Dynamic Reconfiguration for Software and Hardware Heterogeneous Real-time WSN

International audienceWireless Sensor Network (WSN) technology has imposed itself in civilian and industrial applications as a promising technology for wireless monitoring due to its wireless connectivity, removing many hardware constraints. Initially used in low frequency sampling applications, the increasing performances of electronic circuits has driven WSNs to integrate more powerful computation units, paving the way for a new generation of applications based on distributed computation. These new applications (process control, active control, visual surveillance, multimedia streaming) involving medium to heavy computation present real-time requirements at node level where reactivity becomes a primary concern as well as at the network level where latency must be bounded. In this paper, we present the implementation of a high-level language MinTax coupled with an in-situ compilation solution for real time Operating Systems enabling energy-aware dynamic reconfiguration while supporting hardware heterogeneity in Wireless Sensor Networks

Heterogeneous Wireless Sensor Network Simulation

International audienceBased on our previous work on the development of a Wireless Sensor Network (WSN) simulation platform, we present here its ability to run simulations on heterogeneous nodes. This platform allows system-level simulations with low level accurate models, with graphical inputs and outputs to easily simulate such distributed systems. In the testbed we consider, the well known IEEE 802.15.4 standard is used, and different microcontrollers units (MCU) and radiofrequency transceivers compose the heterogeneous nodes. It is also possible to simulate complex networks or interacting networks; that is a more realistic case, as more and more hardware devices exist and standards permit their interoperability. This simulation platform can be used to explore design space in order to find the hardware devices and IEEE 802.15.4 algorithm that best fit a given application. Packet Delivery Rate (PDR) and packet latency can be evaluated, as other network simulators do. Energy consumption of sensor nodes is detailed with a very fine granularity: partitioning over and into hardware devices that compose the node is studied

Reconfiguration dynamique et simulation fine modélisée au niveau de transaction dans les réseaux de capteurs sans fil hétérogènes matériellement-logiciellement

Cette thèse porte premièrement sur la reconfiguration dynamique et la simulation hétérogène dans les Réseaux des Capteurs sans Fil. Ces réseaux sont constitués d une multitude de systèmes électroniques communicants par radio-fréquence, très contraints en énergie. La partie de communication radio entre ces nœuds est la plus consommatrice. C est pourquoi la minimisation du temps effectif est désirée. On a implémenté une solution qui consiste à envoyer au nœud un fichier de reconfiguration codé utilisant un langage de programmation haut niveau (MinTax). Le nœud sera capable de compiler ce fichier et générer le code object associé à son architecture, in-situ. Grâce au caractère abstrait du MinTax, plusieurs architectures matérielles et systèmes d exploitation sont visés. Dans un deuxième temps, ce travail de thèse est lié au simulateur de réseaux de capteurs IDEA1TLM.IDEA1TLM permet de prédire quels circuits et configurations sont les plus adéquats à une application sans fil donnée. Ce simulateur a été amélioré pour permettre la simulation rapide des systèmes électroniques matériellement différents dans le même réseau ainsi que le logiciel présent sur les noeuds. Mots clés : Reconfiguration dynamique, Compilation in-situ, MinTax, Hétérogénéité, IDEA1TLM.This PhD thesis concerns the dynamic reconfiguration and simulation of heterogeneous Wireless Sensor Networks. These networks consist of a multitude of electronic units called ?nodes ?, which communicate through a radio interface. The radio interface is the most power-consuming on the node. This is why the minimisation of the radio-time would lead to improved energy efficiency. We have implemented a software solution which consists in sending an update to a node which is coded in a high-level language (MinTax). This file is compiled by the node and machine code is generated for the target hardware architecture. Owing to the abstract nature of MinTax, multiple hardware architectures. as well as operating systems are supported. As a second part of this PhD, work has been focused on a network simulator called IDEATLM.IDEA1TLM allows us to predict which circuits and configurations are the most appropriate for a given task. This solution has been improved to allow a faster simulation of electronic systems which are different from a hardware standpoint, yet part of the same network, as well as to model the actual software running on them.LYON-Ecole Centrale (690812301) / SudocSudocFranceF

Design Framework for Heterogeneous Hardware and Software in Wireless Sensor Networks

International audienceWireless Sensor Networks are composed of many autonomous resource-constrained sensor nodes. Constrains are low energy, memory and processing speed. Nowadays, several limitations exist for heterogeneous Wireless Sensor Networks: various hardware and software are hardly supported at design and simulation levels. Meanwhile, to optimize a self-organized network, it is essential to be able to update it with new nodes, to ensure interoperability, and to be able to exchange not only data but functionalities between nodes. Moreover, it is difficult to make design space exploration, as accurate hardware-level models and network-level simulations have very different (opposite) levels. We propose a simulator-based on SystemC language-that allows such design space explorations. It is composed of a library of hardware and software blocks. More and more sophisticated software support is implemented in our simulator. As trend is to deploy heterogeneous nodes, various software levels have to be considered. Our simulator is also thought to support many levels: from machine code to high level languages

Reconfiguration dynamique et simulation fine modélisée au niveau de transaction dans les réseaux de capteurs sans fil hétérogènes matériellement-logiciellement

