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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.
121

WDSC: Wi-Fi Direct with spontaneous connection / WDSC: Wi-Fi Direct with spontaneous connection

Ricardo Cesar Corrêa 30 June 2016 (has links)
O consumo de dados em dispositivos móveis cresce em taxas que dobram a cada ano. Tal crescimento demonstra como os dispositivos móveis ganham importância e como eles têm sido usados no dia a dia da população. Entretanto, o acesso à Internet ainda possui alto custo e nem sempre está disponível. Esse cenário apresenta o desafio de mantermos o uso dos dispositivos móveis acessível e viável, mesmo quando a Internet não esteja disponível. A comunicação direta entre os dispositivos é vista como alternativa para comunicação sem Internet e, consequentemente, para a redução do tráfego de dados nas redes de celulares. Além disso, ela pode ser útil para manter os dispositivos comunicando entre si mesmo desconectados da Internet. O protocolo Wi-Fi Direct (WD) é uma referência para esse tipo de comunicação, uma vez que seu protocolo não demanda infraestrutura de rede pré-estabelecida para que a comunicação aconteça e utiliza hardware padrão para comunicação Wi-Fi. Apesar dessas vantagens, seu uso é pouco difundido, o que o torna desconhecido pelos usuários, sendo uma das possíveis causas a complexidade de uso. De forma diferente, a conexão com a Internet, que acontece de forma quase espontânea, no WD as partes envolvidas precisam se envolver ativamente, na escolha e autorização, para que a conexão seja estabelecida. A complexidade da comunicação entre dispositivo pode ser constatada quando os usuários utilizam a Internet para enviar dados mesmo que o dispositivo alvo esteja ao lado da origem. Para superar esse obstáculo, a conexão entre os dispositivos deve ser tão ou mais simples do que a ação de enviar um e-mail ou uma mensagem instantânea usando a Internet. Para lidar com esse cenário, este trabalho propõe uma alternativa para comunicação entre dispositivos próximos que não demanda autorização manual prévia a cada conexão com um dispositivo, e que, ainda assim, permita que o usuário decida se quer ou não usar os dados transmitidos por uma conexão. Para isso definimos uma arquitetura que possibilite a conexão e transferência de dados entre os dispositivos próximos sem a necessidade de intervenção prévia do usuário e implementamos o conceito proposto no sistema operacional para dispositivos móveis Android / The consumption data on mobile devices is growing at rates double every year. This growth demonstrates how mobile devices gain importance and how they have been used in everyday life of the population. However, the internet also has high cost and is not always available. This scenario presents the challenge of maintaining the use of affordable and viable mobile devices even when the Internet is not available. Direct communication between the devices is regarded as no alternative for internet communication and, consequently, to reduce the data traffic in cellular networks. Furthermore, it can be useful to keep the devices communicating among themselves disconnected from the Internet. The Wi-Fi Direct (WD) protocol is a reference to this type of communication, since its protocol does not require pre-established network infrastructure for communication to happen and uses standard hardware for Wi-Fi communication. Despite these advantages, its use is not widespread, making it unknown to the users, one of the possible causes of the complexity of use. Differently, the connection to the Internet, which happens almost spontaneously, the WD parties need to engage actively in the selection and authorization for the connection to be established. The complexity of communication between device can be found when users use the Internet to send data even if the target device is adjacent to the source. To overcome this obstacle, the connection between the devices should be as or more simple than the action of sending an email or an instant message using the Internet. To handle this scenario, this paper proposes an alternative for communication between nearby devices that does not require prior manual authorization for each connection to a device, and that still allow the user to decide whether or not to use the data transmitted by a connection. For this we define an architecture that enables the connection and data transfer between nearby devices without the need for prior user intervention and implement the concept proposed in the Android operating system for mobile devices
122

