Because of the popularity of wireless communication technologies, people can access servers without the restriction of place and time. With the rapid development of mobile devices, such as smart phones and iPads, the frequency of wireless networks have increased. Roaming services ensure service provision without location constraints. A secure roaming authentication protocol is critical for the security and privacy of users when accessing services by roaming. It ensures the authenticity of mobile users, and foreign and home servers. After authentication, the session key for the mobile user and the foreign server is established for secure communication. In addition, a secure roaming protocol may provide anonymity for mobile users. When the mobile user requests a service, the server is unable to identify two requests from the same user. For the current anonymous authentication protocols, the foreign server must fulfill the revocation check by the computation linear to the number of revoked users. It makes the protocol infeasible in practical environments. This thesis proposes a strong anonymous authentication protocol, using two-stage authentication, in which the home server is involved in the initial authentication to eliminate the revocation list and issues a timely anonymous credential for subsequent authentication after successful authentication. It reduces the computation costs for the revocation check and minimizes the size of the revocation list. Finally, this thesis also provides security proofs and comparisons of the proposed authentication mechanism.

A growing number of IEEE 802.11-based wireless LANs have been set up in many public places in the recent years. These wireless LANs provide convenient network connectivity to users. Although mobile nodes allowed roaming across wireless LANs, handoff latency becomes an obstacle when mobile nodes migrate between different IP networks. Advanced, the link-layer handoff process disrupts the association when a mobile node moves from one access point to another. Even without discussing the latency of Mobility Protocols, this link-layer handoff latency already made many real time applications can not meet their requirements. In this dissertation, it is proposed three schemes to solve the problems occurred in the different network layers. These schemes not only reduce the latency of whole handoff procedure but also have no violation to the existing specifications in the IEEE 802.11 standard and compatible with existing devices. L2-Optimize and AIL used to minimize the duration of link-layer handoff. With LASP, Mobility handoff can be reduced to an acceptable situation. Therefore, even real time applications can meet their requirements when users are roaming across wireless LANs.

The purpose of this research was to assess stakeholder interest pertaining to best management practices for free-roaming horses in the Chilcotin, British Columbia. The study site is located between the towns of Hanceville to the east and Tatla Lake to the west. A case study approach was adopted, utilizing on-site observation, document analysis and semi structured interview methods. Analysis, through the reduction and interpretation of data, allowed for the emergence of the themes and subthemes. Themes were free-roaming horse interaction with both the biophysical and socioeconomic landscape as well as management. British Columbia government, ranchers, First Nations and Non Governmental Organizations were interviewed on their awareness and interaction with free-roaming horses, the management and policies pertaining to the species. Free-roaming horses have historically represented a social and economic resource, although stakeholders have had little input into management decisions. Antiquated policies, clashing social values, changing land title and land use and difficult economic times have resulted in a lack of clarity regarding jurisdiction, and therefore management, for the free-roaming horses. Management goals are not clear due to lack of classification as livestock or wildlife under provincial or federal legislations. A strategy, which promotes decentralization, collaboration and transparency in decision and policy-making is recommended. Multi-stakeholder research is the first step toward creating such a strategy.

The purpose of this research was to assess stakeholder interest pertaining to best management practices for free-roaming horses in the Chilcotin, British Columbia. The study site is located between the towns of Hanceville to the east and Tatla Lake to the west. A case study approach was adopted, utilizing on-site observation, document analysis and semi structured interview methods. Analysis, through the reduction and interpretation of data, allowed for the emergence of the themes and subthemes. Themes were free-roaming horse interaction with both the biophysical and socioeconomic landscape as well as management. British Columbia government, ranchers, First Nations and Non Governmental Organizations were interviewed on their awareness and interaction with free-roaming horses, the management and policies pertaining to the species. Free-roaming horses have historically represented a social and economic resource, although stakeholders have had little input into management decisions. Antiquated policies, clashing social values, changing land title and land use and difficult economic times have resulted in a lack of clarity regarding jurisdiction, and therefore management, for the free-roaming horses. Management goals are not clear due to lack of classification as livestock or wildlife under provincial or federal legislations. A strategy, which promotes decentralization, collaboration and transparency in decision and policy-making is recommended. Multi-stakeholder research is the first step toward creating such a strategy.

