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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Energy-aware routing protocols in Wireless Sensor Networks

Abusaimeh, Hesham January 2009 (has links)
Saving energy and increasing network lifetime are significant challenges in the field of Wireless Sensor Networks (WSNs). Energy-aware routing protocols have been introduced for WSNs to overcome limitations of WSN including limited power resources and difficulties renewing or recharging sensor nodes batteries. Furthermore, the potentially inhospitable environments of sensor locations, in some applications, such as the bottom of the ocean, or inside tornados also have to be considered. ZigBee is one of the latest communication standards designed for WSNs based on the IEEE 802.15.4 standard. The ZigBee standard supports two routing protocols, the Ad hoc On-demand Distance Vector (AODV), and the cluster-tree routing protocols. These protocols are implemented to establish the network, form clusters, and transfer data between the nodes. The AODV and the cluster-tree routing protocols are two of the most efficient routing protocols in terms of reducing the control message overhead, reducing the bandwidth usage in the network, and reducing the power consumption of wireless sensor nodes compared to other routing protocols. However, neither of these protocols considers the energy level or the energy consumption rate of the wireless sensor nodes during the establishment or routing processes.
102

Contribution aux communications intra-véhicule et inter-véhicules / Contribution to Intra-Vehicular and Inter-Vehicular Communications

Ayaida, Marwane 10 December 2012 (has links)
Les véhicules modernes sont équipés de périphériques permettant d'automatiser des tâches (changement de vitesse de transmission, régulation de vitesse, etc.) ou de fournir des services à l'utilisateur (aide à la conduite, détection d'obstacles, etc.). Les communications entre les véhicules permettent d'élargir ces services grâce à la collaboration de plusieurs véhicules (prévention des accidents, gestion du trafic routier, etc.). La multiplication de ces périphériques, de leurs interfaces et protocoles rend l'échange de données plus complexe. Par ailleurs, la communication inter- véhicules est plus contraignante à cause de la haute mobilité des véhicules. Dans cette thèse, nous proposons la conception d'un canal de communication Connect to All (C2A) qui permet d'assurer l'interopérabilité entre les périphériques embarqués dans un véhicule. En effet, il détecte la connexion à chaud d'un équipement, le reconnaît et lui permet d'échanger des données avec les autres périphériques connectés. La conception du canal commence par la modélisation de ce canal en utilisant deux techniques différentes (l'outil de modélisation et de vérification UPPAAL et le Langage de Description et de Spécification (LDS)). La vérification des modèles proposés a pour but de valider le fonctionnement. Ensuite, nous détaillons une implémentation réelle du canal sur une carte embarquée qui vise à démontrer la faisabilité du concept d'interopérabilité de C2A.Nous avons aussi étudié les effets de la mobilité dans la communication inter-véhiculaires grâce à une approche hybride mixant le routage et un service de localisation. Cette approche offre un mécanisme qui permet de réduire les coûts de la localisation des véhicules tout en augmentant les performances de routage. En plus, nous comparons deux applications de cette approche : Hybrid Routing and Grid Location Service (HRGLS) et Hybrid Routing and Hierarchical Location Service (HRHLS) avec des approches originelles pour démontrer la valeur ajoutée. Cette approche est enrichie avec un algorithme de prédiction de mobilité. Ce dernier permet de mieux cerner le déplacement des véhicules en les estimant. De même, l'approche hybride avec prédiction de mobilité Predictive Hybrid Routing and Hierarchical Location Service (PHRHLS) est comparée à HRHLS et l'approche originelle afin de révéler les bénéfices de la prédiction de mobilité. / Modern vehicles are equipped with various devices that aim to automate tasks (shift transmission, cruise control, etc.) or to provide services to the user (driver assistance, obstacle detection, etc.). Communications between vehicles help to expand these services through the collaboration of several vehicles (accident prevention, traffic management, etc.). The proliferation of these devices, their interfaces and protocols makes the data exchange more complex. In addition, inter-vehicle communication is more restrictive because of the vehicles' high mobility.In this work, we propose the design of a communication channel Connect to All (C2A) that ensures the interoperability between embedded devices in a vehicle. In fact, it detects the equipment connection, recognizes it and allows it to exchange data with other devices. The channel design starts by the modelling step using two different techniques (the model checker tool UPPAAL and the Specification and Description Language (SDL). Then, we validate the designed models. We also detail a concrete implementation of the channel on an embedded chip that aims to show the C2A interoperability concept feasibility.We also studied the mobility effects in the inter-vehicular communication through a hybrid approach mixing routing and location-based service. This approach provides a mechanism to reduce vehicle-tracking costs while increasing routing performances. Moreover, we compare two applications of this approach: Hybrid Routing and Grid Location Service (HRGLS) and Hybrid Routing and Hierarchical Location Service (HRHLS) with classical approaches to prove the added value. Then, this approach is improved with a mobility prediction algorithm. The latter allows a better understanding of the vehicle movements by estimating them. Similarly, the hybrid approach with mobility prediction Predictive Hybrid Routing and Hierarchical Location Service (PHRHLS) is compared with the basic approach and HRHLS in order to show the mobility prediction advantages.
103