WLAN : Oskyddad och okontrollerad datakommunikation

Horndahl, Charles, Maric, Kristian January 2005 (has links)
<p>This master’s thesis investigates the technology and security awareness associated with wireless networks (WLAN). It has been stated by the media and theories that many wireless networks are unprotected. This has sparked an interest to investigate the phenomenon in the Jonkoping region. The study is based on the following research questions:</p><p>- What security weaknesses are present with the WLAN-technology and how can these be avoided?</p><p>- How does the wireless infrastructure in the Jonkoping region look like?</p><p>- Why do companies implement the WLAN-technology?</p><p>- Are the companies aware of the risks involved with WLAN?</p><p>We conducted this study in three steps; the first step was to hack a wireless network in a controlled environment in order to investigate the weaknesses of the commonly used security measures. The second step of the study was to scan the wireless networks in Jonkoping, Gnosjo and Nassjo in order to create a picture of the wireless infrastructure of the region. The third step of the study was to contact companies that we found in the second step for interviews to investigate their awareness of the technology and its weaknesses.</p><p>We found that WLANs and their security measures have weaknesses. The commonly used WEP encryption can quite easily be broken and can lure users into a false sense of security. The study shows that companies are aware of this weakness, but use the encryption be-cause it offers a good level of usability and security. It is a compromise between usability and security. Usability is one of the major factors for companies when implementing wireless networks, companies strive for mobility, easy access and ease of use, which the WLAN technology offers. This has lead to an extended wireless infrastructure in cities within the region where one, with ease, can find wireless networks outside buildings. We have noticed an increase in the security awareness as our empirical findings differ from earlier research conducted in other cities. When these studies are compared you can see a trend where the number of unprotected networks decreases. Our contribution to increased wireless security is a checklist of possible security measures to minimize the security threats.</p> / <p>Denna magisteruppsats undersöker tekniken och säkerhetsmedvetandet gällande trådlösa nätverk (WLAN). Då det tidigare uppmärksammats i media och teori att många trådlösa nätverk står oskyddade har detta skapat intresse att undersöka fenomenet i Jönköpingsregionen. Studien baseras på följande frågeställningar:</p><p>- Vilka säkerhetsluckor finns i WLAN och hur kan dessa undvikas?</p><p>- Hur ser WLAN-infrastrukturen ut i Jönköpingsregionen?</p><p>- Varför implementerar företag WLAN-tekniken?</p><p>- Är företag medvetna om riskerna med trådlösa nätverk?</p><p>För att skapa en helhetsbild har vi genomfört studien i tre steg varav vi, i det första steget, genomfört dataintrång i en kontrollerad miljö för att undersöka svagheterna med säkerhetsfunktionerna som används i trådlösa nätverk. I det andra steget undersökte vi med hjälp av bärbar dator trådlösa nätverk i Jönköping, Gnosjö och Nässjö. Detta för att skapa oss en uppfattning om hur WLAN-infrastrukturen ser ut i dagsläget. Steg tre innebar intervjuer med företag som vi funnit i samband med steg två rörande deras medvetenhet om tekniken och dess brister.</p><p>Teorin och vår empiri gav oss underlag att dra slutsatser utifrån våra frågeställningar. Vi fann att WLAN och dess säkerhetsfunktioner har vissa sårbarheter. Den mest förekommande krypteringstekniken, WEP, kan dekrypteras tämligen enkelt och kan vagga in användarna i en falsk säkerhet. Studien visar att företagen är medvetna om detta, men att det handlar om en medveten kompromiss mellan användarvänlighet och säkerhet. Användarvänligheten står till grund för varför företagen väljer att implementera den trådlösa tekniken. Företag eftersträvar mobilitet, smidighet och enkel access, vilket den trådlösa tekniken erbjuder. Detta har lett till en utökad trådlös infrastruktur i städer runtom i regionen där man med lätthet kan hitta trådlösa nätverk utanför byggnader. Vi har noterat ett ökat säkerhetsmedvetande då våra empiriska resultat skiljer sig något från tidigare undersökningar i andra städer. När dessa ställs mot varandra anar man en trend där antalet oskyddade trådlösa nätverk minskar. Vårt bidrag till ökad trådlös säkerhet är en checklista med möjliga åtgärder för att minimera säkerhetsriskerna.</p>
123

Wi-Max tinklo duomenų modelio sudarymas ir tyrimas / Wi-Max network data modeling and analysis

