This thesis contains a theoretical basis for MANET networks. The main focus of the thesis is principles of these networks, their routing protocols and especially on Ad hoc On-Demand Distance Vector (AODV), implementation of this protocol and implementation of new mechanis for peer selection. Thesis contains ETX metric basic and implementation of this metric to AODV protocol. There is a demonstration of simulation of AODV protocol and simulation of AODV-ETX protocol. Simulations are run in Network Simulator 3. AODV and AODV-ETX comparasion are included in thesis.

Vehicles are more frequently being built with hardware that supports wireless communica- tion capabilities. Dedicated short-range communications (DSRC) is a standard that enables the hardware on vehicles to communicate with one another directly rather than through external infrastructure such as a cellular tower. With DSRC supporting small-range communications, multi-hop routing is utilized when a packet needs to reach a long-range destination. A vehicular ad-hoc network (VANET) broadcast protocol (VBP) was developed. This thesis introduces VBP, an open-source framework for simulating multi-hop routing on mobile and wireless vehicular networks. VBP is built for the routing layer of the network simulation tool called network simulator 3 (ns-3) and contains a custom protocol that adapts to various traffic conditions on a roadway. To test VBP we ran six simulations across three traffic levels. Results confirm that VBP successfully routes packets or queues packets when a first or next hop is not available. The development process of VBP is documented to help researchers who are trying to create a custom routing protocol for ns-3.

Modéliser et simuler (M&S) un système cyber-physique (SCP) peut nécessiter de représenter des éléments provenant de trois domaines d'expertise à la fois : systèmes physiques, systèmes d'informations et réseaux de communication (IP). Le simulateur universel disposant de toutes les compétences nécessaires n'existant pas, il est possible de regrouper des modèles issus des différentes communautés, à l'aide d'un multi-modèle. Les défis sont alors 1) intégrer toute l'hétérogénéité du multi-modèle (formalismes, représentations, implémentations), 2) intégrer des modèles IP de façon à ce qu'ils soient en capacité de représenter le transport de données applicatives produites par des modèles externes et 3) les intégrer de façon à ce qu'ils puissent se compléter, pour représenter ensemble les réseaux IP parfois hétérogènes d'un SCP. Pour parvenir à répondre à ces défis, nous nous inscrivons dans la continuité des travaux de M&S autour de MECSYCO, une plateforme de co-simulation basée sur la notion de wrapping DEVS. Nous proposons de définir un cadre général pour réussir à wrapper en DEVS des modèles IP, avec 1) une structuration des différents niveaux de problèmes pour l'intégration de modèles IP dans une co-simulation (délimitation des objectifs et contraintes du wrapping), et 2) une proposition de stratégie de wrapping DEVS de modèles IP et leurs simulateurs. Nous évaluerons notre approche à travers la démonstration de l'intégration de deux simulateurs IP populaires, et d'exemples concrets de M&S de SCP (avec notamment une interconnexion de modèles entre NS-3 et OMNeT++/INET, et une application industrielle utilisée par EDF R&D) / Modeling and simulation (M&S) of cyber-physical systems (CPS) can require representing components from three expertise fields: physics, information systems, and communication networks (IP). There is no universal simulator with all of the required skills, but we can gather and interconnect models provided by the communities, with a multi-model. The challenges are 1) integrating all heterogeneities in a multi-model (formalisms, representations, implementations), 2) integrating IP models in a way enabling them to represent the transport of application data produced by external models, and 3) integrating IP models in a way enabling them to complete each other, to be able to represent CPS heterogeneous IP networks. In order to meet these challenges, we relied our solution on the works around MECSYCO, a co-simulation platform based on the DEVS wrapping principle. We propose to define a comprehensive framework enabling to achieve DEVS wrapping of IP models, with 1) a structuration of different issue levels when integrating IP models in a co-simulation (goals and constraints of the wrapping) and 2) a proposition of a DEVS wrapping strategy for IP models and their simulators. We propose some evaluations of our approach, through the integration of two popular IP simulators, and concrete examples of CPS M&S (inter alia, with an example of a models interconnection between NS-3 and OMNeT++/INET, and an industrial application used by EDF R&D)

