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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

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.
2

Implementation of an IEEE 802.15.4 Based MAC/PHY on a FPGA

Giannikouris, Allyson January 2011 (has links)
The IEEE 802.15.4 standard defines the implementation of a Low-Rate Wireless Personal Area Network (WPAN). While the current version of the standard was ratified in 2006, there is still no readily available Medium Access Control (MAC) layer and/or Physical (PHY) layer for Altera Field Programmable Gate Arrays (FPGAs) in the public domain. This research investigates the implementation of the standard using an Altera FPGA for the MAC layer and PHY layer drivers. The Freescale MC13192 transceiver was used for the physical portion of the PHY layer, which includes the RF front end of the system. The purpose of this research was to implement a basic full function device (FFD), which is capable of acting as a node in the network, as well as co-ordinating it. This allows a simple network to be tested by loading the same code on two FPGA boards, with one configured to act as a coordinator and the other as a device. The flexibility of the standard means that there are several implementation choices to be made, each of which limits the compatibility with devices using other implementation options. The implementation and design decisions made in producing a preliminary core are described in detail. The implementation of the MAC layer primitives is discussed at length as these were not available as source code. These primitives are the building blocks for the core functions of the system. Specifically, the functionality of the Energy Detection (ED) scan, stream transmit and stream receive functions are explored in detail. The code has been implemented using C and is run on the Altera Nios II soft-core processor. The work presented here is an initial implementation meant to serve as a foundation for further research. Additional functionality defined by the standard could be added, or optimization of individual functions could be explored. The current implementation also has the potential to serve as the foundation for research into various sensors which may be part of end devices in the network.
3

The Baseband Signal Processing for 868MHz ASK Mode of the IEEE 802.15.4-2006 Low Rate-Wireless Personal Area Network

Hsu, Guan-Wen 05 August 2009 (has links)
In recent years, the worldwide progress of wireless communication technology has bringing great benefit and convenience to our people¡¦s life. Nowadays, people can use appliances of wireless communication in many fields, such as family-monitoring, automatic system, and smart-type device¡Ketc. However, in order to dealing with the need of low cost and low power communication, the researcher spend many years on developing the specification of IEEE 802.15.4 Low Rate-Wireless Personal Area Network (LR-WPAN) expected be applied in widespread use. In this thesis, we focus on the baseband signal processing for the physical layer specification of the 868/915MHz mode of the IEEE 802.15.4 LR-WPAN. Our design blocks include packet detection, sampling point detection (energy detection), carrier frequency offset (CFO) compensation, carrier phase offset (CPO) compensation, and despreading algorithms. During the process of simulation, we¡¦ll examine whether our design match the criteria of standard such as sensitivity, packet format, and modulation. While our designs achieve the requirement of the standard, we start on quantization. Finally, we¡¦ll realize the algorithm in VHDL and examine it.
4

Implementation of an IEEE 802.15.4 Based MAC/PHY on a FPGA

Giannikouris, Allyson January 2011 (has links)
The IEEE 802.15.4 standard defines the implementation of a Low-Rate Wireless Personal Area Network (WPAN). While the current version of the standard was ratified in 2006, there is still no readily available Medium Access Control (MAC) layer and/or Physical (PHY) layer for Altera Field Programmable Gate Arrays (FPGAs) in the public domain. This research investigates the implementation of the standard using an Altera FPGA for the MAC layer and PHY layer drivers. The Freescale MC13192 transceiver was used for the physical portion of the PHY layer, which includes the RF front end of the system. The purpose of this research was to implement a basic full function device (FFD), which is capable of acting as a node in the network, as well as co-ordinating it. This allows a simple network to be tested by loading the same code on two FPGA boards, with one configured to act as a coordinator and the other as a device. The flexibility of the standard means that there are several implementation choices to be made, each of which limits the compatibility with devices using other implementation options. The implementation and design decisions made in producing a preliminary core are described in detail. The implementation of the MAC layer primitives is discussed at length as these were not available as source code. These primitives are the building blocks for the core functions of the system. Specifically, the functionality of the Energy Detection (ED) scan, stream transmit and stream receive functions are explored in detail. The code has been implemented using C and is run on the Altera Nios II soft-core processor. The work presented here is an initial implementation meant to serve as a foundation for further research. Additional functionality defined by the standard could be added, or optimization of individual functions could be explored. The current implementation also has the potential to serve as the foundation for research into various sensors which may be part of end devices in the network.
5