Impact of Node Mobility on the Voice Quality in Mobile Ad-hoc Network (MANET) / Effekter av Nod Rörlighet på Röst Kvalitet i Mobila Ad hoc-nätverk (MANET)

Mondal, Sharup Barua & Ratan Chandra January 2011 (has links)
Enormous developing electronic technology has brought telecommunication to the sky inspiring popularity. Wireless Network (WN) technology will be emerging so far human. Presently users give the impression loving be connected all the time (everywhere) to the network or Internet through diverse access system, e.g., Universal Mobile Telecommunications System, Mobile Ad-hoc Network (MANET) [9] and Worldwide Interoperability for Microwave Access [30]. In telecommunication; MANET is considered as self-configured unlike nodes creating infrastructure-less network connected by means of WN, as nodes can exchange data packets without a central control [18]. Choosing beyond line of sight (BLOS) communication, MANET can be an intelligent selection, which is flexible for using and cost saving. However, to maintain quality of service (QoS), more or less challenges still have to be resolved [18]. Multimedia as well as VoIP (Voice over Internet Protocol) gaining more popularity as the internet world favored by the huge use of WN (access technologies) [20]. To maintain persistent services in different MANET situation unlike routing protocols (RP) are employed. In this thesis known (MANET) routing protocols OLSR (Optimized Link State Routing) [20], DSR (Dynamic Source Routing) [30] and TORA (Temporally Ordered Routing Algorithm) [14] have been considered for voice traffic as they maintaining dissimilar characteristics in the dissimilar situations as WN factors (like; bandwidth, signal strength, network traffic or load, network size) influencing the voice quality [9]. This thesis work focusing on the impact of node mobility influencing voice quality in unlike RPs in MANET. To decide the best suit RP in the MANET, the OPNET (Optimized Network Engineering Tool) Simulator 16.0 has been brought into play. OLSR is proposed to be best fitting RP for MANETs running VoIP appliance. / Enorma utveckla elektroniska tekniken har fört telekommunikation till himlen inspirerande popularitet. Trådlöst nätverk (WN) teknik kommer att utvecklas så långt mänsklig. För närvarande användare ger intryck kärleksfulla vara ansluten hela tiden (överallt) till nätverket eller Internet via olika system för tillträde, till exempel, Universal Mobile Telecommunications System, Mobil Ad-hoc-nätverk (Manet) [9] och Worldwide Interoperability för Microwave Access-[30 ]. I telekommunikation, är Manet betraktas som själv-konfigurerade skillnad noder skapa infrastruktur mindre nätverk som är anslutet via WN, som noder kan utbyta datapaket utan central styrning [18]. Välja bortom synfältet (Blos) kommunikation, kan Manet vara ett intelligent val, som är flexibel för att använda och kostnadsbesparande. Men för att upprätthålla service (QoS), mer eller mindre problem återstår att lösas [18]. Multimedia samt VoIP (Voice over Internet Protocol) allt mer populärt eftersom internet världen gynnas av den enorma användningen av WN (accesstekniker) [20]. För att behålla ihållande tjänster i olika Manet situationen skillnad routing protokoll (RP) är anställda. I denna kända avhandling (Manet) routingprotokoll OLSR (Optimerad Routing Link State) [20], DSR (Dynamic Source Routing) [30] och Tora (Tidsmässigt ordnad routing algoritm) har [14] ansetts för taltrafik som de upprätthålla olika egenskaper i olika situationer som WN faktorer (som, bandbredd, signalstyrka, nätverkstrafik eller last, nätverkets storlek) Att påverka ljudkvaliteten [9]. Detta examensarbete fokuserar på effekterna av nod rörlighet påverka röstkvalitet i motsats till RPS i Manet. För att avgöra det bäst passar RP i Manet, den OPNET (Optimerad Network Engineering Tool) Simulator 16,0 har kommit in i bilden. OLSR föreslås bli bäst passar RP för MANETs köra VoIP-apparaten. / Bergvägen 18 5tr 196 31 Kungsängen Sweden Mob: 0046(0)737106987
104

