This thesis presents the research work regarding the solution of a localization problem in indoor WLANs by introducing a distributive time division multiplexed localization technique based on the convex semidefinite programming. Convex optimizations have proven to give promising results but have limitations of computational complexity for a larger problem size. In the case of localization problem the size is determined depending on the number of nodes to be localized. Thus a convex localization technique could not be applied to real time tracking of mobile nodes within the WLANs that are already providing computationally intensive real time multimedia services. Here we have developed a distributive technique to circumvent this problem such that we divide a larger network into computationally manageable smaller subnets. The division of a larger network is based on the mobility levels of the nodes. There are two types of nodes in a network; mobile, and stationery. We have placed the mobile nodes into separate subnets which are tagged as mobile whereas the stationary nodes are placed into subnets tagged as stationary. The purpose of this classification of networks into subnets is to achieve a priority-based localization with a higher priority given to mobile subnets. Then the classified subnets are localized by scheduling them in a time division multiplexed way. For this purpose a time-frame is defined consisting of finite number of fixed duration time-slots such that within the slot duration a subnet could be localized. The subnets are scheduled within the frames with a 1:n ratio pattern that is within n number of frames each mobile subnet is localized n times while each stationary subnet consisting of stationary nodes is localized once. By using this priority-based scheduling we have achieved a real time tracking of mobile node positions by using the computationally intensive convex optimization technique. In addition, we present that the resultant distributive technique can be applied to a network having diverse node density that is a network with its nodes varying from very few to large numbers can be localized by increasing frame duration. This results in a scalable technique. In addition to computational complexity, another problem that arises while formulating the distance based localization as a convex optimization problem is the high-rank solution. We have also developed the solution based on virtual nodes to circumvent this problem. Virtual nodes are not real nodes but these are nodes that are only added within the network to achieve low rank realization. Finally, we developed a distributive 3D real-time localization technique that exploited the mobile user behaviour within the multi-storey indoor environments. The estimates of heights by using this technique were found to be coarse. Therefore, it can only be used to identify floors in which a node is located.

Des techniques fiables de radiolocalisation s’avèrent indispensables au développement d’un grand nombre de nouveaux systèmes pertinents. Les techniques de localisation basées sur les réseaux de communication sans-fil (WNs) sont particulièrement adéquates aux espaces confinés et fortement urbanisés. Le présent projet de recherche s’intéresse aux systèmes de localisation en temps réel (RTLS) basés sur les technologies de communication sans-fil existantes. Deux nouvelles techniques de radiolocalisation alternatives sont proposées pour améliorer la précision de positionnement des nœuds sans-fil mobiles par rapport aux méthodes conventionnelles basées sur la puissance des signaux reçus (RSS). La première méthode de type géométrique propose une nouvelle métrique de compensation entre les puissances de signaux reçus par rapport à des paires de stations réceptrices fixes. L’avantage de cette technique est de réduire l’effet des variations du milieu de propagation et des puissances d’émission des signaux sur la précision de localisation. La même métrique est sélectionnée pour former les signatures utilisées pour créer la carte radio de l’environnement de localisation durant la phase hors-ligne dans la deuxième méthode de type analyse de situation. Durant la phase de localisation en temps réel, la technique d’acquisition comprimée (CS) est appliquée pour retrouver les positions des nœuds mobiles à partir d’un nombre réduit d’échantillons de signaux reçus en les comparant à la carte radio préétablie. Le calcul d’algèbre multilinéaire proposé dans ce travail permet l’utilisation de ce type de métrique ternaire, équivalemment la différence des temps d’arrivée (TDOA), pour calculer les positions des cibles selon la technique de CS. Les deux méthodes sont ensuite validées par des simulations et des expérimentations effectuées dans des environnements à deux et à trois dimensions. Les expériences ont été menées dans un bâtiment multi-étages (MFB) en utilisant l’infrastructure sans-fil existante pour retrouver conjointement la position et l’étage des cibles en utilisant les techniques proposées. Un exemple emblématique de l’application des RTLS dans les zones urbaines est celui des systèmes de transport intelligents (ITS) pour améliorer la sécurité routière. Ce projet s’intéresse également à la performance d’une application de sécurité des piétons au niveau des intersections routières. L’accomplissement d’un tel système repose sur l’échange fiable, sous des contraintes temporelles sévères, des données de positionnement géographique entre nœuds mobiles pour se tenir mutuellement informés de leurs présences et positions afin de prévenir les risques de collision. Ce projet mène une étude comparative entre deux architectures d’un système ITS permettant la communication entre piétons et véhicules, directement et via une unité de l’infrastructure, conformément aux standards de communication dans les réseaux ad hoc véhiculaires (VANETs).