This PhD thesis concerns the dynamic reconfiguration and simulation of heterogeneous Wireless Sensor Networks. These networks consist of a multitude of electronic units called ?nodes ?, which communicate through a radio interface. The radio interface is the most power-consuming on the node. This is why the minimisation of the radio-time would lead to improved energy efficiency. We have implemented a software solution which consists in sending an update to a node which is coded in a high-level language (MinTax). This file is compiled by the node and machine code is generated for the target hardware architecture. Owing to the abstract nature of MinTax, multiple hardware architectures. as well as operating systems are supported. As a second part of this PhD, work has been focused on a network simulator called IDEATLM.IDEA1TLM allows us to predict which circuits and configurations are the most appropriate for a given task. This solution has been improved to allow a faster simulation of electronic systems which are different from a hardware standpoint, yet part of the same network, as well as to model the actual software running on them.Cette thèse porte premièrement sur la reconfiguration dynamique et la simulation hétérogène dans les Réseaux des Capteurs sans Fil. Ces réseaux sont constitués d’une multitude de systèmes électroniques communicants par radio-fréquence, très contraints en énergie. La partie de communication radio entre ces nœuds est la plus consommatrice. C’est pourquoi la minimisation du temps effectif est désirée. On a implémenté une solution qui consiste à envoyer au nœud un fichier de reconfiguration codé utilisant un langage de programmation haut niveau (MinTax). Le nœud sera capable de compiler ce fichier et générer le code object associé à son architecture, in-situ. Grâce au caractère abstrait du MinTax, plusieurs architectures matérielles et systèmes d’exploitation sont visés. Dans un deuxième temps, ce travail de thèse est lié au simulateur de réseaux de capteurs IDEA1TLM.IDEA1TLM permet de prédire quels circuits et configurations sont les plus adéquats à une application sans fil donnée. Ce simulateur a été amélioré pour permettre la simulation rapide des systèmes électroniques matériellement différents dans le même réseau ainsi que le logiciel présent sur les nœuds

Dynamic reconfiguration and fine-grained simulation modelled at transaction level in hardware-software heterogeneous Wireless Sensor Networks

Cette thèse porte premièrement sur la reconfiguration dynamique et la simulation hétérogène dans les Réseaux des Capteurs sans Fil. Ces réseaux sont constitués d’une multitude de systèmes électroniques communicants par radio-fréquence, très contraints en énergie. La partie de communication radio entre ces nœuds est la plus consommatrice. C’est pourquoi la minimisation du temps effectif est désirée. On a implémenté une solution qui consiste à envoyer au nœud un fichier de reconfiguration codé utilisant un langage de programmation haut niveau (MinTax). Le nœud sera capable de compiler ce fichier et générer le code object associé à son architecture, in-situ. Grâce au caractère abstrait du MinTax, plusieurs architectures matérielles et systèmes d’exploitation sont visés. Dans un deuxième temps, ce travail de thèse est lié au simulateur de réseaux de capteurs IDEA1TLM.IDEA1TLM permet de prédire quels circuits et configurations sont les plus adéquats à une application sans fil donnée. Ce simulateur a été amélioré pour permettre la simulation rapide des systèmes électroniques matériellement différents dans le même réseau ainsi que le logiciel présent sur les nœuds.This PhD thesis concerns the dynamic reconfiguration and simulation of heterogeneous Wireless Sensor Networks. These networks consist of a multitude of electronic units called ?nodes ?, which communicate through a radio interface. The radio interface is the most power-consuming on the node. This is why the minimisation of the radio-time would lead to improved energy efficiency. We have implemented a software solution which consists in sending an update to a node which is coded in a high-level language (MinTax). This file is compiled by the node and machine code is generated for the target hardware architecture. Owing to the abstract nature of MinTax, multiple hardware architectures. as well as operating systems are supported. As a second part of this PhD, work has been focused on a network simulator called IDEATLM.IDEA1TLM allows us to predict which circuits and configurations are the most appropriate for a given task. This solution has been improved to allow a faster simulation of electronic systems which are different from a hardware standpoint, yet part of the same network, as well as to model the actual software running on them

Reprogramming hardware-software heterogeneous Wireless Sensor Networks

International audienceReprogramming (reconfiguring) software running on the nodes of a WSN (Wireless Sensor Networks) is needed to update or add new functionalities or fix existing bugs. Reducing the amount of data sent to the node via the radio interface means reducing the energy consumed by the sender and receiver nodes, enabling them to run for longer. We present a solution for performing such functionality exchanges on different node hardware, each running under different operating systems. The universality of our solution is based upon the semantics of a high-level language called MinTax which is compiled in-situ, on the node itself. In order to validate the feasibility of a hardware-software heterogeneous WSN, we present the case of a functionality sent between two different hardware nodes, one running ContikiOS and the other, FunkOS

A cycle-accurate transaction-level modelled energy simulation approach for heterogeneous Wireless Sensor Networks

International audienceWireless Sensor Networks are networks made up of tiny sensor nodes, in medium to large quantities, from several tens to hundreds and even thousands. They are used in fields ranging from military, medical, to structural health monitoring for buildings for example. We have introduced an instruction set simulator in our IDEA1 WSN design framework to account for a fine-grained representation of the software running on the node hardware. We modelled the communication between the nodes' microcontrollers and their radio interface and microcontroller and sensor, respectively. This was done at transaction level by use of the SystemC simulation kernel. An application was developed, consisting of eight nodes compressing this abstract and sending it to their coordinator

Energy-centric simulation and design space exploration for wireless sensor networks

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CHRONIC CONSTIPATION IN CHILDREN. AN UPDATE ON EVALUATION AND MANAGEMENT

Constipation is a common problem in childhood, with a children prevalence varying between 0.7% and 29.6%. Constipation is encountered in all pediatric age groups, with variably severity and duration, from mild and short to severe and chronic forms, with faecal impact and encopresis. This article review the epidemiological, clinical and therapeutically aspects of children constipation, functional in the majority of cases