Improving Low Power Listening (LPL) Mechanism to Save Energy Consumption in WSN

As stated in the literature, Low Power Listening (LPL) duty cycle is one of the most common energy conservation solution for WSN. By using channel check mechanism, the purpose of LPL solutions is to reduce the energy consumption of the listening phase. In this paper, we propose to study the performances and limitations of this kind of solutions. Therefore, we deploy a ContikiMAC LPL on both real and simulated WSN platform to demonstrate the impact of LPL on the energy consumptions of the node radio and microcontroller but also on the application Quality of Service. Based on the obtained results, shortcomings of LPL solutions are highlighted and potential improvements are discussed such as the use of multi-parameter dynamic duty cycle

Preserving Privacy in secured ZigBee Wireless Sensor Networks

International audienceWe expose concretely the information leakage occurring in an IEEE 802.15.4-based ZigBee meshed network. We deploy an IoT platform and used a killerbee sniffer to eavesdrop the communication between the motes. Metadata and control traffic are exploited in depth to recover protocol instances, routes, identity, capability and activity of the devices. We experiment different levels of security for the communications from none to the best available. Even when security is enforced, information leakages are not avoided. We propose simple countermeasures to prevent an outsider from monitoring a ZigBee network

Energy-aware Cross-level Model for Wireless Sensor Networks

ISBN: 978-1-61208-744-3International audienceIn the design stage, Wireless Sensor Network developers generally need simulation tools to save both time and costs. These simulators require accurate models to precisely describe the network components and behaviours, such as energy consumption. Nevertheless, although the model has grown in complexity over last years, from layered-stack to cross-level, the energy aspects are not yet well implemented. In this paper, we suggest an energy-aware cross-level model for Wireless Sensor Networks. Our modelling approach allows for parameters that belong to different levels to interact with each other and to analyse their impact on energy consumption. To validate this approach, the energy-aware cross-level model for network radiofrequency activities is first provided. The results obtained using suggested scenarios are compared with those collected from a well-known simulator: NS2. Finally, the usefulness of our model in Wireless Sensor Network design process is demonstrated thanks to a case study aimed at comparing and selecting the most energy-efficient wireless link protocol

A Cross-level model for power-aware Wireless Sensor Networks design

In many Wireless Sensor Network (WSN) applications, it is important to optimize the global energy efficiency to enhance both the node autonomy and the whole WSN lifetime. In this context, the achievement of a power-aware design is a complex task due to the impact over the WSN energy consumption of different parameters, which are inherent to application, network or node levels. Therefore, a cross-level energy model is a useful way to estimate this energy consumption, leading designers to take correct decisions at the earliest design stages. Thus, this paper describes the principles of a cross-level energy model, which tries to address some weakness of existing WSN simulators in terms of energy modelling

An Approach for Modelling Wireless Sensor Networks: Focusing on the Design Concept and Energy Awareness

In the design stage, Wireless Sensor Network developers generally need simulation tools to save time and money. These simulators require accurate models to precisely describe the behaviors of network nodes. Nevertheless, although model complexity has grown from layered-stack to cross-level, the energy aspects are not yet well implemented. In this paper, we suggest an energy-aware cross-level model for Wireless Sensor Network. Our modelling approach allows parameters that belong to different levels to interact and affect each other. This approach is used to predict the nodes energy consumption and to estimate the lifetime of the system. First, the results obtained from the implementation of our approach will be compared with those collected from a well-known simulator, Network Simulator version 2 using a set of basic scenarios. Then, the utility of our approach in the Wireless Sensor Network design process is highlighted using detailed scenarios that cover different types of interactions

Cross-level energy model for power-aware Wireless Sensor Networks design​

In many Wireless Sensor Network (WSN) applications, it is important to optimize the global energy efficiency in order to enhance node autonomy. Several factors impact the energy consumption in WSN, such as the purpose of the application, the network architecture, the hardware and software of the nodes. With all these factors in view, the definition of a model can provide a useful way to estimate this energy consumption. In this context, we propose a model that is energy-aware, phase-based and protocol-independent. Based on the energy consumption observation of typical WSN applications, our model introduces the pattern concept. It consists of different phases that take place periodically following a frequency Fp. The proposed model is first validated against a well-known simulator (NS2) using different scenarios and considering two wireless link protocols: 802.11a and 802.15.4. Our idea is to use this kind of simulator to monitor the energy consumed in WSN from different points of view. On one hand, the cross-level concept would be applied to minimize the computation resources needed to study the energy consumption of the entire system. On the other hand, at the same time, it offers the possibility to point out for details at different levels of the network. For example, with this simulator, both the consumed energy at the system level and the instantaneous power at the node level could be obtained and analyzed at the same time