Beroendet av temperatur, läge och inkapsling på RSS och PER i ett radiokommunikationssystem som används i ugnar

Oskar, Broo January 2016 (has links)
Denna studie har undersökt möjligheten att implementera ett trådlöst kommunikationssystem i en ugnsmiljö. Den trådlösa kommunikationstekniken som har använts är av standarden IEEE 802.15.4. För denna undersökning har ett trådlöst mätsystem för temperatur konstruerats. För att hålla nere temperaturen på detta mätsystem har kapslingsmaterialen keramik och glasull använts. Resultatet av mätningarna visar att kvalitén på radiokommunikationen kan förväntas vara god för de testade förhållande med kapsling och en temperatur upp till 200 grader. För de testade förhållandena i ugnsmiljön visar mätresultat att positionering är av större betydelse än värmeutvecklingen och kapslingen. / This study has explored the possibility to implement a wireless communication system in an ovenenvironment. For this exploration a wireless measurement system for temperature have beenconstructed. The technology of use is a radio communication system with the standard IEEE 802.15.4. The high temperature in the oven environment is kept down at the electronic by using anenclosure. The enclosure material that have been examined is a ceramic layer and a fibreglasslayer. The result of this study shows that the quality of the radio communication for the tested enclosureis expected to be good for temperatures up to 200 degrees. For the test cases the relation betweenthe radio module’s positioning is more important than the increase of temperature and the use ofan enclosure.
6

Investiga??o do impacto da mobilidade de elementos da rede IEEE 802.15.4 atrav?s do desenvolvimento de uma plataforma de simula??o / Mobility impact research on IEEE 802.15.4 network through simulation platform

Silva, Lu?s Fabiano da 17 December 2008 (has links)
Made available in DSpace on 2016-04-04T18:31:28Z (GMT). No. of bitstreams: 1 Luis Fabiano da Silva.pdf: 1657202 bytes, checksum: 723f6467468487e790c6953fa87da62b (MD5) Previous issue date: 2008-12-17 / The IEEE 802.15.4 network standard is being used as a suitable solution for wireless sensor networks in many environments and areas of expertise. This kind of network has specific characteristics that differ from others types of wireless network. This work intends to analyse the mobility impact on IEEE 802.15.4 elements. For this reason it was developed a simulation platform that contains specific requirements necessary to evaluate and compare environments with and without mobility. The results will show that the mobility of elements in the scenarios evaluated caused degradation of the signal at short distances, but for distances between 30 and 40 meters in mobility caused an improvement in the rate of transmission of elements, as well as at distances greater than 60 meters. / O padr?o de rede IEEE 802.15.4 vem sendo utilizado como solu??o adequada para redes de sensores sem fio em muitos ambientes e ?reas de atua??o. Este tipo de rede tem caracter?sticas espec?ficas que a diferem de outros tipos de rede sem fio. Este trabalho visa avaliar o impacto da mobilidade de elementos na rede IEEE 802.15.4. Para isso, foi desenvolvida uma plataforma de simula??o que contem os requisitos espec?ficos necess?rios para avaliar e comparar ambientes com e sem mobilidade. Os resultados v?o mostrar que a mobilidade dos elementos nos cen?rios avaliados provocou degrada??o do sinal em pequenas dist?ncias, mas em dist?ncias entre 30 e 40 metros a mobilidade causou uma melhora na taxa de transmiss?o dos elementos, assim como em dist?ncias maiores que 60 metros.
7

