Subject of this thesis was the issue of effectiveness of wireless networks from the perspective of services. Become acquainted with WiFi network standard IEEE 802.11 with protocols and principles of WiFi networks and services. It should be focused on the quality of service QoS. In teoretical part of this thesis are described problems considering wireless networks, layer model and types of nets used in WiFi. Standard IEEE 802.11 is analysed in details including supplements and used packets. Special attention is paid to the quality of service QoS. Next are discussed the principles and application services as VoIP, videoconferencing, video streaming and others in WiFi network. On the basis of obtained knowledge is designed extensive WiFi network with assured supply of services. For modelling and simulation of wireless network is used software development environment Opnet Modeler. Model of wireless network is used to optimize and analyse this wireless communication network. In thesis are also simulated properties of data which are sensitive to delay. In last part of thesis is created a laboratory work, which contains a submission of task, detailed theory, wiring diagram, instructions for elaboration, guidelines for simulation and example of elaboration of task. Work is about comparison of network with used 802.11b and 802.11e standard, and support of quality of service QoS.

This master’s thesis is focused on ensuring of Quality of Service (QoS) in wireless network for standards IEEE 802.11 a/b/g/n. First part of this thesis is focused on the theory of this issue. It covers methods of data transfer in computer networks and individual transfer parameters especially on parameters needed to ensure quality of service. It also describes standards for wireless data transmission and protocols for real time data transmission. The second part is devoted to OPNET modeler and to simulations created on this program. Simulations are focused on real-time data transfer and compare the standards in terms of delay and jitter.

This thesis discusses wireless network standards 802.11a/b/g/n. First part explains basic principles of networks and media access. Next the standard IEEE 802.11, general QoS parameters and their application in wireless networks, according to standard 802.11e are analyzed. Second part of the thesis verifies the acquired knowledge in simulating program Opnet - effects of the delay, jitter and packet loss on VoIP call are tested. In the last part of the thesis a network for video streaming has been designed. The video was streamed in different qualities and the influence of other network traffic (with and without the support of QoS) on the video streaming was tested.

Das Ziel dieser Arbeit ist es, ein Handover-Verfahren für ein Siemens Handset zu entwickeln. Die Entwicklungsumgebung beruht auf den Wireless-LAN Standards 802.11 der IEEE (Institute of Electrical and Electronics Engineers). Dabei liegen die Schwerpunkte auf den Standardisierungen 802.11f und 802.11i, wobei sich eine neue Arbeitsgruppe (IEEE 802.11r) direkt mit dem Thema "Handover" beschäftigen wird. Das Handset soll selbständig die Verwaltung und Einleitung des Handovers übernehmen und lediglich insofern vom Access Point unterstützt werden, dass dieser als Informationssammler dient und somit Entscheidungshilfen geben kann.

As the IoT market continues to grow, so does the need for secure wireless communication. Drones have become a popular gadget among both individuals and various industries during the last decade, and the popularity continues to grow. Some drones use Wi-Fi technology for communication, such as the Parrot ANAFI, which introduces many of the same security threats that are frequently found in general IoT. Therefore, this report covers a common group of cyberattacks, known as denial-of-service attacks, their effects on the Parrot ANAFI, and their ease of use. A threat model was created to have an overview of the system architecture, and all of the identified threats were assessed using DREAD. All of the software tools used in this report can be found for free on the Internet using search engines and simple key words. The results showed that the drone is generally secure, but it is vulnerable to a certain denial-of-service attack, which can open the door to multiple attack surfaces if the password for the drone’s Wi-Fi is not strong enough. Some suggestions for mitigating these threats are presented at the end of the report. / I takt med att IoT-marknaden fortsätter att växa ökar också behovet av säker trådlös kommunikation. Drönare har blivit en populär pryl bland såväl privatpersoner som diverse industrier under det senaste decenniet, och populariteten fortsätter att växa. Vissa drönare använder Wi-Fi-teknik för kommunikation, till exempel Parrot ANAFI, vilket introducerar många av de säkerhetshot som ofta existerar bland IoT i allmänhet. Den här rapporten täcker därför en välkänd grupp av cyberattacker, som kallas denial-of-service-attacker, deras effekter på Parrot ANAFI och deras användarvänlighet. En hotmodell skapades för att ha en överblick över systemarkitekturen och alla identifierade hot rangordnades med hjälp av DREAD. Alla programvaruverktyg som används i denna rapport kan hittas gratis på Internet med hjälp av enkla sökningar på nyckelord. Resultaten påvisar att drönaren i allmänhet är säker, men att den är sårbar för en viss typ av denial-of-service-attack, vilket kan öppna dörren till flera attackytor om lösenordet för drönarens Wi-Fi inte är tillräckligt starkt. Några förslag för att mildra dessa hot presenteras i slutet av rapporten.

