Submitted by Neusa Fagundes (neusa.fagundes@unioeste.br) on 2017-09-01T19:08:17Z No. of bitstreams: 1 AnibalM_Diniz2017.pdf: 2918535 bytes, checksum: ae39600214cf1d4dcb6e70a9e1eaa150 (MD5) / Made available in DSpace on 2017-09-01T19:08:17Z (GMT). No. of bitstreams: 1 AnibalM_Diniz2017.pdf: 2918535 bytes, checksum: ae39600214cf1d4dcb6e70a9e1eaa150 (MD5) Previous issue date: 2017-03-08 / The modern agriculture is based on the application of techniques, methodologies and equipment that optimize their processes, thus increasing agricultural production, reducing costs and interfering less in nature. An important area of research in Agricultural Engineering is the development and use of equipment and sensors electronic to support increased agricultural productivity. This work presented a contribution to irrigation through the development and use of free software and hardware for direct measurements of soil moisture and temperature values during the plant cycle, thus allowing optimize the use of water in the process. In the system proposal, four moisture sensors were used, one resistive and three capacitive. The research was carried out in the laboratory and the soil used in the experiment was collected at the Experimental Nucleus of Agricultural Engineering of the State University of the West of Paraná. The soil was characterized as typical Distroferric Red Latosol and very clayey texture (66%). The soil was discarded and oven dried, then divided into 20 containers with addition of known water volumes in each. A network of Mesh-type sensors was developed to read and transmit data read to a single Gateway. The sensor node was designed and built with an Arduino Nano, NRF24L01 radio, capacitive sensors of type SHT20 and DHT22 in addition to FC-28 that is resistive. The system also featured a Real Time Clock DS1302, three photovoltaic cells and battery charger circuit. The Gateway circuit that connects the system to the internet was built with an Arduino Uno. Domoticz software was used to store the data and make it available on a server connected to the Internet. The data were obtained from the sensors placed in the containers and one of the results was the cubic modeling of the relationship between each of the sensors, the TDR and the greenhouse method. The values of the coefficient of statistical determination obtained show that the models that best explain the relation between the values obtained by the greenhouse method are the TDR and the resistive sensor, although the other sensors also presented a good coefficient of determination. The consumption of the sensor node board is 168 mW and the distance tested between devices up to 100 m showed that there was no loss of the data packet. The cost obtained from a node was R$ 251.00 and the Gateway R$ 115.00. The cost of a new TDR in Brazil of the model used in the experiment is R$ 176,000.00. Therefore, the analysis of the data presented showed the feasibility of using the sensors proposed in the network and resulted in a model to be applied for each device at a viable cost to the rural producer. / A agricultura moderna está baseada na aplicação de técnicas, metodologias e equipamentos que otimizem os seus processos, aumentando, assim, a produção agrícola, reduzindo custos e interferindo menos na natureza. Uma área importante de pesquisa na Engenharia Agrícola é o desenvolvimento e a utilização de equipamentos e sensores eletrônicos para apoiar o aumento da produtividade agrícola. Este trabalho apresentou uma contribuição para a Irrigação através do desenvolvimento e uso de software e hardware livre para medições diretas das grandezas de umidade e temperatura no solo durante todo o ciclo da planta, permitindo assim que sistemas otimizem a utilização da água no processo. Na proposta do sistema foram utilizados quatro sensores de umidade, um resistivo e três capacitivos. A pesquisa foi realizada em laboratório e o solo utilizado no experimento foi coletado no Núcleo Experimental de Engenharia Agrícola da Universidade Estadual do Oeste do Paraná. O solo foi caracterizado como Latossolo Vermelho Distroférrico típico e textura muito argilosa (66%). O solo foi desterroado e seco em estufa, depois dividido em 20 recipientes com adição de volumes de água conhecidos em cada um deles. Foi desenvolvida uma rede de nós sensores do tipo Mesh para ler e transmitir os dados lidos para um Gateway único. O nó sensor foi projetado e construído com um Arduino Nano, rádio NRF24L01, sensores capacitivos do tipo SHT20 e DHT22 além do FC-28 que é resistivo. O sistema também contou com um Real Time Clock DS1302, três células fotovoltaicas e circuito carregador de bateria. O circuito do Gateway que conecta o sistema à internet foi construído com uma Arduino Uno. Para armazenar os dados e disponibilizá-los utilizou-se o software Domoticz em um servidor conectado à internet. Os dados foram obtidos a partir dos sensores colocados nos recipientes e um dos resultados foi a modelagem cúbica da relação entre cada um dos sensores, o TDR e o método da estufa. Os valores do Coeficiente de Determinação estatística obtidos indicam que os modelos que melhor explicam a relação entre os valores obtidos pelo método da estufa são o da TDR e do sensor resistivo, apesar de que os outros sensores também apresentaram um bom coeficiente de determinação. O consumo da placa do nó sensor é de 168 mW e a distância testada entre os dispositivos até 100 m demonstrou que não houve perdas do pacote de dados. O custo obtido de um nó foi de R$ 251,00 e do Gateway de R$ 115,00. O custo de um TDR novo, no Brasil, do modelo utilizado neste experimento é de R$ 176.000,00. Logo, a análise dos dados apresentada mostrou a viabilidade de se utilizar os sensores propostos em rede e resultou em um modelo a ser aplicado para cada dispositivo a um custo viável ao produtor rural.