Réseaux de capteurs et vie privée / Wireless sensor networks and privacy

Dos Santos, Jessye 28 August 2017 (has links)
Les médias et de nombreuses études scientifiques évoquent fréquemment la notion de vie privée en lien avec des exemples de cyber attaques. Le vol par des hackers de 12 millions d’identifiants d’utilisateurs Apple en 2012 illustre que les objets communicants sont des maillons vulnérables exploités par les hackers pour accéder aux données personnelles des usagers. Dans cette thèse, nous allons étendre la notion de vie privée aux objets eux-mêmes, au-delà des utilisateurs, en montrant que dans des réseaux de capteurs sans fil où les communications ont lieu de machine à machine, la connaissance des adresses fixes des différents appareils constituant le réseau représente une source d’information permettant de déduire beaucoup d’éléments de contexte et d’environnement.Actuellement, tous les standards de communication sans fil intègrent la capacité de sécuriser les données transportées, y compris les protocoles de communication dédiés aux réseaux de capteurs, conçus pour fonctionner en milieu contraint et à basse consommation. Cependant, l’en-tête des trames envoyées sur l’air comportant les informations nécessaires au routage et au bon fonctionnement du réseau, figure toujours en texte clair. La collecte de ces métadonnées par écoute passive représente un danger pour les environnements et les applications qui font usage de ces réseaux.Le travail mené dans cette thèse a pour objectif d’explorer comment de simples attaques passives sur des réseaux meshés basés sur le standard IEEE 802.15.4, visant à collecter et exploiter les métadonnées de ces trames échangées sur l’air, permettent d’inférer des informations critiques sur le réseau lui-même, l’environnement dans lequel il est déployé et les comportements des personnes qui en font usage. Plusieurs solutions visant à dissimuler les adresses des nœuds du réseau sont ensuite étudiées. Ces solutions sont de deux types : soit elles rendent anonymes les dispositifs empêchant de remonter à la source des messages, soit elles reposent sur l’utilisation de pseudonymes permettant de conserver la possibilité d’auditer le trafic.Afin d’évaluer les caractéristiques et les performances de ces solutions, un simulateur a été mis en œuvre afin de reproduire le comportement d’un réseau de capteurs meshés embarquant l’OS Contiki. Ce simulateur a permis d’évaluer la solution la plus prometteuse issue de l’état de l’art, nommée MT6D, en comparant ses performances avec un réseau de référence ne dissimulant pas les métadonnées. Cette analyse a fait ressortir certains inconvénients, en particulier l’augmentation importante des trames de contrôle nécessaires au routage, et a permis d’élaborer les spécifications d’une solution plus optimale pour l’embarqué.Nous avons ainsi introduit Ephemeral, qui présente la capacité de dissimuler les adresses des dispositifs dans les messages envoyés sur l’air, par l’usage de pseudonymes, sans augmenter la quantité de trames de contrôle indispensables au routage. Une fois mis en œuvre avec le simulateur afin de valider les performances théoriques attendues, Ephemeral est déployé en environnement réel sur un réseau de capteurs IEEE 802.15.4 équipant un bâtiment. Ce retour d’expérimentation permet de confirmer qu’Ephemeral constitue une solution économe du point de vue de la consommation d’énergie et de la bande passante du réseau, pour masquer les identifiants des dispositifs impliqués dans les communications. / Privacy notion is frequently linked with cyber attack examples by media and scientific researches. In 2012, the hacking of 12 millions Apple user identifiers demonstrates that connected objects represent leaks exploited by hackers to access to user personal data. In this thesis, we will extend the privacy notion to the objects. To do this, we will show that in wireless sensor networks where communications are carried out from machine-to-machine, the knowledge of the static addresses of the devices within the network discloses information allowing deduction about elements of context and environment.Nowadays, the wireless communication standards provide security mechanisms whatever the communication protocols used including the low power ones designed to run on constrained environment. However, the frame header that comprises necessary information for routing and for the proper functioning of the network is always sent in clear text. Collecting and gathering these metadata by eavesdropping is dangerous for the environments and applications based on these networks.The work carried out in this thesis aims to explore how simple passive attacks on meshed networks based on IEEE 802.15.4 used to collect and exploit metadata allow to infer critical information about the network, the environment where the network is deployed and the behavior of users. Two kinds of solutions to hide the node addresses are studied. The first one provides anonymity for the devices. In the second kind of solutions, pseudonyms are used by nodes enabling the capability to audit the traffic within the network.To evaluate the characteristics and the performances of the solutions, a simulator has been used to reproduce the behavior of a meshed wireless sensor network embedding Contiki OS. This simulator allows to compare the performances of MT6D the most promising solution of our state of the art with that of a reference network do not mask the metadata. With this analyze, we can highlight some drawbacks and more especially the control frames overhead needed for the routing. We give the necessary specifications to deploy the most optimal solution for the embedded devices.Thus we propose Ephemeral that allows hiding device addresses provided in the sent frames by using pseudonyms without overhead on the control frames. After deployment in the simulation environment to evaluate expected theoretical performances, Ephemeral has been tested in real environment. The network is made up of twenty IEEE 802.15.4 sensor nodes deployed on a building. The results show that Ephemeral is an efficient low power and bandwidth-saving solution to hide device identifiers used in wireless communications.
8

