Inst. Telekommunikationssysteme

220 Items

Recent Submissions
Self-Management – Potentiale, Probleme, Perspektiven

Herrmann, Klaus ; Mühl, Gero ; Geihs, Kurt (2004)

Gordon Moores Gesetz vom exponentiellen Wachstum der Transistordichte pro Quadrat-Zoll hat seit 1965 die IT-Industrie geprägt. Mit der damit einhergehenden Explosion der Rechnerleistung wurde die Software immer leistungsfähiger, und man ist dazu übergegangen, Rechnersysteme zu vernetzen und Anwendungen zu verteilen. Eine Folge dieser Entwicklungen ist die rapide zunehmende Komplexität der moder...

An Architecture for a Next Generation VoIP Transmission System

Hoene, Christian ; Clüver, Kai ; Weil, Jan (2007)

Packetized speech transmission systems implemented with Voice over IP are gaining momentum against the traditional circuit switched systems despite the fact that packet switched VoIP is two to three times less efficient than its circuit switched counterpart. At the same time, it only supports a rather bad “toll” quality. We believe that it is time for a new architecture developed from scratch –...

Kommunikation zwischen autonomen Agenten

Geihs, Kurt ; Jahr, Ulf ; Zapf, Michael (2001)

Softwareagenten sind Programme, die einen Auftrag autonom und weitgehend selbständig ausführen. Man spricht von mobilen Agenten, wenn diese Programme selbstbestimmt ihre Ausführungsumgebung in einem Netzwerk wechseln können. Die Mobilität der Software impliziert ein neues Programmierparadigma für verteilte Systeme, das die bekannten Interaktionskonzepte herkömmlicher Verteilungsplattformen erwe...

Ziel-orientierter Entwurf von Multi-hop Medienzugriffsprotokollen

Zirwas, Wolfgang ; Habetha, Jörg ; Karl, Holger (2003)

Die Benutzung von Relais in einem drahtlosen Kommunikationssystem kann unterschiedlichen Zielen dienen: der Erweiterung der Abdeckung oder der Erhöhung der Kapazität einer Zelle, aber auch zur Verbesserung der Energieeffizienz. Zu diesem Zweck müssen unterschiedliche Probleme, z.B. der Wegewahl und Weiterleitung, gelöst werden. Hier wird aufgezeigt, wie sich das Ziel in der Gestaltung eines gee...

Autonomie in IT-Systemen

Jaeger, Michael C. ; Werner, Matthias ; Mühl, Gero ; Heiß, Hans-Ulrich ; Laude, Uwe ; Ruge, Christian (2008)

Die Erforschung und Anwendung von autonomen Systemen ist momentan in der Informatik ein Themengebiet von wachsendem Interesse. Die Aussicht, mit autonomen Verfahren komplexe Systeme handhabbar zu machen und Kosteneinsparungen bei deren Betrieb zu erzielen, hat bereits die Softwareindustrie auf dieses Thema gelenkt und zu neuartigen Produkten geführt. Andererseits darf die Verlässlichkeit eines ...

Towards Energy-Aware Multi-Core Scheduling

Richling, Jan ; Schönherr, Jan H. ; Mühl, Gero ; Werner, Matthias (2009)

There are two major current trends that can easily be identified in computer industry: (i) the shift towards massively parallelization fostered by multi-core technology resulting in growing numbers of cores per processor and (ii) the increasing importance of energy-awareness in computing due to rising energy costs and environmental awareness. In current operating systems, these two issues are o...

Stochastic Packet Loss Model to Evaluate QoE Impairments

Hohlfeld, Oliver (2009)

The estimation of quality for real-time services over telecommunication netb4works requires realistic models for impairments and failures during transmission. We focus on the classical Gilbert-Elliott model whose second-order statistics is derived over arbitrary time-scales. The model is used to fit packet loss processes of backbone and DVB-H traffic traces. The results show that simple Markov ...

Next Generation Service Delivery Platforms and Service Overlay Networks

Kellerer, Wolfgang ; Magedanz, Thomas (2010)

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Next Generation Service Delivery Platforms

Kellerer, Wolfgang ; Magedanz, Thomas (2012)

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Optimization of Elastic Cloud Brokerage Mechanisms for Future Telecommunication Service Environments

Campowsky, Konrad ; Carella, Giuseppe ; Magedanz, Thomas ; Schreiner, Florian (2012)

Cloud computing mechanisms and cloud-based services are currently revolutionizing Web as well as telecommunication service platforms and service offerings. Apart from providing infrastructures, platforms and software as a service, mechanism for dynamic allocation of compute and storage resources on-demand, commonly termed as “elastic cloud computing” account for the most important cloud computi...

