as resource and cost constraints. In this paper, we will present an advanced architecture for bridging the gap between pervasive devices like wireless sensors and the Internet. Various widespread concepts and technologies are combined to create a practical solution.

[HdWM08a]
Dirk Henrici, Patric de Waha, and Paul Müller. Bridging the Gap Between Pervasive Devices and Global Networks. March 2008.
[ bib | dspace ]

For the future, it is envisioned that an incredibly high number of inexpensive pervasive devices surrounds us. These devices are networked so that they can exchange data with their environment. Already today we have global networks like the Internet, and there are already many attempts to connect sensors and actuators to these networks. However, there are a variety of problems like security, scalability, reliability, as well as resource and cost constraints. In this paper, we will present an advanced architecture for bridging the gap between pervasive devices like wireless sensors and the Internet. Various widespread concepts and technologies are combined to create a practical solution.

[MR08]
Paul Müller and Bernd Reuther. Future Internet Architecture - A Service Oriented Approach. In In it - Information Technology, Volume 50, Number 6, 2008, Oldenbourg Verlag, Munich, 2008.
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[HM08]
Dirk Henrici and Paul Müller. Providing Security and Privacy in RFID Systems Using Triggered Hash Chains. January 2008.
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RFID technology shall increase security, e.g. by helping to prevent counterfeiting. But the technology also causes privacy issues. In this paper, after highlighting goals and problems, an approach called Triggered Hash Chains is pro-posed to address the problems. The approach combines concepts of two very different, widely known RFID protocols, i.e. the Hash-based ID variation approach and the Hash chain approach. The resulting proposal joins the advantages of both protocols. The approach is evaluated using a variety of criteria that are relevant in practice.

[TGFE+08]
Phuoc Tran-Gia, Anja Feldmann, Jörg Eberspächer, Martina Zitterbart, Paul Müller, and Hans Schotten. G-Lab Phase 1 Studien und Experimentalplattform für das Internet der Zukunft. Technical report, University of Kaiserslautern, Germany, 2008.
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Das heutige Internet besitzt eine große wirtschaftliche Bedeutung, basiert jedoch größtenteils noch auf Mechanismen und Algorithmen, die in den 70er und 80er Jahren entwickelt wurden. Neue Anwendungen im geschäftlichen und privaten Bereich stellen Anforderungen, für die das Internet ursprünglich nicht konzipiert war und sehen sich Sicherheitsproblemen gegenüber, die auf Defizite in der Architektur des Interne hinweisen. Von besonderem Interesse ist dabei das Wechselspiel zwischen den Möglichkeiten der Technik und den Anforderungen der Applikationen. Dies wird bei Untersuchungen im Rahmen der Studien in G-Lab explizit mit betrachtet.

[MJGM07]
Jochen Müller, Florian Jostock, Joachim Götze, and Paul Müller. Workflow Monitoring in Service-Orientierten Architekturen. In Volker Nissen, Mathias Petsch, Hagen Schorcht - Service-orientierte Architekturen - Chancen und Herausforderungen bei der Flexibilisierung und Integration von Unternehmensprozessen, October 2007.
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[MLM07]
Paul Müller, Peter Liggesmeyer, and Erik Maehle. Proceedings of the 33rd EUROMICRO Conference 2007. IEEE, August 2007.
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[HKM07]
Markus Hillenbrand, Aneta Kabzeva, and Paul Müller. A Presence Service for the Venice Service Grid. In 33rd Euromicro SEAA conference, August 2007.
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A Presence Service for the Venice Service Grid

[HGM07]
Markus Hillenbrand, Joachim Götze, and Paul Müller. A File System Service for the Venice Service Grid. In 33rd Euromicro SEAA conference, August 2007.
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A File System Service for the Venice Service Grid

[MJ07]
Paul Müller and Eike Jessen. 21. DFN-Arbeitstagung über Kommunikationsnetze. May 2007.
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[HGZM07]
Markus Hillenbrand, Joachim Götze, Ge Zhang, and Paul Müller. A Lightweight Service Grid based on Web Services and Peer-to-Peer. In KiVS 2007, February 2007.
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What is The Grid? This question has been asked by many people and has been answered by many more. On our way to the One Grid, it is currently only possible to distinguish between several Computational, Data and Service Grids. This paper introduces Venice, a lightweight Service Grid that allows for easy service deployment, easy maintenance and easy service usage. It contains management services, information services and application services that can be used to build distributed applications upon. Its main focus in on providing a flexible and dependable infrastructure for deploying services that do not require special knowledge and expertise in Grid computing.

[MGM06]
Jochen Müller, Joachim Götze, and Paul Müller. Eine Web-Architektur zur Unterstützung interaktiver Prozesse in der Flächennutzungsplanung. In 36. Jahrestagung der Gesellschaft für Informatik (GI), Dresden, Germany, October 2006.
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In einem Flächennutzungsplan (FNP), auch vorbereiteter Bauleitplan genannt, wird festgelegt, wie die Flächen innerhalb einer Gemeinde genutzt werden sollen. Der FNP soll die verschiedenen räumlichen Nutzungsansprüche, wie beispielsweise Wohnen, Verkehr oder Gewerbe koordinieren und zu einem abgewogenen Gesamtkonzept zusammenzuführen. Durch die unterschiedlichen Interessen der Akteure, die im Rahmen der Flächennutzungsplanung beteiligt werden, ergibt sich jedoch ein sehr komplexer und dadurch kosten- und zeitintensiver Prozess. Im Einsatz moderner Informations- und Kommunikationstechnologien zur Unterstützung des gesamten Workflows wird ein hohes Optimierungspotential gesehen [Stein03].

[MBK06]
Paul Müller, Claudia Baltes, and Patrick Koppen. Self-Management in heterogenous Networks using a Service-Oriented Architecture. In IEEE CCNC 2007 4th (IEEE Consumer Communications and Networking Conference), October 2006.
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Self-Managing Networks promise to help network administrators in their daily work and are less error-prone. This paper introduces an architecture for monitoring a local area network and protecting it against misuse. A regulatory system to automatically separate or restrict a malicious host from the network is introduced. Whereby the focus is to support even heterogenous networks. Various sensors like an IDS or accounting system may make the decision that a host should be detached or rate-limited. A request is sent to the regulatory system and the problem is to automatically determine the best way to enforce this regulation as there are various possibilities e.g. disabling a port or applying packet filters. Modules for locating the host and configuring the network devices complete the presented solution.

