Model-based provisioning and management of adaptive distributed communication in mobile cooperative systems

Adaptation of communication is required to maintain the reliable connection and to ensure the minimum quality in collaborative activities. Within the framework of wireless environment, how can host entities be handled in the event of a sudden unexpected change in communication and reliable sources? This challenging issue is addressed in the context of Emergency rescue system carried out by mobile devices and robots during calamities or disaster. For this kind of scenario, this book proposes an adaptive middleware to support reconfigurable, reliable group communications. Here, the system structure has been viewed at two different states, a control center with high processing power and uninterrupted energy level is responsible for global task and entities like autonomous robots and firemen owning smart devices act locally in the mission. Adaptation at control center is handled by semantic modeling whereas at local entities, it is managed by a software module called communication agent (CA). Modeling follows the well-known SWRL instructions which establish the degree of importance of each communication link or component. Providing generic and scalable solutions for automated self-configuration is driven by rule-based reconfiguration policies. To perform dynamically in changing environment, a trigger mechanism should force this model to take an adaptive action in order to accomplish a certain task, for example, the group chosen in the beginning of a mission need not be the same one during the whole mission. Local entity adaptive mechanisms are handled by CA that manages internal service APIs to configure, set up, and monitors communication services and manages the internal resources to satisfy telecom service requirements

L'intertextualité dans les publications scientifiques

La base de données bibliographiques de l'IEEE contient un certain nombre de duplications avérées avec indication des originaux copiés. Ce corpus est utilisé pour tester une méthode d'attribution d'auteur. La combinaison de la distance intertextuelle avec la fenêtre glissante et diverses techniques de classification permet d'identifier ces duplications avec un risque d'erreur très faible. Cette expérience montre également que plusieurs facteurs brouillent l'identité de l'auteur scientifique, notamment des collectifs de chercheurs à géométrie variable et une forte dose d'intertextualité acceptée voire recherchée

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Multimedia

The nowadays ubiquitous and effortless digital data capture and processing capabilities offered by the majority of devices, lead to an unprecedented penetration of multimedia content in our everyday life. To make the most of this phenomenon, the rapidly increasing volume and usage of digitised content requires constant re-evaluation and adaptation of multimedia methodologies, in order to meet the relentless change of requirements from both the user and system perspectives. Advances in Multimedia provides readers with an overview of the ever-growing field of multimedia by bringing together various research studies and surveys from different subfields that point out such important aspects. Some of the main topics that this book deals with include: multimedia management in peer-to-peer structures & wireless networks, security characteristics in multimedia, semantic gap bridging for multimedia content and novel multimedia applications

Formal Methods for Wireless Systems

I sistemi wireless sono costituiti da dispositivi che comunicano tra loro per mezzo di un canale radio. Questo paradigma di rete presenta molti vantaggi, ma la presenza del canale radio lo rende intrinsecamente vulnerabile. Di conseguenza, in tale ambito la sicurezza rappresenta un tema importante. I meccanismi di sicurezza messi a punto per i sistemi cablati presentano molti limiti quando vengono utilizzati in una rete wireless. I problemi principali derivano dal fatto che essi operano in modo centralizzato e sotto l'ipotesi di un “mondo chiuso”. Pertanto tecniche formali sono necessarie per stabilire una connessione matematicamente rigorosa tra la modellazione e gli obiettivi di sicurezza. Nella presente tesi si applica il formalismo ben noto del "process calculus" per modellare le principali caratteristiche della comunicazione wireless. Il contributo scientifico è essenzialmente teorico. Verrà proposto un primo process calculus per modellare il passaggio del tempo nei sistemi wireless. Verranno dimostrate alcune interessanti proprietà relative al tempo. Inoltre verrà presentata una rigorosa trattazione dei problemi di collisione. Verranno fornite anche “equivalenze comportamentali” (behavioural equivalence) e verranno dimostrate una serie di leggi algebriche. L'usabilità del calcolo verrà mostrata modellando il Carrier Sense Multiple Access, un diffuso protocollo di livello MAC in cui un dispositivo ascolta il canale prima di trasmettere. Verranno poi analizzati alcuni aspetti di sicurezza, in particolare verrà proposto un modello di trust per le reti ad hoc mobili. Tali reti sono costituite da nodi mobili che comunicano senza l’ausilio di altre infrastrutture. Le reti di tale calcolo verranno modellate come sistemi multilivello perché le relazioni di trust associano ai nodi livelli di sicurezza in base al loro comportamento. Tale modello di trust verrà incluso in un process calculus per reti ad hoc che sarà dotato di equivalenze comportamentali a partire dalle quali verrà sviluppata una "teoria osservazionale" (observational theory). Saranno garantiti sia alcune interessanti proprietà relative alla sicurezza, come la safety in presenza di nodi compromessi, sia risultati di non interferenza. Tale calcolo verrà utilizzato per analizzare una versione “sicura” di un algoritmo per il leader election nelle reti ad hoc. Verrà fornita anche una codifica del protocollo di routing per reti ad hoc chiamato endairA. Infine, il calcolo sul trust verrà esteso con aspetti legati al tempo, per spiegare la relazione tra tempo e trust. Infine quest’ultimo calcolo verrà applicato per dare una codifica del protocollo di routing per reti ad hoc chiamato ARAN.Wireless systems consist of wireless devices which communicate with each other by means of a radio frequency channel. This networking paradigm offers much convenience, but because of the use of the wireless medium it is inherently vulnerable to many threats. As a consequence, security represents an important issue. Security mechanisms developed for wired systems present many limitations when used in a wireless context. The main problems stem from the fact that they operate in a centralised manner and under the assumption of a \closed world". Formal techniques are therefore needed to establish a mathematically rigorous connection between modelling and security goals. In the present dissertation we apply the well-known formalism of process calculus to model the features of wireless communication. The scientic contributions are primarily theoretical.We propose a timed process calculus modelling the communication features of wireless systems and enjoying some desirable time properties. The presence of time allows us to reason about communication collisions. We also provide behavioural equivalences and we prove a number of algebraic laws. We illustrate the usability of the calculus to model the Carrier Sense Multiple Access scheme, a widely used MAC level protocol in which a device senses the channel before transmitting. We then focus on security aspects, in particular we propose a trust model for mobile ad hoc networks, composed only of mobile nodes that communicate each other without relying on any base station. We model our networks as multilevel systems because trust relations associate security levels to nodes depending on their behaviour. Then we embody this trust model in a process calculus modelling the features of ad hoc networks. Our calculus is equipped with behavioural equivalences allowing us to develop an observational theory. We ensure safety despite compromised nodes and non interference results. We then use this calculus to analyse a secure version of a leader election algorithm for ad hoc networks. We also provide an encoding of the endairA routing protocol for ad hoc networks. Finally, we extend the trust-based calculus with timing aspects to reason about the relationship between trust and time. We then apply our calculus to formalise the routing protocol ARAN for ad hoc networks

Security in Distributed, Grid, Mobile, and Pervasive Computing

This book addresses the increasing demand to guarantee privacy, integrity, and availability of resources in networks and distributed systems. It first reviews security issues and challenges in content distribution networks, describes key agreement protocols based on the Diffie-Hellman key exchange and key management protocols for complex distributed systems like the Internet, and discusses securing design patterns for distributed systems. The next section focuses on security in mobile computing and wireless networks. After a section on grid computing security, the book presents an overview of security solutions for pervasive healthcare systems and surveys wireless sensor network security