Les réseaux sans fil sont devenus une technologie importante dans le secteur des télécommunications. L'une des principales technologies des réseaux sans fil sont les réseaux mobiles ad hoc (MANET). MANET est un système d'auto-configuration (autonome) des routeurs mobiles où les routeurs sont libres de se déplacer de façon aléatoire et de s'organiser arbitrairement. La topologie des réseaux sans fil peut alors changer rapidement et de manière imprévisible avec une grande mobilité et sans aucune infrastructure fixe et sans administration centrale. Les protocoles de routage MANET sont Ad Hoc on Demand Distance Vector (AODV), Optimized Link State Routing (OLSR), Topology Dissemination Based on Reverse-Path Forwarding (TBRPF) et Dynamic Source Routing (DSR).En raison des caractéristiques des réseaux mobiles ad hoc, les principaux problèmes concernent la sécurité, les performances du réseau et de la qualité de service. En termes de performances, AODV offre de meilleures performances que les autres protocoles de routage MANET. Cette thèse porte donc sur le développement d'un protocole sécurisé et sur l'acheminement optimisé basé sur le protocole de routage AODV. Dans la première partie, nous combinons la fonction de gateway de AODV + et la méthode reverse de R-AODV pour obtenir le protocole optimisé en réseau hybride. Le protocole proposé appelé AODV-UI. Mécanisme de demande inverse dans R-AODV est utilisé pour optimiser le rendement du protocole de routage AODV et le module de passerelle de AODV + est ajouté à communiquer avec le noeud d'infrastructure. Nous effectuons la simulation en utilisant NS-2 pour évaluer la performance de AODV-UI. Paramètres d'évaluation de la performance sont le taux de livraison de paquets de bout en bout retard et les frais généraux de routage. Les résultats des simulations montrent que AODV-UI surperformé AODV + en terme de performance.La consommation d'énergie et les performances sont évaluées dans les scénarios de simulation avec un nombre différent de noeuds source, la vitesse maximale différente, et également des modèles de mobilité différents. Nous comparons ces scénarios sous Random Waypoint (RWP) et Reference Point Group Mobility (RPGM) modèles. Le résultat de la simulation montre que sous le modèle de mobilité RWP, AODV-UI consommer petite énergie lorsque la vitesse et le nombre de nœuds accéder à la passerelle sont augmentés. La comparaison des performances lors de l'utilisation des modèles de mobilité différents montre que AODV-UI a une meilleure performance lors de l'utilisation modèle de mobilité RWP. Globalement, le AODV-UI est plus appropriée pour l'utilisation de modèle de mobilité RWP.Dans la deuxième partie, nous proposons un nouveau protocole AODV sécurisé appelé Trust AODV en utilisant le mécanisme de la confiance. Les paquets de communication sont envoyés uniquement aux nœuds voisins de confiance. Calcul de confiance est basée sur les comportements et les activités d'information de chaque nœud. Il est divisé en Trust Global (TG) et Trust Local (TL). TG est un calcul de confiance basée sur le total de paquets de routage reçues et le total de l'envoi de paquets de routage. TL est une comparaison entre les paquets reçus au total et nombre total de paquets transmis par nœud voisin de nœuds spécifiques. Noeuds concluent le niveau de confiance totale de ses voisins en accumulant les valeurs TL et TG. Quand un noeud est soupçonné d'être un attaquant, le mécanisme de sécurité sera l'isoler du réseau avant que la communication est établie. [...] / Currently wireless networks have grown significantly in the field of telecommunication networks. Wireless networks have the main characteristic of providing access of information without considering the geographical and the topological attributes of a user. One of the most popular wireless network technologies is mobile ad hoc networks (MANET). A MANET is a decentralized, self-organizing and infrastructure-less network. Every node acts as a router for establishing the communication between nodes over wireless links. Since there is no administrative node to control the network, every node participating in the network is responsible for the reliable operation of the whole network. Nodes forward the communication packets between each other to find or establish the communication route. As in all networks, MANET is managed and become functional with the use of routing protocols. Some of MANET routing protocol are Ad Hoc on Demand