[CGB+06]
Ivica Crnkovic, Paul Grünbacher, Stefan Biffl, Peter Merz, and Paul Müller. Proceedings of the 32nd Euromicro Conference on Software Engineering and Advanced Applications. IEEE, September 2006.
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[DEF+06b]
Tobias Dussa, Ursula Epting, Bartol Filipovic, Gerti Foest, Joachim Götze, Christian Grimm, Markus Hillenbrand, Christian Kohlschütter, Ralf Lohner, Paul Müller, Marcus Pattloch, Stefan Piger, Tobias Straub, and Jan Wiebelitz. Use Cases for Authorization in Grid-Middleware. Technical report, University of Kaiserslautern, Germany, September 2006.
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Security services in Grid environments, especially the authentication but also parts of the user authorization are largely based on PKI and X.509 certificates. In contrast to the well-established authentication infrastructures, the harmonization of authorization mechanisms as implemented in the examined Grid middlewares – Globus Toolkit 4, gLite and UNICORE – turns out to be a complex challenge. As a preliminary work towards a common D-Grid wide AAI, a study of the different authorization approaches for common use cases was conducted. The aim of this work was to examine the feasibility of a common authorization infrastructure of these Grid middlewares. The use cases were defined from two different perspectives: authorization measures by users and by administrators. The regarded application areas were computing and information services as well as data and VO management. All results are based on practical experiences. Only the means supported by a standard deployment of the respective middleware have been considered, i.e. without additional (3rd party) software. The report confirms the predominant notion of the inhomogeneous and coarse grained authorization mechanisms in current Grid middlewares. Furthermore, we found that authorization functionality differs greatly especially between Globus Toolkit 4 and gLite on one side and UNICORE on the other side. This most prominently results from the current lack of the VO paradigm in UNICORE. Thus, a harmonization of the authorization infrastructure appears feasible on a high-level between the first two middlewares. The inclusion of UNICORE in such a concept requires substantial modifications of the middleware itself.

[HM06]
H.-G. Hegering and Paul Müller. Grids - es bleiben noch große Herausforderungen. In PIK - 29. Jahrgang, Heft 3 2006, S. 130 f, September 2006.
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[HGM06e]
Markus Hillenbrand, Joachim Götze, and Paul Müller. Web Services Directory based on Peer-to-Peer Technology. In 32nd EUROMICRO Conference, Cavtat, Croatia, Aug/Sep 2006, August 2006.
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Service-oriented architectures foster the interaction of a multitude of different services. In order to ensure flawless service interaction a directory service is needed that can be used to find suitable services for a desired task. A centralized solution for local services might be suitable for small systems, but on a larger scale - when systems start to inter- act via Federations of Trust - the need for an highly available and easily maintainable directory service arises.

[HGM06d]
Markus Hillenbrand, Joachim Götze, and Paul Müller. Venice - A Lightweight Service Grid. In 32nd EUROMICRO Conference, Cavtat, Croatia, Aug/Sep 2006, August 2006.
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What is the Grid? This question has been asked by many people and has been answered by many more. On our way to the One Grid, it is currently only possible to distinguish between several Computational, Data and Service Grids. Venice is becoming a lightweight Service Grid that allows for easy service deployment, easy maintenance and easy service usage.

[HGM06b]
Dirk Henrici, Joachim Götze, and Paul Müller. A Hash-based Pseudonymization Infrastructure for RFID Systems. In IEEE Security, Privacy and Trust in Pervasive and Ubiquitous Computing International Workshop (IEEE SecPerU 2006) at IEEE International Conference on Pervasive Services (ICPS 2006); June 29th, 2006; Lyon; France, June 2006.
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Many proposals have been made to solve the privacy implications of RFID systems: The main idea to ensure location privacy is to change the identifiers of RFID tags regularly. For building inter-organizational RFID systems, pseudonyms can be used to provide a link to the respective owner of a tag without affecting location privacy. Based on these considerations, in this paper a pseudonymization infra¬structure is presented that is based on one-way hash functions and thus is a better fit for the specific demands of resource scarce tags than approaches based on public key cryptography.

[MZLM06]
Jochen Müller, Ge Zhang, Jean-Christophe Lapayre, and Paul Müller. Service-oriented Support of Cooperative Workflows – Considerations for Urban Planning Processes. In 11th Conference of the Association for Information And Management, Luxemburg, June 2006.
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Web-based information sources have evolved to an essential element in our daily and professional life. To process this faster and faster growing amount of information, web portals provide personalized access to specific information and communication services. In this paper, an example from urban planning is given. In this workflow, different actors are interacting in an ad-hoc manner. Therefore, a Portal Architecture has been built up, which provides the relevant information. This paper proposes a Service Orientated Architecture to provide access to business processes, software applications and hardware resources in a workflow oriented way.

[MPJ06]
Paul Müller, Gerhard Peter, and Eike Jessen. 20. DFN-Arbeitstagung über Kommunikationsnetze. June 2006.
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[HGM06a]
Dirk Henrici, Joachim Götze, and Paul Müller. Hash-based Pseudonymity for Ubiquitous Devices. In International Conference on Computational Science and its Applications, UASS'06 Ubiquitous Application & Security Service; May 8th-11th, 2006; Glasgow, UK, May 2006.
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The concept of onion routing is a well known technique for implementing pseudonymous communication in the Internet. Unfortunately, it heavily relies on enciphering and deciphering which is well beyond the capabilities of resource-scarce ubiquitous devices like RFID transponders. This paper presents a more lightweight technique with similar characteristics that is based on one-way hash functions.