El reciente aumento en la implementación de redes inalámbricas nos obliga a contemplar con más cuidado el aspecto de la seguridad en este tipo de redes. Así como en el caso de las típicas redes de datos con cables (siendo la tecnología Ethernet la más utilizada para estos casos), tiene que asegurarse que los usuarios de una red inalámbrica se encuentren conectados a ésta de una manera segura, teniendo en cuenta que ahora el medio de transmisión ya no se restringe a un cable, sino que se encuentra en todo el ambiente que lo rodea. Debe de comprobarse que el usuario sea quien dice ser (autenticación), que solo tenga acceso a los recursos que le corresponda (autorización) y también llevar a cabo un registro de las actividades que haga dentro de la red (contabilidad); realizando todo esto de una manera segura y sin que sujetos ajenos a la red puedan estar leyendo información confidencial ni mucho menos tratar de modificarla. En esta tesis se tiene pensado explicar el diseño e implementación que se debería de llevar a cabo dentro de un escenario dado para la instalación de una red inalámbrica segura que contemple la administración de sus usuarios por medio de una plataforma de gestión Web basada en PHP, integrada a un servidor de directorios LDAP con compatibilidad hacia implementaciones libres y cerradas de dicho protocolo, un servidor de autenticación RADIUS y un servidor de base de datos MySQL. Se estudiarán los principales aspectos aplicados en redes inalámbricas Wi-Fi, poniendo especial énfasis en la seguridad de la red y de sus usuarios con mecanismos tales como: WPA2 (IEEE 802.11i), 802.1X, EAP, RADIUS, entre otros.

Approved for public release; distribution in unlimited. / In spite of the fact that wireless network technology has been available for long period of time, there has been very limited wireless networks deployments around the world before 1997 due to the lack of widely recognized standard for wireless networks. Thanks to the approval of the IEEE 802.11 family of standards in 1997, the world has witnessed tremendous deployment and proliferation of wireless networks in all aspects of life. Although the IEEE 802.11 family of standards has been ratified to design radio transceivers for wireless computer stations capable of interconnecting with other wireless computer stations in close proximity, the technology has been successfully employed to design and implement wireless networks with great number of distant wireless computer stations with reasonable data throughput and flexibility. This thesis explores the wireless network technology and the primary building blocks and components of a wireless network. It also explores the IEEE 802.11 standard and its technical specifications including the Physical layer (PHY), the Media Access Control layer (MAC) and the ongoing task forces. Additionally, the thesis examines the wireless network security including the vulnerabilities, ongoing improvements and recommendations. Next, it investigates the market for available wireless devices compatible with the IEEE 802.11 standard that can be used to build a wireless network with high data throughput and high level of security. Subsequently, the thesis formulates a design plan for civilian wireless network with different scenarios in order to provide a speedy solution to the limited broadband service availability in the Sultanate of Oman. Additionally, the thesis formulates a generic design plan for a military wireless network with different scenarios that can be rapidly deployed in the field of operations. / Computer Engineer, Royal Army of Oman

The rapid expansion of wireless information technology (IT) coupled with a dramatic increase in security breaches forces organizations to develop comprehensive strategies for managing security risks. The problem addressed was the identification of security risk management practices and human errors of IT administrators, putting the organization at risk for external security intrusion. The purpose of this non-experimental quantitative study was to investigate and determine the security risk assessment practices used by IT administrators to protect the confidentiality and integrity of the organization's information. The research questions focused on whether the security risk management practices of IT administrators met or exceeded the minimally accepted practices and standards for wireless networking. The security risk assessment and management model established the theoretical framework. The sample was 114 participants from small to medium IT organizations comprised of security engineers, managers, and end users. Data collection was via an online survey. Data analysis included both descriptive and inferential statistical methods. The results revealed that greater than 80% of participants conducted appropriate risk management and review assessments. This study underscored the need for a more comprehensive approach to managing IT security risks. IT managers can use the outcome of this study as a benchmark for evaluating their current risk assessment procedures. Experiencing security breaches in organizations may be inevitable. However, when organizations and industry leaders can greatly reduce the cost of a data breach by developing effective risk management plans that lead to better security outcomes, positive social change can be realized.