Intelligent Buildings in Smart Grids: A Survey on Security and Privacy Issues Related to Energy Management

During the last decade, the smart grid (SG) concept has started to become a reality, mainly thanks to the technical progress achieved in telecommunications, informatics and power electronics, among other domains, leading to an evolution of the traditional electrical grid into an intelligent one. Nowadays, the SG can be seen as a system of smart systems that include cyber and physical parts from different technologies that interact with each other. In this context, intelligent buildings (IBs) constitute a paradigm in which such smart systems are able to guarantee the comfort of residents while ensuring an appropriate tradeoff of energy production and consumption by means of an energy management system (EMS). These interconnected EMSs remain the objective of potential cyber-attacks, which is a major concern. Therefore, this paper conducts a survey, from a multidisciplinary point of view, of some of the main security and privacy issues related to IBs as part of the SG, including an overview of EMS, smart meters, and the main communication networks employed to connect IBs to the overall SG. Future research directions towards a security enhancement from both technical and human perspectives are also provided

PERFIL SOCIODEMOGRÁFICO E CLÍNICO-EPIDEMIOLÓGICO DOS CASOS DE DENGUE NO MUNICÍPIO DE QUIXADÁ-CE NO PERÍODO DE 2013 A 2015

A dengue é uma das principais doenças predominantes no Brasil, por se tratar de uma afecção causada por um vírus, e transmitida por um vetor, tem como consequência uma vasta área de atuação, facilitando assim sua transmissão, que há décadas vem ocasionando uma série de agravos para a população