[DEF+06a]
Tobias Dussa, Ursula Epting, Bartol Filipovic, Gerti Foest, Jürgen Glowka, Joachim Götze, Christian Grimm, Markus Hillenbrand, Christian Kohlschütter, Siegfried Makedanz, Siegfried Makedanz, Paul Müller, Marcus Pattloch, Stefan Piger, Tobias Straub, and Jan Wiebelitz. Analyse von AA-Infrastrukturen in Grid-Middleware. Technical report, University of Kaiserslautern, Germany, March 2006.
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Neben einer allgemeinen Beschreibung der zugrunde liegenden Verfahren ist es das wesentliche Ziel dieser Analyse, die übergreifend über verschiedene Middlewares gemeinsam nutzbaren Komponenten einer AA-Infrastruktur zu identifizieren. Die Ergebnisse dieser Analyse werden in dem nächsten Projektabschnitt für die Planung einer einheitlichen AA-Infrastruktur im D-Grid verwendet.

[HGM06c]
Markus Hillenbrand, Joachim Götze, and Paul Müller. Creating Dependable Web Services Using User-transparent Replica (Extended and Updated Version). In Journal of Digital Information Management Vol. 4 No. 1 March 2006, March 2006.
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Dependability is a major concern in software development, deployment, and operation. A commonly accepted solution for providing fault tolerant services on the Internet is to create replica of the services and to deploy them to several hosts. Whenever the service or the underlying node or network fails, another service is ready to take over. In the Venice project, several techniques are combined to create a dependable framework for deploying and managing distributed services using replica on several distinct network nodes.

[SM06]
Gerhard Steinebach and Paul Müller. Dynamisierung von Planverfahren der Stadtplanung durch Informations- und Kommunikationssysteme. In Schriften zur Stadtplanung Band 4, Herausgeber: Prof. Dr.-Ing. Gerhard Steinebach, 2006.
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[CGB+05]
Ivica Crnkovic, Paul Grünbacher, Stefan Biffl, Paul Müller, Peter Merz, Martin Törngren, and Konrad Klöckner. Proceedings of the 31th EUROMICRO Conference 2005. IEEE, September 2005.
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[HM05]
Markus Hillenbrand and Paul Müller. Springer Verlag, chapter Web Services and Peer-to-Peer (in: Peer-to-Peer Systems and Applications). Springer Verlag, September 2005.
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[ZRM05]
Ge Zhang, Bernd Reuther, and Paul Müller. A Model for User Based Traffic Accounting. In 31. Euromicro Conference, Porto, Portugal, August 2005.
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Today’s traffic accounting systems are based on the assumption that one IP address is associated with one user. But this assumption cannot be applied to multi-user systems, where an IP address can be shared by multiple users at the same time. In this case an IP address can not be uniquely mapped to a single user. In order to provide finer granularity traffic accounting information we suggest a user based traffic accounting concept which can collect and analyze network resource usage metrics on the basis of users. This is an extension to current traffic accounting methods. With this not only IP address attribute but also user attribute are used as aggregating index in collecting the network resource usage information. This paper introduces user based traffic accounting technology and discusses several different mechanisms for user based traffic accounting. The implementation of a user based traffic accounting prototype system with Agent mechanism is introduced. Performance test results indicate that, if carefully designed the user based traffic accounting system affects performance of the system in which it resides only slightly.

[HGM05a]
Markus Hillenbrand, Joachim Götze, and Paul Müller. Creating Dependable Web Services Using User-transparent Replica. In International Conference on Next Generation Web Services Practices, NWeSP, Seoul, Korea, August 2005.
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Dependability is a major concern in software development, deployment, and operation. A commonly accepted solution for providing fault tolerant services on the Internet is to create replica of the services and to deploy them to several hosts. Whenever the service or the underlying node or network fails, another service is ready to take over. In the Venice project, several techniques are combined to create a dependable framework for deploying and managing distributed services using replica on several distinct network nodes.

[HGM05b]
Markus Hillenbrand, Joachim Götze, and Paul Müller. Voice over IP - Considerations for a Next Generation Architecture. In 31. Euromicro Conference, Porto, Portugal, August 2005.
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Voice over IP is on its way to becoming an alternative to the classical telephony system because more and more Voice over IP providers offer their solutions on the Internet and try to increase their clientele. But current Voice over IP technology is still in its commercial and technological infancy and has not yet proven to be worldwide accessible, usable and scalable as the classical telephony system has proven in the past 100 years. In this paper, an architecture1 for a next generation Voice over IP model will be outlined and discussed. The main focus lies on interoperability between different Voice over IP providers as well as dependability and robustness.

[HPM05]
Dirk Henrici, David Prantl, and Paul Müller. Site Multihoming and Provider-Independent Addressing Using IPv6. In International Conference on Communication Systems and Applications; IASTED CSA 2005; July 19th-21st, 2005; Banff, Alberta; Canada, July 2005.
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Using IPv6, multihoming and Internet service provider migration are still not satisfactorily solved problems. This leads to delay in the adaptation of the new protocol version. This contribution aims to address both of the two stated problems while retaining the advantages of strictly hierarchical addressing and routing. The solution presented in this paper consists of two building blocks: So called Unique Local Addresses that are intended to be used instead of the deprecated IPv6 site local addresses can be employed as globally valid, provider-independent identifiers. Using address mapping at site exit routers, a feature-rich multihoming solution can be created without breaking the end-to-end model. The proposed solution has many advantages: It is simple and compatible to current Internet standards. No changes at all are required at hosts, and the solution is designed to keep network management easy.

[MKM05]
Jochen Müller, Andreas Kümpel, and Paul Müller. Integration und Orchestrierung von Geschäftsprozessen in Web Applikationen – Ein Service-Orientierter Ansatz. In GMDS/GI Workshop Enterprise Application Integration 2005, Marburg, July 2005.
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Mit dem zunehmenden Einsatz des Electronic Business werden Geschäftsprozesse und Anwendungssysteme über die Grenzen eines Unternehmens geöffnet und mit denen anderer Geschäftspartner kombiniert. Die „Business Process Execution Language for Web Services“ ermöglicht es, Geschäftsprozesse zu beschreiben und einzelne Web Services miteinander zu kombinieren, um durchgängige Geschäftsprozesse sowohl auf Anbieter, als auch auf Kundenseite zu unterstützen. In dieser Arbeit wird ein Konzept vorgestellt wie existierende Web Portale erweitert werden, um so die Abarbeitung von Geschäftsprozessen service-orientiert zu ermöglichen.

