Localisation par méthodes "range-based" et "range-free" de stations mobiles communicantes dans un réseau sans fil

Session Posters & DemosInternational audienceLa localisation des équipements mobiles communicants est une problématique importante pour les réseaux de capteurs sans fil, en particulier en intérieur, là où le GPS est inutilisable. Les algorithmes de localisation existants se rangent en deux catégories : "range-based" et "range-free". Les techniques "range- based" partent d'une évaluation de la distance entre émetteur et récepteur radio. Nous présentons, pour cette catégorie de systèmes de localisation, un état de l'art suivi de nos premiers travaux de métrologie, résultats utiles aux propositions et modélisations futures. Par rapport au principe "range-based", la technique "range-free" est plus économique en matériel car elle se contente de l'information de connectivité liée à la portée radio. Nous proposons un nouvel algorithme " range-free " qui fonctionne sur deux types de nœuds classés suivant le nombre d'ancres à portée. Les résultats de nos simulations montrent que l'algorithme proposé a une meilleure précision que les méthodes existantes, telles que Centroid, CPE ou DV-hop

Improvement of range-free localization technology by a novel DV-hop protocol in wireless sensor networks

International audienceLocalization is a fundamental issue for many applications in wireless sensor networks. Without the need of additional ranging devices, the range-free localization technology is a cost-effective solution for low-cost indoor and outdoor wireless sensor networks. Among range-free algorithms, DV-hop (Distance Vector - hop) has the advantage to localize the mobile nodes which has less than three neighbour anchors. Based on the original DV-hop algorithm, this paper presents two improved algorithms (Checkout DV-hop and Selective 3-Anchor DV-hop). Checkout DV-hop algorithm estimates the mobile node position by using the nearest anchor, while Selective 3-Anchor DV-hop algorithm chooses the best 3 anchors to improve localization accuracy. Then, in order to implement these DV-hop based algorithms in network scenarios, a novel DV-hop localization protocol is proposed. This new protocol is presented in detail in this paper, including the format of data payloads, the improved collision reduction method E-CSMA/CA, as well as parameters used in deciding the end of each DV-hop step. Finally, using our localization protocol, we investigate the performance of typical DV-hop based algorithms in terms of localization accuracy, mobility, synchronization and overhead. Simulation results prove that Selective 3-Anchor DV-hop algorithm offers the best performance compared to Checkout DV-hop and the original DV-hop algorithm

Amélioration de la Localisation dans les Réseaux de Capteurs sans Fil par Méthodes "Range-free"

Dans le contexte des réseaux de capteurs sans fil, la technique de localisation ”range-free” est plus efficiente, par rapport au principe ”range-based”. Par conséquent, nous avons focalisé nos travaux de cette thèse sur les techniques ”range-free”. Afin de permettre à chaque noeud mobile ou normal de choisir son propre algorithme de localisation, nous avons proposé un mécanisme adapté en scindant les noeuds normaux en deux classes: les noeuds de la première classe ont au moins 3 ancres voisines, alors que les noeuds de la deuxième classe ont moins de trois ancres voisines. Pour les noeuds normaux de la classe 1, nous avons proposé un nouvel algorithme ”Mid-perpendicular”. Pour les noeuds normaux de la classe 2, nous avons proposé deux nouveaux algorithmes ”Checkout DV-hop” et ”Selective 3-Anchor DV-hop”.Pour simuler et évaluer la performance de nos trois nouveaux algorithmes dans le contexte protocolaire des réseaux, nous avons pris soin de proposer deux protocoles associés : ”DV-hopprotocol” et ”Classe-1 protocol”. Par la suite, nous avons combiné ces deux protocoles pour obtenir notre ”adaptive range-free localization protocol”. Basé sur nos protocoles, en utilisant le simulateur WSNet, nous avons simulé différents algorithmes ”range-free” dans le contexte des réseaux de capteurs conformes au standard IEEE 802.15.4. Les résultats ont été présentés et analysés en termes de précision de la localisation, charge du réseau, mobilité des noeuds, et synchronisation de ces derniers.In the context of wireless sensor networks, the range-free localization technique is more costeffective than the range-base scheme. Therefore, in this thesis we focus on the range-free technique.In order to permit each normal node to choose its suitable localization algorithm, we proposed anadaptive mechanism to categorize normal nodes into two classes: the normal nodes having at least 3 neighbor anchors are class-1 nodes, while others are class-2 nodes. For class-1 normal nodes, we proposed a new algorithm named as Mid-perpendicular. For class-2 normal nodes, we proposed twoalgorithms Checkout DV-hop and Selective 3-Anchor DV-hop.In order to simulate and evaluate the performance of our three new algorithms, we proposed two protocols: DV-hop protocol and Class-1 protocol. Then we combined these two protocols into our adaptive range-free localization protocol. Based on our protocols, using the network simulator WSNet,we simulate the concerned range-free localization algorithms in the IEEE 802.15.4 wireless network.The comparative network simulation results are presented and analyzed in terms of localization accuracy, overhead, node mobility, and node synchronizatio

