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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Uživatelská aplikace pro konfiguraci bezdrátového modulu Zigbee / Application for Zigbee Device Configuration

Brož, Kamil January 2012 (has links)
The diploma thesis includes the ZigBee networks and compares them with other PAN IEEE 802.15.4 networks. It describes the formation of ZigBee networks. It describes physical, MAC, network and application layer in the form of Bitcloud. Thesis includes practical implementation in the form of ZigBee application BeeCon which allows set network parameters on Iris modules.
52

Energy-Efficient Routing for Greenhouse Monitoring Using Heterogeneous Sensor Networks

Behera, Trupti Mayee, Khan, Mohammad S., Mohapatra, Sushanta Kumar, Samail, Umesh Chandra, Bhuiyan, Md Zakirul Alam 01 July 2019 (has links)
A suitable environment for the growth of plants is the Greenhouse, that needs to be monitored by a continuous collection of data related to temperature, carbon dioxide concentration, humidity, illumination intensity using sensors, preferably in a wireless sensor network (WSN). Demand initiates various challenges for diversified applications of WSN in the field of IoT (Internet of Things). Network design in IoT based WSN faces challenges like limited energy capacity, hardware resources, and unreliable environment. Issues like cost and complexity can be limited by using sensors that are heterogeneous in nature. Since replacing or recharging of nodes in action is not possible, heterogeneity in terms of energy can overcome crucial issues like energy and lifetime. In this paper, an energy efficient routing process is discussed that considers three different sensor node categories namely normal, intermediate and advanced nodes. Also, the basic cluster head (CH) selection threshold value is modified considering important parameters like initial and residual energy with an optimum number of CHs in the network. When compared with routing algorithms like LEACH (Low Energy Adaptive Clustering Hierarchy) and SEP (Stable Election Protocol), the proposed model performs better for metrics like throughput, network stability and network lifetime for various scenarios.
53

Stochastic Estimation and Control over WirelessHART Networks: Theory and Implementation

Pesonen, Joonas January 2010 (has links)
There is currently a high interest of replacing traditional wired networks with wireless technology. Wireless communications can provide several advantages for process industries with aspect to exibility, maintenance and installation. The WirelessHART protocol provides a standardized wireless technology for large automation networks that explore wireless communication. However, wireless networks introduce time delays and losses in the communication system, which denes requirements for designing estimators and controllers that can tolerate and compensate for the losses and delays. This thesis consists of several contributions. First, we develop tools for analyzing the delay and loss probabilities in WirelessHART networks with unreliable transmission links. For given network topology, routing and transmission schedule the developed tools can be used to determine the latency distributions of individual packets and quantify that a packet will arrive within a prescribed deadline. Secondly, we consider estimation and control when sensor and control messages are sent over WirelessHART networks. The network losses and latencies are modelled and compensated for by timevarying Kalman lters and LQG controllers. Both optimal controllers, of high implementation complexity, and simple suboptimal schemes are considered. The control strategies are evaluated on a simulation model of a flotation process in a Boliden mine where the wired sensors of the existent solution are replaced by a WirelessHART network scheduled for time-optimal data collection. Finally, we implement a WirelessHART-compliant sensor on a Tmote sky device and perform real experiments of wireless control on a water tank process.
54

Implementation of LPWAN protocols for Water Sense : Integration of LoRa and Contiki OS with the Rime stack

Dyi, Barry January 2022 (has links)
The purpose of this thesis rose from tackling a specific project led by Cybercom Group. Water Sense was proposed after municipalities expressed the need to conveniently conduct measurements on water in Swedish lakes, and remotely get access to these data. The varying and infrequent nature of measurements result in an inefficient power consumption when a conventional sensor platform is used. Internet of Things is a relatively new and ever-evolving field for wireless sensor networks, where Low Power Wide-Area Network protocols are utilized to cleverly save power. One of these LPWAN protocols is LoRaWAN, a MAC layer protocol that runs on top of the PHY layer protocol LoRa. The chosen platform hardware for sensor nodes is an Adafruit feather equipped with a LoRa radio module, and the Contiki operative system was to be imported and integrated. Contiki OS is developed for small IoT systems with low-power, while offering networking mechanisms and a range of protocols typically utilized in WSNs. The adaptive and modular nature of Contiki allows for custom pairing of protocols to target a specific topology. LoRaWAN has a number of constraints that are disadvantageous for Water Sense, most prominently being a single-hop protocol. Contiki already supports several platforms with drivers, but the CPU and radio module of the Adafruit feather are not one of them. The goal was to integrate the LoRa PHY hardware with Contiki and have an adaptive platform for Water Sense and other scenarios. Unfortunately not all initial goals were achieved, and the physical layer was not fully integrated with Contiki’s APIs. However, the drivers needed for an operational physical layer were completed and range test could be conducted. Therefore, this thesis details the work done for implementing the physical layer and a study on Contiki’s data link protocols in proposed configurations for Water Sense.
55

