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Mobil datakonsumtion har drastiskt ökat de senaste åren vilket belastar de existerande kommunikationsnätverken. I och med den ökade belastningen av existerande infrastrukturer krävs det nya kommunikationslösningar. Detta har i sin tur skapat ett behov för dataavlastning på fasta nätverk, exempelvis Wi-Fi-nätverk. I denna studie undersöker vi genom simuleringar hur vi kan underhålla ett storskaligt och dynamiskt Bluetooth meshnätverk i en miljö likt Stortorget under Malmöfestivalen. Vi implementerar en nätverkstopologi för Bluetooth, scatternettopologin, i nätverkssimulatorn NS-3 och utför simuleringar där vi provocerar förändringar i topologin. Resultaten av våra simuleringar visar på att nätverket lyckas återhämta sig vid förändring i topologin, att scatternettopologin minst klarar av 240 dynamiska mobila noder samt att max 3 noder påverkas vid förändringar i topologin för simuleringar av upp till 240 noder. / Mobile data consumption has drastically increased in the recent years which stress theexisting communication networks. As an effect of the increased load a demand for newcommunication solutions has arisen, creating a need for data offloading onto fixed networks such as Wi-Fi. In this thesis, we aim to study how to maintain and reconstruct a large and dynamic Bluetooth mesh network in an environment such as Stortorget during Malmöfestivalen. We implement a network topology specific for Bluetooth, the scatternet topology, in the network simulator NS-3 and run simulations in which we provoke changes in the network topology. The result of our simulations shows that the network is able to heal itself when the topology changes, that the scatternet topology can manage up to 240 dynamic mobile nodes and that at most 3 nodes are affected when the topology changes during simulations of up to 240 nodes.

<p> Wireless communication has been thriving in recent years. Developments in the hardware and software industries enable more and more devices to be embedded in wireless communication modules. All kinds of interesting applications based on wireless connections are emerging, demanding simple and efficient ways to inter-connect different devices. Bluetooth is an industry standard initially proposed by Ericsson, IBM, Microsoft and some other leading IT companies to meet this growing demand. Initially, it intended to provide universal low cost, low power, and low complexity wireless interface to various devices. Furthermore, it also proposed to provide the possibility of interconnecting a number of mobile devices to form a network. However, the details of network formation and operation have not yet been regulated. In this work, we will investigate Bluetooth enabled network formation issues (especially when the traffic patterns on the network are well known).</p> <p> In this thesis, we use a small indoor area network model with a wired infrastructure network installed in the wall. A number of mobiles are distributed in the area and require inter-connectivity with each other and/or the outside world through multiple gateways. Unbalanced traffic in the network may result in hotspots leading to poor network throughput. Therefore, a centralized network formation algorithm is needed for Bluetooth networks to solve this problem.</p> <p> This thesis proposes novel Network Formation based on a Traffic Distribution (NFTD) mechanism. This centralized mechanism co-ordinates the behavior of mobiles and is implemented on gateways (also called access points). It forms the network topology according to the traffic distribution so that the path length of hotspot flows can be limited in order to maximize the network capacity. Last but not least, infrastructure networks provide free high-speed links for mobiles to further increase network capacity. The proposed mechanism is a promising mechanism as supported by simulation results.</p> / Thesis / Master of Applied Science (MASc)

Los silenciadores son componentes utilizados para reducir las emisiones sonoras emitidas por los automóviles. Para lograrlo se reduce la efectividad del motor debido al efecto denominado contrapresión. Esto ocurre puesto que para reducir la intensidad de las emisiones sonoras se reduce la velocidad de circulación de los gases de escape provocando que se interrumpa la libre circulación del flujo y se tenga que destinar parte de la potencia del motor en expulsar correctamente gases de combustión. Por esta razón se ha diseñado un sistema que permite modificar los modos de operación del silenciador (denominado en inglés Muffler). Con este sistema mecatrónico se brinda la posibilidad de mantener la reducción de las emisiones sonoras para lugares urbanos respetando las normas legales que permiten un límite máximo de 88 dB para vehículos livianos; pero también se ofrece la posibilidad de modificar el sistema para que la salida de los gases de escape sea libre. Con la expulsión libre del flujo de gases se logra aumentar la eficiencia del motor del automóvil y a la vez disminuir el consumo de gasolina cuando el usuario se encuentre en carreteras o pistas de carreras. También se brindan otros tipos de configuraciones que permiten combinar ambas características buscando un equilibrio entre el sonido y la eficiencia. El sistema es controlado mediante una aplicación instalada en un dispositivo móvil inteligente (Smartphone). Esta aplicación permite realizar la conexión con el silenciador mediante la tecnología inalámbrica Bluetooth. Mediante la aplicación se puede seleccionar uno de los cuatro estados en los que se puede configurar al silenciador. Además se muestra en la pantalla del Smartphone la animación de la configuración interna del sistema, la cual corresponde al estado de funcionamiento que selecciona el usuario. Finalmente el sistema está diseñado para que su instalación sea sencilla, para que sea alimentado desde la batería y para que sea compatible con todo tipo de automóvil.