An innovative structure for thin-film band-pass filters was proposed and analyzed. This structure was employed in the design, fabrication, and development of 3D IPD diplexers on glass substrates with double-side metallization electrically connected by through-vias. Through modeling, design, fabrication and characterization of the WLAN 3D IPD glass diplexers, the proposed filter structure was shown to enable miniaturized and high-performance RF passives. Further, component-level shield structures were developed to provide electromagnetic interference isolation between thin-film passives that are placed less than 100 µm apart. Glass substrates were designed, fabricated and characterized to demonstrate the shield effectiveness of metallized trench and via-array-based shields. The integration of such shields in miniaturized WLAN RF modules enables up to 60dB EM isolation in the frequency range of 1- 20GHz. Advanced RF module technologies based on 3D IPAC concept were designed and demonstrated with ultra-thin low-loss organic and glass substrates, integrating the proposed WLAN actives with miniaturized diplexer and EM shields. Double-side integration of such high-performance components on ultra-thin glass substrates enables up to 8x volume miniaturization including more than 3x reduction in area. Thus, the advanced components demonstrated in this research, vis-a-vis miniaturized diplexers and component-level EMI shields; integrated with actives in ultra-thin glass substrates using the 3D IPAC concept, can enable highly-miniaturized smart systems with multiband wireless communication capabilities.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Distributed processing is coming to data acquisition. The desire for smart sensors that can preprocess data, is growing. Making sensors themselves intelligent will reverse the historic trend toward smaller and cheaper sensors. Incorporating current sensor technology into data acquisition nodes in a network will create a distributed data acquisition, DAQ, environment that can acquire data from around the world over the Internet. The future is now.

<p>Detta arbete beskriver och analyserar vilka förutsättningar som är viktiga att ta hänsyn till vid en installation av ett trådlöst nätverk hos SYSteam. Ämnet trådlösa nätverk är omfattande och komplext och många i branschen saknar idag kompetens inom området. Det finns en uppsjö av olika komponenter, krypteringar och tillvägagångssätt. Detta arbete har utförts i samarbete med SYSteam Network Center (SNC), som vill undersöka möjligheterna och vilka förutsättningar som krävs för att kunna erbjuda ett gemensamt trådlöst nätverk som uppfyller kraven att vara säkert, skalbart och centralt administrerbart från SNC. SNC vill skaffa sig en uppfattning om vilket behov som de olika bolagen hos SYSteam i Huskvarna har av ett trådlöst nätverk, och därmed få fram en gemensam bild av hur ett trådlöst nätverk bör utformas. Som en del av detta intervjuas personer inom respektive bolag. SNC önskar sedan kunna erbjuda SYSteams bolag i Huskvarna ett gemensamt trådlöst nätverk som beaktat samtligas intresse. Genom intervjuerna gick det att urskilja följande problem i SYSteams nuvarande nätverkslösning:</p><p>Dagens struktur hämmar samarbete mellan bolag.</p><p>Avsaknaden av en smidig gästaccess ger ett dåligt intryck på gäster.</p><p>Gäster och personal är idag bundna till ett begränsat antal switchportar.</p><p>Anslutna gäster får åtkomst till delar av SYSteams interna klientnät. Gästerna bör endast komma åt de delar som de absolut behöver.</p><p>För att kunna behandla och bearbeta de olika problemen utförs en behovsanalys. Utifrån behovsanalysen studeras lämplig litteratur i syfte att förse SNC med en omfattande analys om tekniken, affärsnyttan och mervärden som ett trådlöst nätverk kan erbjuda, men också hur ett trådlöst nätverk bör administreras och säkras. Resultatet fokuserar även på vilka utmaningar och problem som kan förekomma i en trådlös miljö, samt ger förslag på hur SNC i Huskvarna bör utforma ett trådlöst nätverk. SNC står inför en stor utmaning med att erbjuda ett trådlöst nätverk som kan upplevas användarvänligt men som samtidigt måste uppfylla vissa säkerhetskrav. Arbetet visar att om man tar hänsyn till de utmaningar som finns och kartlägger de problem som finns så är det möjligt att utforma ett skalbart, säkert nätverk som samtidigt tar hänsyn till användarvänligheten. Ett gemensamt trådlöst nätverk kan erbjuda SYSteam i Huskvarna följande:</p><ul><li>Förbättrat samarbete mellan bolagen genom att medarbetarna blir mer mobila.