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Étude et développement d'un réseau de capteurs synchronisés à l'aide d'un protocole de communication sans fil dédié à l'Internet des objets / Study and development of synchronized sensors network using a wireless communication protocol dedicated to the Internet of ThingsGilbert, Johann 18 September 2018 (has links)
Depuis les 20 dernières années, l'essor de l'IoT et du "cloud computing" a conditionné le besoin dedéployer massivement, et globalement, des capteurs afin d'alimenter des bases de données et améliorerla précision des algorithmes d'analyse. Pour répondre à ces demandes, de nouveaux réseaux basés surles bandes de fréquences ISM ont été déployés. Nous avons donc appréhendé de façon complète cestechnologies afin de garantir une qualité maximale pour nos produits mais aussi proposer des conseilsjustes dans un secteur ou abus de langage et promesses de performances sont monnaie courante.Cependant, le nombre grandissant d'objets émettant sous la fréquence du gigahertz lève un doutequant à l'impact sur la santé des êtres vivants. Dès lors, coupler l'aspect non invasif des VLC avecl'Internet des Objets permettrait non seulement de réduire les risques pour les êtres humains maisaussi de limiter la saturation des bandes radio.Néanmoins, les techniques d'aujourd'hui consistent principalement en la réalisation de systèmesdiffusant l'information depuis une source unique vers plusieurs récepteurs, ce qui est l'inverse du paradigmede l'IoT. Dans cette étude, nous avons donc réalisé un nouveau design basé sur les VLC qui meten place une topologie de réseau en étoile 3. Ce système, basé sur un concentrateur disposant d'une ouplusieurs caméra en guise de photo-récepteurs, est optimisé pour plus d'autonomie. Ainsi, la vitessede transmission peut être gérée dynamiquement sans être connue par les autres éléments du système. / In the last 20 years, the coming up of Internet of Things and Cloud Computing has conditionedthe need to deploy sensors everywhere to feed databases and analytics. To meet this requirements,new kind of networks have been massively deployed based on the sub-gigahertz frequency which haveunknown effect on human health.Couple the non-invasive aspect of the Visible Light Communication (VLC) with IoT could notonly reduce potential risks for human health but also avoid radio band saturation. However, today'stechniques consist mainly in broadcast data from light sources to receivers which is the opposite of theIoT paradigm. In this study, we will present a new design where the gateway is not a classic photodiodebut a camera.With this camera based method, we are able to design a star network using VLC. Even if the datarate is not the same as standard method, we are now able to collect data emanating from many sensorsat once with only one photoreceptor. This system also includes the ability of discriminate LED matrix,which transfer the same data faster, and single LED. Finally, data rate can be handle autonomouslyby the system to provide an optimal data transfer.
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WAN-optimering för sjöfarten : En möjlighet att effektivisera datakommunikationen till sjössAxelsson, Johannes January 2013 (has links)
Verksamheten ombord på fartyg blir mer beroende av datakommunikation och många av arbetsuppgifterna ombord underlättas genom att besättningen kan nå information lagrad på annan plats. Fartygens bredbandsanslutning sker till största delen via satellitkommunikation där långa avstånd och begränsad datahastighet resulterar i att datakommunikationen blir ineffektiv. I denna studie undersöks vilken prestandaförbättring som utrustning för nätverksoptimering kan innebära för långsamma WAN-förbindelser via satellit. Undersökningen visade att det största problemet med anslutningar via satellit är den signalfördröjning som uppkommer vid långa sändningsavstånd. Detta medför att det blir prestandaproblem för datatrafiken och användare upplever anslutningen som långsam. För att åtgärda detta finns utrustning som hanterar datatrafiken och genom olika tekniker kan öka prestandan på anslutningen. För att undersöka hur stor prestandaförbättringen kan vara genomfördes ett antal olika experiment med utrustning för nätverksoptimering. Experimenten genomfördes genom att utvärdera filöverföringar med och utan nätverksoptimering. Resultaten visar att utrustningen för nätverksoptimering ger en stor prestandaförbättring vid filöverföringar. / Shipboard operations have become more reliant of data communication and many of the duties on board may be facilitated if the crew can access information stored elsewhere. The broadband connection between ship and shore is mostly done via satellite communication where long distances and limited data rate results in inefficient data communication. This study examines network optimization and the performance improvement this can have regarding slow WAN connections via satellite. The survey showed that the biggest issue with data communication via satellite is the signal delay caused by the long transmission distance which means that there will be performance degradation for data traffic and users will experience the data communication as slow. To solve this there is equipment that enhances the performance of the connection and handles the data communication by implementing various techniques. To investigate how much the performance improvement can be this study carried out a number of experiments with network optimization equipment. The experiments evaluated file transfer with and without network optimization. The results show that the network optimization gives a major performance improvement regarding file transfer.
