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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.
1

Zigbee för längre avstånd

Arnberg, Jerker January 2006 (has links)
I dag går utvecklingen av trådlösa nätverk snabbt framåt. Zigbee är en helt ny teknik som bygger på IEEE 802-15-4 standarden. Zigbee utvecklades av the Zigbee Alliance som består av en rad stora elektronikföretag. Zigbee är en teknik som inriktar sig på låg energiförbrukning och låg kostnad. Tekniken är tänkt att användas för att ställa in och läsa av sensorer av olika slag. Denna rapport är ett resultat av ett examensarbete som går ut på att utreda om Zigbee tekniken kan användas för lite längre avstånd. Arbetet resulterade i två demoapplikationer för ett enkel zigbee system, och färdigskriven kod för en möjlighet att använda Zigbee för länge avstånd.
2

Sistema domótico baseado em redes Zigbee

Santos, José Alberto da Cunha Machado January 2009 (has links)
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Automação). Faculdade de Engenharia. Universidade do Porto. 2009
3

A 868/915 MHz Band ZigBee Physical Layer Design and Synchronization Mechanism Design of DVB-T Demodulators

Chang, Chih-Yi 04 July 2006 (has links)
This thesis includes two topics. The first topic is a 868/915 MHz band ZigBee physical layer design. The second topic is a synchroniza- -tion design of DVB-T demodulators. The first topic includes simulations and a hardware design. This chip is a physical layer design for IEEE Std 802.15.4 standard applications, including both a transmitter and a receiver for 868/915 MHz band. The measurement of the maximum power is about 144 µW at 2.4 MHz. This chip is proved to be compliant with a low power consumption requirement. The second topic mainly includes an introduction of the DVZB-T transmitter, equivalent channel model, a demodulation design of the receiver and simulations. The algorithms of the receiver include symbol timing synchronization, frequency offset estimation and its compensation and scattered pilots synchronization.
4

The Baseband Signal Processing and Circuit Design for 915 MHz Amplitude Shift Keying Modulation Mode of the IEEE 802.15.4 ¡V 2006 Low Rate-Wireless Personal Area Network

Liao, Kuan-yuen 29 July 2009 (has links)
The IEEE 802.15.4 is defined as a Low-Rate Wireless Personal Area Network, which is also called ZigBee. The characteristics of ZigBee are low power consumption for battery life, extremely low cost, short-range operation. According to 915 MHz Amplitude Shift Keying Modulation part of IEEE 802.15.4 ¡V 2006, we designed transmitter and receiver in base band part. In the later article, we will introduce my algorithm design, the Quantization and the Architecture in hard- ware implementation, the simulations, and the final verifying work of the layout that we did. Finally, we make a conclusion of this thesis, and we bring up the possible improvement in this design. In my algorithm of the ZigBee receiver, I fined a new table to replace the original table of spec IEEE 802.15.4 to solve multi-sequence interference, which can improve the performance about 0.2 to 0.4dB. My algorithm is lower 1.5dB than the Ideal receiver, which simulate in none carrier frequency offset (CFO) and none sample time offset, but both of mine are biggest. Then, my architecture implementation in hardware is lower about 1.5dB than my algorithm. Completed the hardware circuit design and simulations, I applied for a layout in 0.18-um CMOS technology.
5

Analysis of Zigbee Wireless Data Communication Through Baled Hay

Dittmer, Colburn 01 December 2011 (has links)
Hay that has been baled with incorrect moisture content or that has been under the influence of moisture has potential to generate heat and create a fire hazard. Traditional means of monitoring baled hay temperature in storage, by inserting a pipe probe with thermometer, are time consuming. A ZigBee wireless sensor network could be used to remotely monitor internal hay bale temperatures. Tests were conducted to determine the maximum amount of hay through which a 2.4 GHz ZigBee module could transmit data and the resulting signal strength (RSSI). Based on analysis of the data, a ZigBee transmitter with 2 mW transmitting power can transmit data through 9 ft of baled hay and a ZigBee transmitter with 50 mW transmitting power can transmit data through 18 ft of baled hay. In general, RSSI decreased significantly with each additional 3 ft of baled hay.
6

Sensoriamento de ambiente utilizando o padrão ZigBee / Environment sensing using ZigBee standard