[en] A FRAMEWORK FOR SIMULATION OF MOBILE AD HOC NETWORKS / [pt] UM FRAMEWORK PARA SIMULAÇÃO DE REDES MÓVEIS AD HOC

ALEXANDRE MELE 28 August 2003 (has links)
[pt] Uma rede móvel ad hoc consiste de uma coleção de dispositivos computacionais portáteis, equipados com uma interface de comunicação sem fio, com uma distribuição arbitrária e dinâmica no espaço, e onde cada host também serve de roteador para os demais hosts, descobrindo e mantendo rotas multi-hop entre os hosts. De uma forma geral, os protocolos para redes móveis ad hoc são mais complexos do que os protocolos para as redes fixas, devido à várias características destas redes, como por exemplo, a topologia dinâmica, a interferência mútua, o acesso compartilhado e a largura de banda restrita dos enlaces sem fio, bem como a operação com energia restrita e menor quantidade de recursos disponíveis nos hosts móveis. Um grande foco da pesquisa em redes móveis ad hoc tem sido o desenvolvimento, a análise e a comparação de protocolos de roteamento. Por isto, existe a demanda por ambientes para a prototipação rápida, a simulação e a depuração de protocolos de roteamento (e de outras camadas) para este tipo de redes. Preferencialmente estes ambientes devem ser flexíveis, ser simples de usar, e permitir definir vários níveis de abstrações para descrever as características físicas da rede móvel, tais como o padrão de mobilidade, os enlaces sem fio, consumo de energia, etc. Esta dissertação trata do projeto e implementação de um framework para a simulação de redes móveis ad hoc que visa facilitar a criação de ambientes para prototipação, teste, análise de desempenho e complexidade de protocolos para este tipo de redes. / [en] A mobile ad hoc network consists of a set of portable computational devices, equipped with a wireless communication interface, that are randomly and dynamically distributed in space, and where each host serves as a router for the other hosts by discovering and maintaining multi-hop routes among the hosts. In general, protocols for mobile ad hoc networks are more complex than equivalent protocols for static networks, due to several properties of such networks, such as its dynamic topology, the mutual interference, concurrent access and smaller communication bandwidth of the wireless links, as well as, operation with restricted amount of energy, and scarce resources of the mobile devices. A main focus of research in mobile ad hoc networks has been the development, analysis and comparison of routing protocols for such networks. Therefore, there is some demand for environments that facilitate the rapid prototyping, the simulation and the debugging of protocols at the network and other layers for such networks. These environments should preferably be flexible, easy to use, and allow for the definition of different levels of abstractions for modeling the main characteristics of the mobile network, such as the pattern of mobility, the wireless links, the energy consumption, etc. This thesis describes the design and implementation of a framework for the simulation of mobile ad hoc networks, which aims at supporting the development of concrete simulation environments for prototyping, testing and doing the complexity and performance analysis of protocols for such networks.
105

Routing on the Channel Dependency Graph:

Domke, Jens 20 June 2017 (has links) (PDF)
In the pursuit for ever-increasing compute power, and with Moore's law slowly coming to an end, high-performance computing started to scale-out to larger systems. Alongside the increasing system size, the interconnection network is growing to accommodate and connect tens of thousands of compute nodes. These networks have a large influence on total cost, application performance, energy consumption, and overall system efficiency of the supercomputer. Unfortunately, state-of-the-art routing algorithms, which define the packet paths through the network, do not utilize this important resource efficiently. Topology-aware routing algorithms become increasingly inapplicable, due to irregular topologies, which either are irregular by design, or most often a result of hardware failures. Exchanging faulty network components potentially requires whole system downtime further increasing the cost of the failure. This management approach becomes more and more impractical due to the scale of today's networks and the accompanying steady decrease of the mean time between failures. Alternative methods of operating and maintaining these high-performance interconnects, both in terms of hardware- and software-management, are necessary to mitigate negative effects experienced by scientific applications executed on the supercomputer. However, existing topology-agnostic routing algorithms either suffer from poor load balancing or are not bounded in the number of virtual channels needed to resolve deadlocks in the routing tables. Using the fail-in-place strategy, a well-established method for storage systems to repair only critical component failures, is a feasible solution for current and future HPC interconnects as well as other large-scale installations such as data center networks. Although, an appropriate combination of topology and routing algorithm is required to minimize the throughput degradation for the entire system. This thesis contributes a network simulation toolchain to facilitate the process of finding a suitable combination, either during system design or while it is in operation. On top of this foundation, a key contribution is a novel scheduling-aware routing, which reduces fault-induced throughput degradation while improving overall network utilization. The scheduling-aware routing performs frequent property preserving routing updates to optimize the path balancing for simultaneously running batch jobs. The increased deployment of lossless interconnection networks, in conjunction with fail-in-place modes of operation and topology-agnostic, scheduling-aware routing algorithms, necessitates new solutions to solve the routing-deadlock problem. Therefore, this thesis further advances the state-of-the-art by introducing a novel concept of routing on the channel dependency graph, which allows the design of an universally applicable destination-based routing capable of optimizing the path balancing without exceeding a given number of virtual channels, which are a common hardware limitation. This disruptive innovation enables implicit deadlock-avoidance during path calculation, instead of solving both problems separately as all previous solutions.
106

Redundance v datových sítích / Redundancy in data networks

Šoun, Jan January 2010 (has links)
This thesis focuses on redundancy in data networks and on technologies which are used to achieve high availability in network infrastructure. This thesis is based on industry standards published by well-known standardization authorities. One proprietary technology which can effectively replace these standards and simplify the whole network is also presented in more detail. The theoretical part individually describes all such technologies and standards. The practical part deals with an appropriate combination of these technologies and their application in a specific product environment. This work is meant to describe the whole concept of high availability in network infrastructure and should be instrumental in understanding how these technologies are deployed in practice.
107

Arquitetura e implementação de um serviço de informações topologicas e de engenharia de trafego para sistemas RWA / Architecture and implementation of a topological information and traffic engineering service to RWA systems

