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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.
61

Bluetooth Mesh Networks: Evaluation of Managed Flooding in Different Environments

Hanna, Ayham, Assaf, Alaa January 2023 (has links)
Bluetooth Mesh networks have gained popularity across various industries, showcasing their significant impact on network solutions. This technology is particularly notable for its low power consumption, making it a preferred choice for efficient and sustainable network development.  The objective of this study investigates the behavior of Bluetooth Mesh networks in various environments, aiming to improve network performance and provide guidance for optimal network design. This was achieved by performing experiments in multiple environments.  Data collection and regression analysis along with comparative visualization were employed to understand the relationship between these variables, including distance, number of packets sent, environment, latency, and packet loss ratio.   The results showed a significant relationship between distance and latency in the office and forest environments, as well as between distance and packet loss ratio in all environments. The number of packets sent has impact on latency and packet loss ratio.  The findings contribute to the development of more reliable and efficient communication systems for Internet of Things applications, as well as providing insights into the performance characteristics of the Bluetooth Mesh network in various scenarios.
62

Investigating the impact of physical layer transmission for Bluetooth LE Audio

Arponen, Kevin, Björkman, Axel January 2023 (has links)
Bluetooth Low Energy (BLE) is a widely used low-energy version of Bluetooth’swireless protocol. To meet increasing requirements of modern wireless audio devices,Bluetooth LE Audio was released with its new Low Complexity CommunicationsCodec (LC3) being much more data efficient than its predecessor Low Complexity SubBand Coding. Because of its increased data efficiency, LC3 opens the door of exploring usage ofvarious physical layer configurations, especially those with lower data rates. Thedifference in performance when streaming audio with the uncoded LE 2M and 1Mconfigurations, compared to using the LE coded S=2 and S=8 configurations (whichhave a lower throughput) points to a research gap which this thesis aims to fill. To be able to gather data necessary to fill the identified gap, multiple iterations of bothsoftware and hardware artefacts were made. The produced artefacts were designed torun the same Bluetooth version (LE Audio) and switch between the physical layerconfigurations. Throughput and current consumption in varied ranges was measuredthrough usage of the artefacts. The results from the experiments show that for energy optimization, an adaptive schemewould not be beneficial over only using LE 2M. However, an adaptive scheme for thephysical layer can be used for LE Audio to improve range and stability. This doeshowever, come with the cost of increased energy consumption.
63

Energy comparison of wireless data transfer in an energy critical driven system : Digitizing analog meters for the world of IoT - An energy study in a concrete environment

Kantis, Simon, Magnusson, Eric January 2022 (has links)
Digitizing analog meters into the IoT where meters can be read remotely is a solution which is both environmentally and economically beneficial. This study investigate show energy critical systems can gain a longer lifespan by optimizing their energy consumption. The purpose of this study is to evaluate the energy consumption of energy critical systems with different wireless data transfer protocols. This is conducted with experiments and observations.The data was collected by setting up two testbeds where the wireless transmission interfaces WiFi and BLE were used to send data between two microcomputers. These testbeds measured the energy consumption when altering with the variables of the two transmission protocols.The result shows that the internal protocols of WiFi were greatly affected by the changes made in the variables compared to BLE during the experiments. The results also show that when calibrating the different variables, the energy consumption is reduced by up around 52%. Furthermore, the result indicates that there is energy to saveif you optimize transmission power to a specific environment.In this study, BLE has little to no change to the energy consumption when changing the different variables. When investigating the internal protocols of WiFi, they are greatly affected by the different variables being changed. A lower transmission power can be more energy efficient but at the cost of shorter range and eventually a higher packet loss.
64