Wireless Sensor System for Airborne Applications

Berdugo, Albert, Grossman, Hy, Schofield, Nicole, Musteric, Steven 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Adding an instrumentation / telemetry system to a test vehicle has historically required an intrusive installation for wiring and powering all elements of the system from the sensor to the telemetry transmitter. In some applications there is need for a flexible and modular instrumentation and telemetry system that can be installed with minimal intrusiveness on an aircraft without the need for permanent modifications. Such an application may benefit from the use of a miniaturized, inexpensive network of wireless sensors. This network will communicate its data to a central unit installed within the aircraft. This paper describes recent efforts associated with the Advanced Subminiature Telemetry System (ASMT) Initial Test Capability Project. It discusses the challenges in developing a wireless sensor network system for use in an airborne environment. These include selection of frequencies, COTS wireless devices, batteries, system synchronization, data bandwidth calculations, and mechanical structure for external installation. The paper will also describe the wireless network architecture as well as the architecture of the wireless sensor and the central control unit.
9

Application of IEEE 802.15.4 for home network

Jonsson, Tobias, Acquaye, Gabriel January 2008 (has links)
<!--st1\:*{behavior:url(#ieooui) } -->&lt;!--[endif]--&gt; <!-- /* Font Definitions */ @font-face {font-family:Garamond; panose-1:2 2 4 4 3 3 1 1 8 3; mso-font-charset:0; mso-generic-font-family:roman; mso-font-pitch:variable; mso-font-signature:647 0 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; mso-layout-grid-align:none; punctuation-wrap:simple; text-autospace:none; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 70.85pt 70.85pt 70.85pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> To implement a utility wireless sensor network, investigation of different wireless protocols has been performed. The protocols are Bluetooth, Wi-Fi, IEEE 802.15.4 and Zigbee. Consecutively literature studies have made it comprehensible to understand the function of the protocols that are suitable for development of wireless sensor networks. The importance of low cost, low power, reliable and high-quality properties for long distances are significant. IEEE 802.15.4 and Zigbee protocol are proper to implement as a wireless sensor network.   To reduce the human efforts in the configuration of the system, a comfortable method is implemented to facilitate the procedure. The applied method is based on an automatic configuration of the system. The configuration and the decision taking are implemented in the software. The system is designed to avoid interference to other wireless networks with the possibilities of reconfiguration. A uniform hardware and software design with separate functions of the system decided by a subsequent command for configuration is preferable. This imposes an advantage that increases the flexible potential of the system when a uniform solution is implemented.   To support the basic communication principles and control of the system, a buffer implementation has been introduced. The functionality of decision taking is distributed, configured by system commands from the host system. Detecting of system commands requires a properly operating buffer management. In consideration to the power consumption in reference to battery utilizations, the settings of RF-module and microcontroller have a powerful impact to reduce the power consumption. All possibilities of hibernates and avoidance of unnecessarily transmitting, should be deactivated to minimize the power consumption.
10

Performance Evaluation of Time Syncrhonization and Clock Drift Compensation in Wireless Personal Area Network

Wåhslén, Jonas, Orhan, Ibrahim, Sturm, Dennis, Lindh, Thomas January 2012 (has links)
Efficient algorithms for time synchronization, including compensation for clock drift, are essential in order to obtain reliable fusion of data samples from multiple wireless sensor nodes. This paper evaluates the performance of algorithms based on three different approaches; one that synchronizes the local clocks on the sensor nodes, and a second that uses a single clock on the receiving node (e.g. a mobile phone), and a third that uses broadcast messages. The performances of the synchronization algorithms are evaluated in wireless personal area networks, especially Bluetooth piconets and ZigBee/IEEE 802.15.4 networks. A new approach for compensation of clock drift and a realtime implementation of single node synchronization from the mobile phone are presented and tested. Finally, applications of data fusion and time synchronization are shown in two different use cases; a kayaking sports case, and monitoring of heart and respiration of prematurely born infants. / <p>QC 20130605</p>

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