Inst. Telekommunikationssysteme

228 Items

Recent Submissions
Analysis of coexisting graphical and textual representations of requirements based on activity diagrams and structured text

Beckmann, Martin (2019)

Due to increasing complexity and the tendency towards more customized products, the development of modern technical systems demands more and more effort. In an attempt to reduce the effort required, engineering models are being adopted to a greater extent in all phases of development. Among the affected development phases is requirements engineering. As a result, engineering models, which almos...

Multi-path aware internet transport selection

Tiesel, Philipp S. (2019)

When the Internet experiment started more than 30 years ago, no one could foresee its expansion — What started as an experiment to interconnect a few research computers has become an essential global infrastructure of humanity. Originally, there was usually only one way to transport data between two computers; this has changed dramatically — today’s Internet offers us way more diverse transport...

ISP traffic management via flow optimization

Akonjang, Emmanuel Obi (2019)

A major challenge that Internet Service Providers (ISPs) face today, is the growing traffic volume that they must handle. The situation becomes even more complex, as users' demands become more volatile or when new application trends emerge that fundamentally change traffic dynamics and composition. Thus, ISPs are always compelled to deal with such changes, in a proper, effcient, and timely ...

Web performance pitfalls data

Enghardt, Theresa (2019-03)

This dataset contains data from the experiment runs of the paper "Web Performance Pitfalls", published by Springer in the Conference Proceedings of the Passive and Active Measurement Conference 2019 (PAM 2019). It includes the load times, HAR files, and resource timing log files Web page loads. In total, the dataset consists of 50 experiment runs, each loading 1000 Web pages, using different br...

Data and container placement in scalable data analytics platforms

Renner, Thomas (2018)

Distributed dataflow systems process large volume of data in parallel on multiple machines. In production, multiple dataflow applications are scheduled for execution in virtual containers on a per-job basis. Furthermore, they access datasets partitioned into datablocks across the cluster machines' disks. Runtime performance is important for many of these jobs, as their users expect fast results...

A Location Prediction Algorithm for Mobile Communications Using Directional Antennas

Lu, Xiaofeng ; Lio, Pietro ; Hui, Pan ; Jin, Haifei (2013)

A directional communication scheme, TRAC, is proposed in this paper to deal with issues in mobile directional communications. Directional communication can bring benefits in terms of spatial reuse, power consumption, and security. Using direction antennas implies that the transmitters must know the direction or location of the receiver. It is necessary to predict the receiver's location to keep...

Knowledge Representation of Requirements Documents Using Natural Language Processing

Schlutter, Aaron ; Vogelsang, Andreas (2018)

Complex systems such as automotive software systems are usually broken down into subsystems that are specified and developed in isolation and afterwards integrated to provide the functionality of the desired system. This results in a large number of requirements documents for each subsystem written by different people and in different departments. Requirements engineers are challenged by compre...

Geofences on the Blockchain: Enabling Decentralized Location-based Services

Victor, Friedhelm ; Zickau, Sebastian (2018)

A decentralized ride- or carsharing application is among the early proposals of what smart contracts on blockchains may enable in the future. To facilitate use cases in the field of location-based services (LBS), smart contracts need to receive trustworthy positioning information, and be able to process them. We propose an approach on how geofences can be defined in smart contracts, and how sup...

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...