47 research outputs found

    Simulation and Performance Analysis of MP-OLSR for Mobile Ad hoc Networks

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    Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile nodes which dynamically exchange data without reliance on a fixed base station or a wired backbone network, which makes routing a crucial issue for the design of a ad hoc networks. In this paper we discussed a hybrid multipath routing protocol named MP-OLSR. It is based on the link state algorithm and employs periodic exchange of messages to maintain topology information of the networks. In the mean time, it updates the routing table in an on-demand scheme and forwards the packets in multiple paths which have been determined at the source. If a link failure is detected, the algorithm recovers the route automatically. Concerning the instability of the wireless networks, the redundancy coding is used to improve the delivery ratio. The simulation in NS2 shows that the new protocol can effectively improve the performance of the networks

    Protocole de routage à chemins multiples pour des réseaux ad hoc

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    Ad hoc networks consist of a collection of wireless mobile nodes which dynamically exchange data without reliance on any fixed based station or a wired backbone network. They are by definition self-organized. The frequent topological changes make multi-hops routing a crucial issue for these networks. In this PhD thesis, we propose a multipath routing protocol named Multipath Optimized Link State Routing (MP-OLSR). It is a multipath extension of OLSR, and can be regarded as a hybrid routing scheme because it combines the proactive nature of topology sensing and reactive nature of multipath computation. The auxiliary functions as route recovery and loop detection are introduced to improve the performance of the network. The usage of queue length metric for link quality criteria is studied and the compatibility between single path and multipath routing is discussed to facilitate the deployment of the protocol. The simulations based on NS2 and Qualnet softwares are performed in different scenarios. A testbed is also set up in the campus of Polytech’Nantes. The results from the simulator and testbed reveal that MP-OLSR is particularly suitable for mobile, large and dense networks with heavy network load thanks to its ability to distribute the traffic into different paths and effective auxiliary functions. The H.264/SVC video service is applied to ad hoc networks with MP-OLSR. By exploiting the scalable characteristic of H.264/SVC, we propose to use Priority Forward Error Correction coding based on Finite Radon Transform (FRT) to improve the received video quality. An evaluation framework called SVCEval is built to simulate the SVC video transmission over different kinds of networks in Qualnet. This second study highlights the interest of multiple path routing to improve quality of experience over self-organized networks.Les réseaux ad hoc sont constitués d’un ensemble de nœuds mobiles qui échangent des données sans infrastructure de type point d’accès ou artère filaire. Ils sont par définition auto-organisés. Les changements fréquents de topologie des réseaux ad hoc rendent le routage multi-sauts très problématique. Dans cette thèse, nous proposons un protocole de routage à chemins multiples appelé Multipath Optimized Link State Routing (MP-OLSR). C’est une extension d’OLSR à chemins multiples qui peut être considérée comme une méthode de routage hybride. En effet, MP-OLSR combine la caractéristique proactive de la détection de topologie et la caractéristique réactive du calcul de chemins multiples qui est effectué à la demande. Les fonctions auxiliaires comme la récupération de routes ou la détection de boucles sont introduites pour améliorer la performance du réseau. L’utilisation de la longueur des files d’attente des nœuds intermédiaires comme critère de qualité de lien est étudiée et la compatibilité entre routage à chemins multiples et chemin unique est discutée pour faciliter le déploiement du protocole. Les simulations basées sur les logiciels NS2 et Qualnet sont effectuées pour tester le routage MP-OLSR dans des scénarios variés. Une mise en œuvre a également été réalisée au cours de cette thèse avec une expérimentation sur le campus de Polytech’Nantes. Les résultats de la simulation et de l’expérimentation révèlent que MP-OLSR est particulièrement adapté pour les réseaux mobiles et denses avec des trafics élevés grâce à sa capacité à distribuer le trafic dans des chemins différents et à des fonctions auxiliaires efficaces. Au niveau application, le service vidéo H.264/SVC est appliqué à des réseaux ad hoc MP-OLSR. En exploitant la hiérarchie naturelle délivrée par le format H.264/SVC, nous proposons d’utiliser un codage à protection inégale (PFEC) basé sur la Transformation de Radon Finie (FRT) pour améliorer la qualité de la vidéo à la réception. Un outil appelé SVCEval est développé pour simuler la transmission de vidéo SVC sur différents types de réseaux dans le logiciel Qualnet. Cette deuxième étude témoigne de l’intérêt du codage à protection inégale dans un routage à chemins multiples pour améliorer une qualité d’usage sur des réseaux auto-organisés

    QoE enhancement for H.264/SVC video transmission in MANET using MP-OLSR protocol

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    International audienceThis paper addresses the problem of enhancing video service quality for Mobile Ad Hoc Networks (MANET) scenarios. We offer Multipath Optimized Link State (MP-OLSR) routing protocol for H.264/SVC bitstream forwarding in the MANET network. Besides the usage of a suitable routing protocol, the video quality can be further enhanced by using the scalable encoding feature of Scalable Video Coding (SVC) combined with Unequal Error Protection (UEP). SVC is an extension of the H.264/AVC video compression standard used for high-quality video bitstreams encoding, providing spatial, temporal and quality scalability. To evaluate video quality, the Video Quality Metric (VQM) is used. We chose 5 different video contents for our simulations characterized by various temporal and spatial complexities. These video references are taken from the Video Quality Expert Group (VQEG). The results show that multipath routing combined with UEP can effectively improve the quality of video communication over MANET in terms of VQM and successful video decoding

