The simulation of mobile networks relies on a reliable movement generation. Random movement patterns are frequently used in simulators. In this report, the performance of the popular setdest movement generator, which is built into the ns2 open source simulator, is investigated using two statistical tests: quadrat count test and the variance to mean ratio (VMR) test. The results show a non-uniform distribution of nodes during the simulation with a bias towards placing the nodes in the center of the simulated area. We propose and implement a di erent method for random movement generation in the ns2 simulator and show that our movement generator improves the randomness of the node distribution during the simulation. The new generator was successfully tested with the ns2 simulator.

With the rapid development in the areas of mobile manufacturing and multimedia communications, there is an increasing demand for Networked Virtual Environment (NVE) applications, such as Augmented Reality (AR), virtual walk-throughs, and massively multiplayer online games (MMOGs), on hand-held devices. Unfortunately, downloading and rendering a complex 3D scene is very computationally intensive and is not compatible with current mobile hardware specifications nor with available wireless bandwidth. Existing NVE applications deploy client/server based 3D streaming over thin mobile devices, which suffer from single point of failure, latency, and scalability issues. To address these issues, image-based rendering (IBR) and cloud-based 3D streaming have been introduced. The former introduces visual artifacts that reduce, and usually cancel, the realistic behaviors of the Virtual Environment (VE) application, while the latter is considered very expensive to implement. Peer-to-peer (P2P) 3D streaming is promising and affordable, but it has to tackle issues in object discovery and selection as well as content provider strategies. Distributing VE content over a mobile ad-hoc network (MANET) makes the system difficult to update due to the dynamic nature of the mobile clients. In order to tackle these issues, we came up with a novel protocol that combines the pros of both central and distributed approaches. Our proposed hybrid protocol, called OCTET, enables 3D scene streaming over thin devices in a way that can cope with current mobile hardware capabilities and mitigate the challenges of client/server and P2P 3D streaming. In fact, OCTET provides strategies that select, prioritize, and deliver only those objects that contribute to the user’s visible scene. OCTET is implemented using the "ns-2" simulation environment, and extensive experiments have clearly demonstrated significant achievements in mobile resource utilization, throughput, and system scalability.

Made available in DSpace on 2014-06-12T15:57:34Z (GMT). No. of bitstreams: 2 arquivo3208_1.pdf: 2070521 bytes, checksum: e116b054c78a9f150df6289d879355a2 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Rede Móvel Ad Hoc (MANET) é uma rede sem fio onde os nós podem se mover livremente e formar, dinamicamente, topologias de rede temporárias e arbitrárias sem qualquer controle centralizado ou infra-estrutura de comunicação estabelecida previamente. Nestas redes, os nós agem de maneira cooperativa, encaminhando pacotes uns aos outros, de forma a possibilitar a comunicação entre pares de nós que se encontram fora do alcance direto de transmissão sem fio. Nos últimos anos, as pesquisas direcionadas à MANETs têm recebido grande atenção do governo, academia e indústria. Contudo, ainda existem algumas questões em aberto relativas à implantação de MANETs que impedem o desenvolvimento de aplicações reais e difusão das mesmas. O avanço das pesquisas nesta área poderia melhorar o desempenho atual no uso destas redes, bem como propiciar o surgimento de novos campos de aplicação. Além disso, ainda existe um grande potencial econômico a ser explorado no que se refere ao uso de redes móveis ad hoc. Um dos principais desafios relativos à implantação de MANETs é a configuração adequada dos endereços de rede. Tais endereços precisam ser únicos dentro do mesmo domínio de roteamento, ou em outras palavras, um MANET não deve conter dois dispositivos configurados com o mesmo endereço de rede. A configuração estática dos nós ad hoc não é viável devido à natureza dinâmica destas redes, e esquemas tradicionais desenvolvidos para as redes infraestruturadas não são adequados. Estas questões motivaram algumas pesquisas destinadas à permitir que os nós se configurarem sem intervenção humana, resultando em uma série de métodos para configuração automática de endereços. Estas soluções, no entanto, apresentam uma série de limitações, relacionadas principalmente à aplicabilidade em cenários restritos ou introdução elevada de sobrecarga na rede. Este trabalho apresenta um método escalável e eficiente para alocação e organização do espaço de endereçamento em redes móveis ad hoc. Uma revisão bibliográfica dos trabalhos existentes é apresentada, considerando as vantagens e limitações de cada um. Por fim, o trabalho apresenta uma avaliação preliminar do método proposto, considerando diferentes cenários e métricas