Kostkevičius, Arvydas 16 August 2007 (has links)
Darbe “Modeling and analysis of Wi-Max network data” supažindinama su plačiajuosčio bevielio ryšio technologija – Wi-Max. Analizuojama literatūra, kuri aprašo Wi-Max veikimo principą, nagrinėjami šios technologijos ypatumai, ji lyginama su kitomis bevielio ryšio technologijomis. Apžvelgiamos šios technologijos perspektyvos. Tinklo duomenų modelis suteikia galimybę teikti papildomas paslaugas vartotojams, leidžia stebėti ir analizuoti Wi-Max duomenų perdavimo tinklą. Rementis IEEE 802.16e standartu, sudaryta metodika tinklo duomenų modeliui kurti. Išanalizuota Wi-Max technologijos tinklo duomenų struktūra, kuri sėkmingai pritaikyta tinklo duomenų modelio metodikos kūrimui. Sudarytos tinklo duomenų modelio specifikacijos ir pagal jas sukurtas tinklo duomenų modelis. Atliktas tinklo duomenų modelio eksperimentinis tyrimas ir pateikti šio tyrimo rezultatai. Rementis eksperimento rezultatais įvertintos Wi-Max technologijos realios galimybės. / This master‘s thesis familiarizes with the wireless broadband networking technology – WiMAX. The work includes literature analysis of WiMAX performance principles, research of technological peculiarities and comparison with other wireless technologies. The perspective of this technology is also overviewed. The model of network data allows providing additional services to the customers, as well as monitoring and analyzing of WiMAX data transmission network. The methodology of creating the model is based on IEEE 802.11e standard. Structure of WiMAX data networks is analyzed and successfully applied to implementation of methodology for model of WiMAX network data. The specifications for network data model were created and the model implemented according to them. The experimental analysis of the model was performed and results presented herein. The realistic capabilities of WiMAX technology were evaluated using the results of experiment.
124

Bristfällig säkerhet inom trådlösa routrar med fokus på WPS

Juhlin, Tobias, Wangberg, Dan January 2014 (has links)
I denna rapport undersöks WPS-funktionen då det uppmärksammats säkerhetshåli den. Intervjuer, tester och observationer har gjorts för att undersöka problemenmed WPS. De tester och intervjuver som gjorts indikerar att säkerhetsbristen i WPS-funktionen har säkrats upp med extra funktioner. / In this report the WPS-function is evaluated due to the vulnerabilty of the protocol.Interviews, tests and observations have been conducted to evaluate the problems withWPS. The tests and interviews conducted indicates that the vulnerability of the WPS-function has been secured with extra functions.
125

Bristfällig säkerhet inom trådlösa routrar med fokus på WPS

Juhlin, Tobias, Wangberg, Dan January 2014 (has links)
I denna rapport undersöks WPS-funktionen då det uppmärksammats säkerhetshål i den. Intervjuer, tester och observationer har gjorts för att undersöka problemen med WPS. De tester och intervjuver som gjorts indikerar att säkerhetsbristen i WPS-funktionen har säkrats upp med extra funktioner. / In this report the WPS-function is evaluated due to the vulnerabilty of the protocol. Interviews, tests and observations have been conducted to evaluate the problems with WPS. The tests and interviews conducted indicates that the vulnerability of the WPS-function has been secured with extra functions.
126

Ramverk för Soft Front Panels och nyttjandet av wifi i känsliga miljöer / Framework for Soft Front Panels and the Utilization of Wifi in Sensitive Environments

Johansson, Tobias, Arvidsson, Martin January 2018 (has links)
Denna rapport täcker framtagandet av en prototyp för ett ramverk av soft front panels för testutrustning hos Saab Support and Services [1]. Prototypen ska användas av Saab i en utvärdering rörande en möjlig implementation och nyttan av ett sådant ramverk i Saabs befintliga system. Under framtagandet av prototypen har även en utredning rörande möjligheterna och problemen med att använda WiFi i känsliga miljöer utförts. Denna utredning är kopplad till prototypen i den mening att det finns ambition från Saab att använda liknande system trådlöst. Prototypen är även framtagen för att stödja WiFi som medel för kommunikation med den utrustning den är kopplad mot. Efter en utvärdering av olika ramverk valdes WPF som ramverk för framtagandet av prototypen. Programmeringen skedde i programmeringsspråket C# och XAML. Prototypen kopplades initialt upp mot simulerade instrument, för att ge ökad flexibilitet under utvecklingen. Den färdiga prototypen testades med faktiskt hårdvara tillsammans med simulerade PXI-moduler och uppvisade ett gott resultat. Fördjupningen angående användningen av WiFi i känsliga miljöer resulterade i ett antal förslag på åtgärder för att motverka störningar och signalläckage, så som användningen av WiFi-protokoll med höga frekvensband och ”defensive jamming”. / This report covers the creation of a prototype for a framework of soft front panels for test equipment at Saab Support and Services [1]. The prototype will be used by Saab in an evaluation regarding the possible implementation and benefits of such a framework in Saabs current system. During the creation of the prototype there has been an in-depth look at the possibilities and problems regarding the use of WiFi in sensitive environments. This in-depth look is tied to the prototype in such a way that there is an ambition at Saab of utilizing similar systems wirelessly. The prototype has been created in such a way that it supports WiFi as means of communication with the equipment it is connected to. After an evaluation of different frameworks WPF was chosen for the development of the prototype. The programming was done in the programming language C# and XAML. The prototype was initially connected to a set of simulated instruments, for increased flexibility during the development. The completed prototype was tested with actual hardware together with simulated PXI-modules and the results where satisfactory. The in-depth look regarding the use of WiFi in sensitive environments resulted in a number of suggestions for actions to counter interference and leakage of signals, such as the use of WiFi-protocols using a high frequency band and ”defensive jamming”.
127