La llegada de nuevas tecnologías está creando nuevos escenarios para el consumo de publicidad siguiendo principios que permiten la personalización e interacción con los usuarios finales de forma directa. Los anunciantes y las marcas deben considerar todos los puntos de encuentro posibles con el público objetivo para que de este modo se logre una comunicación productiva. Con el transcurso del tiempo, el teléfono móvil ha dejado de representar un símbolo diferenciado de las clases privilegiadas y se ha tornado en un elemento útil e indispensable en la vida de la mayoría de las personas. Además, es el dispositivo que permanece activo más tiempo que cualquier otro medio y el más personal, por lo que es ideal para alcanzar a una audiencia perfectamente segmentada en el espacio y tiempo correcto. Por ello, el presente trabajo de tesis se centra en el estudio y diseño de un Sistema de Marketing de Proximidad empleando la tecnología inalámbrica Bluetooth disponible en los terminales móviles. A lo largo del desarrollo, se citarán casos de uso en otras partes del mundo donde este sistema ya ha empezado a aplicarse y se incluirá una muestra del estado actual de interés de los usuarios por esta nueva plataforma de publicidad.

In recent years, an increasing number of devices have been developed for operation in the bands allocated by the Federal Communications Commission (FCC) for license-free operation. Given the rules governing devices in these bands, it is possible for interference created by these devices to significantly reduce the overall capacity of these bands. Two such protocols are Bluetooth and IEEE 802.11b. Several methods have been presented in the literature for managing interference between these two devices. However, these approaches are generally not practical, since they either require the purchase of specialized hardware or do not comply with the current versions of existing protocols. In this dissertation, an approach is presented that is not only backwards-compatible, but requires the algorithm to be implemented in only a small subset of the devices operating in the local environment for the coexistence algorithm to function properly. An analytical solution for this coexistence approach when applied to generic networks is presented. A method is also presented for the backwards-compatible integration of some medium access control (MAC) protocols into Bluetooth devices. A case study of the Bluetooth/IEEE 802.11b coexistence problem is presented in this dissertation, as well as a proposed coexistence mechanism, collision-based multiple access (CBMA). A form of adaptive frequency hopping (AFH) is presented in this dissertation, as well as a combined CBMA/AFH strategy. The CBMA algorithm is shown be able to significantly reduce the impact of a Bluetooth link on an IEEE 802.11b link. The AFH algorithm is shown to have comparable performance to the CBMA algorithm. A combined CBMA/AFH algorithm presented, is shown to not only have an impact on the IEEE 802.11b link that is not greater than the CBMA-only implementation, but the Bluetooth link throughput is shown to be significantly greater than either the CBMA or AFH implementation alone. / Ph. D.

A wireless sensor node (WSN) system, capable of sensing animal motion and transmitting motion data wirelessly, is an effective and efficient way to monitor pigs' activity. However, the raw sensor data sampling and transmission consumes lots of power such that WSNs' battery have to be frequently charged or replaced. The proposed work solves this issue through WSN edge computing solution, in which a Random Forest Classifier (RFC) is trained and implemented into WSNs. The implementation of RFC on WSNs does not save power, but the RFC predicts animal behavior such that WSNs can adaptively adjust the data sampling frequency to reduce power consumption. In addition, WSNs can transmit less data by sending RFC predictions instead of raw sensor data to save power. The proposed RFC classifies common animal activities: eating, drinking, laying, standing, and walking with a F-1 score of 93%. The WSN power consumption is reduced by 25% with edge computing intelligence, compare to WSN power that samples and transmits raw sensor data periodically at 10 Hz. / Master of Science / A wireless sensor node (WSN) system that detects animal movement and wirelessly transmits this data is a valuable tool for monitoring pigs' activity. However, the process of sampling and transmitting raw sensor data consumes a significant amount of power, leading to frequent recharging or replacement of WSN batteries. To address this issue, our proposed solution integrates edge computing into WSNs, utilizing a Random Forest Classifier (RFC). The RFC is trained and deployed within the WSNs to predict animal behavior, allowing for adaptive adjustment of data sampling frequency to reduce power consumption. Additionally, by transmitting RFC predictions instead of raw sensor data, WSNs can conserve power by transmitting less data. Our RFC can accurately classify common animal activities, such as eating, drinking, laying, standing, and walking, achieving an F-1 score of 93%. With the integration of edge computing intelligence, WSN power consumption is reduced by 25% compared to traditional WSNs that periodically sample and transmit raw sensor data at 10 Hz.