Zuliani, Luiz Gustavo 12 April 2006 (has links)
Orientador: Mauricio Ferreira Magalhães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-08T01:20:28Z (GMT). No. of bitstreams: 1 Zuliani_LuizGustavo_M.pdf: 512812 bytes, checksum: cab94937633f70467669b12635e8ccb1 (MD5) Previous issue date: 2006 / Resumo: Redes totalmente ópticas (fotônicas) controladas por GMPLS (Generalized MultiProtocol Label Switching) são a promessa para lidar com o crescente volume de tráfego IP. Os protocolos de sinalização e roteamento GMPLS, principalmente OSPF (Open Shortest Path First) e RSVP (Resource ReSerVation Protocol), trabalham de tal modo que o cálculo da rota para circuitos ópticos não considera a disponibilidade de comprimentos de onda (labels). Esta solução não é ótima em termos do uso de recursos de rede e da probabilidade de bloqueio de novos circuitos. Para aprimorar este quadro, algoritmos RWA (Routing and Wavelength Assignment) mais eficientes poderiam ser usados para calcular a rota e o comprimento de onda simultaneamente. Estes algoritmos RWA necessitam conhecer a topologia óptica de um modo ainda não descrito pelas atuais especificações do protocolo OSPF. Esta dissertação propõe extensões de Engenharia de Tráfego para o protocolo OSPF para permitir que o plano de controle GMPLS se beneficie do uso de algoritmos RWA mais eficientes. Um protótipo foi desenvolvido e instalado em uma rede óptica emulada para verificar a praticabilidade da solução proposta baseado na sobrecarga de tráfego gerado no plano de controle / Abstract: GMPLS-controlled all-optical networks are the promise to handle the increasing volume of IP traffic. The GMPLS routing and signaling protocols, mainly OSPF and RSVP, work in such a way that the route calculation for optical circuits does not take into account the wavelength (label) availability. This is not optimal in terms of network resources usage and blocking probability of new circuits. To deal with this scenario, more efficient RWA algorithms could be used to calculate the route and the wavelength assignment at one time. These RWA engines need to know the optical topology in a way that is not described by current OSPF standards. This dissertation proposes Traffic Engineering extensions to the OSPF protocol to enable the GMPLS control plane to take advantage of the most effective RWA classes. A prototype was developed and deployed in an optical-emulated copper-based network to verify its feasibility based on the bandwidth overhead generated in the control plane / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica
108

Uso de grafos evolutivos no roteamento em redes dinâmicas: algoritmos, fluxos e limites / Using evolving graphs in routing of dynamic networks: algorithms, flows and bounds

Julian Geraldes Monteiro 13 July 2007 (has links)
O comportamento dinâmico das redes sem fio as torna muito peculiares e de difícil análise. No entanto, algumas destas redes, como as de sensores com funcionamento intermitente, redes periódicas ou cíclicas e as do sistema de satélites de órbita baixa têm um comportamento dinâmico relativamente previsível, pois as variações da topologia da rede no tempo são quase que determinísticas. Recentemente, um modelo teórico -- grafos evolutivos -- foi proposto com o intuito de capturar o comportamento dinâmico destas redes e formalizar algoritmos de roteamento de custo mínimo, além de outros. Os algoritmos e idéias obtidos com este modelo são teoricamente muito eficientes, mas, no entanto, antes deste trabalho não existiam estudos do uso destes modelos em situações práticas. Assim, o objetivo deste trabalho é analisar a aplicabilidade da teoria de grafos evolutivos na construção de protocolos de roteamento eficientes em cenários realistas. Foram implementados dois protocolos de roteamento para redes móveis ad hoc baseados nos algoritmos de grafos evolutivos, são eles: Jornada que Chega Mais Cedo e Jornada Mais Curta. Extensivas simulações foram realizadas utilizando o simulador de redes NS2 e os resultados foram comparados com outros quatro protocolos clássicos para este tipo de rede: AODV, DSR, OLSR e DSDV. Os resultados preliminares mostram que este recente modelo tem muito potencial para ser uma ferramenta poderosa no desenvolvimento e análise de algoritmos para redes dinâmicas com comportamento previsível. No entanto, foram apontados alguns aspectos que precisam ser melhores estudados para que estes algoritmos possam ser utilizados em situações reais. / The assessment of routing protocols for wireless networks is a difficult task, because of the networks\' highly dynamic behavior and the absence of benchmarks. However, some of these networks, such as intermittent wireless sensors networks, periodic or cyclic networks, and low earth orbit satellites systems, have more predictable dynamics, as the temporal variations in the network topology are somehow deterministic, which may make them easier to study. Recently, a graph theoretic model -- the evolving graphs -- was proposed to help to capture the dynamic behavior of these networks, in view of the construction of least cost routing and other algorithms. The algorithms and insights obtained through this model are theoretically very efficient and intriguing. However, before this work there was no study on the use of such theoretical results into practical situations. Therefore, the objective of our work is to analyze the applicability of the evolving graph theory in the construction of efficient routing protocols in realistic scenarios. We use the NS2 network simulator to first implement two evolving graph based routing protocols: Foremost Journey and Shortest Journey, They are evaluated and compared to four major ad-hoc protocols: AODV, DSR, OLSR and DSDV. Interestingly, our experiments show that evolving graphs have all the potentials to be an effective and powerful tool in the development and analysis of algorithms for dynamic networks, with predictable dynamics at least. In order to make this model widely applicable, however, some practical issues still have to be addressed and incorporated into the model.
109