Managing cloud ecosystems

Slawik, Mathias (2018)

In recent years, the ever-growing proliferation of cloud services led to the creation of large cloud ecosystems. The most prominent example is the cloud ecosystem of Amazon Web Services (AWS), which now has over 8,000 partners and more than $ 18 billion in revenue in 2017. In addition to these "giants", many smaller ecosystems address more specific challenges. An example is the TRESOR cloud eco...

Blockchain-based Supply Chain Traceability: Token Recipes model Manufacturing Processes

Westerkamp, Martin ; Victor, Friedhelm ; Küpper, Axel (2018)

Growing consumer awareness as well as manufacturers’ internal quality requirements lead to novel demands on supply chain traceability. Existing centralized solutions suffer from isolated data storage and lacking trust when multiple parties are involved. Decentralized blockchain-based approaches attempt to overcome these shortcomings by creating digital representations of physical goods to facil...

Dynamic resource allocation for distributed dataflows

Thamsen, Lauritz (2018)

Distributed dataflow systems enable users to process large datasets in parallel on clusters of commodity nodes. Users temporarily reserve resources for their batch processing jobs in shared clusters through containers. A container in this context is an abstraction of a specific amount of resources, typically a number of virtual cores and an amount of memory. For their production batch jobs, use...

Prototyping nfv-based multi-access edge computing in 5G ready networks with open baton

Carella, Giuseppe Antonio ; Pauls, Michael ; Magedanz, Thomas ; Cilloni, Marco ; Bellavista, Paolo ; Foschini, Luca (2017)

With the increasing acceptance of Network Function Virtualization (NFV) and Software Defined Networking (SDN) technologies, a radical transformation is currently occurring inside network providers infrastructures. The trend of Software-based networks foreseen with the 5th Generation of Mobile Network (5G) is drastically changing requirements in terms of how networks are deployed and managed. On...

Seamless interoperability and data portability in the social web for facilitating an open and heterogeneous online social network federation

Göndör, Sebastian Jürg (2018)

Online Social Networks (OSN) have become an integral part of our everyday lives. We express ourselves, create and collect content such as images or videos, share content and information with our friends and colleagues, exchange messages, or keep track of what's happening in the world. Yet, despite social communication being implicitly a distributed, decentralized phenomenon, most OSN services a...

Data-driven estimation and neurophysiological assessment of perceived visual quality

Bosse, Sebastian (2018)

Perceptual quality is one of the key aspects of modern multimedia communication systems. Nevertheless, the questions of how to reliably assess quality as perceived by humans, how to computationally estimate perceived quality and how to incorporate computational models of quality in multimedia systems can still not be answered satisfactorily, despite decades of research. However, these problems ...

Implementation of Cognitive Driver Models in Microscopic Traffic Simulations

Cristea, Roland ; Rulewitz, Stefan ; Radusch, Ilja ; Hübner, Karl ; Schünemann, Björn (2016)

In order to perform microscopic traffic simulations as realistically as possible, a detailed modelling of each individual driver is essential. Currently established microscopic traffic simulators follow a rather static approach to model the driver's behaviour. Individual emotional in uences and temporarily occurring distracting factors are heavy to implement in the established state-of-the-art ...

Explanation Retrieval in Semantic Networks

Michalke, Vanessa N. ; Hartig, Kerstin (2016)

Spreading Activation is a well-known semantic search technique to determine the relevance of nodes in a semantic network. When used for decision support, meaningful explanations of semantic search results are crucial for the user’s acceptance and trust. Usually, explanations are generated based on the original network. Indeed, the data accumulated during the spreading activation process contain...

Good RE artifacts? I know it when I use it!

Femmer, Henning ; Vogelsang, Andreas (2017)

The definition of high-quality or good RE artifacts is often provided through normative references, such as quality standards or text books (e.g., ISO/IEEE/IEC-29148). We see various problems of such normative references. Quality standards are incomplete. Several quality standards describe quality through a set of abstract criteria. When analyzing the characteristics in detail, we see that th...

Time-dependent recommender systems for the prediction of appropriate learning objects

Krauß, Christopher (2018)

This dissertation deals with adaptive learning technologies which aim to optimize Technology Enhanced Learning (TEL) offerings to fit the individual learner’s needs. Thereby, Recommender Systems play a key role in supporting the user’s decision process for items of interest. This works very well for e-commerce and Video on Demand services. However, it is found to be the case that these traditio...