Wireless sensor networks and privacy

Les médias et de nombreuses études scientifiques évoquent fréquemment la notion de vie privée en lien avec des exemples de cyber attaques. Le vol par des hackers de 12 millions d’identifiants d’utilisateurs Apple en 2012 illustre que les objets communicants sont des maillons vulnérables exploités par les hackers pour accéder aux données personnelles des usagers. Dans cette thèse, nous allons étendre la notion de vie privée aux objets eux-mêmes, au-delà des utilisateurs, en montrant que dans des réseaux de capteurs sans fil où les communications ont lieu de machine à machine, la connaissance des adresses fixes des différents appareils constituant le réseau représente une source d’information permettant de déduire beaucoup d’éléments de contexte et d’environnement.Actuellement, tous les standards de communication sans fil intègrent la capacité de sécuriser les données transportées, y compris les protocoles de communication dédiés aux réseaux de capteurs, conçus pour fonctionner en milieu contraint et à basse consommation. Cependant, l’en-tête des trames envoyées sur l’air comportant les informations nécessaires au routage et au bon fonctionnement du réseau, figure toujours en texte clair. La collecte de ces métadonnées par écoute passive représente un danger pour les environnements et les applications qui font usage de ces réseaux.Le travail mené dans cette thèse a pour objectif d’explorer comment de simples attaques passives sur des réseaux meshés basés sur le standard IEEE 802.15.4, visant à collecter et exploiter les métadonnées de ces trames échangées sur l’air, permettent d’inférer des informations critiques sur le réseau lui-même, l’environnement dans lequel il est déployé et les comportements des personnes qui en font usage. Plusieurs solutions visant à dissimuler les adresses des nœuds du réseau sont ensuite étudiées. Ces solutions sont de deux types : soit elles rendent anonymes les dispositifs empêchant de remonter à la source des messages, soit elles reposent sur l’utilisation de pseudonymes permettant de conserver la possibilité d’auditer le trafic.Afin d’évaluer les caractéristiques et les performances de ces solutions, un simulateur a été mis en œuvre afin de reproduire le comportement d’un réseau de capteurs meshés embarquant l’OS Contiki. Ce simulateur a permis d’évaluer la solution la plus prometteuse issue de l’état de l’art, nommée MT6D, en comparant ses performances avec un réseau de référence ne dissimulant pas les métadonnées. Cette analyse a fait ressortir certains inconvénients, en particulier l’augmentation importante des trames de contrôle nécessaires au routage, et a permis d’élaborer les spécifications d’une solution plus optimale pour l’embarqué.Nous avons ainsi introduit Ephemeral, qui présente la capacité de dissimuler les adresses des dispositifs dans les messages envoyés sur l’air, par l’usage de pseudonymes, sans augmenter la quantité de trames de contrôle indispensables au routage. Une fois mis en œuvre avec le simulateur afin de valider les performances théoriques attendues, Ephemeral est déployé en environnement réel sur un réseau de capteurs IEEE 802.15.4 équipant un bâtiment. Ce retour d’expérimentation permet de confirmer qu’Ephemeral constitue une solution économe du point de vue de la consommation d’énergie et de la bande passante du réseau, pour masquer les identifiants des dispositifs impliqués dans les communications.Privacy notion is frequently linked with cyber attack examples by media and scientific researches. In 2012, the hacking of 12 millions Apple user identifiers demonstrates that connected objects represent leaks exploited by hackers to access to user personal data. In this thesis, we will extend the privacy notion to the objects. To do this, we will show that in wireless sensor networks where communications are carried out from machine-to-machine, the knowledge of the static addresses of the devices within the network discloses information allowing deduction about elements of context and environment.Nowadays, the wireless communication standards provide security mechanisms whatever the communication protocols used including the low power ones designed to run on constrained environment. However, the frame header that comprises necessary information for routing and for the proper functioning of the network is always sent in clear text. Collecting and gathering these metadata by eavesdropping is dangerous for the environments and applications based on these networks.The work carried out in this thesis aims to explore how simple passive attacks on meshed networks based on IEEE 802.15.4 used to collect and exploit metadata allow to infer critical information about the network, the environment where the network is deployed and the behavior of users. Two kinds of solutions to hide the node addresses are studied. The first one provides anonymity for the devices. In the second kind of solutions, pseudonyms are used by nodes enabling the capability to audit the traffic within the network.To evaluate the characteristics and the performances of the solutions, a simulator has been used to reproduce the behavior of a meshed wireless sensor network embedding Contiki OS. This simulator allows to compare the performances of MT6D the most promising solution of our state of the art with that of a reference network do not mask the metadata. With this analyze, we can highlight some drawbacks and more especially the control frames overhead needed for the routing. We give the necessary specifications to deploy the most optimal solution for the embedded devices.Thus we propose Ephemeral that allows hiding device addresses provided in the sent frames by using pseudonyms without overhead on the control frames. After deployment in the simulation environment to evaluate expected theoretical performances, Ephemeral has been tested in real environment. The network is made up of twenty IEEE 802.15.4 sensor nodes deployed on a building. The results show that Ephemeral is an efficient low power and bandwidth-saving solution to hide device identifiers used in wireless communications

