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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

Cross-layer optimized video streaming in heterogeneous wireless networks

Ojanperä, T. (Tiia) 09 June 2013 (has links)
Abstract This dissertation studies the impact of heterogeneous wireless networks on the design and implementation of mobile video streaming services. The aim is to enable Quality of Service (QoS) sensitive video streaming services to take full advantage of the access diversity of heterogeneous networks in order to optimize their operation in terms of quality and efficiency of network resource usage. This nevertheless requires support beyond the layered communication architecture of today’s Internet. The thesis proposes an architecture for end-to-end cross-layer signaling and control for video streaming systems. The architecture supports extensive context informa- tion transfer in heterogeneous networks; thus, enabling the efficient management of video stream adaptation and user terminal mobility in a diverse and dynamic network environment. This thesis also studies and proposes cross-layer enhancements for adaptive video streaming and mobility management functions enabled by the cross- layer architecture. These include cross-layer video adaptation, congestion-triggered handovers, and concurrent utilization of multiple access networks in the video stream transport. For the video adaptation and multipath transmission, the flexible adaptation and transmission capabilities of the novel scalable video coding technology are used. Regarding the mobility management, the proposed solutions essentially enhance the handover decision-making of the Mobile IP protocol to better support QoS-sensitive video streaming. Finally, the thesis takes a holistic view on the application adaptation and mobility management, and proposes a solution for coordinated control of these two operations in order to achieve end-to-end optimization. The resulting mobile video streaming system architecture and the cross-layer control algorithms are evaluated using network simulations and real prototypes. Based on the results, the proposed mechanisms can be seen to be viable solutions for improving video streaming performance in heterogeneous wireless networks. They require changes in the communication end-points and the access network but support gradual deployment. This allows service providers and operators to select only a subset of the proposed mechanisms for implementation. The results also support the need for cross-layer signaling and control in facilitating efficient management and utilization of heterogeneous wireless networks. / Tiivistelmä Väitöskirja tutkii langattomien ja heterogeenisen verkkoympäristöjen vaikutusta erityisesti mobiilikäyttöön suunnattuihin suoratoistovideopalveluihin (streaming). Työn tavoitteena on löytää keino optimoida verkkoyhteyden palvelunlaadulle (QoS) herkän suoratoistovideon toiminta sekä videopalvelun laadun että verkon tiedonsiirtokapasiteetin käytön osalta. Tämä tapahtuu mahdollistamalla heterogeenisten verkkojen tehokas käyttö suoratoistovideopalvelujen tapauksessa. Tavoitellut parannukset vaativat kuitenkin muutoksia nykyiseen kerroksittaiseen Internet-arkkitehtuuriin. Väitöskirjassa esitetään arkkitehtuuri protokollakerrosten välisen tiedon (cross-layer) välitykseen ja hyödyntämiseen suoratoistovideopalvelujen tiedonsiirron kontrolloinnissa. Arkkitehtuuria voidaan käyttää laaja-alaiseen kontekstitiedon välitykseen tietoverkoissa, mikä mahdollistaa tehokkaan videopalvelun adaptoinnin ja päätelaitteen liikkuvuudenhallinnan heterogeenisissa verkoissa, joissa palvelunlaatu vaihtelee. Väitöskirja myös ehdottaa erilaisia ratkaisuja videopalvelun adaptoinnin ja tiedonsiirron parantamiseksi arkkitehtuuria hyödyntämällä. Näihin lukeutuvat usealle protokollakerrokselle toteutettu videon adaptointi, verkkoyhteyden ruuhkautumiseen reagoiva yhteydensiirto sekä usean verkkoyhteyden samanaikainen käyttö videopalvelun tiedonsiirrossa. Videon adaptoinnissa ja siirrossa hyödynnetään uutta skaalautuvaa videonkoodausteknologiaa, joka mahdollistaa vaaditun, joustavan videobittivirran muokkauksen. Liikkuvuudenhallinnan osalta työssä keskitytään pääosin kehittämään Mobile IP -protokollan päätöksentekoa suoratoistovideopalvelujen tapauksessa. Lopuksi väitöskirjassa esitetään kokonaisvaltainen ja koordinoitu ratkaisu videopalvelun adaptoinnin sekä päätelaitteen liikkuvuuden hallintaan päästä päähän -optimoinnin saavuttamiseksi. Tuloksena esitetyt järjestelmäarkkitehtuuri ja protokollakerrosten välistä tietoa käyttävät hallinta-algoritmit evaluoitiin simulaatioiden ja oikeiden prototyyppien avulla. Tulokset osoittavat, että ehdotettuja menetelmiä voidaan käyttää parantamaan suoratoistovideopalvelujen suorituskykyä heterogeenisissa verkoissa. Ratkaisut vaativat muutoksia verkko- ja palveluarkkitehtuureihin, mutta niiden asteittainen tai osittainen käyttöönotto on mahdollista. Tulokset osoittavat myös protokollakerrosten välisen tiedon tarpeellisuuden langattomien ja heterogeenisten verkkojen tehokkaassa käytössä.
122