The tremendous growth in the development of wireless networking techniques attracts growing attention to this research area. The ease of development, low installation and maintenance costs and self healing abilities are some of the qualities that make the multi-hop wireless mesh network a promising solution for both - rural and urban environments. Examining the performance of such a network, depending on the external conditions and the applied routing protocol, is the main aim of this research. It is addressed in an empirical way, by performing repetitive multistage network simulations followed by a systematic analysis and a discussion. This research work resulted in the implementation of the experiment and analysis tools, a comprehensive assessment of the simulated routing protocols - DSDV, AODV, OLSR and HWMP, and numerous observations concerning the simulation tool. Among the major findings are: the suitability of protocols for wireless mesh networks, the comparison of rural and urban environments and the large impact of conditions such as propagation, density and scale of topology on the network performance. An unexpected but valuable outcome is the critical review of the ns network simulator. / Mobile number: +48 660144055

Mesh network is gaining importance as the next generation network for many high speed applications such as multimedia streaming. This is because it is easy and inexpensive to setup mesh networks with mobile and PDA devices and can be used as a private network. Hence research is active in the field of routing protocols and routing metrics to improve the mesh network performance. Though most of the protocols are evaluated based on simulation, we implemented protocols based on a few metrics like Expected Transmission Count (ETX) Per-hop Packet Pair Delay (Pkt Pair) and WCETT (Weighted Cumulative Expected Transmitted Time) to investigate the performance of the network through experiments. An advanced version of DSR protocol called LQSR (Link Quality Source Routing) protocol of Microsoft Research along with MCL (Mesh Connectivity Layer) allows multiple heterogeneous adapters to be used in mesh network. Since wireless adapters of 802.11a standard offer 12 non-interfering channels and 802.11b/g standard offer 3 non-interfering channels, using multiple adapters of different bands operating on non-interfering channels to improve capacity and robustness of mesh networks was also investigated. In this thesis we explore the possibility of increasing the coverage area of Wireless Mesh Networks (WMN) to enhance the capacity of WMN and minimize the problems due to interference. Theoretical achievable capacity to every node in a random static wireless ad-hoc network with ideal routing is known to be where n is the total number of nodes in the network. Therefore, with increasing number of nodes in a network, throughput drops significantly. Our measurements show that throughput in a single WMN for different path length is closer to the throughput with nodes across two WMNs of the same path length. We propose to interconnect the networks by using multiple wireless adapters in a gateway node configured with the SSID of the networks in operation. We exploit the DSR protocol feature of assigning locally unique interface indices to its adapters. Performance of a network depends heavily on the metrics used for routing packets. Different metrics were studied in the thesis by setting up a 10-node testbed with a combination of nodes with single and two radios. Testbed was partitioned into two networks with two gateway nodes. Performance of multi-radio performance with the above metrics was compared with baseline single radio nodes in the network with the same metric. It is found that multi-radio nodes out-perform single radio nodes in the multi-hop scenario. Also, operating multi-mesh networks using multiple interfaces configured to those networks in a gateway node increases the coverage area and robustness without loss of performance.