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An Overview of Monitoring Challenges That Arise With SD-WAN / Övervakningsutmaningar som introduceras med SD-WANBlidborg, Emilia January 2022 (has links)
Software-Defined Wide Area Networks is a technology that has received a lot of attention in recent years. The technology enables direct Internet access without having to direct traffic through a data center. It also enables the use of less expensive Internet connections to build the Wide-Area Network, expensive Multiprotocol LabelSwitchingconnectionsarenolongernecessary. This results in greater responsibility for enterprises when it comes to ensuring performance within the network, where the previous dedicated links with a guaranteed performance by Internet Service Provider have been replaced with unpredictable best-effort connections. The project targets the challenges Software-Defined Wide Area Networks introduces in terms of monitoring, by examining the required network transparency between Wide-Area Network edges. A selection of Network Management Systems was evaluated with the requirements specification as a basis. The results show that more diligent monitoring at the edges is needed. Visibility into the underlay network, providing transportation, has to be available. Where the enterprises need to be able to examine path-selection of traffic per application. To ensure that the root of problems can be located in case of performance issues. This was not obtained by the evaluated Network Management Systems. Moreover, it turned out that there was no common standard available for monitoring the technology at the time of the project. The lack of knowledge in the field aimed to decrease with the degree project and the result is of greatest interest to companies that have made the transition to Software-Defined Wide Area Networks or are about to do so. / Software-Defined Wide Area Networks är en teknik som har fått mycket uppmärksamhet de senaste åren. Tekniken möjliggör direkt internetåtkomst utan att behöva dirigera trafik genom datacentret. Det möjliggör också användningavbilligareinternetanslutningar för att bygga Wide-AreaNetwork, dyra Multiprotocol Label Switching anslutningar är inte längre nödvändiga. Detta resulterar i ett större ansvar för företag när det gäller att säkerställa prestanda inom nätverket, där de tidigare dedikerade länkarna med garanterad prestanda av internetleverantörer har ersatts med oförutsägbara anslutningar som skickar trafik efter bästa förmåga. Examensarbetet riktar sig mot de utmaningar som Software-Defined Wide Area Networks innebär när det gäller övervakning, genom att undersöka den nödvändiga nätverkstransparensen mellan Wide-Area Network kanterna. Ett urval av nätverkshanteringssystem utvärderades med en definierad kravspecifikation som grund. Resultaten visar att det behövs mer noggrann övervakning i Wide-Area Network kanterna. Insyn i transportlagret måste vara tillgänglig och företagen behöver kunna granska vägval av trafik per applikation, för att säkerställa att ursprungsfel går att lokaliseras i händelse av prestandaproblem. Detta erhölls inte av de utvärderade nätverkshanteringssystemen. Det visade sig dessutom att det inte fanns någon gemensam standard tillgänglig för övervakning av tekniken vid tidpunkten för examensarbetet. Examensarbetet syftar till att minska kunskapsbristen inom området och resultatet är av störst intresse för företag som gjort övergången till Software-Defined Wide Area Networks eller är på väg att göra det.
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INSTRUMENTING AN AIRBORNE NETWORK TELEMETRY LINKLaird, Daniel, Temple, Kip 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 / The Central Test and Evaluation Investment Program (CTEIP) Integrated Network Enhanced Telemetry (iNET) program is currently testing a wireless local area networking (WLAN) in an L-band telemetry (TM) channel to evaluate the feasibility and capabilities of enhancing traditional TM methods in a seamless wide area network (WAN). Several advantages of networking are real-time command and control of instrumentation formats, quick-look acquisition, data retransmission and recovery (gapless TM) and test point real-time verification. These networking functions, and all others, need to be tested and evaluated. The iNET team is developing a WLAN based on 802.x technologies to test the feasibility of the enhanced telemetry implementation for flight testing.