This performance-based project scrutinizes indeterminacy as a mediating force impinging upon our behaviour and its subsequent impact on the nature and constituency of engagements and dialogue between people in urban spaces. Concepts centering on the dynamics of departure are being investigated with focus upon the Multi User Virtual Environment (MUVE), Second Life as a facet of real life (the term 'real life' will henceforth be referred to in this document within the context of Second Life, as First Life). Experienced through the vehicle of the Roaming Body, our meetings and encounters with people and places frequently manifest as disjunct communiqués and mis-engagements. I am asserting that this is due to the inevitability in our existence of indeterminacy acting as a significant factor in the articulation of our relations with others, reinforcing our description as time-based entities traversing the passage of the everyday. I maintain that this is frequently evidenced in our behaviours through the occurrence (notwithstanding arrivals) of a continual, pre-emptive state of departure. Indeterminacy implies motion and emerges, as Massumi asserts, through ‘… an unfolding relation to its own nonpresent potential to vary …’. We, as humans, are constantly being drawn away – always either approaching or embracing involuntarily, a 'state-of-Leaving’ which co-mingles with and unerringly erodes our efforts to stay engaged with another in the here and now. In my dance and video practice, interventionist dance strategies are being used to prompt and interrogate the constituents of departure within encounters in designated public places. Experimental movement frameworks employed are informed by the discipline of Contact Improvisation Dance and Authentic Movement. The working process is being documented using a range of video narrative.

The diploma thesis is focused on exploring the possibility of VoIP service in a wireless network of University of Economics, Prague. This thesis describes the basic principles of VoIP and related wireless technologies necessary for its quality and stable operation. Subsequently, different configurations of wireless network and end clients are tested and compared, including its impact on ordinary users, in a laboratory environment with idle and fully utilized frequency band. Finally, a roaming operation with the use of several advanced 802.11 standards is tested in the real environment of the Old building in Žižkov. In conclusion, the ideal settings for all telecommunication devices are recommended in order to maximize the quality of VoIP operation and to minimize the negative impact on ordinary users.

