Efficient collection of sensor data via a new accelerated random walk

Motivated by the problem of efficiently collecting data from wireless sensor networks via a mobile sink, we present an accelerated random walk on random geometric graphs (RGG). Random walks in wireless sensor networks can serve as fully local, lightweight strategies for sink motion that significantly reduce energy dissipation but introduce higher latency in the data collection process. In most cases, random walks are studied on graphs like Gn,p and grid. Instead, we here choose the RGG model, which abstracts more accurately spatial proximity in a wireless sensor network. We first evaluate an adaptive walk (the random walk with inertia) on the RGG model; its performance proved to be poor and led us to define and experimentally evaluate a novel random walk that we call γ-stretched random walk. Its basic idea is to favour visiting distant neighbours of the current node towards reducing node overlap and accelerate the cover time. We also define a new performance metric called proximity cover time that, along with other metrics such as visit overlap statistics and proximity variation, we use to evaluate the performance properties and features of the various walks

Energy Optimal Data Propagation in Wireless Sensor Networks

We propose an algorithm which produces a randomized strategy reaching optimal data propagation in wireless sensor networks (WSN).In [6] and [8], an energy balanced solution is sought using an approximation algorithm. Our algorithm improves by (a) when an energy-balanced solution does not exist, it still finds an optimal solution (whereas previous algorithms did not consider this case and provide no useful solution) (b) instead of being an approximation algorithm, it finds the exact solution in one pass. We also provide a rigorous proof of the optimality of our solution.Comment: 19 page

Accelerated collection of sensor data by mobility-enabled topology ranks

We study the problem of fast and energy-efficient data collection of sensory data using a mobile sink, in wireless sensor networks in which both the sensors and the sink move. Motivated by relevant applications, we focus on dynamic sensory mobility and heterogeneous sensor placement. Our approach basically suggests to exploit the sensor motion to adaptively propagate information based on local conditions (such as high placement concentrations), so that the sink gradually “learns” the network and accordingly optimizes its motion. Compared to relevant solutions in the state of the art (such as the blind random walk, biased walks, and even optimized deterministic sink mobility), our method significantly reduces latency (the improvement ranges from 40% for uniform placements, to 800% for heterogeneous ones), while also improving the success rate and keeping the energy dissipation at very satisfactory level

ISPCell: an interactive image-based streaming protocol for wireless cellular networks

Remote interaction with immersive 3D environments with acceptable level of quality of experience has become a challenging and interesting research topic. Due to the high data volume required to provide a rich experience to the user, robust and effcient wireless transport protocols have yet to be developed. On the other hand, cellular network technology has been widely deployed and is growing fast. The provision of remote interactive 3D environments over wireless cellular networks has several interesting applications, and it imposes some unsolved issues. Node mobility creates unstable bandwidth, which is a problem when providing smooth interaction to users. Although PDAs and cell phones are low resource devices, which makes it prohibitive to load and render entire virtual environments, they can still render images with relative ease. Based on this idea, this paper proposes a streaming system which relies on an image-based rendering approach, and is composed of several modules: a packetization scheme for images, an image-based rendering approach based on view morphing and its corresponding RTP payload format, and finally a bandwidth feedback mechanism and rate control. This paper illustrates some of the problems faced in this area, and provides a first step towards their solutions. We discuss our algorithms and present a set of simulation experiments to evaluate the performance of the proposed schemes.8th IFIP/IEEE International conference on Mobile and Wireless CommunicationRed de Universidades con Carreras en Informática (RedUNCI

Planification des présentations multimédias

Dû à la croissance de la complexité et du volume de l'information à communiquer, les systèmes classiques de présentation de l'information, où il faut prévoir toutes les situations à l'avance, sont devenus inadaptés. De nouvelles techniques de traitement de l'information sont nécessaires. Dans ce mémoire, nous présentons un système de présentation multimédia (PPM) basé sur la technique de la planification. Chaque présentation multimédia est composée de séquences de film (animation multimédia). Chaque séquence de film est à son tour composée d'actions de base qui sont préencodées dans le système. La combinaison de ces actions de base est réalisée d'une manière dynamique par un planificateur appelé TLPLan. Notre système procède, par la suite, à une extension de ce plan en un film. Cette transformation du plan en un film est réalisée par un système auteur appelé Director. L'idée de coupler le système auteur (Director) avec le planificateur (TLPLan) permet à notre système d'être adaptable et flexible. Il est adaptable parce qu'il suffit de changer la librairie des actions de base et les médias impliqués pour le faire fonctionner avec une nouvelle application. Il est flexible, car toutes les situations ne sont pas prévues à l'avance: l'usager peut formuler de nouvelles tâches à présenter et le planificateur trouve des plans qui satisfont ces tâches. Autrement dit, l'usager décrit les caractéristiques du film et non le film lui-même; c'est le planificateur qui trouve le film et PPM décide quels médias utiliser et comment les coordonner. Il est certainement plus agréable de suivre des présentations produites par notre système que de lire des pages de texte ou de dessins avec des références croisées

