Search results for "Telecommunication"

Learning-based multiresolution transforms with application to image compression

2013

In Harten's framework, multiresolution transforms are defined by predicting finer resolution levels of information from coarser ones using an operator, called prediction operator, and defining details (or wavelet coefficients) that are the difference between the exact and predicted values. In this paper we use tools of statistical learning in order to design a more accurate prediction operator in this framework based on a training sample, resulting in multiresolution decompositions with enhanced sparsity. In the case of images, we incorporate edge detection techniques in the design of the prediction operator in order to avoid Gibbs phenomenon. Numerical tests are presented showing that the …

EU transition in power sector

2019

Abstract In the past, much of Europe’s electricity grid network has been designed in consideration of the locations of conventional generation plants. However, a large share of today's renewables production – notably variable wind and solar – does not correspond to this grid architecture. Interconnectors, in addition to internal infrastructure, are key to creating new electricity corridors to connect areas of surplus to areas of scarcity. In this context, in 2014 the European Council, in recognizing that a fundamental role of transmission infrastructure is to enable the integration of areas of high renewable energy potential with main consumption areas, endorsed the proposal by the European…

Improving IEEE 802.11 Performance in Chain Topologies through Distributed Polling and Network Coding

2009

Wireless multi-hop networks often rely on the use of IEEE 802.11 technology. Despite of the robustness of the IEEE 802.11 Distributed Coordination Function (DCF) for working in various network scenarios, it has been proven that critical inefficiencies can arise in the case of multi-hop packet forwarding. In this paper, we propose a MAC scheme, based on the virtualization of the Point Coordination Function, optimized for working on chain topologies with bidirectional traffic flows. Our scheme is based on a token-like access mechanism coupled with network coding. The basic idea is the use of multiple Point Coordinators (PCs) along the node chain, which are elected by passing special token fra…

Perceptual image quality assessment using a normalized Laplacian pyramid

2016

Localization-Free Power Cartography

2018

Author's accepted manuscript (postprint). © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. Spectrum cartography constructs maps of metrics such as channel gain or received signal power across a geographic area of interest using measurements of spatially distributed sensors. Applications of these maps include network planning, interference coordination, power con…

Facilitating IP deployment in a MARTE-based MDE methodology using IP-XACT: a XILINX EDK case study

2012

International audience; In this paper we present framework for the deployment of hardware IPs at high-levels of abstraction. It is based in a model- driven approach that aims at the automatic generation of Dynamic Partial Reconfiguration designs created in Xilinx Platform Studio (XPS). Contrary to previous approaches, we make use of the IP-XACT standard to facilitate the deployment of hardware IPs, their parameterization and subsequent integration. We propose an extension to the MARTE profile for IP deployment, and we introduce the necessary model transformations to obtain a high- level representation from an IP-XACT component library. These models are then used to create a platform in MART…

Design and implementation of a long-range low-power wake-up radio and customized DC-MAC protocol for LoRaWAN

2019

In this paper, we present the design and implementation of a long-rage wake-up radio (WuR) and customized duty cycled (DC) MAC protocol for wireless IoT devices. The WuRx achieves a sensivity of −70 dBm by consuming just 0.032 mA, thereby optimizing the energy consumption of battery powered long-range wireless IoT devices. Reducing the power consumption of these devices minimizes the overall costs when deployed in large scale.

WiHAR : From Wi-Fi Channel State Information to Unobtrusive Human Activity Recognition

2020

A robust and unobtrusive human activity recognition system is essential to a multitude of applications, such as health care, active assisted living, robotics, sports, and tele-immersion. Existing well-performing activity recognition methods are either vision- or wearable sensor-based. However, they are not fully passive. In this paper, we develop WiHAR—an unobtrusive Wi-Fi-based activity recognition system. WiHAR uses the Wi-Fi network interface card to capture the channel state information (CSI) data. These CSI data are effectively processed, and then amplitude and phase information is used to obtain the spectrogram. In the subsequent step, the time-variant mean Doppler shift (MDS) caused …

Anomaly‐based intrusion detection systems: The requirements, methods, measurements, and datasets

2021

International audience; With the Internet's unprecedented growth and nations' reliance on computer networks, new cyber‐attacks are created every day as means for achieving financial gain, imposing political agendas, and developing cyberwarfare arsenals. Network security is thus acquiring increasing attention among researchers, practitioners, network architects, policy makers, and others. To defend organizations' networks from existing, foreseen, and future threats, intrusion detection systems (IDSs) are becoming a must. Existing surveys on anomaly‐based IDS (AIDS) focus on specific components such as detection mechanisms and lack many others. In contrast to existing surveys, this article co…

The M/G/1/1 queue with repeated attempts and different types of feedback effects

1985

Queueing systems with repeated attempts have wide practical use in designing switching networks and computer systems. The model presented in this paper not only takes into account repetitions by congestion but also considers the feedback effects from all types of failures in establishing a connection. A semi-regenerative analysis is applied in order to determine the characteristics of the underlying queueing process. Bedienungssysteme mit wiederholten Versuchen sind von groβem praktischen Nutzen bei der Bemessung von Vermittlungseinrichtungen und Computersystemen. Das Modell, das in dieser Arbeit vorgestellt wird, berucksichtigt nicht nur Wiederholungen nach vorangegangener Blockierung, son…