Le monde des réseaux de capteurs sans fil ‘RCSF’ a connu de grands progrès au cours de ces dernières années. Ainsi, les RCSF ont pu intégrer divers champs d’application (environnement, militaire, médecine, domotique ...) dont quelques-uns ayant des exigences en termes de qualité de service ‘QdS’. Cependant, la garantie de la QdS dans un RCSF pose des problèmes de recherche non triviaux, à cause de la nature peu fiable de la communication sans fil et des limitations des ressources des nœuds RCSF (processeur, mémoire, énergie ...). Dans le cadre de cette thèse, nous nous sommes focalisés sur les protocoles MAC afin d’améliorer le support de QdS dans les RCSF. Plus particulièrement, le standard IEEE 802.15.4. Les mécanismes de conservation d’énergie proposés par ce standard sont efficaces et présentent une flexibilité par rapport aux besoins des applications. Néanmoins, le temps de sommeil des nœuds affecte considérablement le délai de communication, donnant naissance à un compromis énergie/délai. Pour résoudre ce problème, nous avons amélioré ce standard pour un meilleur support des applications temps-réel. L’approche proposée permet de réduire le délai de communication de manière significative, même pour de faibles rapports cycliques, grâce au nouveau format de la supertrame. Les performances ont été validées par simulation et sur des plateformes de nœuds RCSF réelles. Nous avons proposé également un modèle de simulation pour le standard IEEE 802.15.4 sous le simulateur NS-3. / In the last years, Wireless Sensor Networks ‘WSN’ knew a tremendous evolution which attracted many applications. WSN has several characteristics that make it a unique research field, such as, WSN nodes’ constraints and the unreliable (lossy) wireless communication. The IEEE 802.15.4 standard is the first standard designed for this type of networks known as LR-WPANs ‘Low-Rate Wireless Personal Area Network’. The energy conservation mechanism proposed by the current standard is quite efficient and very flexible. This flexibility comes from the ability to configure different duty cycles to meet specific applications’ requirements. However, this mechanism has a considerable impact on the end-to-end delay. Our approach resolves the energy/delay trade-off by avoiding the storage of the real-time data in the coordinator during sleep time, more particularly in Multi-source Multi-sink networks. A new superframe structure is adopted and a deterministic reception scheduling is used. In this thesis, we also proposed a new WPAN model for the Network Simulator 3 ‘NS-3’.

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Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-02T12:36:23Z No. of bitstreams: 1 PedroMaiaDeSantana_DISSERT.pdf: 2069422 bytes, checksum: 1a983f5131609d3cf7fe3bd96b0ef27d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-04T13:34:35Z (GMT) No. of bitstreams: 1 PedroMaiaDeSantana_DISSERT.pdf: 2069422 bytes, checksum: 1a983f5131609d3cf7fe3bd96b0ef27d (MD5) / Made available in DSpace on 2018-04-04T13:34:36Z (GMT). No. of bitstreams: 1 PedroMaiaDeSantana_DISSERT.pdf: 2069422 bytes, checksum: 1a983f5131609d3cf7fe3bd96b0ef27d (MD5) Previous issue date: 2017-12-07 / Este trabalho tem como objetivo realizar um estudo sobre a aplica??o de redes LTE no espectro ISM (Industrial Scientific and Medical) e seu consequente impacto sobre tecnologias comumente coexistentes na mesma faixa de frequ?ncia. Inicialmente, ? realizada uma elucida??o te?rica sobre as regulamenta??es que envolvem o uso de espectro n?o-licenciado. Na sequ?ncia, s?o apresentadas as principais solu??es de coexist?ncia do LTE nesse meio, destacando-se o mecanismo recentemente padronizado pelo 3GPP, o LTE-LBT, e tecnologias espec?ficas de empresas pioneiras na ?rea, tais como a solu??o LTE-DC. Como elemento pr?tico complementar ? investiga??o te?rica inicial, s?o desenvolvidas an?lises de desempenho das respectivas solu??es utilizando o simulador ns-3. A novidade do trabalho ? materializada pela apresenta??o de uma proposta de solu??o para o mecanismo Carrier-Sensing Adaptive Transmission (CSAT). Essa solu??o, baseada em aprendizado de m?quina, visa melhorar o desempenho conjunto dos sistemas que coexistem na faixa ISM. Este trabalho tamb?m prop?e uma solu??o de coexist?ncia do LTE-DC consigo pr?prio a partir de uma abordagem utilizando teoria dos jogos. Essas solu??es s?o comparada com as solu??es cl?ssicas e o seus ganhos s?o evidenciado em cen?rios definidos por ?rg?os de padroniza??o mundial. / This work aims to perform a study about the application of LTE networks in ISM (Industrial Scientific and Medical) spectrum and its impact over technologies that communly coexist in the same frequency range. Initially, it?s made a theoretical elucidation about regulamentations involving the non licensed spectrum usage. In sequence, it?s presented the main LTE coexistence solutions in this field, highlighting the recent mechanism standardized by 3GPP, the LTE-LBT, and specific technologies of pioneering companies in this domain, like LTE-DC solution. As a practical element complementary to the initial theoretical investigation, it?s developed performance analyzes of the respective solutions using ns-3 simulator. The novelty of the work is materialized by the presentation of a solution proposal for the Carrier-Sensing Adaptive Transmission (CSAT). This solution, based on machine learning, aims to improve the joint performance of systems that coexist in the ISM band. This work also propose a solution for LTE-DC self-coexistence by a game theory approach. These solutions are compared to the classical ones and their gains are evidenced in scenarios defined by global standardization institutions.