Made available in DSpace on 2014-06-12T15:58:24Z (GMT). No. of bitstreams: 2 arquivo4095_1.pdf: 1892388 bytes, checksum: 36bca1d45a0d20795951c6d7db402746 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / A popularidade de dispositivos móveis como meio de comunicação tem crescido nos últimos anos devido à facilidade de uso, custo e as mais variadas tecnologias. O aumento no número dessas opções como WiFi, Bluetooth ou até mesmo rede de telefonia móvel permitem uma maior conectividade desses dispositivos móveis na rede. Determinadas tarefas, como compartilhamento de stream de vídeo, implicam diferentes requisitos, o que pode requerer diferentes tecnologias de rede. Nos cenários de emergência, que incluem operações militares, força-tarefa para desastres e grupos de busca e resgate, onde se pressupõe a ausência de infraestrutura, o uso de redes sem fio e a permanente conectividade podem ser requisitos essenciais para realização de algumas tarefas. Para tanto o uso de um protocolo de roteamento que seja adequado a esse ambiente é de fundamental importância. Este trabalho faz um estudo comparativo de um novo protocolo de roteamento para redes heterogêneas ad hoc, chamado Heterogeneous Routing Protocol ou simplesmente HTR, focado em cenários de emergência, com um dos protocolos de roteamento para redes ad hoc mais usado, o OLSR. A fim de fazer uma análise robusta e escalável, o protocolo HTR foi implementado no simulador NS-3 e comparado ao OLSR através de métricas como taxa de entrega, atraso, pacotes perdidos, entre outros

Vehicular Ad Hoc Network (VANET) is a sub class of mobile ad hoc networks. VANET provides wireless communication among vehicles and vehicle to road side equipments. The communication between vehicles is used for safety, comfort and for entertainment as well. The performance of communication depends on how better the routing takes place in the network. Routing of data depends on the routing protocols being used in network. In this study we investigated about different ad hoc routing protocols for VANET. The main aim of our study was to identify which ad hoc routing method has better performance in highly mobile environment of VANET. To measure the performance of routing protocols in VANET, we considered two different scenarios i.e. city and highway. Routing protocols were selected carefully after carrying out literature review. The selected protocols were then evaluated through simulation in terms of performance metrics i.e. throughput and packet drop. After simulation results, we used MATLAB to plot the graph to compare the results of selected routing protocols with each other. Moreover, we computed the sum of output from each scenario to clearly present the difference in results. From results, we observe that A-STAR shows better performance in form of high throughput and low packet drop as compare to AODV and GPSR in city environment, while GPSR shows better performance as compare to AODV in both highway and city environment of VANET. Based on the results of performance metrics in different environments of VANET, we realized that position based routing method of VANET outperformed the traditional ad hoc topology based routing. However, it is hard to provide any universal routing protocol that can deal with all the various environments of VANET. The selection of a single routing protocol is hard in VANET because the protocol performance depends on vehicle speed, driving environment etc. That may vary from one environment of network to another.

Now a day, it is no longer optional to have security solutions even inevitable for every kind of organizations and individuals. There are number of generic tools which are common for organizations as well as for individual users to provide security which includes; Anti-Spam, Anti-Virus etc., and network security have become essential issue in MANET. Security is one of the main issues in the MANET especially with respect to size and complexity of the network. The aim of the thesis is to discuss different aspects of security in MANET (e.g. multi-layer intrusion detection technique in multi hop network of MANET, security problems relates between multihop network and mobile nodes in MANET etc) and also implement some of the solutions (e.g. comparative study of different routing protocol (AODV, DSR and TORA) security threats within MANET network like intruder behavior, tapping and integrity, MANET link layer and network layer operations with respect to information security etc) with respect to MANET network. This report also discusses different number of scenarios of MANET network which we implement in our simulation. In our simulation we use to implement different routing protocols and also did comparative study that which one is better with respect to different aspects. We also use to implements mechanisms of intruder behavior, tapping and integrity, and MANET link layer and network layer operations with respect to information security.