Monsignore, Ferdinando 26 February 2007 (has links)
A comunicação sem fio (wireless) vem sofrendo uma enorme expansão nos últimos anos. Para esse tipo de comunicação foram criados alguns padrões, destacando-se o Wi-Fi, o Bluetooth e mais recentemente o ZigBee. Este último, o ZigBee, engloba aplicações de monitoração e sensoriamento de sistemas, o que o torna adequado para aplicações residenciais. Essa característica do ZigBee motivou o desenvolvimento desse trabalho, cujo objetivo foi o de avaliar o padrão ZigBee através de uma aplicação de monitoração e sensoriamento para uso residencial, utilizando um kit de desenvolvimento da Microchip. Esse trabalho consiste em dois nós se comunicando via ZigBee, onde um nó possui um sensor de movimento, uma lâmpada e um LED (que simula um aparelho de ar condicionado) e um segundo nó, que pode ser conectado a um PC via USB utilizando um hardware externo desenvolvido. Esse nó ainda possui um sensor de temperatura, um sensor de luminosidade (LDR) e um sinalizador acústico. Os resultados obtidos mostram que o ZigBee é um padrão eficiente para aplicações de monitoração e sensoriamento de ambientes. / A huge expansion has occurred in wireless communication in the last few years. Some wireless standards were created, like Wi-Fi, Bluetooth and more recently the ZigBee standard, that includes monitoring and sensing systems application. This characteristic makes the ZigBee standard appropriate for residencial applications. This ZigBee characteristic motivated the development of this work, which objective was evaluate the ZigBee standard through a monitoring and sensing application for residencial use, using a evelopment kit by Microchip. This application has two nodes communicating through ZigBee. One node has a motion sensor, a lamp and a LED (that simulates an air conditioner device) and the second one can be connected to a PC through USB using a developed external hardware. This node also has a temperature sensor, a light dependent resistor (LDR) and a beep. The reached results shows that ZigBee is an efficient standard for environment monitoring and sensing.
7

Sensoriamento de ambiente utilizando o padrão ZigBee / Environment sensing using ZigBee standard

Ferdinando Monsignore 26 February 2007 (has links)
A comunicação sem fio (wireless) vem sofrendo uma enorme expansão nos últimos anos. Para esse tipo de comunicação foram criados alguns padrões, destacando-se o Wi-Fi, o Bluetooth e mais recentemente o ZigBee. Este último, o ZigBee, engloba aplicações de monitoração e sensoriamento de sistemas, o que o torna adequado para aplicações residenciais. Essa característica do ZigBee motivou o desenvolvimento desse trabalho, cujo objetivo foi o de avaliar o padrão ZigBee através de uma aplicação de monitoração e sensoriamento para uso residencial, utilizando um kit de desenvolvimento da Microchip. Esse trabalho consiste em dois nós se comunicando via ZigBee, onde um nó possui um sensor de movimento, uma lâmpada e um LED (que simula um aparelho de ar condicionado) e um segundo nó, que pode ser conectado a um PC via USB utilizando um hardware externo desenvolvido. Esse nó ainda possui um sensor de temperatura, um sensor de luminosidade (LDR) e um sinalizador acústico. Os resultados obtidos mostram que o ZigBee é um padrão eficiente para aplicações de monitoração e sensoriamento de ambientes. / A huge expansion has occurred in wireless communication in the last few years. Some wireless standards were created, like Wi-Fi, Bluetooth and more recently the ZigBee standard, that includes monitoring and sensing systems application. This characteristic makes the ZigBee standard appropriate for residencial applications. This ZigBee characteristic motivated the development of this work, which objective was evaluate the ZigBee standard through a monitoring and sensing application for residencial use, using a evelopment kit by Microchip. This application has two nodes communicating through ZigBee. One node has a motion sensor, a lamp and a LED (that simulates an air conditioner device) and the second one can be connected to a PC through USB using a developed external hardware. This node also has a temperature sensor, a light dependent resistor (LDR) and a beep. The reached results shows that ZigBee is an efficient standard for environment monitoring and sensing.
8

Comando e monitorização de sistemas de actuação via redes wireless - ZigBee

Azevedo, Carlos Manuel Oliveira January 2010 (has links)
Tese de mestrado integrado. Engenharia Mecânica (Opção de Automação). Faculdade de Engenharia. Universidade do Porto. 2010
9

Gateway ZigBee - Modbus/TCP

Pereira, Pedro Miguel Carvalho January 2009 (has links)
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major de Automação). Faculdade de Engenharia. Universidade do Porto. 2009
10

BLUETOOTH / ZIGBEE NETWORKS AND DEVELOPMENT OF PORTABLE 6LOWPAN STACK

Gaddam, Nagavenkat kumar January 2013 (has links)
Wireless sensor networks (WSN’s) are becoming popular in military and civilian applications such as surveillance, monitoring, disaster recovery, home automation and many others. Prolonged network lifetime, scalability, node mobility and load balancing are important requirements for many WSN applications. This thesis work presents the investigation of scalability and power consumption in different wireless module such as Bluetooth, Zigbee to deploy in the large scale wireless sensor network application by simulation the network topologies, analysis and comparison of both the wireless module in OPNET and running the WSN application using Zigbee in Real environment. In order to increase the scalability and reduce the power consumption we use the Internet protocol version 6 (IPv6) over Low Power Wireless Personal Area Network (6LoWPAN), we worked on the programming of the 6LoWPAN protocol stack and analysis of the results using the perytons network protocol analyzer.

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