APSEN Analysis for Beyond 3G Wireless Networks / APSEN Analysis for Beyond 3G Wireless Networks

QADEER, MUHAMMAD, KHAN, MUHAMMAD HUMRAN January 2009 (has links)
The beyond 3G official IEEE name for next generation of wireless technology, some people also called it as 4G (fourth-generation) mobile communication systems. Beyond 3G will be used largely to contain not only cellular telephone systems but also several types of broadband wireless access communication systems, have been attracting much interest in the mobile communication field. A new age has begun for telecommunication industry. Over the past decade wireless industry has grown at a remarkable pace, consequently level of technology development goes beyond the level of customer desire. Application flexibility and being highly dynamic will be the main features of beyond 3G services of interest to users. Being there all these emerging technologies in one cellular network has opened the work of designing and optimization of the networks to be viewed from a different perspective. APSEN analysis for Beyond 3G wireless networks has been discussed. “AP” stands for application layer, analysis of services and applications. “SE” stands for session layer, analysis of session management protocol and “N” for network layer, analysis for network protocols. The main purpose of our research is to focus on the challenges offered at APSEN for beyond 3G wireless network. There are a lot of research challenges in each of the different layers but focus will be on APSEN. The objective is to take a look at and familiarize with some of the major challenges offered at APSEN for beyond 3G wireless network. Qualitative approach has been used which will help us to collect wide range of information and enhance our knowledge by analyzing the perspectives of different researchers.
123

Managing control information in autonomic wireless networking

Luoto, M. (Markus) 02 October 2017 (has links)
Abstract As mobile Internet access traffic continues to grow at an explosive rate and wireless networks continue to diverge into multiple access technologies with partly overlapping sets of features, new solutions for efficient use of these networks are vital. Cognitive network management provides tools to tackle this challenge by automatically learning from past experience the characteristics and usage patterns of the connected devices, thus enabling autonomic optimization of those connections. Cognitive network management requires a vast amount of information in order to function effectively, making collaboration of the networked devices essential as the best sources of information are scattered throughout the network. This makes efficient information dissemination one of the key enablers for autonomic networking. This dissertation studies managing control information related to autonomic selection of access networks and adapting services in a heterogeneous wireless network environment. It presents a solution to simple and efficient information dissemination in the form of Distributed Decision Engine— a CEP-like system enabling the building of a highly scalable and dynamic messaging system enabling dissemination, analysis and control of the complex series of interrelated events in the network. The dissertation also presents results showing a clear benefit in using cross-layer and cross-domain information in a modern wireless environment and validates the final prototype implementation of DDE with laboratory measurements. Effective use of disseminated cross-layer information is another key element in autonomic wireless networking. This dissertation also focuses on intelligent decision-making based on cross-layer information by presenting test results which attest that the performance of an autonomic wireless networking system can be improved by using cognitive techniques in its management algorithms, and that hierarchy and coordination can be utilized to minimize the effect of conflicting decisions of the system. / Tiivistelmä Mobiilin Internet-liikenteen räjähdysmäinen kasvu ja langattomien verkkojen jatkuva jakautuminen useisiin tekniikoihin vaativat uusia ratkaisuja näiden verkkojen tehokkaaseen käyttöön. Kognitiivinen verkon hallinta mahdollistaa oppimisen, minkä avulla laitteiden yhteyksiä voidaan optimoida autonomisesti aiemman kokemuksen perusteella. Tällainen optimointi vaatii kuitenkin valtavan määrän verkosta ja laitteista kerättyä tietoa, mikä tekee tehokkaasta tiedonjakelusta keskeisen elementin autonomisessa verkon hallinnassa. Tässä väitöskirjassa tutkitaan verkon valintaan ja palveluiden sopeuttamiseen vaadittavan tiedon välittämistä ja hallintaa autonomisissa langattomissa verkoissa. Ratkaisuna yksinkertaiseen ja tehokkaaseen tiedonvälitykseen esitellään hajautettu Distributed Decision Engine -komponentti, joka mahdollistaa skaalautuvan tiedon jakelu-, analysointi- ja hallintajärjestelmän rakentamisen. Lisäksi väitöskirjassa kuvataan myös tuloksia, jotka osoittavat, että verkkokerrosten välisen tiedon käyttämisellä voidaan saavuttaa selvää etua, sekä tuloksia, jotka vahvistavat DDE-prototyyppitoteutuksen toimivuuden laboratoriomittauksin. Verkkokerrosten välisen tiedon tehokas hyödyntäminen on toinen keskeinen tekijä autonomisessa langattomien verkkojen hallinnassa. Väitöskirjassa käsitellään myös älykästä päätöksentekoa kyseisen informaation pohjalta sekä esitellään tuloksia, jotka osoittavat, että päätöksentekoa autonomisessa langattomien verkkojen hallinnassa voidaan parantaa kognitiivisilla tekniikoilla. Lisäksi esitetyt tulokset osoittavat, että hierarkialla sekä koordinoinnilla voidaan minimoida ristiriitaisten päätösten vaikutukset järjestelmään.
124

