A Novel Family of Geometric Planar Graphs for Wireless Ad Hoc Networks

International audienceWe propose a radically new family of geometric graphs, i.e., Hypocomb, Reduced Hypocomb and Local Hypocomb. The first two are extracted from a complete graph; the last is extracted from a Unit Disk Graph (UDG). We analytically study their properties including connectivity, planarity and degree bound. All these graphs are connected (provided the original graph is connected) planar. Hypocomb has unbounded degree while Reduced Hypocomb and Local Hypocomb have maximum degree 6 and 8, respectively. To our knowledge, Local Hypocomb is the first strictly-localized, degree-bounded planar graph computed using merely 1-hop neighbor position information. We present a construction algorithm for these graphs and analyze its time complexity. Hypocomb family graphs are promising for wireless ad hoc networking. We report our numerical results on their average degree and their impact on FACE routing. We discuss their potential applications and some open problems

Mobile-Beacon Assisted Sensor Localization with Dynamic Beacon Mobility Scheduling

International audienceIn mobile-beacon assisted sensor localization, beacon mobility scheduling aims to determine the best beacon trajectory so that each sensor receives sufficient beacon signals with minimum delay. We propose a novel DeteRministic bEAcon Mobility Scheduling (DREAMS) algorithm, without requiring any prior knowledge of the sensory field. In this algorithm, beacon trajectory is defined as the track of depth-first traversal (DFT) of the network graph, thus deterministic. The mobile beacon performs DFT under the instruction of nearby sensors on the fly. It moves from sensor to sensor in an intelligent heuristic manner according to RSS (Received Signal Strength)-based distance measurements. We prove that DREAMS guarantees full localization (every sensor is localized) when the measurements are noise-free. Then we suggest to apply node elimination and topology control (Local Minimum Spanning Tree) to shorten beacon tour and reduce delay. Through simulation we show that DREAMS guarantees full localization even with noisy distance measurements. We evaluate its performance on localization delay and communication overhead in comparison with a previously proposed static path based scheduling method

Planarisation de graphes dans les réseaux ad-hoc

We propose a radically new family of geometric graphs, i.e., Hypocomb, Reduced Hypocomb and Local Hypocomb. The first two are extracted from a complete graph; the last is extracted from a Unit Disk Graph (UDG). We analytically study their properties including connectivity, planarity and degree bound. All these graphs are connected (provided the original graph is connected) planar. Hypocomb has unbounded degree while Reduced Hypocomb and Local Hypocomb have maximum degree 6 and 8, respectively. To our knowledge, Local Hypocomb is the first strictly-localized, degree-bounded planar graph computed using merely 1-hop neighbor position information. We present a construction algorithm for these graphs and analyze its time complexity. Hypocomb family graphs are promising for wireless ad hoc networking. We report our numerical results on their average degree and their impact on FACE routing. We discuss their potential applications and pinpoint some interesting open problems for future research

Enhancing nodes cooperation in ad hoc networks

International audienceAd hoc networks are distributed, self-organized wireless networks. By their nature, it is easy for a malicious user to enter this kind of networks with the intention of disturbing the way they are behaving by not participating to the network. This kind of behavior is a form of selfishness where nodes want to save their energy by not routing packets. Many solutions based on virtual currency mechanisms or on reputation mechanisms have been shown to increase the networks reliability for this kind of problems. We advocate in this paper that this issue can be treated with local algorithms that have minor drawbacks compared to sophisticated solutions developed in other works. We conduct an evaluation of our solution, which shows satisfying enough results to be used in civilian spontaneous networks

Algorithmes pour l'estimation des données dans les réseaux de capteurs

International audienceLa collecte des données est un des enjeux majeurs dans les réseaux de capteurs. En effet, les communications induites par la transmission de données réduisent considérablement la durée de vie du réseau. Une des techniques utilisées pour réduire la quantité de données transférées est l'agrégation et selon le type des données étudiées, une des possibilités est l'utilisation de série temporelle ARMA. Dans cet article, nous proposons quatre algorithmes d'agrégation de données s'appuyant sur le modèle AR permettant ainsi la diminution de la consommation d'énergie dans les réseaux de capteurs et augmentant la durée de vie de ceux-ci