[HGMM05a]
Markus Hillenbrand, Joachim Götze, Jochen Müller, and Paul Müller. A Single Sign-On Framework for Web-Services-based Distributed Applications. In 8th International Conference on Telecommunications ConTEL, Zagreb, Croatia, June 2005.
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[HGMM05b]
Markus Hillenbrand, Joachim Götze, Paul Müller, and Jochen Müller. Role-based AAA for Service Utilization in Federated Domains. In 19. DFN Arbeitstagung Düsseldorf, May 2005.
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The Web service specifications managing authentication and authorization are still a work in progress. A large-scale application built today is in need of a solid authentication and authorization infrastructure. A role-based authentication, authorization and accounting (AAA) concept is able to provide the services needed, while it is possible to gain additional flexibility to handle the co-operation between different authentication and authorization infrastructures.

[JLMM05]
Andreas Jonen, Volker Lingnau, Jochen Müller, and Paul Müller. Balanced E-Gov-Decision-Card: Entscheidungsunterstützung bei E-Government-Projekten. In 7. internationale Tagung General Online Research 2005, March 2005.
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[MGS05b]
Paul Müller, Reinhard Gotzhein, and Jens Schmitt. Tagungsband der 14. ITG/GI Fachtagung Kommunikation in verteilten Systemen (KiVS 2005), Kurzbeiträge und Workshop zu Peer-to-Peer-Systemen und -Anwendungen. Lecture Notes in Informatics GI, March 2005.
[ bib | dspace ]

[MGS05a]
Paul Müller, Reinhard Gotzhein, and Jens Schmitt. Tagungsband der 14. ITG/GI Fachtagung Kommunikation in verteilten Systemen (KiVS 2005). Springer, March 2005.
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[MLH+05]
Jochen Müller, Torsten Lenhart, Dirk Henrici, Markus Hillenbrand, and Paul Müller. Developing Web Applications for Mobile Devices. In 1. International Conference on Distributed Frameworks for Multimedia Applications DFMA'2005, Besancon, France, February 2005.
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Today even small mobile devices access the Internet. Therewith, mobility issues have become an important technical and economic topic - not only in new but in proven and successful web applications as well. The main problem derives from a growing heterogeneity in hardware and software of mobile devices. To overcome this problem, this paper presents a framework to develop Web Applications for Mobile Devices.

[ZMM05]
Ge Zhang, Jochen Müller, and Paul Müller. Designing Web Service Accounting Systems. In Workshop on Web Services: Business, Financial and Legal Aspects Geneva, Switzerland, February 22, 2005, February 2005.
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Web Service technology is attracting increasing attention not only from academy and institutes for study and research purposes but also from commercial areas for business purposes. How to reasonably reflect the value of the Web Services is a very important concern must be considered. Web Service Accounting is the process of collecting Web Service usage information for the purpose of charging and billing. Through accounting service providers can cover costs and make profit from their provided Web Services. This paper introduces a Web Service Accounting system architecture and explains the detail techniques about the entities of the accounting system.

[HZM05]
Markus Hillenbrand, Ge Zhang, and Paul Müller. Facilitating the Interoperability among Different VoIP Protocols with VoIP Web Services. In 1. International Conference on Distributed Frameworks for Multimedia Applications DFMA'2005, Besancon, France, February 2005.
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With the development of the internet the VoIP technology is becoming a popular service on the internet platform. Several VoIP protocols have been suggested to realize the VoIP communication. But different VoIP protocol clients cannot interoperate directly. This paper suggests a VoIP Web service infrastructure to facilitate the interoperability among different VoIP protocols. With this infrastructure all VoIP protocols signaling handling details will be hidden through the corresponding web service abstraction. Therefore different VoIP protocols can utilize the common web service interfaces to achieve the interoperability.

[MMV05]
Paul Müller, Jochen Müller, and Aline Verney. Manager l’intelligence d’une region - un systeme d'informations sur les clusters d’Enterprises fonde sur XML. In European Competitive Intelligence Symposium, Poitiers, Frankreich, 27-28.01.2005, January 2005.
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[HM04b]
Dirk Henrici and Paul Müller. Sicherheit und Privatsphäre in RFID-Systemen. In VDE-Kongress 2004, Berlin, October 2004.
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RFID-Technik hat ein enormes Potential, es gibt bereits jetzt eine Vielzahl von Anwendungen. Der Schutz der Privatsphäre hat in Entwicklung und Vermarktung der Technologie jedoch noch einen geringen Stellenwert. Im Rahmen des Beitrags wird in die mit der RFID-Technik zusammenhängenden Probleme in Bezug auf Systemsicherheit und Privatsphäre eingeführt und daraus abgeleitet, welche Maßnahmen ergriffen werden müssen.

[MHM04]
Jochen Müller, Dirk Henrici, and Paul Müller. Computer-Aided Dynamic Processes for Urban Land Use Planning. In 30th EUROMICRO, Rennes, France, September 2004.
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Urban Land Use Planning is a sophisticated process in which many different parties are involved. A software framework aims at supporting this procedure.

[SMC+04]
Ralf Steinmetz, Andreas Mauthe, Ivica Crnkovic, Magnus Larsson, Paul Müller, Jens Schmitt, Stefan Biffl, and Paul Grünbacher. Proceedings of the 30th EUROMICRO Conference 2004. IEEE, August 2004.
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[HMM04b]
Markus Hillenbrand, Paul Müller, and Kristian Mihajloski. A Software Deployment Service for Autonomous Computing Environments. In International Conference on Intelligent Agents, Web Technology and Internet Commerce - IAWTIC'2004, Gold Coast, Australia, July 2004.
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With Web services and Grid services being deployed on a larger scale, users as well as service providers often encounter the problem of software components needed to be installed before accessing or invoking a service. Autonomous computing includes system architectures where those software components can automatically be found and seamlessly integrated. A dedicated software deployment service accessible by all entities of a service oriented software architecture helps performing automatic software installation and update, moving a step closer to autonomous computing environments. This paper introduces such a deployment service and outlines an initial model of the work in progress.