Development and Characterization of an IoT Network for Agricultural Imaging Applications

Wahl, Jacob D 01 June 2020 (has links) (PDF)
Smart agriculture is an increasingly popular field in which the technology of wireless sensor networks (WSN) has played a large role. Significant research has been done at Cal Poly and elsewhere to develop a computer vision (CV) and machine learning (ML) pipeline to monitor crops and accurately predict crop yield numbers. By autonomously providing farmers with this data, both time and money are saved. During the past development of a prediction pipeline, the primary focuses were CV and ML processing while a lack of attention was given to the collection of quality image data. This lack of focus in previous research presented itself as incomplete and inefficient processing models. This thesis work attempts to solve this image acquisition problem through the initial development and design of an Internet of Things (IoT) prototype network to collect consistent image data with no human interaction. The system is developed with the goals of being low-power, low-cost, autonomous, and scalable. The proposed IoT network nodes are based on the ESP32 SoC and communicate over-the-air with the gateway node via Bluetooth Low Energy (BLE). In addition to BLE, the gateway node periodically uplinks image data via Wi-Fi to a cloud server to ensure the accessibility of collected data. This research develops all functionality of the network, comprehensively characterizes the power consumption of IoT nodes, and provides battery life estimates for sensor nodes. The sensor node developed consumes a peak current of 150mA in its active state and sleeps at 162µA in its standby state. Node-to-node BLE data transmission throughput of 220kbps and node-tocloud Wi-Fi data transmission throughput of 709.5kbps is achieved. Sensor node device lifetime is estimated to be 682 days on a 6600mAh LiPo battery while acquiring five images per day. This network can be utilized by any application that requires a wireless sensor network (WSN), high data rates, low power consumption, short range communication, and large amounts of data to be transmitted at low frequency intervals.
56

QoS ISSUES AND QoS CONSTRAINED DESIGN OF WIRELESS SENSOR NETWORKS

WANG, XIAODONG 21 July 2006 (has links)
No description available.
57

Asynchronous Localization for Wireless Sensor Networks

Yan, Chunpeng 16 April 2009 (has links)
No description available.
58

Evaluation of Bluetooth Low Energy in Agriculture Environments

Bjarnason, Jonathan January 2017 (has links)
The Internet of Things (IoT) is an umbrella term for smart things connected to the Internet.Precision agriculture is a related concept where connected sensors can be used to facilitate, e.g. more effective farming. At the same time, Bluetooth has been making advancements into IoT with the release of Bluetooth Low Energy (BLE) or Bluetooth smart as it is also known by. This thesis describes the development of a Bluetooth Low Energy moisture- and temperature sensor intended for use in an agricultural wireless sensor network system. The sensor was evaluated based on its effectiveness in agricultural environments and conditions such as weather, elevation and in different crop fields. Bluetooth Low Energy was chosen as the technology for communication by the supervising company due to its inherent support for mobile phone accessibility.Field tests showed that the sensor nodes were largely affected by greenery positioned betweentransmitter and receiver, meaning that these would preferably be placed above growing crops foreffective communication. With ideal placement of the sensor and receiving unit, the signal wouldreach up to 100 m, meaning that a receiving unit would cover a circle area with radius 100 m.Due to Bluetooth being largely integrated in mobile devices it would mean that sensor data couldeasily be made accessible with a mobile app, rather than acquiring data from an online web server.
59