A Range-Free Localization Protocol for Wireless Sensor Networks

Localization is a fundamental issue for many wirelessnetwork applications. Without additional ranging devises, therange-free localization scheme offers a cost-effective solution forlow-cost indoor sensor networks. As a typical range-freealgorithm, DV-hop (Distance Vector - hop) algorithm has theadvantage to localize normal nodes that have less than threeneighbor anchors. In order to implement the DV-hop basedalgorithms in network scenarios, we create a new DV-hoplocalization protocol. This new protocol is presented in this paperwith details, including the frame formats, the improvement ofmedium access method, as well as parameters used in decidingthe end of each DV-hop step. Finally, using the new localizationprotocol, we investigate into some DV-hop algorithms (DV-hop,Checkout DV-hop and Selective 3-Anchor DV-hop) in terms oflocalization accuracy and synchronization. Simulation resultsshow the good performance of our localization protocol

CSI-based passive intrusion detection bound estimation in indoor NLoS scenario

Passive intrusion detection is important for many indoor safety applications. By utilizing widespread WiFi infrastructures, channel state information (CSI) based intrusion detection methods have attractive advantages such as low cost, non-line-of-sight (NLoS) support, and privacy protection. However, existing CSI-based methods lack in-depth and intensive analysis of intrusion detection bound. To the best of our knowledge, this is the first work that precisely characterizes and models CSI-based intrusion detection bound in typical indoor NLoS scenario. A bound is defined as an intruder’s farthest position from the transmitter during intrusion detection. To derive a model for the bound, we first derived an intrusion-disturbed NLoS channel model by analyzing the influence of human intrusion on the NLoS wireless channel. Subsequently, based on the channel model, we further derived an intrusion detection bound model. Based on the derived bound model, we proposed a practical system to estimate the real intrusion detection bound. Extensive experiments were conducted based on practical systems. The experimental and simulation results verified and demonstrated the effectiveness of the derived bound model. Our work not only reveals the fundamental performance limit of the basic intrusion detection method in an indoor NLoS scenario, but also provides a valuable reference for bound estimation for other fine-grained wireless sensing applications

A Two-level Range-free Localization Algorithm for Wireless Sensor Networks

International audienceLocalization of mobile nodes has been a fundamental issue for wireless sensor networks. The existing localization algorithms can be classified into two categories: range-based and range-free. Range-free scheme is more cost-effective than range-based scheme. This paper proposes double-level range-free algorithm for localization (DRAL), which consists of two methods. One is Mid-Perpendicular method, proposed for normal nodes which have at least three neighbor anchors. The other is Checkout DV-hop method, proposed for normal nodes which have less than three neighbor anchors. Simulation results show that the proposed algorithm DRAL has higher precision than the existing localization algorithms such as Centroid, CPE and DV-hop, while calculation cost only increases a little

Improving Localization Accuracy Using Selective 3-Anchor DV-hop Algorithm

localizatio

A Two-level Range-free Localization Algorithm for Wireless Sensor Network

Wireless Sensor Networ