Link Quality Metrics in Large Scale Indoor Wireless Sensor Networks Pouvoir estimer la qualite du0027un lien sur la base du0027un minimum de paquets est essentiel pour un reseau de capteur sans fil multisaut en environnement indoor compte tenu du cout energetique de cette estimation et de ses consequences sur la stabilite des routes construites sur ces liens. Notre etude su0027appuie ainsi sur des experimentations intensives menees sur une plateforme Senslab (citewww_senslab) qui nous ont permis de trouver des lois de distribution suivies par les metriques physiques (RSSI, LQI) pour 3 categories de liens (bons, mauvais, intermediaires) regroupes par plage de PRR (Packet Reception Ratio). Sur la base de ces distributions, nous observons comment elles peuvent nous aider a discriminer les differents liens et ainsi les utiliser dans de futures experimentations pour ameliorer lu0027efficacite de protocoles de routage de reseaux de capteurs dans le choix des liens.

Evaluation of a Link Quality Estimator in an Outdoor WSN Using a Dedicated Node Industrial Wireless Sensor Networks (IWSN) demand deterministic and reliable communication. Adaptive mechanisms, such as channel adaptation and channel hopping, can be applied to deal with the temporal and spatial variations in link quality that can appear in an IWSN. The first step to effectively use such mechanisms is to estimate the quality of the links in the network, which can provide useful information for the adaptive mechanisms, in order to improve important metrics, such as the packet reception rate, and energy consumption. In this context, this paper evaluates experimentally a link quality estimator, which uses dedicated nodes to estimate the link quality in realtime, without imposing a high overhead. A longterm experiment was performed in a fuel loading plant and the results showed that the estimator is accurate and reactive for the scenario considered in the paper. From the results obtained in the experiment, it was also possible to observe the quality of the 16 channels defined by the IEEE 802.15.4 standard in the 2.4 GHz band, for different nodes, and discuss how the adaptive mechanisms could be used to increase the network quality of service, by picking the appropriate channels for each link during the network operation.