No description available.

The Parking Guidance and Information (PGI) system is an important application of Intelligent Transport System (ITS), which has been shown to be an effect service for traffic information and parking management. The roadside Variable Message Sign (VMS) board has been the usual media for the publication of parking information in early PGI systems, and its performance over the years has been studied via simulations and questionnaire surveys. However, survey results show significant discrepancies across various traffic networks in different areas. More recently, parking information services have become available on other media such as mobile and in-vehicle devices. In contrast to VMS-based systems, PGI systems based on new media, especially the in-vehicle class of devices, have not been studied separately. This thesis aims to conduct research into the performance of PGI systems based on invehicle devices, by simulating and comparing a VMS-based PGI system with a Vehicle On-Board Device (VOBD)-based PGI system. A specially designed simulator utilising a routing algorithm known as the Ad hoc On-Demand Distance Vector (AODV) routing protocol in computer networks, has been created in MATLAB. The simulation minimises the influence of specific structures of traffic networks that may be found in some networks, but not others. This is done by simulating a grid-based road network where the capacities of parking stations and their geographic distribution are randomly allocated within specific zones, and the parking demand in each run of simulations is variable load. The results of simulations, including the information reliability, reduction of travel time, demand on on-street parking and the utilisation rates of parking stations, are analysed for multiple scenarios where the compliance rate, the information update policy and the strategy of human behaviour are varied. The analyses reveal a significant advantage of VOBD-based PGI systems over VMS-based PGI systems in terms of the quality of information and the reduction of travel time. At the same time, the analyses highlight the limitations of a PGI system when the demand and supply of parking stations is not appropriately balanced.

Le développement des technologies de réseaux de capteurs incite les industries à envisager des alternatives réduisant les coûts et la complexité tout en améliorant la fiabilité. Parmi les solutions sans fil actuelles, la technologie LP-WPAN IEEE 802.15.4/ZigBee dispose des mécanismes et des garanties nécessaires pour une utilisation industrielle. Nous proposons des mécanismes de synchronisation entièrement déterministe permettant l'utilisation du standard IEEE 802.15.4 en mode balisé dans un réseau maillé, ainsi qu'une méthode de routage adaptative « AODV en » pour les messages transmis dans un réseau étendu. En premier lieu, nous analysons la technologie IEEE 802.15.4/ZigBee, plus particulièrement sa capacité à conserver son comportement déterministe et économe en énergie dans une architecture de réseau maillé. Cette étude met en évidence plusieurs insuffisances du standard. Notre contribution consiste à palier à ces manques par une synchronisation centralisée réactive aux changements de topologie, esquivant les collisions de balises et de GTS. Ces modifications seront apportées au niveau de la sous-couche MAC. En second lieu, aucun des protocoles de routage (couche 3 du modèle ISO) actuellement les plus utilisés, ne prennent en compte simultanément les critères indispensables au contexte des communications dans un environnement industriel à fortes contraintes sur la consommation et sur le temps. Nous proposons un mécanisme de routage réactif adaptatif recherchant les routes optimisant la durée de vie des noeuds du réseau contraints énergétiquement, et basé sur l'optimisation conjointe du délai et de la consommation. Pour cela, nous avons analysé et évalué la consommation de chacun des noeuds sans fil autonomes utilisant le standard. Nous avons ainsi proposé des informations de délai et de niveau de charge de la batterie de chacun des noeuds, prises en considération dans notre mécanisme de routage adaptatif. L'ensemble de nos propositions sont validées en utilisant diverses méthodes dont les réseaux de Petri temporisés, la simulation et le prototypage. Les résultats obtenus sont exposés à la suite de chacune de nos contributions.

The Parking Guidance and Information (PGI) system is an important application of Intelligent Transport System (ITS), which has been shown to be an effect service for traffic information and parking management. The roadside Variable Message Sign (VMS) board has been the usual media for the publication of parking information in early PGI systems, and its performance over the years has been studied via simulations and questionnaire surveys. However, survey results show significant discrepancies across various traffic networks in different areas. More recently, parking information services have become available on other media such as mobile and in-vehicle devices. In contrast to VMS-based systems, PGI systems based on new media, especially the in-vehicle class of devices, have not been studied separately. This thesis aims to conduct research into the performance of PGI systems based on invehicle devices, by simulating and comparing a VMS-based PGI system with a Vehicle On-Board Device (VOBD)-based PGI system. A specially designed simulator utilising a routing algorithm known as the Ad hoc On-Demand Distance Vector (AODV) routing protocol in computer networks, has been created in MATLAB. The simulation minimises the influence of specific structures of traffic networks that may be found in some networks, but not others. This is done by simulating a grid-based road network where the capacities of parking stations and their geographic distribution are randomly allocated within specific zones, and the parking demand in each run of simulations is variable load. The results of simulations, including the information reliability, reduction of travel time, demand on on-street parking and the utilisation rates of parking stations, are analysed for multiple scenarios where the compliance rate, the information update policy and the strategy of human behaviour are varied. The analyses reveal a significant advantage of VOBD-based PGI systems over VMS-based PGI systems in terms of the quality of information and the reduction of travel time. At the same time, the analyses highlight the limitations of a PGI system when the demand and supply of parking stations is not appropriately balanced.