An Enhanced Body Area Network to Wirelessly Monitor Biometric Information

Moore, Levi M. January 2017 (has links)
No description available.
65

The Smart Home From a Security Perspective

Christensson, Daniel, Eriksson, Emelie January 2019 (has links)
Based on the fact that many electronic devices are digitalized in our world in order to facilitate our lives, there is a large potential for development in the home. Smart Home solutions are giving us the opportunity to control and manage for example alarms, electricity and surveillance but the technology's rapid improvement paves the way for issues related to security. The objectives for this work will bring up common communication technologies, security and vulnerabilities in the context of a Smart Home and what could be done for future work. In order to investigate the objectives, a literature study has been conducted together with an experiment. The experiment result exploits a weakness in a common Smart Home technology used in the network enable devices in the form of threats and vulnerabilities. In order to mitigate and minimize threats and vulnerabilities one conclusion is that a security policy could be produced. This security policy should provide the user with good practice of how to manage security in order to mitigate vulnerabilities and threats within the Smart Home.
66

結合藍牙低功耗的 IEEE 802.11無線網路負載平衡機制 / Load Balance for IEEE 802.11 Wireless LAN with Bluetooth Low Energy

李致賢, Lee, Chih Hsien Unknown Date (has links)
在使用者較為密集的場合中,常會碰到無線網路壅塞的問題,例如在一個大型會議廳中,常會在各個IEEE 802.11頻道上部署不同的WiFi AP(Access Point),來分散使用者的連線。但是由於IEEE 802.11的連線機制是屬於使用者主導(client driven),只能透過使用者去選定AP進行連線,對於使用者裝置來說,,連線到不同AP的優先順序,是依照接收到不同AP的信號強度(RSSI)作為排序指標。這種做法會讓在空間上使用者分佈不平均的環境中,造成多數使用者UE只連線到少數AP,而其餘AP資源閒置無用的情形。 本論文提出一個IEEE 802.11的負載平衡解決方案,結合藍牙低功耗(Bluetooth Low Energy,BLE)及IEEE 802.11成為一個智慧型AP架構。我們利用藍牙低功耗通訊協定GATT (Generic Attribute Profile)分派AP給不同使用者進行連線,再結合馬可夫鏈平穩狀態分佈(Markov Chains Stationary Distribution)演算法,依照使用者在AP網路拓樸中的歷史分佈紀錄,將多個AP的分派轉化為Erlang-C模型的排隊系統以計算AP分派規則,藉此達到系統的負載平衡。 / Usually, a user crowded space encounters wireless network congestion problem. For example, a large conference hall often deploys different wireless AP (Access Point) on each IEEE 802.11 channel to separate users’ connections. However, since the connection mechanism of IEEE 802.11 is client driven, the AP connection is selected by the user and the selection is according to the received signal strength (RSSI) from different APs. This conventional approach may result in most of the user devices connect to relatively limited number of APs, and the resource of the rest of the APs left unused. This paper proposes a smart AP architecture which is able to manage load balance for IEEE 802.11 Wireless LAN using Bluetooth Low Energy (BLE) GATT (Generic Attribute Profile) protocol in order to appropriately assign AP to different user devices. The core AP assignment algorithm is based on Markov chain stationary distribution. Simulation results show that the proposed BM-MS (BLE Management with Markov-Chains Stationary Load Balance) method outperforms RSSI based method in terms of system throughput and average user data rate.
67

Intra-Vehicle Connectivity : Case study and channel characterization

Sellergren, Albin January 2018 (has links)
The purpose of this thesis was to investigate the feasibility of a wireless architectural approach for intra-vehicle communications. The current wired architecture was compared to a wireless approach based on three prominent wireless protocols, namely Bluetooth Low-Energy, Ultra Wide-Band, and 60 GHz Millimeter wave technology. The evaluation was focused on their potential use within the intra-vehicle domain, and judged by characterizing properties such as frequency, bandwidth utilization, and power efficiency. A theoretical study targeting the propagating behavior of electromagnetic waves was also involved. In particular, wireless behavior has been investigated both in general aspects as well as specifically aimed towards the intra-vehicle application. The theoretical study was then concluded and presented with a course of action regarding wireless connectivity. Beneficial design considerations, potentials and challenges were highlighted together with a discussion on the feasibility of a wireless architectural approach. Suggestions for future work and research have been given, which include further expansion of targeted protocols, alleviating the restricted security aspects, and extend the physical aspects onto more software based approaches.
68