</li><li>Effektivare möten.</li><li>En bättre miljö för projektgrupper – ökar deras rörlighet.</li><li>Att kommunikationen internt mellan bolag kommer att underlättas och förbättras.</li><li>Flexibiliteten ökar samt en ökning av motivationen bland personalen. </li><li>Att professionaliteten höjs internt.</li><li>Ett smidigt och användarvänligt gästnätverk vilket kommer förbättra bilden av SYSteam. Det ökar kundens upplevelse och tillfredställer kundens behov och kan resultera i att kundens lojalitet ökar.</li><li>Kundkontakten kommer att underlättas.</li></ul> / <p>This report describes and analyzes the requirements for a wireless network installation. The subject wireless network is both extensive and complex, and results of that many in the branch are missing the accurate qualifications. There is an abundance of different components, encryptions and procedures. This report has developed in cooperation with SYSteam Network Center (SNC), who wants to investigate the requirements and opportunities a common wireless network might provide. The common wireless network shall fulfill the need of security, scalability and to be centrally administrated. SNC wants knowledge about the different needs, that the internal SYSteam company in Huskvarna have about a common wireless network. And thereby be able to summarize a mutual image of how a wireless network should be designed. As a part of this, people from different companies at SYSteam where interviewed. SNC would like to offer the SYSteam companies situated in Huskvarna a common wireless network, which pays attention to everyone’s interests. The interviews gave the following notice that there were problem in the network solution used today:</p><ul><li>Today’s network structure restrains the cooperation between internal companies. </li><li>The missing of a flexible guest access gives a bad impression to external guests. </li><li>Today guests and staff are bound to a limited amount of switchports. </li><li>Connected guests get access to parts of SYSteam internal clientnetwork. The guests should only get access to what they absolutely require.</li></ul><p>To be able to handle and process the problems a three-steep analyze have been made, primary to understand the requirement of the organization, to clearly define the problems and what opportunities a wireless network may have. From these three steps, proper literature have been studied in purpose to provide SNC with a comprehensive analyze about the technique, business considerations and what value a wireless network provides. The result focuses about what uprising challenge a wireless network may originate and the problems it could contain. In the conclusion, guide principles how a wireless network should be designed adjusted for SNC is formed. SNC is today facing a big challenge in order to offer a wireless network which shall meet the requirements of user-friendly and secured demands. The work shows, if consideration is taken to available challenges and survey existing problems, it’s possible to design a scalable, secured network which also provides user-friendly management. An example a common wireless network can offer SYSteam in Huskvarna can be one of the following:</p><ul><li>Cooperation improvements between companies, clients become even more mobile. </li><li>Meetings become more efficient. </li><li>Offer a better environment for project teams, due to increased mobility. </li><li>Offer an ordinary guest access. </li><li>The internal communication will facilitate and improve between companies.</li></ul>