Analýza a predikce datového provozu v mobilní ad hoc síti / Analysis and prediction of data traffic in mobile ad hoc network

Konečný, Daniel January 2014 (has links)
The diploma thesis „Analysis and prediction of data traffic in mobile Ad Hoc network“ focuses on the radio propagation models of services in MANET (Mobile Ad-hoc) networks. It describes MANET networks and covers the theoretical analysis of routing protocols, radio wave propagation and propagation models of simulation enviroment NS-3 (Network Simulator 3). Furthermore, there is processed the creation process of model MANET networks with the routing protocol AODV (Ad Hoc On Demand Distance Vector) in the simulation environment NS-3. For analysis purposes there were implemented new functions to capture value of SNR (Signal to Noise Ratio) and throughtput. For this reason a physical layer of one of NS-3 model was modified. As an result there is a simulation build that compared several number of propagaion models.
110

Proposition de nouveaux mécanismes de protection contre l'usurpation d'identité pour les fournisseurs de services Internet / Proposal for new protections against identity theft for ISPs

Biri, Aroua 25 February 2011 (has links)
De plus en plus d’organisations sont informatisées et plus une organisation est grande, plus elle peut être la cible d’attaques via Internet. On note également que les internautes utilisent de plus en plus Internet pour faire des achats sur des sites de commerce électronique, pour se connecter à l’administration en ligne, pour voter de manière électronique, etc. Par ailleurs, certains d’entre eux ont de plus en plus d'équipements électroniques qui peuvent être raccordés à Internet et ce dans divers sites (domicile, voiture, lieu de travail, etc.). Ces équipements forment ce qu’on appelle un réseau personnel qui permet la mise en place de nouvelles applications centrées sur l’internaute. Les fournisseurs de services Internet peuvent ainsi étoffer leurs offres de services en présentant une offre de sécurisation de ce genre de réseau. Selon le rapport du cabinet « Arbor Networks » intitulé « Worldwide Infrastructure Security Report », les menaces identifiées comme les plus sévères sont relatives aux attaques de déni de service distribué. Ce type d’attaque a pour but de rendre indisponible un service en empêchant les utilisateurs légitimes de l'utiliser. Il utilise la technique de l’usurpation d’identité qui consiste en la création de paquets (de type IP, ARP, etc.) avec une adresse source forgée et ce dans le but d’usurper un système informatique ou d’usurper l’identité de l’émetteur. La technique de l’usurpation d’identité permet ainsi de rendre un service indisponible, d’écouter, de corrompre, de bloquer le trafic des internautes ou de nuire au bon fonctionnement des protocoles de routage et des réseaux personnels des clients. De plus, la technique de l’usurpation d’identité est également utilisée pour des activités interdites par la loi « Hadopi » en rigueur en France comme le téléchargement illégal. De ce fait, les fournisseurs de services Internet se doivent de prémunir leurs clients des attaques basées sur la technique de l’usurpation d’identité. Ces dits fournisseurs comptent sur les protocoles de routage qu’ils déroulent pour participer au bon acheminement des données de leurs clients. Cependant, le protocole intra-domaine OSPF et le protocole inter-domaine BGP sont vulnérables aux attaques utilisant la technique de l’usurpation d’identité qui peuvent conduire à l’acheminement des paquets vers des destinataires non légitimes ou au déni de service. Nous proposons donc deux mécanismes dédiés respectivement au protocole intra-domaine OSPF et au protocole inter-domaine BGP. D’une part, afin de protéger les routeurs OSPF contre les attaques utilisant la technique d’usurpation d’identité, nous avons préconisé le stockage de l’identité et du matériel cryptographique dans un coffre-fort électronique que sont les cartes à puce. Les cartes déroulent ensuite un algorithme de dérivation de clés avec les cartes des routeurs voisins ainsi qu’avec celle du routeur désigné. Les clés dérivées entre les cartes à puce servent à signer les messages OSPF et à authentifier le niveau MAC. Nous avons décrit par la suite la plateforme du démonstrateur et les scénarios de tests adoptés pour évaluer les performances de notre prototype et les comparer avec ceux du logiciel Quagga sur la base de trois critères : le temps requis pour traiter une annonce d'état de liens, le temps de convergence ainsi que le temps de re-calcul