[HMM04a]
Dirk Henrici, Jochen Müller, and Paul Müller. Sicherheit und Privatsphäre in RFID-Systemen. In 18. DFN-Arbeitstagung, 1.-4. Juni 2004, Düsseldorf, June 2004.
[ bib | dspace ]

RFID-Systeme sind in aller Munde: Sie sollen Warenwirtschaftssysteme revolutionieren und auch in einer Vielzahl anderer Anwendungsbereiche hilfreiche Dienste leisten. Für die damit verbundene Kostenersparnis und die neuen Möglichkeiten wird der Schutz von Daten und der Privatsphäre der Nutzer noch vernachlässigt. In diesem Beitrag werden die Bedrohungen dargestellt und einige bisher vorgeschlagene Lösungsansätze diskutiert. Zur Überwindung der identifizierten Schwachstellen wird ein anwendungsneutrales Framework für RFID-Systeme vorgestellt, mit dem der Schutz der Privatsphäre technisch verankert werden kann.

[HMM04c]
Markus Hillenbrand, Paul Müller, and Harald Müller. Voice over IP als Web Service. In 18. DFN Arbeitstagung in Düsseldorf, June 2004.
[ bib | dspace ]

Die Umstellung der klassischen leitungsgebundenen Telefontechnik auf eine moderne und auf längere Sicht kostengünstigere Voice over IP Infrastruktur rückt zunehmend ins Blickfeld der Entscheidungsträger in mittleren und größeren Unternehmen. Doch ein unter Umständen hoher Integrations- und Administrationssaufwand bleibt bei den bisher angebotenen Lösungen auf Basis von H.323 und SIP weiterhin ein wichtiger Hemmfaktor. Die Einfachheit und Offenheit von Web Services als Architektur für verteilte Anwendungen und Systeme bringt viele Vorteile für Anbieter und Nutzer solcher Dienste. Eine Kombination der beiden Technologien Web Services und Voice over IP birgt ein großes Potenzial, um das Telefonieren über das Internet weiter zu verbreiten und für Nutzer und Anbieter einen ähnlich hohen, wenn nicht gar besseren Komfort wie in der klassischen Telefonie zu bieten.

[MMK04]
Paul Müller, Jochen Müller, and Holger Klus. Eine XML-basierte Referenzarchitektur für ein Clusterinformationssystem. In GI-EMISA-Fachtagung Sozialinformatik in Oldenburg, May 2004.
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[HM04c]
Dirk Henrici and Paul Müller. Tackling Security and Privacy Issues in Radio Frequency Identification Devices. In 2nd International Conference on Pervasive Computing, Pervasive 2004; April 21-23, 2004; Linz/ Vienna; Austria, April 2004.
[ bib | dspace ]

This paper introduces shortly into the security and privacy issues of RFID systems and presents a simple approach to greatly enhance location privacy by changing traceable identifiers securely on every read attempt. The scheme gets by with only a single, unreliable message exchange. By employing one-way hash functions the scheme is safe from many security threats.

[VMHM04]
Aline Verney, Jochen Müller, Markus Hillenbrand, and Paul Müller. Réseau de capeurs mobiles basé sur des services Web. In mCube 2004, Première Conférence Nationale sur le Multimédia mobile, Montbéliard-Sochaux, 30-31 März 2004, Frankreich, March 2004.
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Certains domaines de recherche reposent plus sur la simulation que sur l'expérience et la réalisation de simulation passe par l'élaboration de modèles fondés sur des données mesurées ou calculées. Afin de recueillir des données pertinentes, il est important de disposer d'appareils de mesures performants et fiables. Le présent article décrit un système fondé sur un réseau d'appareils mobiles munis de capteurs et qui répond précisément à ces attentes. Seront alors présentés non seulement un prototype de dispositif mobile mais aussi la conception et la réalisation d'une plateforme middleware accessible à l'aide de services Web. La description des mécanismes de collecte et de transfert des données au format XML mais aussi les thèmes de la sécurité et du système de paiement du service seront également abordés. Enfin, l'étude de divers scenarii de services Web dédiés à l'automobile permettra de dévoiler les développements futurs du système.

[SFM04a]
Gerhard Steinebach, Hans-Dieter Feser, and Paul Müller. Stadtentwicklungskonzeption StadtTechnopole Kaiserslautern. In Schriftenreihe zur Stadtplanung, Band 2, 2004.
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[JLMM04]
Andreas Jonen, Volker Lingnau, Jochen Müller, and Paul Müller. BALANCED IT-DECISION-CARD Ein Balanced Scorecard-Basiertes Instrument für das Investitionscontrolling von Projekten in der Informationstechnologie. In Wirtschaftsinformatik 4/2004: IV-Controlling, January 2004.
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This paper introduces a Balanced IT-Decision-Card. It aims at overcoming the shortcomings of common decision making processes on large Information Technology (IT) projects. The investment decision should be based on an evaluation process that takes into account monetary and non-monetary measures. Given this infinite amount of data, decision makers need tools that present the important information in a simple and structured way. Therefore, this working paper makes use of the latest findings of cognition theory. Furthermore, the IT project must be integrated in the overall IT strategy, so that synergies with other IT projects can be realized. Following this argumentation, the Balanced Scorecard approach is adopted to control the investment process of IT-projects.

[HKM+04]
Dirk Henrici, Michael Kleis, Paul Müller, Bernd Reuther, and Detlef Bosau. Part of: CaberNet Vision of Research and Technology Development in Distributed and Dependable Systems, Chapter 11, chapter CaberNet Report: Distributed Multimedia Platforms. Part of: CaberNet Vision of Research and Technology Development in Distributed and Dependable Systems, Chapter 11, January 2004.
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This document presents a CaberNet vision of Research and Technology Development (RTD) in Distributed and Dependable systems. The Network of Excellence is the collective author of this new document, which was put together by integrating contributions coming from many CaberNet partners. A dedicated CaberNet Plenary workshop (November 2003) and a one-day meeting of the CaberNet Links-to-Industry Forum (December 2003) were organised to consolidate the Network understanding of the RTD Vision. The Vision document is intended to serve as a policy-directing document. But it is equally valuable as a high level overview of recent and current activities in the selected areas, emphasising directions in which R&D in distributed and dependable systems are likely to be moving in the future.

