Now showing 1 - 8 of 8
  • Publication
    Roll-out of Giga-bit Copper
    ( 2018)
    Hincapie, Daniel
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    Leibiger, Mathias
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    G.fast is the latest digital subscriber line (DSL) technology that provides Giga-bit access from the distribution point (DP). Although it promises to satisfy the short and mid-term requirements of internet-based services, providers are not upgrading instantaneously all legacy systems to G.fast. Instead, the consolidation process is progressive and therefore must minimize the impacts on legacy systems such VDSL2, providing seamless migration and friendly coexistence experience. To achieve this goal, service providers are considering to avoid mutual interference using non-overlapping band-plans. This strategy reduces G.fast data rates and coverage, though. A less harmful approach is to allow partial overlapping, but the benefits and spectrum that must be removed to reduce the impact are unknown. In this work, we analyze the performance impact that G.fast roll-out conveys when VDSL2 systems served from a cabinet are gradually upgraded to G.fast deployed at the DP. We carry out a simulation study to evaluate the mutual performance losses when G.fast is first introduced with a low user share in different fiber-to-the-cabinet (FTTC) scenarios. Based on the obtained results, we select representative access network topologies to determine the expected minimum and maximum losses as the user share progressively increases. In order to establish the benefits and drawbacks of implementing G.fast band-plans that partially overlap with VDSL2, we evaluate G.fast and VDSL2 performance when the operative start frequency of G.fast is set along VDSL2 spectrum. We consider in our study both the current version of G.fast and its recently proposed long reach (LR) extension that aims to achieve longer coverage range by enabling larger bit-constellation size (Bmax = 12bits) and higher maximum aggregate transmit power (MAXATP = 8dBm). The obtained numerical results are intended to help service providers estimate the impact of G.fast on existing VDSL2 systems, as well as its under-performance when they jointly operate indifferent network topologies. So they can evaluate: 1) which FTTC scenarios are eligible for deploying G.fast and how much it impacts non-upgraded users; 2) how much performance degradation to expect during the progressive deployment of G.fast; and 3) the expected data rate loss for G.fast when its spectrum is partially limited, and how much this strategy reduces the impact on VDSL2.
  • Publication
    Resiliente Netze mit Funkzugang
    (VDE, 2017)
    Fettweis, Gerhard P.
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    Franchi, Norman
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    Bittner, Frank
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    Dekorsy, Armin
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    Dillinger, Markus
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    Dyka, Zoya
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    Einsiedler, Hans J.
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    Fitzek, Frank
    ;
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    Glänzer, Martin
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    Hentschel, Tim
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    Hofmann, Frank
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    Hoffmann, Marco
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    Irmer, Ralf
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    Janßen, Uwe
    ;
    ; ;
    Knorr, Rudi
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    Kraemer, Rolf
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    Kornbichler, Andreas
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    Kückelhaus, Markus
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    Langendörfer, Peter
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    Menges, Georg
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    Merz, Peter
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    Meyer, Michael
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    Mühleisen, Maciej
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    Müller, Andreas
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    Ruchhaupt, Lutz
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    Redana, Simone
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    Reinartz, Michael
    ;
    ;
    Riedl, Johannes
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    Schotten, Hans
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    Schulz, Dirk
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    Schupke, Dominic
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    Thümmler, Christoph
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    Timm-Giel, Andreas
    ;
    Wiebus, Christian
    ;
    Willmann, Sarah
    ;
    Zimmermann, Gerd
    Die Digitalisierung der Gesellschaft und Industrie schreitet unaufhörlich voran, und die Bedeutung des Zugangs zu uneingeschränkter mobiler Vernetzung für unser gesellschaftliches und berufliches Leben nimmt somit ebenfalls stetig zu. Mit der Entwicklung der 5G Mobilfunkgeneration, aber auch echtzeitfähiger lokaler Funknetze werden in Zukunft digitale drahtlose Kommunikationsnetze eine Vielzahl neuer industrieller Anwendungen erschließen und dabei technische Anforderungen erfüllen, die bisher nur durch kabelgebundene Netze erfüllt werden konnten. Die stetige Erhöhung der Datenrate, die Minimierung von Ende-zu-Ende Latenzen zur Erfüllung von Echtzeitanforderungen und die Steigerung der Netzzuverlässigkeit sind aktuell zentrale Forschungsziele und Entwicklungsziele bei der Optimierung von Netzen mit Funkzugang.