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.

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.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

A Mobile Ad Hoc Network (MANETs) is a collection of wireless hosts that can be rapidly deployed as a multi hop packet radio network without the aid of any established infrastructure or centralized administration. Such networks can be used to enable next generation of battlefield applications envisioned by the military, including situation awareness systems for maneuvering war fighters, and remotely deployed unmanned microsensor networks. Ad Hoc networks can also provide solutions for civilian applications such as disaster recovery and message exchanges among safety and security personnel involved in rescue missions. Existing solutions for wired network Intrusion Detection Systems (IDSs) do not suit wireless Ad Hoc networks. To utilize either misuse detection or anomaly detection to monitor any possible compromises, the IDS must be able to distinguish normal from anomaly activities. To enable intrusion detection in wireless Ad Hoc networks, the research problems are: • How to efficiently collect normal and anomaly patterns of Ad Hoc networks? The lifetime of the hosts is short and Ad Hoc networks do not have traffic concentration points (router, switch). • How to detect anomalies? The loss could be caused by host movement instead of attacks. Unexpectedly long delay could be caused by unreliable channel instead of malicious discard. In this thesis, we have proposed a novel architecture that uses specification based intrusion detection techniques to detect active attacks against the routing protocols of mobile Ad Hoc networks. Our work analyzes some of the vulnerabilities and discuss the attacks against the AODV protocol. Our approach involves the use of an FSM (Finite State Machine) for specifying the AODV routing behavior and the distributed network monitors for detecting the sequence number attack. Our method can detect most of the bad nodes with low false positive rate and the packet delivery ratio can also be increased with high detection rate. For packet dropping attack, we present a distributed technique to detect this attack in wireless Ad Hoc networks. A bad node can forward packets but in fact it fails to do so. In our technique, every node in the network will check the neighboring nodes to detect if any of them fail to forward the packets. Our technique can detect most of the bad nodes with low false positive rate and the packet delivery ratio can also be increased. The proposed solution can be applied to identify multiple malicious nodes cooperating with each other in MANETs and discover secure routes from source to destination by avoiding malicious nodes acting in cooperation. Our technique will detect the sequence number and Packet Dropping attacks in real time within its radio range with no extra overhead. For resource consumption attack, the proposed scheme incurs no extra overhead, as it makes minimal modifications to the existing data structures and functions related to bad listing a node in the existing version of pure AODV. The proposed scheme is more efficient in terms of the resultant routes established, resource reservations, and computational complexity. If multiple malicious nodes collaborate, they in turn will be restricted and isolated by their neighbors, because they monitor and exercise control over forwarding RREQs by nodes. Hence, the scheme successfully prevents Distributed attacks. The proposed scheme shifts the responsibility of monitoring this parameter to the node's neighbor, ensuring compliance of this restriction. This technique solves all of the problems caused due to unnecessary RREQs from a compromised node. Instead of self-control, the control exercised by a node's neighbor results in preventing this attack. Experiments show that the tool provides effective intrusion detection functionality while using only a limited amount of resources. The loop freedom property has been reduced to an invariant on pairs of nodes. Each node decides & transmits its decision to a control center. Robustness to Threats, Robustness to nodes destruction: Loss of Performance (in terms of ratio) is least for Distributed Option and highest for Centralized Option and Robustness to observations deletion. All the proposed schemes were analyzed and tested under different topologies and conditions with varying number of nodes .The proposed algorithms for improving the robustness of the wireless Ad Hoc networks using AODV protocol against Packet Dropping Attack, Sequence Number attack and resource consumption attack have been simulated for an illustrative network of about 30 nodes. Our experiments have shown that the pattern extracted through simulation can be used to detect attacks effectively. The patterns could also be applied to detect similar attacks on other protocols.

This work deals with routing protocols for ad hoc wireless networks. First ad hoc networks are introduced. Routing protocols are then classified according to several criteria. Four routing protocols algorithms are described. They are proactive protocols DSDV and CGSR, reactive DSR and hybrid ZRP. Next AODV routing protocol is described in details. Advantages and disadvantages of AODV and two variants of AODV are also introduced. A new protocol is designed based on the disadvantages of the AODV protocol. This work also describes the implementation and integration of the new protocol in the ns-2 simulator. Results of the simulations are presented.