    Vulnerability Analysis of the Simple Multicast Forwarding (SMF) Protocol for Mobile Ad Hoc Networks

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    If deployments of Mobile Ad Hoc Networks (MANETs) are to become common outside of purely experimental settings, protocols operating such MANETs must be able to preserve network integrity, even when faced with careless or malicious participants. A first step towards protecting a MANET is to analyze the vulnerabilities of the routing protocol(s), managing the connectivity. Understanding how these routing protocols can be exploited by those with ill intent, countermeasures can be developed, readying MANETs for wider deployment and use. One routing protocol for MANETs, developed by the Internet Engineering Task Force (IETF) as a multicast routing protocol for efficient data dissemination, is denoted "Simplified Multicast Forwarding" (SMF). This protocol is analyzed, and its vulnerabilities described, in this memorandum. SMF consists of two independent components: (i) duplicate packet detection and (ii) relay set selection, each of which presents its own set of vulnerabilities that an attacker may exploit to compromise network integrity. This memorandum explores vulnerabilities in each of these, with the aim of identifying attack vectors and thus enabling development of countermeasures.Afin d'augmenter le nombre de déploiements de réseaux ad hoc dehors des "testbeds" purement expérimentals, des protocoles de routage des réseaux ad hoc doivent être en mesure de préserver l'intégrité du réseau, même lorsqu'ils sont confrontés avec des participants imprudents ou malicieux. Un premier pas vers la protection d'un réseau ad hoc est d'analyser les vulnérabilités du protocole de routage qui gère la connectivité du réseau. En comprenant comment ces protocoles de routage peuvent être exploités par des personnes ayant de mauvaises intentions, des contre-mesures peuvent être développées. Un protocole de routage pour des réseaux ad hoc, développé par l'Internet Engineering Task Force (IETF) comme protocole de routage de multicast pour la diffusion efficace des données, est appelé "Simplified Multicast Forwarding" (SMF). Ce protocole est analysé, et ses vulnérabilités décrites dans ce rapport. SMF est constitué de deux composantes indépendantes: (i) la détection des paquets dupliqués et (ii) la sélection des relais, dont chacun présente son propre ensemble de vulnérabilités qu'un attaquant peut exploiter pour compromettre l'intégrité du réseau. Ce rapport explore des vulnérabilités dans chacune des deux composantes, afin d'identifier les vecteurs d'attaque, ainsi de permettre de développer des contre-mesures

    Multipath Optimized Link State Routing for Mobile ad hoc Networks

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    Multipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications. Our protocol, called MP-OLSR (MultiPath OLSR), is a multipath routing protocol based on OLSR. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints

    Multipath optimized link state routing for mobile ad hoc networks

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    International audienceMultipath routing protocols for Mobile Ad hoc NETwork (MANET) address the problem of scalability, security (confidentiality and integrity), lifetime of networks, instability of wireless transmissions, and their adaptation to applications. Our protocol, called MP-OLSR (MultiPath OLSR), is a multipath routing protocol based on OLSR. The Multipath Dijkstra Algorithm is proposed to obtain multiple paths. The algorithm gains great flexibility and extensibility by employing different link metrics and cost functions. In addition, route recovery and loop detection are implemented in MP-OLSR in order to improve quality of service regarding OLSR. The backward compatibility with OLSR based on IP source routing is also studied. Simulation based on Qualnet simulator is performed in different scenarios. A testbed is also set up to validate the protocol in real world. The results reveal that MP-OLSR is suitable for mobile, large and dense networks with large traffic, and could satisfy critical multimedia applications with high on time constraints

    Implementation of Multipath and Multiple Description Coding in OLSR

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    In this paper we discussed the application and the implementation of multipath routing and multiple description coding (MDC) extension of OLSR, called MP-OLSR. It is based on the link state algorithm and employs periodic exchange of messages to maintain topology information of the networks. In the mean time, it updates the routing table in an on-demand scheme and forwards the packets in multiple paths which have been determined at the source. If a link failure is detected, the algorithm recovers the route automatically. Concerning the instability of the wireless networks, the multiple description coding is used to improve reliability of the network transmission, and several methods are proposed to allocate the redundancy in different paths. The simulation in NS2 shows that the new protocol can effectively improve the performance of the networks. The implementation of MP-OLSR is also proposed in the end

    Multipath OLSR: Simulation and Testbed

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    MP-OLSR is a multipath routing protocol based on OLSR (Optimized Link State Routing). The multipath routing protocol is expected to provide more stable routes for the network. In this paper, several topics about MP-OLSR are discussed. We begin with introducing the functionalities of MP-OLSR, which includes topology sensing, routing computation, route recovery and loop detection. Then a testbed is implemented to verify the availability of MP-OLSR. Given OLSR one of the most populated proactive protocols for ad hoc networks, the compatibility between MP-OLSR and OLSR is also discussed. The results based on simulator and our testbed show that MP-OLSR could offer more stable data transmission over the unstable wireless interface. And it could cooperate well with the established OLSR protocol

    Multipath Extension for the Optimized Link State Routing Protocol Version 2 (OLSRv2)

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    RFC 8218, Category Experimental, WG MANET, IET
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