Το έγγραφο είναι μια έρευνα του υποσυστήματος πολυμέσων διαδικτυακού πρωτοκόλλου και μια υλοποιήση ενός περιβάλλοντος προσομοίωσης, γνωστό ως testbed, που βασίζεται σε αυτό το πρωτόκολλο. Στην αρχή γίνεται μια εισαγωγή στην έννοια του IMS. Στο δεύτερο κεφάλαιο, περιγράφουμε τη γενική αρχιτεκτονική του IMS. Στο τρίτο κεφάλαιο, υπάρχει αναφορά στο επίπεδο σηματοδοσίας και όλα τα στοιχεία του. Στο τέταρτο κεφάλαιο περιγράφουμε τις υπηρεσίες που παρέχει το IMS και την αρχιτεκτονική του Open IMS Core που αποτελεί το περιβάλλον προσομοίωσής μας. Τέλος, αναλύουμε τα βήματα με σκοπό να εγκαταστήσουμε τον Open IMS Core ρησιμοποιώντας το λειτουργικό σύστημα Linux. / The script is a research of the Internet Protocol Multimedia Subsystem (IMS) and an implementation of a simulation environment, known as testbed and based on this protocol. In the beginning, there is an introduction to the meaning of IMS.In chapter two, we describe the general architecture of IMS. In chapter three, there is a reference to the signalling level and all of its elements. In chapter four we describe the services that IMS provides and the architecture of the Open IMS Core which is our simulation environment. Finally, we analyse the steps in order to install Open Ims Core using Linux operating system.

With the fast adoption of LTE and IEEE 802.11N, more devices are employing multiple antennas to boost the data rate and reliability of the communication link. Traditionally, fixed antennas are used in such devices. In recent years, reconfigurable antennas have been sought out to further boost the performance, which can adaptor to the changing wireless channel by altering their radiation characteristics, and maintain or exceed the performance of fixed antennas. This thesis studies the possibility of performance increase using pattern reconfigurable antennas as receivers. Their performance potential was first estimated using simulations, and then demonstrated using two electrically steerable passive array radiator (ESPAR) antennas against a pair of monopole antennas on a hardware bit error rate (BER) testbed. The former produces equal performance in BER with certain pattern combinations and excels in theoretical capacity with substantial lead making pattern reconfigurable antenna a potent option as receiver in MIMO-related applications.

With the fast adoption of LTE and IEEE 802.11N, more devices are employing multiple antennas to boost the data rate and reliability of the communication link. Traditionally, fixed antennas are used in such devices. In recent years, reconfigurable antennas have been sought out to further boost the performance, which can adaptor to the changing wireless channel by altering their radiation characteristics, and maintain or exceed the performance of fixed antennas. This thesis studies the possibility of performance increase using pattern reconfigurable antennas as receivers. Their performance potential was first estimated using simulations, and then demonstrated using two electrically steerable passive array radiator (ESPAR) antennas against a pair of monopole antennas on a hardware bit error rate (BER) testbed. The former produces equal performance in BER with certain pattern combinations and excels in theoretical capacity with substantial lead making pattern reconfigurable antenna a potent option as receiver in MIMO-related applications.

Orientador: Alexandre Cezar Rodrigues da Silva / Resumo: A simulação de ambientes computacionais é uma das principais técnicas para estudo de protocolos, seu comportamento em redes de computadores e análise da segurança da informação. O acesso a ambientes reais para simulação de smart grids está restrito a poucas universidades e empresas assim como existem poucas ferramentas disponíveis para sua simulação computacional, o que dificulta a realização de pesquisas nesta linha. Neste trabalho objetiva-se a configuração de um ambiente para simulação do protocolo DNP3 utilizando exclusivamente ferramentas open source, utilizando-se técnicas de segurança ofensiva para realizar ataques a rede e então validar o comportamento da simulação e por fim realizar a integração do ambiente de simulação com equipamentos reais. Para isso, foi desenvolvido um testbed virtual através da integração e configuração de diversas ferramentas e softwares open source e posteriormente utilizados os equipamentos do Laboratório de Proteção do Campus III na UNESP de Ilha Solteira, expandindo as funcionalidades do simulador e obtendo um testbed misto com resultados promissores em todos os testes realizados. / Mestre

abstract: This thesis describes a synthetic task environment, CyberCog, created for the purposes of 1) understanding and measuring individual and team situation awareness in the context of a cyber security defense task and 2) providing a context for evaluating algorithms, visualizations, and other interventions that are intended to improve cyber situation awareness. CyberCog provides an interactive environment for conducting human-in-loop experiments in which the participants of the experiment perform the tasks of a cyber security defense analyst in response to a cyber-attack scenario. CyberCog generates the necessary performance measures and interaction logs needed for measuring individual and team cyber situation awareness. Moreover, the CyberCog environment provides good experimental control for conducting effective situation awareness studies while retaining realism in the scenario and in the tasks performed. / Dissertation/Thesis / M.C.St. Computing Studies 2011