Distance Vector (AODV), Optimized Link State Routing (OLSR), Topology Dissemination Based on Reverse-Path Forwarding (TBRPF), and Dynamic Source Routing (DSR).Due to the unique characteristics of mobile ad hoc networks, the major issues to design the routing protocol are a security aspect and network performance. In term of performance, AODV has better performance than other MANET routing protocols. In term of security, secure routing protocol is divided in two categories based on the security method, i.e. cryptographic mechanism and trust based mechanism. We choose trust mechanism to secure the protocol because it has a better performance rather than cryptography method.In the first part, we combine the gateway feature of AODV+ and reverse method from R-AODV to get the optimized protocol in hybrid network. The proposed protocol called AODV-UI. Reverse request mechanism in R-AODV is employed to optimize the performance of AODV routing protocol and gateway module from AODV+ is added to communicate with infrastructure node. We perform the simulation using NS-2 to evaluate the performance of AODV-UI. Performance evaluation parameters are packet delivery rate, end to end delay and routing overhead. Simulation results show that AODV-UI outperformed AODV+ in term of performance. The energy consumption and performance are evaluated in simulation scenarios with different number of source nodes, different maximum speed, and also different mobility models. We compare these scenarios under Random Waypoint (RWP) and Reference Point Group Mobility (RPGM) models. The simulation result shows that under RWP mobility model, AODV-UI consume small energy when the speed and number of nodes access the gateway are increased. The performance comparison when using different mobility models shows that AODV-UI has a better performance when using RWP mobility model. Overall the AODV-UI is more suitable when using RWP mobility model.In the second part, we propose a new secure AODV protocol called Trust AODV using trust mechanism. Communication packets are only sent to the trusted neighbor nodes. Trust calculation is based on the behaviors and activities information’s of each node. It is divided in to Trust Global and Trust Local. Trust global (TG) is a trust calculation based on the total of received routing packets and the total of sending routing packets. Trust local (TL) is a comparison between total received packets and total forwarded packets by neighbor node from specific nodes. Nodes conclude the total trust level of its neighbors by accumulating the TL and TG values. When a node is suspected as an attacker, the security mechanism will isolate it from the network before communication is established. 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Mobilūs Ad-Hoc tinklai yra labai naudingi įvairiose situacijose, tačiau jų realizacijose vis dar neišspręsta daug problemų ir viena iš didžiausių problemų yra saugumas. Maršrutizavimui reikalingi specialiai suprojektuoti maršruto protokolai ir jie yra gana gerai išvystyti, išskyrus saugumo sritį. Darbe aš labiausiai telkiau dėmesį į įvairias aktyvias atakas prieš ad hoc tinklą, vykdomas iškreipiant maršruto parinkimo procesą ir kompromituojant tinklo paslaugų prieinamumą, duomenų vientisumą ir konfidencialumą, o labiausiai į saugaus maršruto parinkimo protokolų, kurie gali būti naudojami siekiant išvengti šių pavojų, analizę. Naujos koncepcijos saugaus maršruto parinkimo protokolas siūlomas, kaip konkretaus atvejo - iš tiesų didelio kenkiančių mazgų kiekio tinkle sprendimas ir sukurtas nesaugaus ad hoc tinklo modelis, kuris naudojamas siekiant imituoti, gauti ir palyginti keleto saugaus maršruto parinkimo protokolų rodiklius. / Mobile Ad-Hoc networks are very useful in certain situations, but raise many challenges and one of the biggest is security. Specially designed routing protocols are required and they are quite well developed except for security area. In this thesis I concentrate on various active attacks on ad-hoc network during routing process, compromising network availability, data integrity and confidentiality and analyze some security aware protocols, that can be used to avoid these risks. New concept routing protocol is proposed, for coping with a specific scenario of really high level of malicious nodes on the network and insecure network model is created, which is used to simulate, get and compare performance metrics of some security aware routing protocols.