Trådlöst campus i Växjö

Dich, Silas January 2005 (has links)
Internet Service Providers (ISP) har på senare år etablerat ett ökat antal Wi-Fi Hotspots på publika platser för att erbjuda Internettjänster så som e-post, Web och andra Internet-baserade program, till resande användare. Exempel på dessa platser är flygplatser, skolor, parker och städer. Växjö universitet har valt att bygga etttrådlöst nätverk på campus som man ska påbörja under sommaren 2005. Uppsatsen tar upp detta som fallstudie för diskussion av ämnet. / Lately Internet Service Providers (ISP) have established an increased amount of Wi-Fi Hotspots at public places to offer Internet based services like e-mail, web surfing etc to roaming users. Example of places like this are airports, schools, parks and cities. Växjö University has decided to implement a wireless network covering the university campus. This project is planned to start during summer of 2005. This project is the unicase for discussion in this bachelor thesis
128

EzMole: A new prototype for securing public Wi-Fi connections

Karlsson, Rickard January 2017 (has links)
When public Wi-Fi networks are being used, it can be hard to know who else that is using the same network or is monitoring the traffic that is traveling across the network. If the network is public and unencrypted anyone can monitor the traffic and to use these networks for work can be very risky. This is a big problem that needs a solution because the information that travels across the public network might have organizational secrets or sensitive personal information that shouldn’t be read by outsiders. One way to significantly increase the security while using these public networks is by configuring and setting up a VPN-tunnel, all traffic will then be sent encrypted. But nowadays many computers and mobile phones runs applications in the background that are actively asking for updates. It can for example be news apps, mail clients or instant messaging services like WhatsApp or Telegram. Since the apps is pushing for updates in the background there is a big risk that these programs are asking for updates and therefore transmit and receives information unencrypted over the public network before they have been able to set up their VPN-tunnel. People might be unaware about this problem and this research can be used to explain the problem and offer a solution to it and that is the reason why this research is important. This research tries to solve the problem and find answers to the research questions, “How to design and implement an affordable intermediate device that offers the user secure access to Internet on public Wi-Fi networks?" and “What are the design principles of that method?”. The proposed solution to solve this problem was to design and implement a new intermediate device, which was called EzMole, in between the public Wi-Fi and the users’ personal devices. The new device will operate and secure the users’ devices from potential malicious users on the public Wi-Fi while the VPN-tunnel is being established. It will also create a new encrypted wireless network that will be used to connect the personal devices to EzMole, for example mobile phone or laptop. The methodology that was used to design and develop the new EzMole-device was the Design Science Research Methodology. It includes six steps that was used during three phases of the project that worked in an iterative process with development, testing and evaluation until the device met the initial requirements of a successful device. There were tests for both functionality and security to make sure that it worked in the right way and that it didn’t have any known security weaknesses or flaws. This was very important since EzMole will be and represent an Internet-of-Things(IoT)-device and therefore the security had a big focus. After the tests, it was time to evaluate it against the initial requirements and the new device lived up to 9/12 requirements and was therefore classified as successful. The research contributes with a universal solution for the research problem and it gives answers to the research questions and in the meantime, reduces the gap in the literature. It also contributes with providing a new piece of hardware that will can help people to connect to the Internet in a more secure way when they are using public Wi-Fi networks.
129

WPS - WiFi Protected Setup : En studie om Wi-Fi Protected Setup som autentiseringsmetod

Lindell, Jonas, Lagerholm, Filip January 2019 (has links)
No description available.
130

Voz e vídeo sobre redes sem fio IEEE 802.11 / Voice and Video over IEEE 802.11 wireless networks.

Conceição, Arlindo Flavio da 15 May 2006 (has links)
Esta tese analisa aplicações de transmissão de voz e vídeo sobre redes Wi-Fi (IEEE 802.11). Os principais problemas observados foram a maior incidência de tráfegos em rajada e os problemas associados à execução de handoffs. Foram propostos algoritmos adaptativos para monitorar e contornar esses problemas. / This thesis examines applications for transmitting voice and video over Wi-Fi (IEEE 802.11). The main problems observed were the higher incidence of bursty traffic and disconnection during handoffs. Adaptive algorithms have been proposed to monitor and work around these problems.

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