Fin 2004, un quart des foyers Européens étaient connectés à l'Internet haut débit. Avec le faible coût des machines toujours plus puissantes, de nombreuses applications multimédias ont pu être élaborées pour satisfaire la demande croissante du grand public. Le besoin d'adaptation des protocoles de communication sous-jacents est essentiel pour ce type d'applications. Les protocoles doivent pouvoir passer à l'échelle et s'adapter aux caractéristiques hétérogènes de ces nouvelles applications. Parallèlement, les transmissions sans fil ont connu un essor sans égal, permettant un accès à l'Internet de n'importe quel endroit. La multiplicité des technologies d'accès (GPRS, UMTS, WIFI, WiMAX, Bluetooth, etc.) et la grande variabilité des caractéristiques des canaux de transmission sans fil ont encore accru ce besoin d'adaptation. Dans ce document d'habilitation, je présente quatre contributions qui mettent en relief le besoin d'adaptation des protocoles de communication. La première concerne un protocole de communication robuste au facteur d'échelle élaboré pour des applications d'environnements virtuels qui mettent en jeu un grand nombre de participants. La seconde décrit un algorithme pour contrôler la transmission de vidéo hiérarchique vers un ensemble hétérogène de récepteurs sur Internet. Les deux contributions suivantes portent sur la transmission<br />sans fil. Je décris un mécanisme de différenciation de services efficace pour transmettre des flots multimédias à débit variable dans les réseaux IEEE 802.11e, ainsi qu'un mécanisme d'adaptation intercouches pour la transmission multimédia dans les réseaux WIFI.

<p>In future mobile networks service quality might be poor. A new measure is needed to be able to assess services in terms of their effectiveness and usefulness despite their lacking visual appeal. Cognitive Quality of Service is a way to measure the effectiveness in use of a networked service.</p><p>This thesis introduces Cognitive Quality of Service and puts it in relation to other ways to measure quality in streaming media. Through four studies the concept is used to improve multicast performance in a WLAN, to assess the effectiveness of simple animations compared to video, to build an application that fuses video and animations and to assess the differences between various levels of streaming video quality.</p><p>Guidelines on how to measure Cognitive Quality of Service are introduced based on a review of available literature and later analyzed in light of the studies presented in the thesis. It turns out that the guidelines are sound and should be used as a basis for assessing Cognitive Quality of Service.</p><p>Finally, the usefullness of Cognitive Quality of Service is analyzed. It turns out that it is especially useful when comparing different media, e.g. animations and video. In the video only case even bit-rate might be a useful predictor of subjective quality.</p> / <p>I framtiden kommer användare att titta på videosekvenser i trådlösa apparater, exempelvis mobiltelefoner. På grund av tekniska faktorer som störningar och på grund av kostnaden för det kommer den kvalitet som de erhåller inte att vara jämförbar med till exempel den kvalitet som kan erhållas när man tittar på tv. Trots det kan man anta att sådan video kan vara intressant och upplysande.</p><p>I avhandlingen introduceras och används begreppet Cognitive Quality of Service (CQoS) - kognitiv servicekvalitet. Begreppet definieras av att den överföring som ger den bästa förståelsen och känslomässiga reaktionen också har bäst CQoS. För att mäta CQoS bör man följa vissa riktlinjer, särskilt som det är svårt att mäta förståelse i samband med att man tittar på video.</p><p>Författaren har tillsammans med medarbetare tittat på hur man kan förbättra förhållandena för själva radioöverföringen (studie I). Genom en algoritm som ger multicast-paket bättre skydd mot kollisioner visas att man kan erhålla förbättrad överföringskapacitet för strömmande video i ett trådlöst nätverk.</p><p>Animeringar är ett alternativ till video som kräver låg bandbredd. I ett experiment har man undersökt hur väl animeringar står sig mot video av olika kvalitet när det gäller att upplysa användaren och ge en bra upplevelse (studie II). Det visade sig att animeringar var bättre för förståelsen medan video gav en bättre känslomässig upplevelse. Vanare åskådare föredrog videon medan ovanare åskådare föredrog animeringarna.</p><p>Frågan som ställdes var då hur man kunde kombinera respektive mediums fördelar för att få en så bra blandning som möjligt. Å ena sidan var animeringarna billiga och lätta att förstå medan videon var dyrare och mer intressant. Ett prototypgränssnitt skapades. Där kunde användaren själv välja vilken mix mellan de två alternativen som skulle visas (studie III). Det visade sig att försökspanelen föredrog video och dessutom ville ha mer information om spelare och match.</p><p>Trots animationernas förträfflighet kan man anta att det ändå är video som kommer att dominera i framtiden. En sista studie genomfördes för att se om man kunde finna liknande resultat vid olika kvalitetsgrader i video som man tidigare hade funnit mellan video och animeringar (studie IV). Det visade sig att så länge man höll sig till ett format var sambanden enklare. Mer var helt enkelt bättre upp till en viss gräns där det inte tillförde mer att öka överföringsresurserna för videon.</p><p>Sammanfattningsvis visar studierna att CQoS kan ge värdefull designkunskap. I synnerhet när man jämför olika presentationsformer som i det här fallet animeringar och video. Nästa steg blir att gå vidare med att applicera CQoS i tvåvägskommunikation, särskilt i Conversational Multimedia (CMM)– ungefär bildtelefoni – där det är särskilt goda möjligheter att sammanställa en för omständigheterna anpassad mediamix.</p>