The usage of UAVs (Unmanned Aircraft Vehicle) is soaring, not just for hobbyists but increasingly for a range of professional and civil applications. Some of the more sophisticated applications that have high data usage and long-range flight requirements are being developed now. The range and capability of typical wireless connectivity technologies are not enough for such applications. Connecting UAVs to the mobile network is a solution. There are lots of benefits which mobile network can provide for UAVs and UTM (Unmanned Aircraft System Traffic Management). However, the anticipation of UAVs was not considered at first in network planning, which creates unexpected coverage conditions. The introduction of UAVs impacts LTE (Long Term Evolution) network in several ways and the network coverage and capacity of UAVs at low altitude is significantly different from that of terrestrial UEs. The thesis work includes investigation about how UAVs impact LTE network and how mobile network coverage and capacity for UAVs change when other factor changes. The impact of methods to enhance the mobile network for UAVs would also part of the research. In this work, a successful simulation in order to investigate UAV’s situation while using 4G LTE cellular networks is developed. In order to properly test the developed framework for a range of different inputs, various generic scenarios were successfully developed and executed. Using this simulation, we have shown that UAV’s network situation is affected by 2 parameters: the height of UAV and the load of the eNodeBs (Evolved Node B). We have successfully demonstrated that UAV at higher attitude may cause more serious network condition in the suburban area compared with the case in the urban area. Finally, an interference mitigation technique: antenna beam selection is applied and tested. We show that it can improve the network condition for UAV at a higher altitude. Some improvements to the model could be a modeling of inter-cell interference and multipath effects. Models of weather condition in UAV’s flying space would also greatly improve the framework. Besides a scheme for modulation and bit error calculation could be used to build a more generic model. In the thesis, antenna propagation and gain models are not perfect, so more accurate model would also be a great improvement. Only antenna beam selection is tested in this thesis and the implementation does not include antenna mechanical design and model building. For further research, more methods like interference cancellation, power control and inter-cell interference coordination can be tested in both simulation and hardware. / Användningen av UAV(Unmanned Aircraft Vehicle): er är stigande, inte bara för hobbyister utan allt mer för en rad professionella och civila applikationer. Några av de mer sofistikerade applikationerna som har hög dataanvändning och krav på lång räckvidd utvecklas nu. Räckvidden och kapaciteten för typiska trådlösa anslutningstekniker räcker inte för sådana applikationer. Att ansluta UAV: er till mobilnätet är en lösning. Det finns många fördelar som mobilnätet kan ge för UAV: er och UTM (Unmanned Aircraft System Traffic Management). Förväntningen på UAV: er beaktades dock inte först i nätverksplanering, vilket skapar oväntade täckningsförhållanden.Införandet av UAV: er påverkar LTE-nätverk (Long Term Evolution) på flera sätt och nätverkets täckning och kapacitet för UAV: er på låg höjd skiljer sig väsentligt från markbundna UE: er.Examensarbetet inkluderar utredning om hur UAV: er påverkar LTE-nätverk och hur mobilnätstäckning och kapacitet för UAV: er förändras när andra faktorer ändras. Effekten av metoder för att förbättra mobilnätverket för UAV: er skulle också vara en del av forskningen. I detta arbete utvecklas en framgångsrik simulering för att undersöka UAV: s situation med användning av 4G LTE-mobilnät. För att korrekt testa det utvecklade ramverket för en rad olika ingångar, utvecklades och genomfördes olika generiska scenarier. Med denna simulering har vi visat att UAVs nätverkssituation påverkas av två parametrar: UAV: s höjd och belastningen på eNodeBs (Evolved Node B). Vi har framgångsrikt visat att UAV vid högre inställning kan orsaka allvarligare nätverkstillstånd i förortsområdet jämfört med fallet i stadsområdet. Slutligen tillämpas och testas en interferensbegränsande teknik: val av antennstråle. Vi visar att det kan förbättra nätverksvillkoret för UAV på högre höjd. Några förbättringar av modellen kan vara modellering av inter-cellstörningar och flervägseffekter. Modeller av väderförhållanden i UAV: s flygutrymme skulle också förbättra ramverket kraftigt. Förutom ett schema för modulering och beräkning av bitfel skulle kunna användas för att bygga en mer generisk modell. I avhandlingen är antennutbredningsoch förstärkningsmodeller inte perfekta, så en mer exakt modell skulle också vara en stor förbättring. Endast val av antennstråle testas i denna avhandling och implementeringen inkluderar inte antennmekanisk design och modellbyggnad. För ytterligare forskning kan fler metoder som interferensavbrott, effektkontroll och inter-cell-interferenskoordination testas i både simulering och hårdvara.