Online Estimation of Battery Lifetime for Wireless Sensors Network

Battery is a major hardware component of wireless sensor networks. Most of them have no power supply and are generally deployed for a long time. Researches have been done on battery physical model and their adaptation for sensors. We present an implementation on a real sensor operating system and how architectural constraints have been assumed. Experiments have been made in order to test the impact of some parameter, as the application throughput, on the battery lifetime

Energy aware software evolution for wireless sensor networks

Wireless Sensor Networks (WSNs) are subject to high levels of dynamism arising from changing environmental conditions and application requirements. Reconfiguration allows software functionality to be optimized for current environmental conditions and supports software evolution to meet variable application requirements. Contemporary software modularization approaches for WSNs allow for software evolution at various granularities; from monolithic re-flashing of OS and application functionality, through replacement of complete applications, to the reconfiguration of individual software components. As the nodes that compose a WSN must typically operate for long periods on a single battery charge, estimating the energy cost of software evolution is critical. This paper contributes a generic model for calculating the energy cost of the reconfiguration in WSN. We have embedded this model in the LooCI middleware, resulting in the first energy aware reconfigurable component model for sensor networks. We evaluate our approach using two real-world WSN applications and find that (i.) our model accurately predicts the energy cost of reconfiguration and (ii.) component-based reconfiguration has a high initial cost, but provides energy savings during software evolution

Online Estimation of Battery Lifetime for Wireless Sensor Network

Battery is a major hardware component of wireless sensor networks. Most of them have no power supply and are generally deployed for a long time. Researches have been done on battery physical model and their adaptation for sensors. We present an implementation on a real sensor operating system and how architectural constraints have been assumed. Experiments have been made in order to test the impact of some parameter, as the application throughput, on the battery lifetime.La batterie est un composant matériel majeur dans les réseaux de capteurs sans fil. Des recherches ont été menées sur les modèles physique des batteries et leur adaptation pour les capteurs. Nous présentons une implantation sur un véritable système d'exploitation de capteurs et comment les contraintes d'architecture ont pu être pris en compte. Des expériences ont ensuite été menées pour tester l'influence de certains paramètres comme le débit d'application sur la durée de vie des batterie

Relais coopératifs dans un réseau de capteurs : performances limites et stratégies

Les réseaux de capteurs ont connu un grand essor ces dix dernières années. Ils interviennent dans tous les domaines de notre vie quotidienne et la rendent plus aisée. Malgré ce grand succès des réseaux de capteurs, plusieurs problèmes restent encore ouverts. La capacité énergétique et la fragilité du canal radio des réseaux de capteurs affectent gravement leurs performances. La communication coopérative représente une solution efficace pour lutter contre l'instabilité du canal radio et afin d'économiser plus d'énergie. Nous proposons dans ce manuscrit, d'utiliser la communication coopérative, en premier lieu, au niveau de la couche MAC afin de mettre en place un accès au canal coopératif et non égoïste. En second lieu, nous utilisons la communication coopérative au niveau de la couche réseau dans le but d'établir des chemins de routage plus stables et plus robustes. ABSTRACT : Wireless sensor networks (WSN) have known a great development during the last decade. They intervene in all the domain of our everyday life to make it easier. Despite the success of WSN several problems have to be solved. The restricted energy capacity and the randomness of the wireless channel seriously affect the performances of the WSN. Cooperative communication represents an efficient solution to reduce the instability of the wireless channel and to optimize energy. In this thesis we propose to use cooperative communications at the MAC and network layer in order to set up a cooperative access to the channel and to establish more robust routing paths