Satisfactory results obtained from sensor networks and the ongoing development in electronics and wireless communications have led to an impressive boost in the number of applications based on WSNs. Along with the growth in popularity of WSNs, previously implemented solutions need further improvements and new challenges arise which need to be solved. One of the main concerns regarding WSNs is the existence of security threats against their routing operations. Likelihood of security attacks in a structure suffering from resource constraints makes it an important task to choose proper security mechanisms for the routing decisions in various types of WSN applications. The main purpose of this study is to survey WSNs, routing protocols, security attacks against routing layer of a WSN, introduction of Trust based models which are an effective defense mechanism against security attacks in WSNs and finally, to implement a proposed Trust based routing protocol in order to overcome security attacks. The study begins with a survey of Sensor Networks, after the introduction of WSNs and their related routing protocols, the issue of security attacks against the network layer of a Sensor Network is described with a presentation of different types of attacks and some of Trust based related works. In the final chapters of this research, a novel Trust based AODV protocol will be proposed, implemented and examined in a simulation environment. For this purpose, multiple number of scenarios will be simulated on the AODV protocol with and without Trust mechanism, then the achieved results will be compared to derive a conclusion.

Satisfactory results obtained from sensor networks and the ongoing development in electronics and wireless communications have led to an impressive boost in the number of applications based on WSNs. Along with the growth in popularity of WSNs, previously implemented solutions need further improvements and new challenges arise which need to be solved. One of the main concerns regarding WSNs is the existence of security threats against their routing operations. Likelihood of security attacks in a structure suffering from resource constraints makes it an important task to choose proper security mechanisms for the routing decisions in various types of WSN applications. The main purpose of this study is to survey WSNs, routing protocols, security attacks against routing layer of a WSN, introduction of Trust based models which are an effective defense mechanism against security attacks in WSNs and finally, to implement a proposed Trust based routing protocol in order to overcome security attacks. The study begins with a survey of Sensor Networks, after the introduction of WSNs and their related routing protocols, the issue of security attacks against the network layer of a Sensor Network is described with a presentation of different types of attacks and some of Trust based related works. In the final chapters of this research, a novel Trust based AODV protocol will be proposed, implemented and examined in a simulation environment. For this purpose, multiple number of scenarios will be simulated on the AODV protocol with and without Trust mechanism, then the achieved results will be compared to derive a conclusion.

Enhancing route request broadcasting protocols constitutes a substantial part of research in mobile ad hoc network routing. In the thesis, enhancements of ad hoc routing protocols, energy efficiency metrics and clustered topology generators are discussed. The contributions include the followings. First, a node caching enhancement of Ad-hoc On-demand Distance Vector (AODV) routing protocol is introduced. Extensive simulation studies of the enhanced AODV in NS2 shows up to 9-fold reduction in the routing overhead, up to 20% improvement in the packet delivery ratio and up to 60% reduction in the end-to-end delay. The largest improvement happens to highly stressed situations. Secondly, new metrics for evaluating energy efficiency of routing protocols are suggested. New node cached AODV protocols employing non-adaptive and adaptive load balancing techniques were proposed for extending network lifetime and increasing network throughput. Finally, the impact of node clustered topology on ad hoc network is explored. A novel method for generating clustered layout in NS2 is introduced and experiments indicate performance degradation of AODV protocols for the case of two clusters.

Each day, the dream of seamless networking and connectivity everywhere is getting closer to become a reality. In this regard, mobile Ad-Hoc networks (MANETs) have been a hot topic in the last decade; but the amount of MANET usage nowadays confines to a tiny percentage of all our network connectivity in our everyday life, which connectivity through infrastructured networks has the major share. On the other hand, we know that future of networking belongs to Ad-Hocing , so for now we try to give our everyday infrastructure network a taste of Ad-Hocing ability; these types of networks are called Wireless Mesh Networks (WMN) and routing features play a vital role in their functionality. In this thesis we examine the functionality of 3 Ad-Hoc routing protocols known as AODV, OLSR and GRP using simulation method in OPNET17.5. For this goal we set up 4 different scenarios to examine the performance of these routing protocols; these scenarios vary from each other in amount of nodes, background traffic and mobility of the nodes. Performance measurements of these protocols are done by network throughput, end-end delay of the transmitted packets and packet loss ratio as our performance metrics. After the simulation run and gathering the results we study them in a comparative view, first based on each scenario and then based on each protocol. For conclusion, as former studies suggest AODV, OLSR and DRP are among the best routing protocols for WMNs, so in this research we don’t introduce the best RP based on the obtained functionality results, instead we discuss the network conditions that each of these protocols show their best functionality in them and suggest the best routing mechanism for different networks based on the analysis from the former part.

