Everlasting sensor networks

Poster for " L'énergie demain. Transition énergétique : recherches et ingénierie " symposium. May 30-31, 2013, MINES ParisTechWithin the team CSAM (Circuits, Systèmes et Applications des Microondes) of IEMN (Institut d'Électronique, de Microélectronique et de Nanotechnologie) and within IRCICA (Institut de Recherche sur les Composants logiciels et matériels pour l'Information et la Communication Avancée - USR CNRS 3080) we develop a research on ultra low power sensor networks. Our goal is to minimize the energy consumption so that the life duration of the network could be infinitely long. We develop studies including nanotechnologies (energy harvesting, storage devices), RF front-ends design, energy management but also radio channel and interference modeling and MAC layer optimization

A simple hybrid statistical–dynamical downscaling method for emulating regional climate models over Western Europe. Evaluation, application, and role of added value?

International audienceA hybrid statistical dynamical downscaling method intended to emulate regional climate models is described and applied to Western Europe. The method is based on a constructed analogues algorithm, already used for statistical downscaling. For emulation, the statistical downscaling relationship is not derived from observations but from climate projections at low and high resolution. The hybrid approach therefore does not rely on the stationarity assumption at low resolution) with the GCM /RCM mode, but not with the RCM / RCM mode. These results are explained by the differences that generally exist at large scale between projected changes by current RCMs and their forcing GCMs. Whether these differences are a testimony of a real added value of RCMs at large scale in the climate change context, or whether they have other causes, is therefore a crucial question

Autonomous Internet of Things predictive control application based on wireless networked multi-agent topology and embedded operating system

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Toward Energy Profiling of Connected Embedded Systems

International audienceA huge number of connected objects are expected to be deployed over the coming years in various areas of everyday life. Many of these objects are energy-constrained and depend on a battery. Thus, energy is a critical resource that limits a large scale deployment, and greatly complicates the development of the embedded software on these objects. Hence, the ability to measure and finely profile the power consumption of such devices, and correlate it with the on-board application is a big challenge to improve the software development. Furthermore, common energy patterns can be extracted from the collected energy figures in order to provide guidelines allowing a proactive energy-based development. In this paper, we present an ongoing work about a lightweight framework for energy profiling of embedded applications source code at a functional granularity. It is driven by an on-line hardware-based measurement technique permitting to gather accurate energy figures. The framework is integrated into an energy-centric iterative development cycle allowing fast revalua-tions of the energy consumed by the targeted functions after each source code modification. Afterwards, we describe our future works about overcoming an unlocked state of art issue relative to asynchronous energy consumption profiling

Energy Consumption of Networked Embedded Systems

International audienceThe Web of Things (WoT) defines the idea of addressing and requesting any surrounding connected device through web applications. These devices are for a large part, tiny, wireless and mostly battery-powered. Therefore, energy represents a critical limiting resource for their large scale deployment in real life applications, such as smart cities or smart buildings. Consequently, the ability to measure, track and finely profile energy consumption of such devices and correlate it with the application driving the device functionalities is a big challenge to improve the development of WoT embedded applications. In this paper, we present our recent ongoing works on energy consumption measurement of networked embedded applications for the WoT area. More particularly, we focus on measuring energy consumption of the well-known Contiki Operating System HTTP web server using two measurement methods, a simulation based method and a real world software based measurement method. Doing this, we quantify and model the gap existing between the simulation and the real world regarding network embedded applications, such as embedded web servers. Afterwards, we describe our aims in using a real world hardware energy consumption measurement method and profile a home-made embedded web server prototype called Smews. This latter could theoretically improve performances and power consumption of WoT applications relying on TCP/IP protocol

All-Solid-State Interdigitated Micro-Supercapacitors Based on Porous Gold Electrodes

Recent developments in embedded electronics require the development of micro sources of energy. In this paper, the fabrication of an on-chip interdigitated all-solid-state supercapacitor, using porous gold electrodes and a PVA/KOH quasisolid electrolyte, is demonstrated. The fabrication of the interdigitated porous gold electrode is performed using an original bottom-up approach. A templating method is used for porosity, using a wet chemistry process followed by microfabrication techniques. This paper reports the first example of an all-gold electrode micro-supercapacitor. The supercapacitor exhibits a specific capacitance equal to 0.28 mF·cm−2 and a specific energy of 0.14 mJ·cm−2. The capacitance value remains stable up to more than 8000 cycles

Génération d'empreintes de périphériques Bluetooth à l'aide d'une radio logicielle à bas coûts

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Génération d'empreintes de périphériques Bluetooth à l'aide d'une radio logicielle à bas coûts

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Automatic Inference of Energy Models for Peripheral Components in Embedded Systems

International audienceSurrounding autonomous embedded devices are in a constant expansion. The advent and the rise of Internet of Things (IoT) enable these objects to take a giant step forward, especially regarding their large scale deployment in real-world applications of the everyday life. A significant part of these objects are battery-powered and energy-dependent. Thus, energy is a critical resource which greatly complicates the development of the embedded software. By decomposing the energy consumption of a battery-powered IoT device, we can see that peripheral components are the major contributors among the overall consumption. Indeed, these components are exploited and repeatedly used by the object to interact and communicate with its surrounding environment during all the application lifetime. Acquire the expertise to handle accurately, during the development stage, the behaviour of every on-board peripheral component is a big challenge to improve the development of IoT embedded applications. To guide the developer in this task, we propose an automated inference procedure of energy models for peripheral components. An accurate automata-based model of the energy consumption can be generated, with only little efforts from the developer, based on real runtime measurements, providing precise energy figures. The proposed process is focused on a lightweight code generation step and simple analyses of the energy output traces, allowing a quick regeneration of the models in the case of a peripheral component modification. We show the potentials of the proposed procedure by real experiments on real peripherals. The obtained results are satisfactory, and we believe that our proposition is able to enhance the embedded development in an energy-constrained environment

Experimental Evaluation of Interference Impact on the Energy Consumption in Wireless Sensor Networks

International audienceIn the era of Internet of Things (IoT), the development of Wireless Sensor Networks (WSN) arises different challenges. Two of the main issues are electromagnetic interference and the lifetime of WSN nodes. In this paper, we show and evaluate experimentally the relation between interference and energy consumption, which impacts the network lifetime. We present a platform based on commercially available low-cost hardware in order to evaluate the impact of electromagnetic interference in 2.4 GHz ISM band on energy consumption of WSN. The energy measurements are obtained separately from each electronic component in the node. Interference and energy measurements are conducted in an anechoic chamber and in an office-type lab environment. X-MAC protocol is chosen to manage the Radio Duty Cycle of the nodes and its energy performance is evaluated. The energy consumption transmitter nodes is analyzed particularly in this work. Moreover, this energy consumption has been quantified and differentiated according to the number of (re-)transmissions carried out by the transmitter as well as the number of ACK packets sent by the receiver for a single packet. Finally, we use a model of real battery to calculate the lifetime of the node for operation within different interference level zones. This study lays the basis for further design rules of communication protocols and development of WSNs