d’une table de routage après un changement. Ces temps augmentent peu avec l’introduction de la carte à puce implémentant les fonctions de sécurité proposées. Ainsi, cette solution permet de renforcer la sécurité du protocole OSPF avec un impact raisonnable sur les performances. D’autre part, afin de protéger les routeurs BGP contre les attaques utilisant la technique d’usurpation d’identité, nous avons préconisé la « clustérisation » des domaines Internet et la sécurisation des liens entre les clusters ainsi qu’au sein de chacun d’eux grâce aux paradigmes de « web of trust » et de la cryptographie sans certificats […] / More and more organizations are computerized and more an organization is great, plus it can be the target of Internet attacks. Moreover, some of them have a growing number of electronic equipments that can be connected to the Internet from various locations (home, car, workplace, etc.). These devices form a so-called personal area network that allows the development of new applications centered on users. The ISPs can then expand their service offerings by providing a secure supply of such networks. According to the report of the firm “Arbor Networks”, entitled "Worldwide Infrastructure Security Report ", the most severe threats are related to distributed denial of service. This type of attack aims to make available a service by preventing legitimate users from using it. It uses the technique of identity theft that involves the creation of packages (like IP, ARP, etc.) with a forged source address and that in order to usurp the Identity of the issuer or of the computer system. Thus, the technique of identity theft allows to render a service unavailable, to listen, to corrupt, to block traffic from Internet users or to undermine the legitimate operation of routing protocols and personal networks. Moreover, the technique of identity theft is also used for prohibited activities by "HADOPI" law in France and related to illegal downloading issues. Thus, the ISPs have a duty to protect their customers from attacks based on the technique of identity theft. The mechanisms of protection against spoofing attacks for access networks are crucial for customer adoption of new applications offered by Internet service providers. This part of the doctoral thesis is part of the European project “MAGNET Beyond" whose vision is to put into practice the concept of personal networks, with the ultimate objective to design, develop, prototype and validate the concept. In the context of user equipment’s access to the network of an Internet services provider from a public place, we proposed a cross-layer protocol based on the principles of information theory. This protocol fixes the security hole not addressed by other proposals that is the attack of identity theft that occurs at the beginning of communication and thus protects users against the middle man attacks. We proposed that the person who wants to have secure access to the Internet must be on a specific circle has been called "RED POINT" so that the attacker is not able to be on the same circle at the same time. The proposed cross-layer protocol can be divided into three phases: the phase of checking the position of the user, the extraction phase of the shared secret of the physical layer and the phase of the derivation of the shared key at the MAC layer. We subsequently validated our solution through a formal tool AVISPA and presented the results of its implementation. In a private context, communication between devices convey users' personal data which may be confidential, so we must prevent equipment not belonging to the legitimate user to access its network. Thus, we proposed two mechanisms of protection against attacks based on spoofing so that illegitimate equipment is unable to impersonate legitimate equipment. The first phase will be dedicated to personal networks and the second will be dedicated to the particular case of medical networks. Regarding the mechanism dedicated to personal networks, we have proposed the use of a protocol based on out-of-band channel in order to provide certificates to user equipments. We derive bilateral key for personal network’s equipments of the same site and between equipments at remote sites. Concerning the particular case of medical networks, we proposed to cover their deployment phases and their operational phases. This proposal was submitted to the IEEE 802.15.6 working group that conducts research for the standardization of medical networks […]

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