  • Publication
    Energy saving potential of adaptive, networked, embedded systems
    ( 2016)
    Heinrich, Patrick
    ;
    ;
    Knorr, Rudi
    This paper presents and evaluates the energy saving potential of adaptive, networked, embedded systems. The aim is to demonstrate the benefits of modeling the energy demand during the development of such systems. For this purpose, the previous developed energy model is applied within a case study and different allocations of software components are compared. The estimated energy demands of these allocations are presented and discussed. The analyzed system of the case study represents an automotive system which executes two advanced driver assistance applications. The system is adaptive, which means that temporally unnecessary applications will be deactivated. Within the evaluated system this deactivation depends on the vehicle speed, which is derived by the New European Driving Cycle. Two different allocations of software components are evaluated.
  • Publication
    Mehrstufiger Rollout hat mehr Vor- als Nachteile
    Das Bundesministerium für Wirtschaft und Energie (BMWi) hat ein Eckpunktepapier zum Rollout für intelligente Netze vorgelegt. Der Artikel wägt einen einmaligen, flächendeckenden gegen einen mehrstufen Rollout ab.
  • Publication
    Early energy estimation of networked embedded systems executing concurrent software components
    ( 2015)
    Heinrich, Patrick
    ;
    Bergler, Hannes
    ;
    This paper presents and evaluates a new approach of modeling energy consumption of embedded systems resulted by concurrent software components. The objective is to enable energy estimation within early phases of system development, which allows system designers to compare different allocations of software components within networked systems. The individual elements of the presented model are: energy consumption of software components themselves, energy consumption resulted by any software component, and energy consumption resulted by specific software components. The The developed model was applied within an automotive case study which shows a theoretical energy saving potential of 36.2 %. This demonstrates the potential and relevance of modeling energy estimation within early development phases.
  • Publication
    Self-learning assessment of communication in distributed embedded systems - a feasibility study
    ( 2014)
    Langer, Falk
    ;
    This paper addresses the problem of evaluating the communication behavior of cyber physical systems. An important problem for the validation of the interaction in the distributed system is missing, wrong or incomplete specification. In this paper, the application of a new approach for assessing the communication behavior based on reference traces is presented and evaluated. The benefit of the approach is that it works automatically, with low additional effort and without using any specification. This paper provides a use case in conjunction with a feasibility study to investigate the applicability of a self-learning anomaly detection methodology. The data of the feasibility study are created by applying the described anomaly detection within a real vehicle network.
  • Publication
    Phantomkreise
    Die Nutzung von Phantomkreisen bedeutet, dass über zwei Übertragungswege (Doppeladern) drei Kommunikationskanäle realisiert werden können. Diese Anfang des 20. Jahrhunderts für die Sprachkommunikation entwickelte Methode ist bis heute nahezu in Vergessenheit geraten. Da für den dritten Kommunikationskanal keine zusätzliche Leitung verlegt werden braucht und somit Kosten gespart werden können, ist der Einsatz von Phantomkreisen für die DSL-Übertragung aus heutiger Sicht hochinteressant. Sowohl Datenraten als auch Reichweiten können so erhöht werden. Laboruntersuchungen der Faunhofer ESK haben gezeigt, dass eine hochbitratige DSL-Übertragung (z.B. ADSL2+ oder VDSL2) über zwei Doppeladern sowie die gleichzeitige Übertragung mittels Phantomkreis möglich ist.
  • Publication
    Künstliches Rauschen
    Ein zentrales Problem, was Netzbetreiber vom Einsatz des energiesparenden Low Power Modus L2 abhält ist, dass dieser Instabilitäten durch zeitvariantes Nebensprechen hervorruft. Benötigt wird somit eine Lösung, die einerseits die Stabilität der Übertragung sichert und außerdem leicht in die seit Jahren gültigen DSL-Standards integriert werden kann. Der Einsatz von virtuellem/künstlichem Rauschen dient der Stabilisierung von xDSL-Systemen bei zeitvariantem Nebensprechen.