Ingeniera Civil Electricista / La evolución de las redes de comunicaciones móviles avanza hacia la unificación de un ambiente heterogéneo en el cual se interconectan entre sí redes de distintos accesos. En este escenario, la mantención de sesiones de internet de los usuarios, cuando éstos se mueven de una red a otra, emerge como uno de los principales desafíos a enfrentar. La introducción de un protocolo de movilidad en la red aparece como solución a este problema, facilitando el roaming entre redes y evitando la reconexión de las sesiones del usuario. El despliegue de redes wireless de área local (WLAN) es un económico medio para acceder a internet a diferencia de las redes celulares con soporte de redes de paquetes. Mientras que las redes WLAN poseen un ancho de banda significativamente mayor al de las redes móviles, estas redes poseen una amplia cobertura que incentiva la interconexión entre ambas tecnologías. En este trabajo se desarrolla un modelo de interconexión de redes celulares y WLANs utilizando Mobile IP. Las simulaciones se realizan en el software computacional OPNET y el soporte de movilidad se enfoca desde el nivel IP utilizando los protocolos Mobile IP en un ambiente global; y Proxy Mobile IP en un ambiente localizado, ambos en su versión IPv4. Los resultados MIP muestran una asimetría entre delays end-to-end producto del camino triangular del tráfico de datos. Esto lleva a una ineficiencia en el ruteo que afecta principalmente a aplicaciones en tiempo real. El roaming hacia la red WLAN provoca una disminución en los delays end-to-end en ambas direcciones situándose entre 56 % y 71 % cuando el estado de la red de internet tiene asociado una baja latencia. El establecimiento de sesiones TCP sube en un 7 % mientras que el control de aplicaciones de descarga FTP baja en 29 %. En el caso de PMIP, el 3-way handshake disminuye en un 14 % mientras que el control de aplicación FTP en un 41 %. Este protocolo no evidencia ineficiencia en el ruteo, tendiéndose además una disminución de delays end-to-end incluso con latencia de red de 100 ms. Lo positivo de enfocar la movilidad desde el nivel IP se encuentra en la indiferencia que supone el tipo de acceso a nivel de capa de enlace. La ventaja de PMIP sobre MIP es que no requiere de software especializado en el cliente, reduciendo así los costos de señalización en el establecimiento del servicio de movilidad. MIP por su parte, es idóneo de ser utilizado en un esquema de interconexión global, por lo que su integración con PMIP puede ser vista de manera complementaria estableciendo un esquema jerárquico con este último proveyendo movilidad a nivel local.

Made available in DSpace on 2016-04-04T18:31:27Z (GMT). No. of bitstreams: 1 Manoel Peluso de Carvalho Filho.pdf: 1548469 bytes, checksum: 813f063c4ea17788aa795465c9e6e6f5 (MD5) Previous issue date: 2008-11-24 / Nowadays, the use of the wireless network technology has grown mainly motivated by the price of equipments, ease of installation, network maintenance and expansion of technical safety. The more you use the wireless network resource, the better should be the treatment related to its safety aspect. As the security level increases, the amount of information transmitted between the equipment decreases. This thesis aims to analyze the performance of WLAN network with the implementation of WEP and WPA / TKIP security protocols in an environment that uses applications whose characteristic is to generate small packets on the network. The LanTraffic TM software is used to generate traffic and also to capture the transmission rate in Kbps that flows through the stations. Three scenarios are simulated varying in the distance between the equipments. For each scenario, a comparative study was made and the WLAN behavior without the security resource analyzed, then it was analyzed with the WEP fitted and finally with the WPA/TKIP configured. To develop the experiments it was used a WLAN network in a controlled environment in the Laboratory Research on Radio System in PUC Campinas. Therefore, there is not external interference in the signal transmitted by equipments. / A utiliza??o da tecnologia de rede sem fio tem crescido ultimamente motivado principalmente pelo pre?o dos equipamentos, facilidade de instala??o, manuten??o da rede e amplia??o das t?cnicas de seguran?a. Quanto mais se utiliza o recurso de rede sem fio maior tem de ser o tratamento em rela??o ao aspecto de seguran?a. A medida que aumenta o n?vel de seguran?a, decresce a quantidade de informa??o transmitida entre os equipamentos. Esse trabalho visa analisar o desempenho