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2017-12-18T16:25:14Z No. of bitstreams: 2 Dissertação - Ciliana Karine Dias Lima - 2017.pdf: 23149224 bytes, checksum: c070892c298f576da2daf6724723a45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-12-19T12:03:47Z (GMT) No. of bitstreams: 2 Dissertação - Ciliana Karine Dias Lima - 2017.pdf: 23149224 bytes, checksum: c070892c298f576da2daf6724723a45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-19T12:03:47Z (GMT). No. of bitstreams: 2 Dissertação - Ciliana Karine Dias Lima - 2017.pdf: 23149224 bytes, checksum: c070892c298f576da2daf6724723a45b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-12-11 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Sustainable development is a present issue in world society and it is also a strategic challenge for Cape Verde’s energy policy in coming years because the large fragilities in the electrical system in Cape Verde such as, dependence on imports of fuels, geographical dispersion, the high costs associated with managing energy systems and the great energy waste. The bet on photovoltaic systems may be one of the alternatives to reducing these fragilities. In this context, the present work highlights the great existent potential for use of renewable energy focused on solar energy. The text describes incentives for the production of electric energy based on renewable sources and presents analyses on the implementation of two grid-connected photovoltaic systems in the island of São Vicente. One of the systems is a photovoltaic rooftop 19.8 kWp plant installed in a public secondary school building and the other system is 3 MWp photovoltaic power plant connected to electrical utility grid in São Vicente Island. The study included design, operation simulation of São Vicente Island distribution network in the presence and absence of photovoltaic systems and financial analyses in order to determine payback time, actual present value, intern return rate of investment and financial sensibility analyses to assess the influence of Wp cost and interest rate on the financial figures. The results show that the implementation of photovoltaic systems is attractive in financial and technical terms, the microgeneration system causes a large reduction in energy acquired by the network, and the large power plant has not worsened the appropriate operating voltage levels and decreased the system's active losses. / O desenvolvimento sustentável é uma questão presente na sociedade mundial e é também um desafio para a política energética de Cabo Verde nos próximos anos, devido às grandes fragilidades do sistema elétrico do arquipélago, tais como a forte dependência da importação dos combustíveis fosseis, a dispersão geográfica, os elevados custos associados à gestão dos sistemas energéticos e o grande desperdício energético. A aposta em sistemas fotovoltaicos é uma das alternativas para a redução dessas fragilidades. Neste contexto, o presente trabalho destaca o grande potencial existente em Cabo Verde para utilização de energia renovável com o foco na fonte solar. O trabalho descreve os incentivos legais locais para a produção de energia elétrica com base em fontes de origem renovável e apresenta a análise da implantação de dois sistemas fotovoltaicos conectados à rede elétrica na ilha de São Vicente. Um deles é um sistema de microgeração fotovoltaica de 19,8 kWp instalado em um edifício público de ensino e o outro é uma usina fotovoltaica de grande porte de 3 MWp, ligada à rede elétrica e também localizada na ilha de São Vicente. O estudo inclui o dimensionamento, a simulação de operação da rede de distribuição da ilha de São Vicente na ausência e na presença de sistemas fotovoltaicos. São feitas análises financeiras a fim de determinar o tempo de retorno dos investimentos, o valor atual líquido e a taxa interna de retorno dos investimentos. Também é feito uma análise de sensibilidade financeira para avaliar a influência do custo do Wp instalado e da taxa de juros do financiamento sobre os parâmetros financeiros. Os resultados mostram que a implementação dos sistemas fotovoltaicos é atrativa em termos financeiros e técnicos. A instalação do sistema de microgeração provoca uma grande redução da energia adquirida junto à rede pela unidade consumidora. É mostrado também que a usina de grande porte notadamente não alterou os níveis de tensão de funcionamento da rede e proporcionou uma diminuição das perdas ativas do sistema.

