Delaunay Triangulation as a New Coverage Measurement Method in Wireless Sensor Network

Sensing and communication coverage are among the most important trade-offs in Wireless Sensor Network (WSN) design. A minimum bound of sensing coverage is vital in scheduling, target tracking and redeployment phases, as well as providing communication coverage. Some methods measure the coverage as a percentage value, but detailed information has been missing. Two scenarios with equal coverage percentage may not have the same Quality of Coverage (QoC). In this paper, we propose a new coverage measurement method using Delaunay Triangulation (DT). This can provide the value for all coverage measurement tools. Moreover, it categorizes sensors as ‘fat’, ‘healthy’ or ‘thin’ to show the dense, optimal and scattered areas. It can also yield the largest empty area of sensors in the field. Simulation results show that the proposed DT method can achieve accurate coverage information, and provides many tools to compare QoC between different scenarios

Comparaison des stratégies de redondance dans les réseaux ad hoc

Session Ad HocInternational audienceDans ce papier, nous analysons une approche originale en combinant les processus de recouvrement de route et de chemin dans un réseau ad hoc hétérogène utilisant deux technologies sans fil Zigbee et WiFi pour améliorer la robustesse du réseau. Nous proposons une architecture de redondance multi-niveau qui s'appuie sur des protocoles normalisés IEEE et IETF. Elle prend en charge toutes les étapes du processus de recouvrement de chemin depuis la détection de la rupture d'un lien sur le chemin primaire jusqu'à la reprise du trafic sur le chemin secondaire. Une formulation analytique de la fiabilité de chacun des trois schémas de recouvrement de base (recouvrement lien par lien, de bout en bout et par segment) est proposée. L'étude de performance montre l'avantage en terme de fiabilité du recouvrement par segment par rapport aux deux autres politiques. Il apparaît aussi qu'en terme de fiabilité, la gestion des pannes de la route primaire doit s'effectuer au niveau du routage par des protocoles multipath plutôt que par la couche transport

Formal Analysis of MCAP Protocol Against Replay Attack

Replay attack is considered a common attacking technique that is used by adversaries to gain access to confidential information. Several approaches have been proposed to prevent replay attack in security-critical systems such as Automated Teller Machines (ATM) systems. Among those approaches is a recent one called the Mutual Chain Authentication Protocol for the Saudi Payments Network transactions (MCAP). This protocol aims to allow Saudi banking systems to overcome existing weaknesses in the currently used Two-Factor Authentication (2FA) protocols. In this paper, we analyze and verify the recent MCAP authentication protocol against replay attacks. Therefore, we examine the mutual authentication between the ATM Terminal, Sponsoring Banks (SBAT), Saudi Payments Network (SPAN) and the Issuing of Financial Bank (CIFI). The paper also provides a formal analysis of the MCAP to conduct formal proofs of the MCAP protocols against replay attacks

Self-organization in Sensor and Actuators Networks: Strategies and their optimizations

In Wireless Sensors and Actuators Networks (WSANs), actuator nodes are nodes richer in resources (processing capacity, power transmission and energy storage) and better suited than sensor nodes to process the data, make decisions based on sensed values and perform appropriate actions. In addition, in order to provide timely action, coordination between sensors and actuators is necessary. Thus, in addition to the classical energy constraints of Wireless Sensor Networks (WSNs), WSANs also impose new challenges such as how to support and benefit from the nodes heterogeneity while preserving energy in the self-powered sensor nodes. New communication protocols, specific to WSANs, are needed. In this report, we propose a hybrid self-organizing data-collection protocol in order to provide energy efficiency, low end-to-end delay and high delivery ratio while taking advantage of the resource available on the actuators nodes in the network. This new self-organization protocol constructs its structure from the actuators and other resource-plentiful nodes. The nature of the structure is different inside and outside of transmission range of these resourceful nodes. Two variant of our proposal are detailed also in this report.Dans un réseau sans fil de capteurs et actionneurs (Wireless Sensors and Actuators Networks WSAN), les nœuds actionneurs sont des nœuds riches en ressources (capacité de traitement, de puissance de transmission et de stockage en mémoire et en énergie) et sont mieux adaptés que les nœuds capteurs à traiter les données, prendre des décisions fondées sur les observations remontées par les capteurs et effectuer les actions appropriées. En outre, afin d'offrir une action dans les délais, la coordination entre les capteurs et les actionneurs est nécessaire. Ainsi, outre les contraintes de l'énergie comme dans les réseaux de capteurs classiques (Wireless Sensor Networks WSN), les WSANs imposent également des contraintes de temps sous la forme de délai de bout-en-bout. Ainsi des nouvelles propositions de communication spécifiques aux WSAN sont nécessaires, qui fournissent un délai de bout-en-bout contrôlé tout en préservant l'énergie au niveau des nœuds capteurs. Dans ce contexte, nous décrivons dans ce rapport une proposition d'auto-organisation dans les WSANs. Notre proposition crée une structure autour de chaque actionneur. Une phase d'initialisation et de construction de gradient s'appuyant sur des anneaux concentriques autour des actionneurs, ensuite une phase de découverte de voisinage, de construction de structure logique et enfin une phase de remontée des observations des capteurs vers les nœuds actionneurs. Deux variantes de notre proposition sont présentées par la suite pour répondre à quelques points faibles de la proposition de base