The thesis simulates the problem of network connectivity that occurs due to the dynamic nature of a network during flight. Nine nodes are provided with initial positions and are flown based on the path provided by leader-follower control algorithm using the server-client model. The application layer provides a point to point connection between the server and client and by using socket programming in the transport layer, a server and clients are established. Each node performs a neighbor discovery to discover its neighbors in the data link layer and physical layer performs the CSMA/CA using RTS/CTS. Finally, multi hop routing is achieved in network layer. Each client connects with server at dedicated interval to share each other location and then moves to next location. This process is continued over a period of several iterations until the relative distance is achieved. The constraints and limitations of the technology are network connectivity is lack of flexibility for random location of nodes, links established with a distant node having single neighbor is unstable. Performance of a system decreases with increase in number of nodes.

Au cours des dernières années, l’utilisation des téléphones portables et tablettes s’est vue croitre de façon significative. De plus, la disponibilité et l’ubiquité de l’accès sans fil a permis de créer un environnement dans lequel les utilisateurs partout où ils sont accèdent en tout temps à des services se trouvant dans le cloud. Cet environnement appelé cloud sans fil consomme une quantité d’énergie significative et est responsable d’émissions considérables en carbone. Cette consommation massive d’énergie et émissions en carbone deviennent un problème majeur dans le secteur des technologies de la communication. Dans ce contexte, nous nous intéressons dans cette thèse à la réduction de la consommation d’énergie et des empreintes en carbone des réseaux d’accès de type mesh et réseaux de campus ainsi que les data centers des infrastructures cloud. Dans la première partie, nous nous intéressons aux réseaux mesh de type TDMA. Nous proposons des solutions pour le problème de routage et ordonnancement des liens qui permettent de réduire la consommation d’énergie dans le réseau. Nous étendons par la suite cette approche pour les réseaux de campus dans un contexte compatible avec le paradigme SDN. Dans la deuxième partie, nous nous intéressons à la réduction de la consommation l’énergie et des empreintes en carbone des infrastructures cloud distribuées, avec des couts variables de l’électricité et d’émission en carbone. Nous proposons des approches d’optimisations dans deux cas de figures : le cas d’un fournisseur cloud souhaitant réduire ses couts et dans le cas où les utilisateurs cloud spécifient des contraintes en carbone sous forme de Green SLA. / Over the last decade, there has been an increasing use of personal wireless devices, such as laptops, smartphones and tablets. The widespread availability of wireless access created an environment in which anywhere at anytime users access data and services hosted in cloud infrastructures. However, such wireless cloud network consumes a non-negligible amount of energy and generates a considerable amount of carbon, which is becoming a major concern in IT industry. In this context, we address the problem of reducing energy consumption and carbon footprint, as well as building green infrastructures in the two different parts of the wireless cloud: (i) wireless access networks including wireless mesh and campus networks, and (ii) data centers in a cloud infrastructure. In the first part of the thesis, we present an energy-efficient framework for joint routing and link scheduling in multihop TDMA-based wireless networks. At a later stage, we extended this framework to cover campus networks using the emerging Software Defined Networking (SDN) paradigm. In the second part of this thesis, we address the problem of reducing energy consumption and carbon footprint of cloud infrastructures. Specifically, we propose optimization approaches for reducing the energy costs and carbon emissions of a cloud provider owning distributed infrastructures of data centers with variable electricity prices and carbon emissions in two different setups: the case of a cloud provider trying to reduce its carbon emissions and operational costs as well as the case where green constraints are specified by the cloud consumers in the form of Green SLAs.

With unmanned aerial vehicles (UAVs), also known as drones, becoming readily available and affordable, applications for these devices have grown immensely. One type of application is the use of drones to fly over large areas and detect desired entities. For example, a swarm of drones could detect marine creatures near the surface of the ocean and provide users the location and type of animal found. However, even with the reduction in cost of drone technology, such applications result costly due to the use of custom hardware with built-in advanced capabilities. Therefore, the focus of this thesis is to compile an easily customizable, low-cost drone design with the necessary hardware for autonomous behavior, swarm coordination, and on-board object detection capabilities. Additionally, this thesis outlines the necessary network architecture to handle the interconnection and bandwidth requirements of the drone swarm. The drone on-board system uses a PixHawk 4 flight controller to handle flight mechanics, a Raspberry Pi 4 as a companion computer for general-purpose computing power, and a NVIDIA Jetson Nano Developer Kit to perform object detection in real-time. The implemented network follows the 802.11s standard for multi-hop communications with the HWMP routing protocol. This topology allows drones to forward packets through the network, significantly extending the flight range of the swarm. Our experiments show that the selected hardware and implemented network can provide direct point-to-point communications at a range of up to 1000 feet, with extended range possible through message forwarding. The network also provides sufficient bandwidth for bandwidth intensive data such as live video streams. With an expected flight time of about 17 minutes, the proposed design offers a low-cost drone swarm solution for mid-range aerial surveillance applications.