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A PMIPv6 Approach to Maintain Network Connectivity during VM Live Migration over the Internet / A PMIPv6 Approach to Maintain Network Connectivity during VM Live Migration over the InternetKassahun, Solomon, Demissie, Atinkut January 2013 (has links)
Live migration is a mechanism that allows a VM to be moved from one host to another while the guest operating system is running. Current live migration implementations are able to maintain network connectivity in a LAN. However, the same techniques cannot be applied for live migration over the Internet. We present a solution based on PMIPv6, a light-weight mobility protocol standardized by IETF. PMIPv6 handles node mobility without requiring any support from the moving nodes. In addition, PMIPv6 works with IPv4, IPv6 and dual-stack nodes. We have setup a testbed to measure the performance of live migration in a PMIPv6 network. Our results show that network connectivity is successfully maintained with little signaling overhead and short VM downtime. As far as we know, this is the first time PMIPv6 is used to enable live migration beyond the scope of a LAN.
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Webová aplikace pro správu síťových prvků Mikrotik / Web application for Mikrotik network nodes managementVaňátko, Matěj January 2016 (has links)
The thesis describes a comprehensive solution of a web application for administration of extensive LAN and WAN networks, which are based on nodes by MikroTik . There is a feasibility study, which says, what modules and what functionality should be included. Also a database structure is clarified and technical procedures of solution of the whole assignment are outlined with an emphasis on universality and maximal simplicity.
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THE FUTURE OF DATA ACQUISITIONWexler, Marty 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / The necessity to acquire and analyze data dates back to the beginning of science itself. Long ago, a scientist may have run experiments and noted the results on a piece of paper. These notes became the data. The method was crude, but effective. As experiments got more complex, the need for better methodologies arose. Scientists began using computers to gather, analyze, and store the data. This method worked well for most types of data acquisition. As the amount of data being collected increased, larger computers, faster processors, and faster storage devices were used in order to keep up with the demand. This method was more refined, but still did not meet the needs of the scientific community. Requirements began to change in the data acquisition arena. More people wanted access to the data in real time. Companies producing large data acquisition systems began to move toward a network-based solution. This architecture featured a specialized computer called the server, which contained all of the data acquisition hardware. The server handled requests from multiple clients and handled the data flow to the network, data displays, and the archive medium. While this solution worked well to satisfy most requirements, it fell short in meeting others. The ability to have multiple computers working together across a local or wide area network (LAN or WAN) was not addressed. In addition, this architecture inherently had a single point of failure. If the server machine went down, all data from all sources was lost. Today, we see that the requirements for data acquisition systems include features only dreamed of five years ago. These new systems are linked around the world by wide area networks. They may include code to command satellites or handle 250 Mbps download rates. They must produce data for dozens of users at once, be customizable by the end user, and they must run on personal computers (PCs)! Systems like these cannot work using the traditional client/server model of the past. The data acquisition industry demands systems with far more features than were traditionally available. These systems must provide more reliability and interoperability, and be available at a fraction of the cost. To this end, we must use commercial-off-the-shelf (COTS) computers that operate faster than the mainframe computers of only a decade ago. These computers must run software that is smart, reliable, scalable, and easy to use. All of these requirements can be met by a network of PCs running the Windows NT operating system.