Wireless sensor networks (WSNs) have been used in many applications by deploying tiny and stationary sensors. In recent years, a lot of studies proposed to introduce mobility capability to sensor nodes in order to exploit the advantages of mobility, particularly to restore connectivity in disjoint WSNs. While the studies demonstrated various capabilities of the proposed connectivity algorithms via simulation, real node and testbed implementations were mostly lacking due to unavailability of proper mobile nodes. Since this may hinder the direct applicability of the algorithms in realistic settings, testbeds which can be constructed with low-cost and commercial-off-the-shelf (COTS) hardware are required for realistic evaluations of the connectivity restoration algorithms. In this thesis, we design a low-cost mobile sensor node called iRobotSense, by integrating iRobot Create platform with IRIS sensor. Then, a mobile sensor network (MSN) testbed of iRobotSense nodes is used to implement and evaluate a widely used connectivity restoration algorithms, namely PADRA. Furthermore, all of the previous works exploiting mobility of the nodes to achieve recovery in a partitioned network have assumed reachability of the nodes to the selected destinations via a direct path movement. However, in real-world applications, such assumption makes the schemes impractical in case of encountering obstacles or intolerable terrains. Besides, even if direct path movement is successful, optimal energy efficiency cannot be attained by neglecting the elevation or friction of the terrain. Thus, in the recovery efforts, terrain type, elevation as well as the obstacles should be taken into account. In this thesis, we re-design an existing connectivity restoration approach in disjoint MSNs to fit these requirements and evaluate the performance issues when realistic terrains are assumed. Rather than following a direct path, movement trajectory is determined based on a path planning algorithm which considers the risk and elevation of terrain sections to be visited while avoiding obstacles and highly elevated terrain sections.

Smart Cyber-Physical Systems (sCPS) are complex systems performing smart coordination that often require decentralized and network resilient operation. New development in the fields of the robotic systems, Industry 4.0 and autonomous vehicular system brings challenges that can be tackled with deployment of ensemble based sCPS, but require further refinement in terms of network resilience and data propagation. This thesis maps the use cases of the sCPS in the aforementioned domains, discusses requirements on the ensemble based architecture in terms of network properties, and proposes recommendations and technical means that help to design network aware ensemble based sCPS. The proposed solutions are evaluated by the means of target systems simulation using state of the art realistic network and vehicular simulators.

Submitted by ANDRÉ LUIZ LATANSIO DE OLIVEIRA null (andrelatansio@gmail.com) on 2017-08-03T12:48:20Z No. of bitstreams: 1 dissertacao_final_submeter.pdf: 6036596 bytes, checksum: debf9708c542db4157e83657c0859084 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-08-03T17:52:18Z (GMT) No. of bitstreams: 1 oliveira_all_me_ilha.pdf: 6036596 bytes, checksum: debf9708c542db4157e83657c0859084 (MD5) / Made available in DSpace on 2017-08-03T17:52:18Z (GMT). No. of bitstreams: 1 oliveira_all_me_ilha.pdf: 6036596 bytes, checksum: debf9708c542db4157e83657c0859084 (MD5) Previous issue date: 2017-07-07 / A simulação de ambientes computacionais é uma das principais técnicas para estudo de protocolos, seu comportamento em redes de computadores e análise da segurança da informação. O acesso a ambientes reais para simulação de smart grids está restrito a poucas universidades e empresas assim como existem poucas ferramentas disponíveis para sua simulação computacional, o que dificulta a realização de pesquisas nesta linha. Neste trabalho objetiva-se a configuração de um ambiente para simulação do protocolo DNP3 utilizando exclusivamente ferramentas open source, utilizando-se técnicas de segurança ofensiva para realizar ataques a rede e então validar o comportamento da simulação e por fim realizar a integração do ambiente de simulação com equipamentos reais. Para isso, foi desenvolvido um testbed virtual através da integração e configuração de diversas ferramentas e softwares open source e posteriormente utilizados os equipamentos do Laboratório de Proteção do Campus III na UNESP de Ilha Solteira, expandindo as funcionalidades do simulador e obtendo um testbed misto com resultados promissores em todos os testes realizados. / The simulation of computational environments is one of the main techniques applied in the study of protocols, the behavior of those protocols in computer networks, and the analysis of information security procedures. Research in the area of smart grid simulation is hampered by the fact that few universities and companies have access to real environments, and further, that the number of computational tools available is limited. This paper therefore aims to configure an environment for the simulation of the DNP3 protocol using exclusively open source tools and by applying offensive security techniques including attacks which seek to exploit network vulnerabilities; subsequently, the proposed simulation behavior is validated. For this purpose, a virtual testbed was developed by integrating and configuring various open source software and tools and later using the Campus III Protection Laboratory equipments at UNESP Ilha Solteira, expanding the simulator functionalities and obtaining a mixed testbed with results promising in all tests performed.