de rede WLAN(Wireless Local ?rea Network) com a implementa??o dos protocolos de seguran?a WEP(Wired Equivalent Privacy) e WPA/TKIP(WI-FI Protected Access / Temporal Key Integrity Protocol). ? utilizado o software LanTrafficTM para gerar tr?fego na rede e tamb?m para capturar a taxa de transmiss?o em Kbps trafegados entre as STAs. S?o emulados tr?s cen?rios variando a dist?ncia entre os equipamentos. Para cada cen?rio foi confeccionado um comparativo e analisado o comportamento da WLAN configurado sem seguran?a, com o WEP habilitado e finalmente com o WPA/TKIP configurado. Para executar os experimentos utilizou-se uma rede WLAN no laborat?rio de pesquisa em sistema de r?dio (LP-SiRa) da PUC Campinas em um ambiente controlado. Com isso n?o h? interfer?ncias na transmiss?o dos sinais emitidos pelos equipamentos Ou seja, sem interfer?ncia externa no sinal transmitido entre os equipamentos.

Electronic tourism is a new type of application that provides information, often location-based, to tourists. The information includes route guidance, listings of nearby points of interest, guided tours with multimedia presentations and experiences shared by visitors. E-tourism applications can also include storing sound and images recorded by visitors. An architecture to support e-tourism called 'UbiTour' is presented in this dissertation. UbiTour provides different services to visitors such as location-based information, route-guidance, announcements and visitor collaboration. UbiTour aims at using 3G for ubiquitous connectivity and WLAN for high-speed, local information, running on a PDA. WLAN, specifically 802.11, provides a high-bandwidth, broadcast-based connection over a very limited area, while 3G provides a ubiquitous, though lower speed, connection across large metropolitan areas. The services provided by UbiTour have different requirements and constraints, some better suited for WLAN and others for 3G. By seamlessly combining the two technologies, UbiTour can provide a powerful electronic tour guide.

<p>Wireless communication is being developed in the last years day by day, there are several standards that talks about it. We are going to go through the IEEE standard 802.11 which talks about wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications. Looking this more carefully we will study MAC specifications and its environment. </p><p>The work that ISY department at Institute of Technology of Linkoping University has proposed is to design a MAC sublayer implementation for WLANs using C language programming and testing it with the test environment called “test bench”. This test bench will simulate LLC sublayer and PHY layer, in this way, our MAC implementation will has to interact with it. Therefore we will simulate a wireless network where we are going to have a short number of stations and we are going to look at carefully the MAC sublayer response in an ad hoc network.</p>

<p>Saab Bofors Dynamics AB is looking for ways to let the employees work wireless in the future. The security in Wireless Local Area Networks (WLAN) has not been considered very reliable, but new standards and protocols have been developed to enhance the security in WLAN. Since most wireless components soon will have built in support for wireless communication, it is important to have a model to deal with secure wireless communication ready. This is necessary because it is important to protect the company’s information related systems, ensure contingency in the daily work and maintaining the trust of the market and the authorities. </p><p>With the release of the standard IEEE802.11i, the possibility to build a secure WLAN has improved considerably. With the combination of standards such as IEEE802.1X and IEEE802.11i, and improved encryption with Advanced Encryption Standard (AES) it is possible to make the wireless network more secure. </p><p>It is important to ensure secure wireless communication between the client and the accesspoint, and to install a personal firewall on every wireless client in the network. There are many aspects to take into consideration when building a WLAN, some are discussed in this report and some are discussed in the secret part of the report for Saab Bofors Dynamics AB only.</p>