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Performances and quality of service of PLC networks for MV and LV distribution systems / Performances et qualité de service dans les réseaux courants porteurs pour des systèmes de distribution moyenne tension et basse tensionLu, Liping 22 November 2006 (has links)
In this thesis, we are interested in a wide-area PLC (Power Line Communication) network to provide a communication infrastructure for monitoring and control of energy distribution and consumption. This work has been carried out as a part of REMPLI (Real-time Energy Management via Power Line and Internet) European project and resulted in the definition of REMPLI PLC. For achieving high network performance and real-time data transfer using medium voltage and low voltage electricity grids, major problems such as dynamic packet routing, quality of service management and real-time event reporting are addressed. We designed an efficient routing protocol to cope with dynamic electricity grid topology changes and to relay packets to reach the destination. REMPLI PLC performance is evaluated using simulations and complemented by analytic studies. It is proved that most of the application requirements can be satisfied by REMPLI PLC. We proposed and implemented a new traffic dispatcher providing differentiated quality of service for applications. Based on ALOHA protocol, some variants have been designed and evaluated for enabling efficient real-time event notification / Dans cette thèse, nous nous intéressons à la problématique liée à la communication numérique sur courant porteur dans l’objectif de fournir une infrastructure de communication qui permet la surveillance et le contrôle de la distribution et de la consommation de l’énergie. Ce travail a été effectué dans le cadre du projet européen REMPLI (Real-time Energy Management via Power Line and Internet) et a produit la spécification REMPLI PLC (Power Line Communication). Pour fournir une meilleure performance de la communication et effectuer le transfert de données en temps réel, en utilisant les réseaux électriques de moyenne tension et de basse tension, les problèmes principaux qui sont le routage dynamique de paquets de données, la gestion de la qualité de service et la notification des événement en temps réel, ont été traités. Nous avons développé un protocole de routage efficace pour s’adapter au changement dynamique de topologie du réseau électrique. Les performances de REMPLI PLC sont évaluées en utilisant des approches de simulation couplée avec des approches analytiques. Il est prouvé que la majorité des besoins applicatifs peuvent être satisfaite par REMPLI PLC. Nous avons proposé et implanté un nouvel “ordonnançeur de traffic” fournissant différents niveaux de qualité de service pour les applications. Des variantes de protocole ALOHA ont été proposées et évaluées afin de vérifier que les propriétés temps réel requises sur les notifications d’événements sont respectées
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Tablet Computer Antenna Array for WWAN/LTE and LTE MIMO OperationsLyu, Chao-an 15 June 2011 (has links)
A tablet computer antenna array for WWAN/LTE and LTE MIMO operations is proposed. The antenna array comprises a main antenna and an auxiliary antenna. The main antenna is an eight-band coupled-fed antenna, which can cover the GSM850/900/1800/1900/UMTS and LTE700/2300/2700 operations. The auxiliary antenna is a three-band antenna, which can cover the LTE700/2300/2500 operation and occupies a small size. Acceptable isolation between the main and auxiliary antennas has also been obtained, which makes it promising for the main and auxiliary antennas to perform LTE MIMO operation in the LTE700/2300/2500 bands. Effects of the internal tablet computer antenna on the user¡¦s body are also studied. The obtained results show that the antenna can meet the 1-g body SAR specification of less than 1.6 W/kg by selecting a proper distance between the antenna and the flat phantom. Also, since the user¡¦s body is a lossy material, a decrease in the antenna¡¦s radiation efficiency is observed when the user¡¦s body is in the vicinity of the internal antenna.
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LTE/WWAN and LTE MIMO Antennas for Ultrabook ComputersLiu, Ying-chieh 12 June 2012 (has links)
In this thesis, WWAN/LTE and LTE MIMO antennas for ultrabook computers are presented. The MIMO antenna system comprises an eight-band LTE/WWAN antenna and a three-band LTE antenna. The bandwidth of the eight-band LTE/WWAN antenna is enhanced by using an embedded parallel resonant circuit, which can result in dual-resonance excitation of the lowest resonant mode of the antenna. The bandwidth of the antenna¡¦s lower band can hence cover the LTE700/GSM850/900 operation. A design technique of improving the isolation of the MIMO antenna system is also presented. The isolation enhancement is obtained by embedding a 0.5-wavelength slot in the conductive supporting plate of the upper cover of the ultrabook computer. The embedded slot can attract the excited surface currents in the conductive supporting plate and decrease the coupling between the MIMO antennas through the coupling of the surface currents. The isolation between the MIMO antennas can hence be enhanced. Moreover, this technique will not lead to decreased radiation efficiency and impedance matching of the MIMO antennas, which is attractive for practical applications.
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