As the vision of the Internet of Things (IoT) becomes a reality, thousands of devices will beconnected to IoT platforms in smart cities and regions. These devices will actively send dataupdates to cloud-based platforms, as part of smart applications in domains like healthcare, trafficand pollution monitoring. Therefore, it is important to study the ability of modern IoT systemsto handle high rates of data updates coming from devices. In this work we evaluated the per-formance of components of the Internet of Things Services Enablement Architecture of theEuropean initiative FIWARE. We developed a testbed that is able to inject data updates usingMQTT and the CoAP-based Lightweight M2M protocols, simulating large scale IoT deploy-ments. Our extensive tests considered the vertical and horizontal scalability of the componentsof the platform. Our results found the limits of the components when handling the load, and thescaling strategies that should be targeted by implementers. We found that vertical scaling is notan effective strategy in comparison to the gains achieved by horizontally scaling the databaselayer. We reflect about the load testing methodology for IoT systems, the scalability needs ofdifferent layers and conclude with future challenges in this topic.

Physical indoor wireless network testbeds as well as outdoor wireless testbeds have the potential to accelerate the pace of research in the field of wireless ad hoc and mesh networking. They form part of a critical chain of steps needed to develop and test ad hoc networking protocols from concept to eventual uptake by industry. Current research in this area makes use of simulations or mathematical models which oversimplify the physical and Medium Access Control layer. In Africa specifically, wireless mesh networking has the potential to make a substantial impact on the lack of telecommunications infrastructure across the continent. A combination of good theoretical analysis, indoor test facilities and rural testbeds forms a perfect suite to carry out meaningful research in the field. A 7x7 wireless grid of closely spaced computers was constructed, making use of highly attenuated 802.11 radios running in ad hoc mode. Modelling and analysis revealed that a suitably attenuated environment was created with variation in signal strength between node pairs following a Gaussian distribution. This emulates a real outdoor network with normal signal propagation issues such as multi-path fading and lack of Fresnel zone clearance. This testbed was then used to evaluate 3 popular MANET ad hoc routing protocols, namely AODV, DYMO and OLSR. OLSR was tested with the standard hysteresis routing metric as well as the ETX routing metric. OLSR showed the best performance in terms of average throughput and packet loss for a medium size (21 node) and large (49 node) mesh network, with the hysteresis routing metric performing best in large networks and ETX performing best in medium sized networks. DYMO also performed very well, considering its low routing overhead, exhibiting the least amount of delay in a large mesh network (49 nodes). The AODV protocol showed the weakest performance in the grid with close to 60% of possible link pairs achieving no route in a 49-node grid. However, it did present the least amount of routing overhead compared with other routing protocols. Finally, a medium-sized rural mesh network testbed consisting of 9 nodes was built in a mountainous area of about 15 square kilometers around an AIDS clinic using the OLSR routing protocol with ETX as the routing metric. The network provided a good service to the satellite-based Internet with throughput rates ranging between 300 kbps for 4 hops and 11000 kbps for 1 hop and an average throughput rate of 2324 kbps. To encourage fair sharing of Internet connectivity, features were installed to limit each user to 40 MB/month of free Internet traffic. A local web server offers cached pages of Wikipedia and Linux repositories to reduce the need for Internet access. VoIP services were also installed between clinic infrastructure to reduce the the need for making expensive GSM calls. It was shown that a mesh network of this size provides a very satisfactory level of broadband service for users accessing a satellite-based Internet facility as well as local VoIP services. / Dissertation (MEng)--University of Pretoria, 2009. / Electrical, Electronic and Computer Engineering / unrestricted