This dissertation endeavors to contribute enhancements in goodputsof the IEEE 802.11-based Wireless Multi-hop Networks (WMhNs).By performing exhaustive simulations, for the deep analysis and detailed assessment of both reactive (AODV, DSR, DYMO) and proactive (DSDV, FSR, OLSR) protocols for varying mobilities, speeds, network loads and scalabilities, it is observed that a routing link metric is a significant component of a routing protocol. In addition to finding all available paths, the fastest end-to-end route is selected by a link metric for the routing protocol. This study aims the quality routing. In the class of quality link metrics, Expected Transmission Count (ETX) is extensively used. Thus, the most recently proposed ETX-based metrics have been analyzed. Though, newly developed metrics over perform ETX but still they can be improved. By profound analysis and particularized comparison of routing protocols depending upon their classes (reactive and proactive) and ETX-based metrics, we come to realize that users always demand proficient networks. In fact, WMhNs are facing several troubles which they expect to be resolved by the routing protocol operating them. Consequently, the protocol depends upon the link metric for providing quality paths. So, we identify and analyze the requirements to design a new routing link metric for WMhNs. Because, considering these requirements, when a link metric is proposed, then : firstly, both the design and implementation of the link metric with a routing protocol become easy. Secondly, the underlying network issues can easily be tackled. Thirdly, an appreciable performance of the network is guaranteed. Keeping in view the issues of WMhNs, increasing demands of users and capabilities of routing protocols, we propose and implement a new quality link metric, Interference and Bandwidth Adjusted ETX (IBETX). As, MAC layer affects the link performance and consequently the route quality, the metric therefore, tackles the issue by achieving twofold MAC-awareness. Firstly, interference is calculated using cross-layered approach by sending probes to MAC layer. Secondly, the nominal bit rate information is provided to all nodes in the same contention domain by considering the bandwidth sharing mechanism of 802.11. Like ETX, our metric also calculates link delivery ratios that directly affect throughput and selects those routes that bypass dense regions in the network. Simulation results by NS-2 show that IBETX gives 19% higher through put than ETX and 10% higher than Expected Throughput (ETP). Our metric also succeeds to reduce average end-to-end delay up to 16% less than Expected Link Performance (ELP) and 24% less than ETX

A mobile ad hoc network (MANET) consists of mobile wireless nodes. The communication between these mobile nodes is carried out without any centralized control. MANET is a self organized and self configurable network where the mobile nodes move arbitrarily. The mobile nodes can receive and forward packets as a router. Routing is a critical issue in MANET and hence the focus of this thesis along with the performance analysis of routing protocols. We compared three routing protocols i.e. AODV, DSR and OLSR. Our simulation tool will be OPNET modeler. The performance of these routing protocols is analyzed by three metrics: delay, network load and throughput. All the three routing protocols are explained in a deep way with metrics. The comparison analysis will be carrying out about these protocols and in the last the conclusion will be presented, that which routing protocol is the best one for mobile ad hoc networks. / In all the three scenarios of small, large and very large networks OLSR gives considerably less delay and high throughput as compared to AODV and DSR. OLSR outperforms AODV and DSR with prominent difference in delay and throughput. While the AODV puts low load on the network in large and very large networks. OLSR outperforms in our study, but it is not necessary that OLSR always perform better in all the networks, its performance may vary by varying the network. / sajj_ali2003@yahoo.com, asad322@gmail.com

AODV (Ad hoc On-demand Distance Vector routing), DSDV (Destination-Sequenced Distance-Vector routing), DSR (Dynamic Source Routing), and OLSR (Optimized Link State Routing protocol) are protocols used for routing management in ad-hoc networks. In a specific sensor data network application, nodes need information about the network topology, i.e. the network nodes and the connections between them. OLSR provides nodes with this information, while the three other protocols do not. This thesis investigates how OLSR compares to AODV, DSDV,and DSR in a low bandwidth network scenario. Two cases were analyzed: One where AODV, DSDV, and DSR distribute topology information in the application layer and one where they do not. The sensor data application was not finished when this thesis project started. Instead, a simplified traffic model of the application was used. In addition to a protocol comparison, this thesis investigates if traffic generated from the model results in high rates of packet loss, assuming low bandwidth conditions. The ns-3 network simulator was used for these investigations. This thesis shows that AODV outperforms the three other protocols regardless of whether AODV, DSDV, and DSR distribute topology information in the application layer or not. Furthermore, it is shown that running the traffic model in the low bandwidth environment is not possible without high rates of packet loss.

There is a big number of people dying every year from car accidents and not solving this problem is a big issue. Communication protocols have been created in mobile ad-hoc network (MANET) to be able to solve this issue. AODV and DSR are two protocols that are used in this communication. The fact that there is mobile nodes makes it hard to keep track of the efficiency of this communication. This study has for objective giving a better understanding as to which protocol performs better and answering four important questions to know to be able to evaluate what protocol is better according to those parameters or criteria. The implemented method to solve this problem is through a meta-analysis and this meta-analysis is done through a qualitative research, literature review for critical literature reading and data collection to select the appropriate studies and exclud- ing the irrelevant studies based on other criteria. The evaluation of these param- eters are based on others’ work and reading the work from critical eyes. This study compares AODV and DSR from the criteria that are chosen. The study has a critical analysis of the results collected through the different papers show that AODV has outperformed DSR in most of the cases and answering the proposed questions in the study. Finally concluding that AODV is more effective in the case of high congestion compared to DSR but making a bit hard to have a clear cut answer when it comes to the criteria but AODV performed better in all the cases in high congestion.