This diploma thesis deals with the possibility of using HDLC (High-Level Data Link Control) protocol for communication and addressing of smart metering devices with a data concentrator. The HDLC protocol is used in two DLMS/COSEM (Device Language Message Specification/Companion Specification for Energy Metering) communication profiles. To simulate these communication profiles, the most appropriate simulation program is selected. Using this simulator, the first communication profile is implemented and the second one is designed. Communication profile based on TCP/IP (Transmission Control Protocol/Internet Protocol) has been fully implemented. To implement the three-layer HDLC communication profile, all options have been thoroughly explored. Using these findings, a process was designed to guide the full implementation. For the first communication profile the qualitative parameters are measured, which are then plotted and evaluated.

Mittelständische und große Unternehmen sehen sich durch die rasant fortschreitende Digitalisierung von Medien und Kommunikation mit dem Problem konfrontiert, ihre Daten konsistent und logisch strukturiert zu verwalten. Häufig wird dieses Problem durch verteilte Strukturen (Filialen, Zweigstellen, Zulieferer, mobile Mitarbeiter) noch verstärkt. Die häufig verwendeten zentralisierten Strukturen (Server, Datenbanken) sind zudem ein wesentlicher Angriffspunkt für die Systemsicherheit und erfordern großen Aufwand zu ihrer Wartung und Aktualisierung.

This masters thesis describes simulation of network using Network Simulator. Model of network and description of simulation is extracted from the analysis of configuration files of active network devices, and translated by a parser. Concept and implementation of the parser is described here. Because IPv4 addressing is not supported in Network Simulator, it was added as a new module. The Network Simulator is also extended by filtering properties of packets using access control lists. Practical usage of the implemented modules is demonstrated on a simulation of real network.

Dans ce travail de thèse, un aperçu général sur les systèmes PON est présenté et sont étudiés les mécanismes et classification PON existants. Après, nous introduisons notre première contribution qui est un algorithme d'allocation dynamique de bande passante pour EPON. Cet algorithme proposé est désigné comme «hcDBA». Par la suite, une amélioration de l'algorithme de hcDBA avec mécanisme de prédiction précoce est présentée. Notre simulation montre bien que notre algorithme hcDBA est performant comparé aux mécanismes existants en termes de taux de perte de paquets et de délai d’accès. Dans notre seconde contribution, nous sommes intéressés au problème de consommation d’énergie qui est un sujet d’actualité dans les réseaux de télécommunication. Les études montrent aujourd’hui que les réseaux d'accès constituent une partie remarquable de la consommation totale d'énergie dans les réseaux de télécommunication. Les organisations ITU-T et IEEE ont publié la recommandation pour la conversation de l'énergie pour les réseaux PONs. Bien que, la consommation totale d'énergie des nœuds ONU est plus importantes que d'autres équipements dans le réseau d'accès fixe, les normes et la plupart des travaux de recherches ont porté sur les économies d'énergie du côté de ONU. Dans cette thèse, nous sommes concentrés sur une méthode d'efficacité énergétique basée sur la conservation de l'énergie du côté de l’OLT. La méthode proposée permet d’économiser de l'énergie en déplaçant dynamiquement des cartes d’OLT en mode de sommeil profond en fonction des charges de trafic entrant et sortant / In this thesis, general overview about PON systems is presented and existing PON mechanisms and classification are investigated. After, a novel dynamic bandwidth allocation algorithm for EPON is introduced. This proposed algorithm is named as “Half Cycling Dynamic Bandwidth Allocation-hcDBA” by the inspiration of its half cycling processing mode. Later, an improvement of hcDBA algorithm with early prediction mechanism is presented. As a result statement of the study, hcDBA algorithm performs better than existing mechanism in terms of packet loss ratio and access delays. Beside, simulation traffic behavior of EPON’s upstream channel has been investigated in order to support the decision of selecting suitable traffic generator in further studies. Energy conversation is one of the hot topics in telecommunication networks. Access networks constitute remarkable portion of the total energy consumption in telecommunication networks. ITU-T and IEEE organizations published recommendation for energy conversation in PONs. While, total energy consumption of ONUs is more than other equipment in fix access network the standards and most of the researches focused on saving energy at ONU side. In this thesis I focused on an energy efficiency method based on energy conversation on OLT side. The proposed method save energy by dynamically moving OLT cards to deep sleep mode according to the incoming and outgoing traffic loads