Beacons & Internet of Things : A design concept for contect-aware mobile interaction with beacons

Selezneva, Nadia, Juskova, Aleksandra January 2014 (has links)
Mobile technology is developing quickly and becomming a part of daily life and communication. Bluetooth Low Energy is presented as a new way of mobile interaction. However there are not enough studies in this field on the interaction between mobile devices and the physical world. In order to understand user needs, and to encourage users to interact, we simulated an interaction process through designing and testing a prototype in a specific indoor environment. Prototype effectiveness and main characteristics for future mobile application was evaluated through a qualitative user study with 20 participants who interacted with our prototype. / Den mobila tekniken växer snabbt och blir en del av våra liv och vår kommunikation. BLE presenteras på ett nytt sätt inom mobilinteraktion. Det förekommer inte tillräckligt med studier inom området för interaktionen mellan mobila enheter och den fysiska världen. För att förstå användarbehov och få användare att interagera har vi simulerat en interaktiv process genom att designa och testa en prototyp i en specifik inomhusmiljö. Utvärdering av prototypens effektivitet och heuristiken har evaluerats genom en kvalitativ studie med 20 användare som har deltagit i interaktionen med vår prototyp.
69

Development of a Bluetooth controller for mobile VR headsets

Holmberg, Tommy January 2018 (has links)
Mobile virtual reality (VR) headsets have been becoming more and more popular. However, the cheapest headsets do not come with any controllers and the ones that do include controllers only uses sensors for rotation, not translational movement. This thesis project aims to develop a prototype of a Bluetooth connected controller for the mobile VR headsets. The controller is based on a MetamotionC board produced by mbientlab Inc., which comes with Bluetooth Low Energy (BLE), an ARM M4 microcontroller, an miniature inertial measurement unit (IMU) sensor (containing a 3-axis accelerometer, a 3-axis gyroscope, and a 3-axis magnetometer and a barometer), a thermometer and other sensors. The only sensors used in this project are the accelerometer, gyroscope, and magnetometer. As a finished prototype, the MetaMotionC is placed on a glove together with five Aruco markers; a 3D model of a hand intended to use as an avatar of the glove was made with Blender and MakeHuman; and a VR room to use the controller with was created in Unity. The 3D hand responds to rotational and translational movements via Bluetooth connection to the IMU sensor on the MetaMotionC. The smartphone camera is used to detect the glove's position with Aruco markers, and the 3D hand is moved to a corresponding location in the VR room. The OpenCV library is used for image processing. The sensor data is filtered with low-pass, median, and thresholding to improve the measurement accuracy. Zero velocity update is used to reset the drift of the integrated accelerations. To reduce the integration error, Romberg's method with a floating window is implemented in Matlab. However, it did not reduce the error enough to make a difference. Thus, the result was unreliable.
70

End-to-end Security Enhancement of an IoT Platform Using Object Security

Tjäder, Hampus January 2017 (has links)
The Internet of Things (IoT) is seen as one of the next Internet revolutions. In a near future the majority of all connected devices to the Internet will be IoT devices. These devices will connect previously offline constrained systems, thus it is essential to ensure end-to-end security for such devices. Object Security is a concept where the actual packet or sensitive parts of the packet are encrypted instead of the radio channel. A compromised node in the network will with this mechanism still have the data encrypted ensuring full end-to-end security. This paper proposes an architecture for using the object security format COSE in a typical constrained short-range radio based IoT platform. The IoT platform utilizes Bluetooth Low Energy and the Constrained Application Protocol for data transmission via a capillary gateway. A proof-of-concept implementation based on the architecture validates that the security solution is implementable. An overhead comparison between current channel security guidelines and the proposed object security solution results in a similar size for each data packet. The thesis concludes that object security should be seen as an alternative for ensuring end-to-end security for the Internet of Things.

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