[SFM04b]
Gerhard Steinebach, Hans-Dieter Feser, and Paul Müller. Stadtentwicklungskonzeption StadtTechnopole Kaiserslautern (Kurzfassung). In Schriftenreihe zur Stadtplanung, Band 1, 2004.
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[HM04a]
Dirk Henrici and Paul Müller. Hash-based Enhancement of Location Privacy for Radio-Frequency Identification Devices using Varying Identifiers. In Workshop on Pervasive Computing and Communications Security (PerSec'04) at IEEE PerCom 2004; March 14-17, 2004; Orlando, Florida; USA, January 2004.
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Radio-Frequency Identification Devices (RFID) may emerge as one of the most pervasive computing technologies in history. On the one hand, with tags affixed to consumer items as well as letters, packets or vehicles costs in the supply chain can be greatly reduced and new applications introduced. On the other hand, unique means of identification in each tag like serial numbers enable effortless traceability of persons and goods. But data protection and privacy are worthwhile civil liberties. This paper introduces a simple scheme relying on oneway hash-functions that greatly enhances location privacy by changing traceable identifiers on every read getting by with only a single, unreliable message exchange. Thereby the scheme is safe from many threats like eavesdropping, message interception, spoofing, and replay attacks.

[HVMK03]
Markus Hillenbrand, Aline Verney, Paul Müller, and Tom Koenig. Web Services for Sensor Node Access. In 5. Cabernet Plenary Workshop, Madeira, Portugal, November 2003.
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Some research areas rely on simulation instead of experiments. And these simulation scenarios need a suitable data basis to operate on. Besides existing databases containing previously acquired or calculated data, sensor networks are a useful way to acquire necessary data. This paper introduces a software and hardware system that allows users to seamlessly access and integrate data provided by wireless and mobile sensors through a dedicated XML and Web Service enabled middleware. It describes the hardware components that have been utilized and combined to create a sensor node, and it outlines a dedicated middleware architecture to manage sensor nodes, the data gathering process and data access.

[JLMM03]
Andreas Jonen, Volker Lingnau, Jochen Müller, and Paul Müller. Unterstützung von Investitionsentscheidungen im IT-Bereich. In Fachtagung IT-Controlling am 19.03.2004 in Bonn, November 2003.
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Investitionsentscheidungen sind die Basis für jegliches unternehmerisches Handeln. Daher ist der Prozess der Investitionsentscheidung eine der wichtigsten betriebswirtschaftlichen Aufgaben. Investitionsstrategien in der IT befinden sich in einer Phase der Umorientierung und Neudefinition. Nach einer Phase des beinahe blinden Investierens in die Informationstechnologie (IT) werden inzwischen immer stärker Investitionen in diesen Bereich durch umfangreiche Kosten-Nutzen-Analysen hinterfragt. Zentrales Instrument in diesem Zusammenhang ist der Net Present Value (NPV), welcher die prognostizierten Einzahlungen und Auszahlungen (Zahlungsströme) auf den Investitionszeitpunkt abzinst, um so eine bessere Bewertungsgrundlage für die Investitionsentscheidung zu haben.

[ZRM03]
Ge Zhang, Bernd Reuther, and Paul Müller. User Oriented IP Accounting in Multi-user Systems. In The 8th IFIP/IEEE International Symposium on Integrated Network Management, Colorado Springs, US, March 2003.
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The traditional IP accounting method is IP address oriented, that means one IP address corresponds to one user, but it can not meet the finer granularity accounting requirement in multi-user systems, in which many users share one or more IP address at the same time. In the multi-user systems the user oriented IP accounting can distinguish the producers of the IP traffics, which come from the same IP address. Hence it is a more accurate accounting method than traditional IP address oriented accounting method. In this paper, we present the technology of the user oriented IP accounting, and describe the principle of this method, and the realization considerations.

[RM02]
Andreas Rippel and Paul Müller. Generisches Vorlesungs- und Übungsmanagement (LeXem). In GI Tagung (ILLS2002) 10/2002 Hannover, October 2002.
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Bei der Durchführung von netzgestützten Vorlesungsveranstaltungen stehen die Dozentinnen und das betreuende Personal vor der Situation, dass die üblichen Verfahrensschritte, wie Anmeldung, Verteilung von Dokumenten, Bewertungen der studentischen Leistungen und Kommunikation, mit verschiedenen Werkzeugen und Medien erfolgt. Oft erfolgt eine Anmeldung noch über Aushänge, sodass Teilnehmerlisten händisch erstellt werden müssen. Teilnehmerlisten sind dann die Basis für Emaillisten, die wiederum die Kommunikation innerhalb der Gruppen ermöglichen. Zunehmend fließen auch studienbegleitende Einzelleistungen in die Endnoten ein, und den Studierenden soll ihr Leistungstand aktuell zugänglich sein. Am Ende der Veranstaltung müssen die Leistungsdaten konsolidiert werden, um die Scheinvergabe vorzubereiten. Dieses Papier beschreibt ein generisches System das die netzgestützte Begleitung der klassischen Vorlesungsformen von der Anmeldung, über der Verteilung der Dokumente und der Kommunikation, bis zur Scheinvergabe ermöglicht. Dabei haben die an einer Vorlesung beteiligten Personengruppen jeweils aktuelle Sichten auf den Datenbestand aus Lehrmaterialien, Nachrichten und Leistungsdaten. Die Zugriffe können dafür auch über gesicherte Kanäle erfolgen.

