654 research outputs found
Energy efficiency analysis of next-generation passive optical network (NG-PON) technologies in a major city network
Ever-increasing bandwidth demands associated with mobile backhaul, content-rich services and the convergence of residential and business access will drive the need for next-generation passive optical networks (NG-PONs) in the long term. At the same time, there is a growing interest in reducing the energy consumption and the associated cost of the access network. In this paper, we consider a deployment scenario in a major city to assess the energy efficiency of various PON solutions from a telecom operator's perspective. We compare five next-generation technologies to a baseline GPON deployment offering similar bandwidths and Quality of Service (QoS) for best-effort high speed connectivity services. We follow two approaches:first, we consider a fixed split ratio (1:64) in an existing Optical Distribution Network (ODN); next, we consider an upgraded ODN with an optimized split ratio for the specific bandwidth and QoS values. For medium bandwidth demands, our results show that legacy PONs can be upgraded to 10G PON without any ODN modification. For future applications that may require access rates up to 1 Gb/s, NG-PON2 technologies with higher split ratios and increased reach become more interesting systems, offering the potential for both increased energy efficiency and node consolidation
An approach for Fault Tolerant and Performance Guarantee Autonomous Robotic Mission
International audienceLong duration autonomous missions are still challenging objectives for robotics. This paper presents a new methodology using performance points of view to guide hardware and software resources management according to mission execution and fault occurrence. Experimental results on a patrolling mission are presented. It also detail how localization guarantee is managed and what impact it has on the overall methodology and its performances
La plus belle harmonie
Si la représentation de l’homme et de la machine a été la clef de voûte de l’âge d’or du cinéma (de L’arrivée d’un train en gare de La Ciotat aux Temps modernes ou de L’arroseur arrosé à Métropolis) il y a beau temps que la machine a disparu des scénarios. La représentation à l’écran du monde du travail industriel et de l’esclavage ouvrier a suivi une courbe continuellement descendante alors même qu’une toute autre mécanique allait peu à peu la supplanter : la « machine humaine » et ses rouag..
Energy efficiency analysis of high speed triple-play services in next-generation PON deployments
Post-peak ICT: graceful degradation for communication networks in an energy constrained future
In recent years, rising energy prices and increasing environmental concerns have boosted research in the so called green ICT and green networking research tracks, aimed at improving the energy efficiency of communications while still offering maximal functionality. In this article we explore a future scenario in which low power networking is no longer optional, but instead becomes a necessity due to fluctuating energy availability. The contribution of this work is twofold. First, we argue why a so called post-peak future scenario, in which we can no longer rely on fossil fuels as our main resource for electricity production, is not unlikely, and what it might entail. Second, we explore the consequences of such a scenario for ICT: How well can current and future infrastructures cope with temporary energy limitations? As an illustration, we present a case study showing the impact of reduced energy availability on a wireless access network
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