A Mobile Ad hoc Network (MANET) consists of a set of communicating wireless mobile nodes or devices that do not have any form of fixed infrastructure or centralized authority. The security in MANET has become a significant and active topic within the research community. This is because of high demand in sharing streaming video and audio in various applications, one MANET could be setup quickly to facilitate communications in a hostile environment such as battlefield or emergency situation likes disaster rescue operation. In spite of the several attacks aimed at specific nodes in MANET that have been uncovered, some attacks involving multiple nodes still receive little attention. A reason behind this is because people make use of security mechanisms applicable to wired networks in MANET and overlook the security measures that apply to MANET. Furthermore, it may also have to do with the fact that no survey or taxonomy has been done to clarify the characteristics of different multiple node attacks. This thesis addresses the aforementioned gap by providing a proper definition and categorization of collaborative attacks against MANET from the various multiple node attacks found. Simulation using OPNET Modeler was used to investigate the performance impact of a collaborative blackhole attack on a mobile ad hoc network. Network throughput, packet delivery ratio and end-to-end delay are the performance metrics used in our result analysis. Based on the analyses of performance metrics made, we realised the consequences of a collaborative blackhole attack on MANET. In order to prevent or reduce these consequences, we also discuss a number of mitigation plans to counteract the different kinds of collaborative attacks. Keywords: MANET, Collaborative Attacks, Multiple Node, Blackhole. / Contact Information: Author(s): Cong Hoan Vu Address: Folkparksvägen 19:08, 372 40 Ronneby, Sweden. E-mail: vuconghoan@gmail.com Adeyinka Soneye Address: Polhemsgatan 27B, LGH 30, 371 40 Karlskrona, Sweden. E-mail: adso07@student.bth.se

The use of mobile ad-hoc networks (MANETs) is growing. The issue of security in MANETs is not trivial, since such networks have no fixed infrastructure and therefor centralised security is not applicable. MANETs are also more sensitive to attacks due to their wireless communication channels and their spontaneous nature. All kind of cooperation requires a sense of trust. The opinion about trust in other entities can be used as a mean to dynamically allow for secure cooperation in MANETs, as soft security. And also to counter some of the inherited security problems of MANETs. To use opinions as a security paradigm in MANETs the opinions about other nodes has to be spread as reputation about a node. This reputation spreading can be done through spreading of opinions or the spreading of evidences about a nodes behaviour. In this work evidence and reputation spreading are compared to each other. This comparison shows that they are quite similar from a security point of view but that they differ in scalability.

No description available.