The recently released High Efficiency Video Coding (HEVC) standard, which halves the transmission bandwidth requirement of encoded video for almost the same quality when compared to H.264/AVC, and the availability of increased network bandwidth (e.g. from 2 Mbps for 3G networks to almost 100 Mbps for 4G/LTE) have led to the proliferation of video streaming services. Based on these major innovations, the prevalence and diversity of video application are set to increase over the coming years. However, the popularity and success of current and future video applications will depend on the perceived quality of experience (QoE) of end users. How to measure or predict the QoE of delivered services becomes an important and inevitable task for both service and network providers. Video quality can be measured either subjectively or objectively. Subjective quality measurement is the most reliable method of determining the quality of multimedia applications because of its direct link to users’ experience. However, this approach is time consuming and expensive and hence the need for an objective method that can produce results that are comparable with those of subjective testing. In general, video quality is impacted by impairments caused by the encoder and the transmission network. However, videos encoded and transmitted over an error-prone network have different quality measurements even under the same encoder setting and network quality of service (NQoS). This indicates that, in addition to encoder settings and network impairment, there may be other key parameters that impact video quality. In this project, it is hypothesised that video content type is one of the key parameters that may impact the quality of streamed videos. Based on this assertion, parameters related to video content type are extracted and used to develop a single metric that quantifies the content type of different video sequences. The proposed content type metric is then used together with encoding parameter settings and NQoS to develop content-based video quality models that estimate the quality of different video sequences delivered over IP-based network. This project led to the following main contributions: (1) A new metric for quantifying video content type based on the spatiotemporal features extracted from the encoded bitstream. (2) The development of novel subjective test approach for video streaming services. (3) New content-based video quality prediction models for predicting the QoE of video sequences delivered over IP-based networks. The models have been evaluated using subjective and objective methods.

The aim of the diploma thesis is to choose network simulator suitable for network technologies laboratory tasks for educational use. Theoretical part of thesis describes basics of network communication, addressing, reference models. Thesis also describes standards Wi Fi, Ethernet and routing protocol OSPF - technologies which are discussed in laboratory tasks. The practical part of diploma thesis describes a few available network simulators suitable for creating two laboratory tasks. Finally, the NS-3 simulator was chosen. Both laboratory tasks include theoretical introduction, detailed description of source code, individual tasks, expected outputs and control questions which senses understanding of discussed technologies.

Diploma thesis deals with creation of laboratory exercises in ns-3 environment. Each one of three exercises consists of theoretical introduction and instructions to carry out the simulation. The first exercise´s topic is routing protocol BGP. The second exercise is focused on transport protocols TCP, UDP, SCTP. In the last exercise, the basic network devices and topologies are simulated. The ARP and RIPv2 protocols are simulated as well.

This diploma thesis focuses on the preparation of an operating system, a simulation environment and the creation of two laboratory exercises explaining network technologies. In the theoretical part protocols DHCP, FTP, TFTP, HTTP, and NAT service are described. The practical part focuses on the installation of ns-3 and GNS3 programmes and their utilization and settings on OS Ubuntu 18.10. Moreover, it deals with the preparation of laboratory exercises created in the simulation programmes mentioned above together with tutorials, self-check questions and HTTP server in the Python programming language.