[HM02]
Markus Hillenbrand and Paul Müller. Werkzeug zum Management von Online-Ressourcen (MORe). In GI Tagung 10/2002 Dortmund, October 2002.
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Beim Erstellen von Online Präsentationen für verschiedene Anlässe und Zielgruppen (Vorlesung, Seminar, Vortrag bzw. Erstausbildung, wissenschaftliche Weiterbildung und Lebenslanges Lernen) steht ein Dozent oft vor dem Problem, seine Inhalte neu aufbereiten und zusammenstellen zu müssen. Für den Office Bereich existieren zwar Werkzeuge, die ihn dabei unterstützen, aber im Online Bereich (HTML, Videos, Audio-Dateien usw.) muss er auf verschiedene Tools zurückgreifen und außerdem wissen, wie die Dateien für den Webzugriff aufbereitet und angeordnet werden müssen. Dieses Papier beschreibt ein Werkzeug, das den Autor so weit unterstützt, dass er (wie aus dem Office Bereich gewohnt) seine Online Präsentation ohne großes Spezialwissen und mit einem einzigen Programm zusammenstellen und verteilen kann.

[REMH02]
Bernd Reuther, Achim Ebert, Paul Müller, and Hans Hagen. Interactive Poster: A powerful communication framework for distributed virtual reality. In IEEE Visualization 2002, Boston, October 2002.
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The communication framework for distributed VR presented in this paper provides a powerful but simple to use communication service for interactive data exchange within groups. It addresses communication connections in LAN as well as connecting different companies via WAN and firewall tunneling. Reliable group communication, distribution of interactive voice and video data, tunneling of IP multicasts, optional data encryption and user authentication complete the services of the communication framework, which have been implemented in pure Java.

[ZRM02]
Ge Zhang, Bernd Reuther, and Paul Müller. Distributed Agent Method for User Based IP Accounting. In 7th CaberNet Radicals Workshop, 13-16 October 2002, Bertinoro (Forlì), Italy, August 2002.
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User based IP accounting is a more accurate technique, which can be used to meet the finer granularity requirement of IP accounting. To implement this technique, a distributed Agent method is suggested. In this paper the work principle of the distributed Agent is described. With the Agent all the required user related traffic information can be collected for the purpose of User based IP accounting.

[KHTM01]
Thomas Kleinberger, Andreas Hilzinger, Klaus Tochtermann, and Paul Müller. Workflow support for Multimedia Learning Objects. In Proc. of WebNet 2001, Orlando, Florida, USA, Oct. 23-27, 2001, pp.700-705 / Association for the Advancement of Computing in Education, Charlottesville, VA, 2001.
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Workflow services can support learning with multimedia objects in eLearning environments. The innovation of our approach is to embed intra multimedia object navigation into the workflow. As a result, it is possible to define an overall learning workflow based on interpretation and interactions of learners and tutors with multimedia objects. A learning process can now be defined as a flow of instructions using interpretation of multimedia objects and interactivity by navigation within the multimedia learning objects.

[KSHM01]
Thomas Kleinberger, Lutz Schrepfer, Andreas Holzinger, and Paul Müller. A Multimedia Repository for Online Educational Content. In Proc. of ED-MEDIA 2001, Tampere, Finland, Jun.26-30, 2001, pp.975-980, 2001.
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We propose an architecture of a multimedia repository for online educational content, that helps to manage the continuously growing amount of electronic learning material. The multimedia repository can be embedded in educational learning environments or in Content Management Systems. It is designed to manage a large amount of interactive multimedia and hypermedia learning material, provides a centralized access to all stored content, preserves the physical quality of the learning material and offers functions for content based searching, browsing and retrieval in different qualities, depending on the users environment and location.

[HKM01]
Andreas Holzinger, Thomas Kleinberger, and Paul Müller. Multimedia Learning Systems based on IEEE Learning Object Metadata (LOM). In Proc. of ED-MEDIA 2001, Tampere, Finland, Jun.26-30, 2001, pp.772-777, 2001.
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One of the hottest topics in recent information systems and computer science is metadata. Learning Object Metadata (LOM) seems to be a very powerful mechanism to represent metadata, because of the great variety of LOM Objects. This is one of the reason why the LOM Standard is cited in a lot of projects in the field of eLearning Systems. We came to the conclusion that this multi media learning (MML) related technology could enhance conventional learning systems. Some applications have many possibilities to interpret and use the information of the Learning Object Metadata base schema. One of the disadvantages of the very complex metadata-structure is the fact, that it is going to be difficult or confusing to determine the relevant elements for a satisfying result. Therefore a Learning System based on the LOM standard is expected to provide an intuitive user interface that supports the user in getting good results. This article describes why metadata is needed, discusses the development from Dublin Core, Gateway to Educational Materials (GEM) and Warwick-Framework to the IEEE LOM and presents four examples of successful implemented systems.

[MRSS00]
Paul Müller, Bernd Reuther, Michael Schneider, and Andreas Schulz. Using Transport Services instead of specific Transport Protocols (304/00). Technical report, University of Kaiserslautern, Germany, July 2000.
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For most applications the used transport service providers are predetermined during the development of the application. This makes it difficult to consider the application communication requirements and to exploit specific features of the network technology. Specialized protocols that are more efficient and offer a qualitative improved service are typically not supported by most applications because they are not com-monly available. In this paper we propose a concept for the realization of protocol independent transport services. Only a transport service is predetermined during the development of the application and an appropriate transport service provider is dynamically selected at run time. This enables to exploit specialized protocols if possible, but standard protocols could still be used if necessary. The main focus of this paper is how a transport service could provide a new transport service provider transparently to existing applications. A prototype is presented that maps TCP/IP based applications to an ATM specific transport service provider which offers a reliable and unreliable transport service like TCP/IP.

[KM00a]
Thomas Kleinberger and Paul Müller. Content Management for Web Based Education. In Proc. of ED-MEDIA 2000, Montreal, Canada, Jun.6-Jul.1, 2000, p. 1784, 2000.
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Based on the newest information and communication technology all the needs of modern educational systems can be met for the first time in one tool and one medium: the computer and the internet. Computer based solutions provide the technological support necessary for the whole teaching and learning process. The greatest advantage is the possible combination of all usable instruments, their flexibility and configurability. With new technologies and new media types it will be possible to support all kinds of training, self-study and continuing education in local or global networks over the web. It is clear that these new methods and technologies require new methods and solutions for the tasks content creation, delivery and archiving in education. Especially the use of new media sets high requirements on these tasks. This article describes how content management systems, a technology already used in other kinds of business, can support these tasks in web based education. After an introduction a definition of content management is given and refined for the area of web based education. Next the main building blocks and features of content management systems are described and the improvements for web based education are highlighted. Finally content management is embedded in the learning workflow.