Dans un contexte de besoins croissants de moyens de communication pour augmenter la sécurité des vols et répondre aux attentes des compagnies et des passagers, le monde de l'aviation civile cherche de nouveaux systémes de communication pouvant répondre à ces objectifs. Les réseaux ad-hoc aéronautiques, AANET (Aeronautical Ad hoc NETworks) représentent une approche innovante pour répondre à cette problématique. Il s'agit de réseaux auto-configurés, n'utilisant pas d'infrastructure fixe et dont la spécificité réside dans le fait que les nfiuds composant le réseau sont des avions commerciaux. Les AANET peuvent être vus comme un sous ensemble des VANET (Vehicular Ad-Hoc Networks) puisqu'ils partagent de nombreuses caractéristiques comme les contraintes imposées sur les trajectoires. Afin d'utiliser le plus eficacement ces réseaux mobiles tout en répondant aux besoins de nouvelles applications, telle que l'information météorologique temps réel sur des phénoménes dangereux, qui nécessitent des communications d'avion à avion, la proposition avancée dans cette thése est d'utiliser le paradigme du routage basé sur le contenu au dessus des AANET. Dans ce type de routage, ce n'est plus une adresse de destination qui est utilisée pour joindre le ou les correspondants, mais le contenu du message qui permet de décider des destinataires. Dans ce paradigme, un émetteur envoi un message possédant des attributs et le message est alors transmis par le réseau uniquement aux terminaux intéressés par le contenu du message. Appliqué à l'information météorologique, cette approche permet à un aéronef détectant un phénoméne dangereux tel qu'un orage de prévenir uniquement les avions intéressés par cet événement, c'est à dire ceux dont la trajectoire passe prés de l'orage dans le temps de vie du phénoméne. Dans cette thése, nous avons choisi de nous appuyer sur le paradigme populaire de publication/souscription (P/S) pour fournir un service de routage basé sur le contenu. Dans cette approche, des éditeurs publient des événements et des nfiuds envoient des abonnements pour déclarer les contenus qui les intéressent au systéme qui est alors en charge de leur faire suivre les événements répondant à leur demande. Aprés un état de l'art sur les systémes P/S existants, notamment ceux adaptés aux VANET, nous avons choisi de tester des solutions paraissant intéressantes dans un contexte AANET. Pour cela, nous avons développé sous Omnet++ un module de mobilité utilisant des reports de position réels afin de rejouer des journées complétes de trafic d'avions réels, ainsi que plusieurs applications aéronautiques s'appuyant sur un systéme P/S permettant de générer des données réalistes. Les résultats montrent que ces solutions ne sont pas complétement adaptées pour un contexte AANET. C'est pourquoi, dans un second temps, nous avons proposé un nouveau systéme P/S pour les AANET. Cette solution s'appuie sur une architecture recouvrante ("overlay network") construite à l'aide d'un algorithme original de regroupement à 1-saut (1-hop clusterisation) adapté aux AANET. Afin de favoriser la stabilité de l'architecture recouvrante, cet algorithme s'appuie sur le nombre de voisins et la mobilité relative entre les nfiuds voisins pour définir les groupes. Les tests réalisés montrent que le systéme P/S s'appuyant sur cette surcouche ofire de meilleurs résultats que les solutions testées précédemment, que ce soit en termes de charge réseau ou de pourcentage d'événements délivrés. / In a context of growing needs of communication means to increase ight safety and meet the expectations of companies and passengers, the world of civil aviation seeks new communication systems that can meet these objectives. The Aeronautical Ad-Hoc Networks, AANETs represent an innovative approach to address this problem. It is self-configured networks, using no fixed infrastructure where the nodes are commercial aircraft. The AANETs can be seen as a subset of the VANET (Vehicular Ad-Hoc Networks) since they share many features as the constraints imposed on the trajectories. In order to use these mobile networks more eficiently while meeting the needs of new applications, such as the transmission of weather information in real time, requiring air to air communications. , we propose in this thesis to use the paradigm of content based routing above AANET. In this kind of routing, it is not a destination address that is used to identify the recipients, but the message content itself. In this paradigm, a transmitter sends a message having attributes and the message is then transmitted by the network to nodes interested by the content of the message. Applied to weather information update, this approach allows an aircraft detecting a dangerous phenomenon such as a thunderstorm to only prevent interested nodes, ie those whose the trajectorycome close to the storm during the lifetime of the event. In this thesis, we have chosen to rely on the popular Publish / Subscribe (P/S) paradigm to provide a content based routing service. In this approach, publishers publish events. On the other side, nodes send subscriptions to declare their interest and the system is then in charge of forward events to nodes that match their needs. After a state of the art about existing P / S systems, particularly those adapted to VANETs, we choose to test the solutions seemed interesting in a AANET context. To accomplish this, we have developed as a Omnet ++ mobility model using real position reports to replay a full day of trafic of aircraft and several aeronautical applications based on a P / S system to generate realistic data. The results show that these solutions are not completely suitable for AANET context. Therefore, in a second step, we proposed a new P / S system which is more eficient on a AANET. This solution is based on an overlay network built thanks to a new of 1-hopping clustering algorithm suitable for AANET. In order to increase the stability of the overlay architecture, this algorithm is based on the number of neighbors and the relative mobility between the nodes to define groups. The tests show that the P/S system based on this overlay provides better results than the previously tested solutions, whether in terms of network load or percentage of transmitted events.