With the increasing shift to the Internet Protocol [3] for all networks and the desire of telecommunications service providers to offer new value to their customers, the need exists to coordinate the delivery of end-to-end quality of service so that providers may offer new services to support their customer’s applications. The key objective of the EuQoS project is to research, integrate, test, validate, and demonstrate end-to-end QoS technologies to support advanced QoS-aware applications over multiple, heterogeneous research, scientific, and industrial network domains. End-to-end quality of service support for multiple applications is a great added value and could become the next major growth spurt in the telecommunications industry. A crucial requirement for the QoS model is that it must not add significant complexity to the existing mechanisms and must be compatible with legacy applications and equipment. Proxy signaling handlers will be used to satisfy the latter constraint. This thesis analyzes possible roaming scenarios and how Authentication, Authorization, and Accounting should be tackled. I seek to provide reasonable solutions and to consider the current environment, always trying to re-use, when possible, the existing architecture and components. / De huvudsakliga målen med EuQoS projektet är att integrera, testa, utvärdera och demonstrera QoS från en ende av kommunikationen till en annan för att stödja avancerade QoS tillämpningar inom multipla nätverksdomäner industrioch forskningsverksamhet. Denna nya teknik är av stort värde och kan komma att bli nästa stora steg i utvecklingen av telekommunikation. Användandet av IPnätverk ökar och i samma takt ökar även efterfrågan av nya och bättre kommunikationstjänster. Därför finns det ett stort behov av QoS hos Internetleverantörerna som ständigt måste tillgodose kundernas önskemål. Det är viktigt att QoS modellen inte komplicerar den redan existerande tekniken. Därför måste den vara kompatibel med befintliga tekniker och utrustning. För att uppfylla dessa krav kommer Proxy signalbehandlare att användas. Den här rapporten behandlar möjliga roaming scenarier och hur AAA bör hanteras. Jag har som mål att presentera rimliga lösningar som tar hänsyn till miljön. För detta används i största möjliga mån redan existerande infrastruktur. / Con la continua evolución de las aplicaciones basadas en el protocolo IP en todas las redes, y el deseo de los proveedores de servicios de telecomunicaciones de ofrecer un valor añadido a sus clientes, cohabita la necesidad de coordinar la entrega de calidad de servicio (QoS) extremo a extremo. De esta forma los proveedores pueden aumentar la oferta de servicios mediante nuevas aplicaciones. El principal objetivo del proyecto EuQoS es investigar, desarrollar, integrar y probar una tecnología independiente de la red de acceso que garantice QoS extremo a extremo. El sistema esta pensado inicialmente para dar soporte a las aplicaciones: VoIP, VoD, video conferencia, y a una aplicación médica llamada MEDIGRAF, sobre múltiples y heterogéneas redes de acceso. Los parámetros que EuQoS tiene en cuenta para la reserva de la calidad de servicio son el ancho de banda, el retardo, la variación del retardo (jitter), y las pérdidas permitidas. Un requisito fundamental para el modelo de QoS es que debe añadir la mínima complejidad posible al existe funcionamiento del sistema y debe ser compatible con el legado de aplicaciones y equipo. Esto se solucionará mediante el uso de señalización a nivel de Proxy. Este proyecto analiza los posibles escenarios de roaming y cómo se debería afrontar la Autenticación, Autorización, y Accounting (AAA) en estas condiciones de itinerancia. En los capítulos iniciales hacen una descripción general del sistema EuQoS, para tener una visión global del proceso de reserva de recursos. Es necesario conocer la estructura completa para lograr una integración mayor y con el menor coste posible. El proyecto EuQoS propone y desarrolla un nuevo mecanismo de QoS que se construye sobre un estado del arte que incorpora los siguientes mecanismos: Monitorización y Medición, Control de Admisión, Gestión de Fallos, Señalización y Negociación de Servicio, Seguridad y AAA, Charging, Ingeniería de Tráfico y Optimización de Recursos. Con el fin de conocer lo que anteriormente otros habían hecho en este campo, antes de escribir una sola línea de este proyecto, llevé a cabo una extensa búsqueda de documentación. Parte de la información utilizada en este documento ha sido extraída de las entregas públicas del proyecto EuQoS hechas a la Comisión Europea. Además de la bibliografía mostrada en las referencias, Ericsson tiene sus propios informes técnicos e implementaciones de protocolos como el protocolo de iniciación de sesión (SIP) y DIAMETER, que se han consultado en varias ocasiones y han contribuido a lo largo de la investigación. Existe una enorme similitud entre la arquitectura del sistema y la de IMS. De esta manera, algunos de los conceptos aplicados a la hora de desarrollar una solución para el caso de roaming para EuQoS se basan en los flujos de señalización utilizados en IMS y en los anteproyectos de nuevos RFCs.

Today mobile network operators utilize IP Packet exchange (IPX) carriers to interconnect their networks with other operators. Mobile network operators are free to choose one IPX carrier for their data traffic and another for their control traffic. This thesis examines the case of control traffic, specifically Stream Control Transmission Protocol (SCTP) carrying Diameter protocol traffic arising from users roaming from their home Long Term Evolution (LTE) network to another operator’s LTE network. The thesis project aims to identify a set of SCTP parameter configurations that can provide improved application/service level availability between two Diameter nodes in different network connectivity environments, specifically for IPX carriers who are Diameter service providers. These service providers provide Diameter connectivity for their customers who are mobile network operators. These mobile network operators in turn provide LTE roaming services to their customers. Unfortunately, applying the ‘One size fits all’ configuration recommendations given in the SCTP documentation is unsuitable for different network environments. In addition, the amount of Diameter signaling traffic is growing at a very rapid rate. Therefore, it is valuable to identify suitable parameter selection criteria for Diameter service providers to ensure 100% Diameter connectivity reliability for their customers. In this thesis project, author investigated how tuning SCTP parameter values affect Diameter message transmission in terms of Round Trip Delay and identified its determining parameters for packet loss recovery performance. Both IPX carriers and mobile network operators may use these values as reference when attempting to ensure high availability of Diameter transmissions under reliable, semi reliable, and unreliable network transport conditions. / Mobilnätsoperatörer använder sig av IP Packet exchange (IPX) tjänstetillhandahållare för att koppla ihop sina nät med andra operatörers nät. Mobilnätsoperatörer kan fritt välja en IPX tjänstetillhandahållare för sin datatrafik och en annan för sin kontrolltrafik. Denna uppsats undersöker fallet för kontrolltrafik, specifikt Stream Control Transmission Protocol (SCTP) kommunikationsprotokoll för Diameter protocol-trafik vid användares roaming från sitt Long Term Evolution (LTE)-hemmanät till en annan operatörs LTE-nät. Examensarbetet avser etablera en uppsättning av SCTP-parameterkonfigurationer som ger förbättrad applikations-/tjänstetillgänglighetsnivå mellan två Diameter-noder i olika nätmiljöer, särskilt för IPX tjänstetillhandahållare som är Diameter tjänstetillhandahållare.  Dessa tjänstetillhandahållare erbjuder Diameter-konnektivitet till sina kunder, som är mobilnätsoperatörer. Dessa mobilnätsoperatörer tillhandahåller i sin tur LTE-roamingtjänster till sina kunder. Tyvärr är det olämpligt att tillämpa de enhetliga konfigurationsrekommendationer, som ges i SCTP- och Diameter-protokollens dokumentation, i olika nätmiljöer. Samtidigt ökar Diameter-signaleringstrafiken mycket snabbt. Därför är det värdefullt att identifiera lämpliga parameterkriterier för Diameter-tjänstetillhandahållare att säkerställa 100% tillförlitlig Diameter-tillgänglighet för sina kunder. I detta examensarbete har författaren undersökt hur trimning av SCTP-parametervärden påverkar Diameter-meddelandeöverföring vad avser överföringstiden tur- och retur, och identifierat de avgörande parametrarna för återställande av paketförluster. Både IPX tjänstetillhandahållare och mobilnätsoperatörer kan använda dessa värden som referens för att åstadkomma hög tillgänglighet för Diameter-överföring vid tillförlitliga, halvtillförlitliga och otillförlitliga nättransportförutsättningar.