In recent years, advancements in the field of wireless communication have led to more innovative consumer products at reduced cost. Over the next 2 to 5 years, short-range wireless devices such as Bluetooth and Wireless Local Area Networks (WLANs) are expected to become widespread throughout hospital environments for various applications. Consequently the medical community views wireless applications as ineludible and necessary. However, currently there exist regulations on the use of wireless devices in hospitals, and with the ever increasing wireless personal applications, there will be more unconscious wireless devices entering and operating in hospitals. It is feared that these wireless devices may cause electromagnetic interference that could alter the operation of medical equipment and negatively impact patient care. Additionally, unintentional electromagnetic radiation from medical equipment may have a detrimental effect on the quality of service (QoS) of these short-range wireless devices. Unfortunately, little is known about the impact of these short-range wireless devices on medical equipment and in turn the interference caused to these wireless devices by the hospital environment. The objective of this research was to design and develop an automated software reconfigurable measurement system (PRISM) to characterize the electromagnetic environment (EME) in hospitals. The portable measurement system has the flexibility to characterize a wide range of non-contiguous frequency bands and can be monitored from a remote location via the internet. In this work electromagnetic interference (EMI) measurements in the 2.4 GHz ISM band were performed in two hospitals. These measurements are considered to be very first effort to analyze the 2.4 GHz ISM band in hospitals. Though the recorded EMI levels were well within the immunity level recommended by the FDA, it can be expected that Bluetooth devices will undergo a throughput reduction in the presence of major interferers such as WLANs and microwave ovens. A Bluetooth throughput simulator using semi-analytic results was developed as part of this work. PRISM and the Bluetooth simulator were used to predict the throughput for six Bluetooth Asynchronous Connectionless (ACL) transmissions as a function of piconet size and interferer distance. / Master of Science

This thesis investigates the interference potential of microwave ovens to Bluetooth data communication. Interference experiments are conducted in the CWT's Bluetooth lab, using CSR™ (Cambridge Silicone Radio) Bluetooth radios and a Tektronics™ Protocol Analyzer to record packet transmissions between the master and slave units. A novel, "quasi-real time" spectral measurement concept is developed to take radio frequency measurements. A LabView program enables a spectrum analyzer to download oven spectral data onto a computer via the instrument's serial port. From this data, three-dimensional plots of microwave radiated power levels versus ISM band frequencies over time periods are produced for different microwave ovens. These plots are compared with the results of interference experiments to explain Bluetooth packet errors. In addition to causing packet errors, emitted oven power levels at certain frequencies are sometimes strong enough to cause data packets to be lost (dropped) as they are transmitted over the air. This is a major problem since the Protocol Analyzer does not "see" these packets and cannot record the transmissions during an experiment. These lost packets can be accounted for if the frequency hopping scheme of the communicating Bluetooth devices is know prior to data transmission. Bluetooth's Frequency Hop Scheme is coded in Matlab for the purpose of predicting a data transmission's hopping sequence. The lost packets on each Bluetooth channel are counted by subtracting the Analyzer's recorded number of data transmissions per channel from the total number of transmissions per channel predicted by Matlab. A method is devised to calibrate the Bluetooth receiver and the spectrum analyzer is used to measure the received power level of Bluetooth signals on a particular frequency (channel). The number of packet errors on a channel is determined from the channel's C/I (carrier-to-interference ratio). If a channel's C/I level falls below the calculated C/I threshold at any instant of time due to oven operation, the packet transmitted at that instant is likely in error. A Matlab program estimates the number of packet errors per channel by counting the number of times the C/I of a channel falls below it's threshold value. The predicted number of packet errors is compared with the measured packet errors from experiments to yield extremely good results. Various oven-interference experiments are conducted in a small building, a large office environment and outdoors. For each experiment, the number of occurrences of transmitted data is plotted for each Bluetooth channel. Composite Excel bar graphs, created from this data, are compared with the oven spectral plots to describe an oven's effect on Bluetooth transmission. It is determined that different ovens cause packet errors on specifically different channels, in addition to channels 52-54 around the oven's 2450 MHz center operating frequency. The interference experiments suggest that placing an oven a radius of 10 m away from Class I (devices in a piconet will not affect data transmission). / Master of Science