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本研究在減低Wimax mesh mode環境中media access階段會造成的delay現象。我們發現當subscriber station (SS)訊務繁忙時，競爭transmission opportunity (TO)以及3-way handshake的過程容易失敗，造成傳輸效率降低，封包的delay也會增加。同時我們也發現封包的延遲還來自minislot的不良配置。因為原始的Wimax mesh mode對於minislot的配置會造成預約過晚的問題，當預約時間被延長，資料就必須無條件的增加等待時間，因此我們將針對這些問題進行改善，降低在訊務繁忙的狀況下，傳輸效率低落的問題。 我們使用兩種方式來改善上述的問題，其一是由Bayer [4]所提出的動態調整holdoff指數(dynamic holdoff exponent)的方式，藉由調整holdoff指數的大小來縮短holdoff時間，以縮短傳輸延遲；另外，我們也提出一個以節點的臨接區域為配置基準(Neighborhood-Based Minislot Allocation, NBMA) 的方法，透過與其相鄰的節點交換訊息，優化minislot的配置。我們用這兩種方式減少IEEE 802.16中媒體存取階段所造成的傳輸延遲。 實驗結果顯示，在網路負載較輕的情況下，NBMA可以有效的將delay降低為原來的七分之一，改善幅度將近85%，抖動率(jitter)的部分亦有20%的改善，並略為提高傳輸效能8%左右；而當網路負載較重時，delay的改善程度仍有40%左右，jitter部分改善了12%，傳輸效能亦有6%的改善。證明了我們的方法確實可行，並且在改善delay方面有顯著的效果。 / IEEE 802.16 mesh network is a new environment of wireless network. It was designed as a self-organized, distributed scheduling, and multi-hop network. However, it is not robust enough to handle a heavy loading environment for lacking of QoS support. Our research is trying to reduce its media access delay, which comes from both TO (transmission opportunity) competition and improper minislot allocation. TO competition will extend the MSH-DSCH (mesh distributed scheduling) interval and slow down the exchanging speed of control message. Improper minislot allocation comes from the distributed scheduling of minislot. When a subscriber station (SS) allocates too much minislot for low-level traffic, it will defer the allocation of other neighbors’ high-level traffic. We use Bayer’s [4] dynamic exponent to reduce holdoff time of SS, and speed up the exchange of control message. On the other hand, we design an “importance factor” (IM-factor) to score the importance of request. Through the exchange of IM-factor, SS and its neighbors will produce a threshold of IM-factor to filter the unimportant requests, and prevent minislot from being assigned too late. In our experiments, the proposed methods can reduce 85% delay and 20% jitter, and increase bandwidth utility by 7%. It shows that our method in reducing transmission delay is pratical and effective.

Excessive droughts on the African continent have caused the Swedish Meteorological and Hydrological Institute to launch a program of gathering data in hopes of producing models for rainfalls and droughts. A sensor capable of gathering such data has already been chosen, however there remains the problem of conveniently retrieving data from each of the sensors spread over a large area of land. To accomplish this goal, a small, cheap and efficient wireless capable module would need to be used. A possible candidate is the new WiFi-module from Espress if designated ESP8266. It is an extremely cheap and versatile wireless SoC that is able to perform the task of a wireless communications adapter for the sensor unit. The point of this thesis is to investigate the suitability of IEEE 802.11 for the task, and produce a piece of firmware for the ESP8266. The firmware shall enable it to be attached to a sensor and operate as a wireless mesh node in a self-organizing WLAN sensor network, enabling data retrieval via WiFi multi-hop deliveries.