Réseaux de capteurs et vie privée

Privacy notion is frequently linked with cyber attack examples by media and scientific researches. In 2012, the hacking of 12 millions Apple user identifiers demonstrates that connected objects represent leaks exploited by hackers to access to user personal data. In this thesis, we will extend the privacy notion to the objects. To do this, we will show that in wireless sensor networks where communications are carried out from machine-to-machine, the knowledge of the static addresses of the devices within the network discloses information allowing deduction about elements of context and environment.Nowadays, the wireless communication standards provide security mechanisms whatever the communication protocols used including the low power ones designed to run on constrained environment. However, the frame header that comprises necessary information for routing and for the proper functioning of the network is always sent in clear text. Collecting and gathering these metadata by eavesdropping is dangerous for the environments and applications based on these networks.The work carried out in this thesis aims to explore how simple passive attacks on meshed networks based on IEEE 802.15.4 used to collect and exploit metadata allow to infer critical information about the network, the environment where the network is deployed and the behavior of users. Two kinds of solutions to hide the node addresses are studied. The first one provides anonymity for the devices. In the second kind of solutions, pseudonyms are used by nodes enabling the capability to audit the traffic within the network.To evaluate the characteristics and the performances of the solutions, a simulator has been used to reproduce the behavior of a meshed wireless sensor network embedding Contiki OS. This simulator allows to compare the performances of MT6D the most promising solution of our state of the art with that of a reference network do not mask the metadata. With this analyze, we can highlight some drawbacks and more especially the control frames overhead needed for the routing. We give the necessary specifications to deploy the most optimal solution for the embedded devices.Thus we propose Ephemeral that allows hiding device addresses provided in the sent frames by using pseudonyms without overhead on the control frames. After deployment in the simulation environment to evaluate expected theoretical performances, Ephemeral has been tested in real environment. The network is made up of twenty IEEE 802.15.4 sensor nodes deployed on a building. The results show that Ephemeral is an efficient low power and bandwidth-saving solution to hide device identifiers used in wireless communications.Les médias et de nombreuses études scientifiques évoquent fréquemment la notion de vie privée en lien avec des exemples de cyber attaques. Le vol par des hackers de 12 millions d’identifiants d’utilisateurs Apple en 2012 illustre que les objets communicants sont des maillons vulnérables exploités par les hackers pour accéder aux données personnelles des usagers. Dans cette thèse, nous allons étendre la notion de vie privée aux objets eux-mêmes, au-delà des utilisateurs, en montrant que dans des réseaux de capteurs sans fil où les communications ont lieu de machine à machine, la connaissance des adresses fixes des différents appareils constituant le réseau représente une source d’information permettant de déduire beaucoup d’éléments de contexte et d’environnement.Actuellement, tous les standards de communication sans fil intègrent la capacité de sécuriser les données transportées, y compris les protocoles de communication dédiés aux réseaux de capteurs, conçus pour fonctionner en milieu contraint et à basse consommation. Cependant, l’en-tête des trames envoyées sur l’air comportant les informations nécessaires au routage et au bon fonctionnement du réseau, figure toujours en texte clair. La collecte de ces métadonnées par écoute passive représente un danger pour les environnements et les applications qui font usage de ces réseaux.Le travail mené dans cette thèse a pour objectif d’explorer comment de simples attaques passives sur des réseaux meshés basés sur le standard IEEE 802.15.4, visant à collecter et exploiter les métadonnées de ces trames échangées sur l’air, permettent d’inférer des informations critiques sur le réseau lui-même, l’environnement dans lequel il est déployé et les comportements des personnes qui en font usage. Plusieurs solutions visant à dissimuler les adresses des nœuds du réseau sont ensuite étudiées. Ces solutions sont de deux types : soit elles rendent anonymes les dispositifs empêchant de remonter à la source des messages, soit elles reposent sur l’utilisation de pseudonymes permettant de conserver la possibilité d’auditer le trafic.Afin d’évaluer les caractéristiques et les performances de ces solutions, un simulateur a été mis en œuvre afin de reproduire le comportement d’un réseau de capteurs meshés embarquant l’OS Contiki. Ce simulateur a permis d’évaluer la solution la plus prometteuse issue de l’état de l’art, nommée MT6D, en comparant ses performances avec un réseau de référence ne dissimulant pas les métadonnées. Cette analyse a fait ressortir certains inconvénients, en particulier l’augmentation importante des trames de contrôle nécessaires au routage, et a permis d’élaborer les spécifications d’une solution plus optimale pour l’embarqué.Nous avons ainsi introduit Ephemeral, qui présente la capacité de dissimuler les adresses des dispositifs dans les messages envoyés sur l’air, par l’usage de pseudonymes, sans augmenter la quantité de trames de contrôle indispensables au routage. Une fois mis en œuvre avec le simulateur afin de valider les performances théoriques attendues, Ephemeral est déployé en environnement réel sur un réseau de capteurs IEEE 802.15.4 équipant un bâtiment. Ce retour d’expérimentation permet de confirmer qu’Ephemeral constitue une solution économe du point de vue de la consommation d’énergie et de la bande passante du réseau, pour masquer les identifiants des dispositifs impliqués dans les communications