A Novel Family of Geometric Planar Graphs for Wireless Ad Hoc Networks

International audienceWe propose a radically new family of geometric graphs, i.e., Hypocomb, Reduced Hypocomb and Local Hypocomb. The first two are extracted from a complete graph; the last is extracted from a Unit Disk Graph (UDG). We analytically study their properties including connectivity, planarity and degree bound. All these graphs are connected (provided the original graph is connected) planar. Hypocomb has unbounded degree while Reduced Hypocomb and Local Hypocomb have maximum degree 6 and 8, respectively. To our knowledge, Local Hypocomb is the first strictly-localized, degree-bounded planar graph computed using merely 1-hop neighbor position information. We present a construction algorithm for these graphs and analyze its time complexity. Hypocomb family graphs are promising for wireless ad hoc networking. We report our numerical results on their average degree and their impact on FACE routing. We discuss their potential applications and some open problems

Lightweight verification of control flow policies on Java bytecode

This paper presents the enforcement of control flow policies for Java bytecode devoted to open and constrained devices. On-device enforcement of security policies mostly relies on run-time monitoring or inline checking code, which is not appropriate for strongly constrained devices such as mobile phones and smart-cards. We present a proof-carrying code approach with on-device lightweight verification of control flow policies statically at loading- time. Our approach is suitable for evolving, open and constrained Java-based systems as it is compositional, to avoid re-verification of already verified bytecode upon loading of new bytecode, and it is regressive, to cleanly support bytecode unloading.Ce rapport présente l'application de politiques de flot de contrôle sur du bytecode Java pour les petits systèmes ouverts. La plupart du temps, l'application de ce type de politiques de sécurité est réalisée par l'observation du système ou l'insertion de code pour assuré en assurer le respect, ce qui n'est pas approprié pour les petits systèmes fortement contraints tels que les téléphones mobiles ou les cartes à puce. Nous présentons une méthode basée sur le proof-carrying code pour faire appliquer ce type de politiques avec une vérification embarquée réalisée au chargement. Notre approche est bien adaptée aux petits systèmes ouverts évolutifs car elle est compositionnelle, pour éviter la revérification du code déjà chargé, et régressive, afin de traiter proprement le déchargement de code déjà installé et vérifié

A verifiable Lightweight Escape Analysis Supporting Creational Design Patterns

This paper presents a compositional escape analysis adapted for use in resource limited embedded systems. This analysis covers the full Java language, including dynamic class loading. Thanks to the use of an effcient verififation algorithm, small embedded systems are able to check the escape analysis information of mobile code. The traditional escape analysis is also extended, taking further steps towards full Java programming support, by adding the support of common design patterns, namely aggregation and factory, in order to allow the programmer to use coding techniques that are usually somewhat inefficient on these constrained systems

Hypocomb: Bounded-degree Localized Geometric Planar Graphs for Wireless Ad Hoc Networks

International audienceWe propose a radically new family of geometric graphs, i.e., Hypocomb, Reduced Hypocomb and Local Hypocomb. T he first two are extracted from a complete graph; the last is extracted from a Unit Disk Graph (UDG). We analytically study their properties including connectivity, planarity and degree bound. All these graphs are connected (provided the original graph is connected) planar. Hypocomb has unbounded degree while Reduced Hypocomb and Local Hypocomb have maximum degree 6 and 8, respectively. To our knowledge, Local Hypocomb is the first strictly-localized, degree-bounded planar graph computed using merely I-hop neighbor position information. We present a construction algorithm for these graphs and analyze its time complexity. Hypocomb family graphs are promising for wireless ad hoc networking. We report our numerical results on their average degree and their impact on FACE routing. We discuss their potential applications and some open problems for future research