Cette thèse étudie la transnationalisation d'un mouvement issu de la confrérie musulman Tidjaniyya : le mouvement Tidjaniyya Ibrahimiyya. Fondé en 1929, ce mouvement a pu s'exporter dans différents pays d'Afrique grâce à une forme de prédication itinérante développée par son fondateur (Ibrahim Niasse, 1902-1975) et ses premiers lieutenants. Depuis la disparition d'Ibrahim Niasse, un groupe hétérogène d'acteurs (les héritiers), poursuivent cette dynamique de transnationalisation en vue, d'une part d'assurer la promotion du mouvement et, d'autre part, d'acquérir une meilleure considération sociale et politique. Cette thèse s'appuie sur l'ethnographie multi-située, l'observation participante, l'analyse de discours et le traitement des archives (internes et externes), en vue d'interroger l'expérience de l'itinérance transnationale chez les héritiers de la Ibrahimiyya. Dans un second temps, il est question de faire l'inventaire des enjeux socio-politiques et économiques qui délimitent la transnationalisation de ce mouvement Ibrahimiyya. / This thesis investigates the trans movement from the Muslim brotherhood Tidjaniyya: the Tidjaniyya Ibrahimiyya movement. Founded in 1929, this movement could be exported to different countries in Africa through a form of itinerant preaching developed by its founder (Ibrahim Nisse, 1902-1975) and his first lieutenant. Since the disappearance of Ibrahim Niasse, a diverse group of stakeholders (the heirs), continuing the momentum of trans nationalization to ensure on the one hand, promoting movement; and secondly, to gain a better social and political status. This thesis is based on the multi-located ethnography, participant observation, discourse analysis and processing records (internal and external), to examine experience of transnational roaming among heirs of Ibrahimiyya.

LoRaWAN is an open networking technology designed for IoT devices that al-lows wireless data transmission over longer ranges than some other wireless tech-nologies, like Wi-Fi or Bluetooth, for devices that are constrained in terms of size,price, and available power. The current design of roaming among networks in LoRaWANis heavily inspired by that of mobile networks, as the use of roaming agreementsis mandated. Roaming agreements create unnecessary administrative overhead thathinders deployments. A roaming model that is quicker and simpler to deploy couldsave money for current users, and could even attract new users to the technology.To circumvent the necessity of roaming agreements, a new, scalable and agreement-less roaming model should be proposed. In this thesis project a literature survey isconducted, investigating similar technologies to find hints or inspiration for a newroaming model. It is found that the broker software architecture pattern put in thecontext of roaming in LoRaWAN suits the requirements quite well, so the new roam-ing model has been developed based on that. A software simulation has been imple-mented to gather data regarding the scalability of the model. It has been found thatthe proposed model is both scalable, and agreement-less.