Praktiska routing-övningar med XMesh

Cristea, Adam, Zhang, Sofia January 2010 (has links)
De senaste åren har drivkraften för forskning inom trådlösa sensornätverk ökat markant. Detta är framförallt på grund av de potentiella fördelar som den nya tekniken tillhandahåller.Vi har efter förfrågan av Ivan Kruzela tagit på oss uppgiften att skapa en laboration som är tänkt att ingå i den andra årskursen för högskoleingenjörerna i Data- och Telekommunikation på Centrum för Teknikstudier (CTS), Malmö Högskola.Laborationen handlar om routing och är den tredje i raden av laborationer med trådlösa sensorer. Protokollet som används heter XMesh och är tillverkat av Crossbow Technology. Ambitionen är att laborationen ska leda till förståelse för hur routing uppstår i trådlösa sensornätverk, med avseende på parametrar och andra faktorer som påverkar nodernas val av rutt.Examensarbetet resulterade i en laborationshandledning med tre tillhörande bilagor. / Over the recent years, research in Wireless Sensor Networks (WSNs) has increased significantly. This is mainly because of the potential advantages that this new technology provides.We have upon request from Ivan Kruzela taken on the task of creating a lab, which is supposed to be included in the second year of the Bachelors’ of Computer and Telecom Engineering at the Centre for Technology Studies (CTS), Malmoe University. The lab deals with routing and the protocol used is named XMesh and is created by Crossbow Technology. The ambition is that the lab will lead to an understanding of how routing occurs in wireless sensor networks, regarding parameters and other factors that affects the routing choices of the nodes.The work resulted in the lab and three associated appendices.
60

Otimização do tempo de vida em redes de sensores sem fio utilizando algoritmo de energia e protocolo difusão direcionada / Optimization of lifetime in nets algorithm using wireless sensors, energy and targeted dissemination protocol

Ginatto, Alex Leal 30 May 2008 (has links)
O notável desenvolvimento da indústria eletrônica observado nos últimos tempos tem permitido aplicações de conjuntos integrados de sensores em ambientes sem fio, conhecidos por wireless sensor networks (WSN), que passam por sensoriamento de processos industriais, ambientes tóxicos, projetos militares de monitoração de variáveis de segurança, até observação de fenômenos físicos naturais. Uma das principais especificações de uma rede WSN, o consumo de energia afeta diretamente a capacidade e tempo de vida útil do sistema, pois, na maioria dos casos, seus módulos possuem baterias independentes e sua substituição nem sempre é tarefa simples. Motivado pela necessidade de oferecer robustez e economia de energia nas redes WSN, o protocolo difusão direcionada se baseia na centralização de dados e a identificação de seus módulos é feita por meio de pares valor-atributo. Sua estrutura permite a adição de componentes de software que podem atuar na análise e modificação dos dados recebidos com o objetivo de alterar o protocolo original. O objetivo principal deste trabalho é investigar um método para otimização do uso de energia disponível em redes WSN com intuito de prolongar seu tempo de vida útil. O metódo consiste em analisar os valores das energias atribuídas aos módulos componentes da rede por meio de incorporação de um algoritmo de rotas baseado em energia ao protocolo difusão direcionada. Comparações de desempenho da rede em relação ao seu tempo de vida e energia dos módulos são realizadas utilizando o simulador NS-2. As simulações feitas em diversos cenários indicaram melhoria de desempenho em relação ao protocolo difusão direcionada original. Os cenários onde o protocolo original foi alterado apresentaram um número maior de rotas descobertas e possibilitaram um aumento de pelo menos 22% no tempo de vida da rede, em relação ao protocolo original. / The notable development of electronic industry in the last years allows the implementation of sensor integrated circuits in wireless environments, known as wireless sensor networks (WSN), which leads to industrial process sensing, toxic environments, military security monitor projects and natural physical phenomenon. As one of the main specifications of a WSN network, the energy consumption directly affects the capacity and the system useful lifetime, since most of the time its modules have independent batteries and their substitution is not always a simple task. Motivated by the need of offering robustness and energy economy for WSN networks, the directed diffusion protocol is data-centric based and its modules identification is made by attribute-value pairs. The directed diffusion structure enables the addition of software components which can act on the analysis and modification of received data with the objective of changing the original protocol. The main objective of this work is to investigate a method for optimization of available energy on WSN networks with the intention of increasing its useful lifetime. The method consists on analyzing the energy values attributed to the component modules of the network by incorporating an energy-based routing algorithm to directed diffusion protocol. Performance comparisons of the network related to its lifetime and modules energy are developed using the NS-2 simulator. Simulations performed in several scenarios indicated a better performance in relation to the original directed diffusion protocol. The scenarios where the original protocol was changed had larger number of discovered routes and allowed a rising of at least 22% on network lifetime, in relation to the original protocol.

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