Effiziente Lokalisierung von Nutzern und Geräten in Smarten Umgebungen

The thesis considers determination of location of sensors and users in smart environments using measurements of Received Signal Strength (RSS). The first part of the thesis focuses on localization in Wireless Sensor Networks and contributes two fully distributed algorithms which address the Sensor Selection Problem and provide the best trade-off between energy consumption and localization accuracy among the algorithms considered. Furthermore, the thesis contributes to Device Free Localization an indoor localization concept providing scalable and highly accurate location estimates (prototype: 0.36m² MSE) while using a COTS passive RFID-System and not relying on user-carried sensors

Remote software upload techniques in future vehicles and their performance analysis

Updating software in vehicle Electronic Control Units (ECUs) will become a mandatory requirement for a variety of reasons, for examples, to update/fix functionality of an existing system, add new functionality, remove software bugs and to cope up with ITS infrastructure. Software modules of advanced vehicles can be updated using Remote Software Upload (RSU) technique. The RSU employs infrastructure-based wireless communication technique where the software supplier sends the software to the targeted vehicle via a roadside Base Station (BS). However, security is critically important in RSU to avoid any disasters due to malfunctions of the vehicle or to protect the proprietary algorithms from hackers, competitors or people with malicious intent. In this thesis, a mechanism of secure software upload in advanced vehicles is presented which employs mutual authentication of the software provider and the vehicle using a pre-shared authentication key before sending the software. The software packets are sent encrypted with a secret key along with the Message Digest (MD). In order to increase the security level, it is proposed the vehicle to receive more than one copy of the software along with the MD in each copy. The vehicle will install the new software only when it receives more than one identical copies of the software. In order to validate the proposition, analytical expressions of average number of packet transmissions for successful software update is determined. Different cases are investigated depending on the vehicle\u27s buffer size and verification methods. The analytical and simulation results show that it is sufficient to send two copies of the software to the vehicle to thwart any security attack while uploading the software. The above mentioned unicast method for RSU is suitable when software needs to be uploaded to a single vehicle. Since multicasting is the most efficient method of group communication, updating software in an ECU of a large number of vehicles could benefit from it. However, like the unicast RSU, the security requirements of multicast communication, i.e., authenticity, confidentiality and integrity of the software transmitted and access control of the group members is challenging. In this thesis, an infrastructure-based mobile multicasting for RSU in vehicle ECUs is proposed where an ECU receives the software from a remote software distribution center using the road side BSs as gateways. The Vehicular Software Distribution Network (VSDN) is divided into small regions administered by a Regional Group Manager (RGM). Two multicast Group Key Management (GKM) techniques are proposed based on the degree of trust on the BSs named Fully-trusted (FT) and Semi-trusted (ST) systems. Analytical models are developed to find the multicast session establishment latency and handover latency for these two protocols. The average latency to perform mutual authentication of the software vendor and a vehicle, and to send the multicast session key by the software provider during multicast session initialization, and the handoff latency during multicast session is calculated. Analytical and simulation results show that the link establishment latency per vehicle of our proposed schemes is in the range of few seconds and the ST system requires few ms higher time than the FT system. The handoff latency is also in the range of few seconds and in some cases ST system requires less handoff time than the FT system. Thus, it is possible to build an efficient GKM protocol without putting too much trust on the BSs