Blockchain and Fog Computining for Cyberphysical Systems: The Case of Smart Industry

© 1970-2012 IEEE. Blockchain and fog computing are being evaluated as potential support for software and a wide spectrum of critical applications. This article presents the knowledge of blockchain and fog computing required to improve cyberphysical systems. Emerging challenges and issues are also discussed

The Trap Coverage Area Protocol for Scalable Vehicular Target Tracking

Vehicle target tracking is a sub-field of increasing and increasing interest in the vehicular networking research area, in particular for its potential application in dense urban areas with low associated costs, e.g., by exploiting existing monitoring infrastructures and cooperative collaboration of regular vehicles. Inspired by the concept of trap coverage area, we have originally designed and implemented an original protocol for vehicle tracking in wide-scale urban scenarios, called TCAP. TCAP is capable of achieving the needed performance while exploiting a limited number of inexpensive sensors (e.g., public-authority cameras already installed at intersections for traffic monitoring), and opportunistic vehicle collaboration, with high scalability and low overhead if compared with state-of-the-art literature. In particular, the wide set of reported results show i) the suitability of our TCAP tracking in the challenging urban conditions of high density of vehicles, ii) the very weak dependency of TCAP performance from topology changes/constraints (e.g., street lengths and speed limits), iii) the TCAP capability of self-adapting to differentiated runtime conditions

Design Guidelines for Blockchain-Assisted 5G-UAV Networks

© 1986-2012 IEEE. Fifth generation (5G) wireless networks are designed to meet various end-user quality of service (QoS) requirements through high data rates (typically of gigabits per second) and low latencies. Coupled with fog and mobile edge computing, 5G can achieve high data rates, enabling complex autonomous smart city services such as the large deployment of self-driving vehicles and large-scale artificial-intelligence-enabled industrial manufacturing. However, to meet the exponentially growing number of connected IoT devices and irregular data and service requests in both low- and high-density locations, the process of enacting traditional cells supported through fixed and costly base stations requires rethought to enable on-demand mobile access points in the form of unmanned aerial vehicles (UAV) for diversified smart city scenarios. This article envisions a 5G network environment that is supported by blockchain-enabled UAVs to meet dynamic user demands with network access supply. The solution enables decentralized service delivery (drones as a service) and routing to and from end users in a reliable and secure manner. Both public and private blockchains are deployed within the UAVs, supported by fog and cloud computing devices and data centers to provide a wide range of complex authenticated service and data availability. Particular attention is paid to comparing data delivery success rates and message exchange in the proposed solution against traditional UAV-supported cellular networks. Challenges and future research are also discussed with highlights on emerging technologies such as federated learning

An energy trade framework using smart contracts: Overview and challenges

© 1986-2012 IEEE. The increasing demand for clean, sustainable and reliable energy sources that are secure and stable requires the integration of renewable and edge energy products with the existing power grid. With the introduction of technological advancements and distributed resources, energy users (aka prosumers) can now generate, store and manage their energy requirements, and share their resources with others. BC is a promising technology that can provide secure and verifiable transactions for P2P energy trading, and promote energy conservation. This article recognizes the best practices for sustainable energy, and highlights the benefits of BC and smart contracts in the energy sector. A distributed trading framework and smart contracts are proposed for future versions of BC and integration with other energy products, and potential solutions are suggested

Trust-based security for the OLSR routing protocol

International audienceThe trust is always present implicitly in the protocols based on cooperation, in particular, between the entities involved in routing operations in Ad hoc networks. Indeed, as the wireless range of such nodes is limited, the nodes mutually cooperate with their neighbors in order to extend the remote nodes and the entire network. In our work, we are interested by trust as security solution for OLSR protocol. This approach fits particularly with characteristics of ad hoc networks. Moreover, the explicit trust management allows entities to reason with and about trust, and to take decisions regarding other entities. In this paper, we detail the techniques and the contributions in trust-based security in OLSR. We present trust-based analysis of the OLSR protocol using trust specification language, and we show how trust-based reasoning can allow each node to evaluate the behavior of the other nodes. After the detection of misbehaving nodes, we propose solutions of prevention and countermeasures to resolve the situations of inconsistency, and counter the malicious nodes. We demonstrate the effectiveness of our solution taking different simulated attacks scenarios. Our approach brings few modifications and is still compatible with the bare OLSR