[KM00b]
Thomas Kleinberger and Paul Müller. Content Management for Web Based Learning. In Proc. of Webnet 2000, San Antonio, Texas, USA, Oct. 30-Nov.4, 2000, pp.329-334, 2000.
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[MRS00]
Paul Müller, Bernd Reuther, and Michael Schneider. ViAA - a virtual ATM API for arbitrary layer 2 access networks. In Computer communications 23, S. 1019-1026, 2000.
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[RM00]
Andreas Rippel and Paul Müller. Transforming Different Textual Sources into a Learning System. In Multimedia for Multimedia: Learning and Teaching at the University in the Next Decade.(Schloss Dagstuhl International Conference and Research Center for Computer Science), 6/2000 Wadern, 2000.
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[RSM00]
Bernd Reuther, Michael Schneider, and Paul Müller. Ein Zugang zu QoS-fähigen Backbone-Netzen über beliebige Layer 2 Technologien. In Praxis der Informationsverarbeitung und Kommunikation PIK 1/00, January 2000.
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[VSRM99]
Om Prakash Vyas, S. Sundar, Bernd Reuther, and Paul Müller. VBR mechanism in ATM: An Experimental Investigation. In CMSC-99, International AMSE conference on Computer Modelling, Simulation and Communication, Jaipur, India, December 1999.
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[Mül99a]
Paul Müller. E-commerce & the Internet. In corporate PURCHASING solutions, Vol. 1/99, January 1999.
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[Mül99b]
Paul Müller. Multimedia und Internet. In Festschrift: Alwin Walther: Pionier des Wissenschaftlichen Rechnens, 1999.
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[MGHvL98]
Paul Müller, Michael Gnoth, Hans Hagen, and Rolf van Lengen. Sichere Kommunikation und visuelle Datenverarbeitung im Krankenhaus. In Innovationen im Krankenhaus, Westpfalz Klinikum Kaiserslautern, November 1998.
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[MS98]
Paul Müller and Klaus Schlüter. City-Netze, Grundlagen der Stadtnetze, Lockruf des Geldes. In Gateway 9/98, September 1998.
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[MG95]
Paul Müller and Hans Peter Großmann. Information Highway in Deutschland - Der Weg zur Informationsgesellschaft. In NET special: Daten-Infobahn, September 1995.
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[MH95]
Paul Müller and Pius Hieber. Die Infobahn - und wer sie baut, betreibt und nutzt. In Technologie & Management 3/95, September 1995.
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[Mül95]
Paul Müller. Broadband Networking. In EU Workshop, Univeristät Ulm, January 1995.
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[MG94b]
Paul Müller and Hans Peter Großmann. UDINE A universal document information and navigation entry. In Computer Networks and ISDN Systems 26 (Suppl. 1) S29-S38, 1994.
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[MG94a]
Paul Müller and Hans Peter Großmann. Anforderungen multimedialer Kommunikation. In Praxis der Informationsverarbeitung und Kommunikation PIK 1/94, January 1994.
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[BKO+91]
F. Bitter, R. Knopp, R. Ochsenkühn, Pius Hieber, W.E. Adam, H.-J. Biersack, and Paul Müller. Nuclear Medicine Image Distribution and Telecommunication through Public Broadband VBN. In Springer, 1991.
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The availability of the public broadband telecommunication network from the Deutsche Bundespost Telekom based on the already existing interim fiber optic broadband network allows data transmission at rates up to 2 MBit/s simulataneously with videoconferencing (140 MBit/s).

[Mül90]
Paul Müller. Least Squares Characterization of Improved Estimation Functions. In Springer Verlag, 1990.
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[MRT90]
Paul Müller, Werner Rothengatter, and Wolfgang Thiel. Modelling the Stagflation Phenomenon in West Germany. An Application of a Catastrophe Modell. In Lucius & Lucius Verlagsgesellschaft mbH, 1990.
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[MHG90]
Paul Müller, Pius Hieber, and Hans-Peter Großmann. Das Vermittelnde Breitband-Netz (VBN) in einer Netzwerkumgebung. In NET Verlagsservice GmbH, 1990.
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[Mül89a]
Paul Müller. The Jackknife and Bootstrap Approach in Regression Analysis. In Springer Verlag, 1989.
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[Mül89b]
Paul Müller. Numerical Classification of Biased Estimators. In Springer Verlag, 1989.
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[Mül89c]
Paul Müller. Simulation Methods in Linear Models. 1989.
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[MR88]
Paul Müller and Werner Rothengatter. Lucius & Lucius Verlagsgesellschaft mbH, chapter Measuring the Relevance of Natural Resources for Production. Lucius & Lucius Verlagsgesellschaft mbH, 1988.
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[MG87]
Paul Müller and Hans-Peter Großmann. Wissensbasierte Steuerung von Methoden- und Datenbanken. In DIFF, Tübingen, 1987.
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[KM87]
Wolfgang Kehr and Paul Müller. Die Informationssysteme der Universitäten in Baden- Württemberg. In ZfBB, Vittorio Klostermann, 1987.
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[Mül85]
Paul Müller. On Selecting the Set of Regressors. In Elsevier Science Ltd, 1985.
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[Mül84a]
Paul Müller. Capital Budgeting of Public Investments in an Economy with Exhaustible Resources. In University Poitiers, 1984.
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[Mül84c]
Paul Müller. Improved Estimation in Econometrics. In Springer Verlag, 1984.
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[Mül84b]
Paul Müller. Entscheidungstheoretisch begründete Schätzverfahren. Verlagsgruppe Athenäum, Hain, Hanstein, 1984.
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[Mül81]
Paul Müller. Die Stein-Rule (SR-) Schatzfunktion. In Institut für Angewandte Wirtschaftsforschung, Tübingen, 1981.
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