Mobility management for the information centric future internet / Gestion de la mobilité pour l'internet du futur centré autour de l'information

Saleem, Muhammad Shoaib 19 November 2012 (has links)
L'Internet d'aujourd'hui a traversé série de changements évolutionnaires dans les quarante ou cinquante dernières années. Il a été conçu pour un réseau avec des nœuds fixes. Au début, le modèle de communication de l'Internet a été basé sur le réseau téléphonique (considéré comme 1er Génération Internet). Plus tard, il a été mis à jour comme un modèle client-serveur où la communication des systèmes d'échanger des données sur des liaisons dédiées. Cette 2ème génération Internet, au cours des années, a été contestée par de nombreux problèmes tels que la congestion du réseau, panne de chemin, les attaques DOS, gestion de la mobilité pour les réseaux sans fil, etc. Les utilisateurs d'Internet recherchent toujours des informations, indépendamment de la localisation (nœud ou serveur) où il se trouve ou stockées. Cette approche est la base d'une architecture où l'information est considérée comme l'unité primaire. Ces réseaux, en général, sont appelés en tant que Network of Information (NetInf), où l'information prend une position centrée remplaçant l'approche centrée sur nœud comme dans l'Internet aujourd'hui. Les problèmes rencontrés par l'Internet aujourd’hui, mentionné ci-dessus, peuvent être traitées avec une approche unificatrice en mettant l'information au centre de l'architecture du réseau. À l'échelle mondiale, cette conception de l'architecture réseau est nommée « Future Information Centric Internet ». En parallèle, l'utilisation de l'Internet mobile a été augmentée durant la dernière décennie. Il a été environ 1,2 milliard abonnements de mobile broad band pour 2,4 milliards d’utilisateurs d'Internet en 2011. En raison d’augmentation de l'efficacité spectrale et ubiquitaire disponibilité de la connectivité cellulaire, la mobilité et la connectivité transparente est désormais considérée comme des produits de base la vie quotidienne. Néanmoins, en cas d'Internet, les solutions de mobilité basées sur IP ne peuvent pas rattraper son retard dans la performance avec l'évolution rapide des réseaux cellulaires. Par conséquent, l'un des principaux objectifs pour l'internet du futur est de concevoir des systèmes de gestion de mobilité qui permettent de surmonter les problèmes dans les réseaux sans fil tels que handover et la gestion de la localisation, multihoming, sécurité, etc. Dans cette thèse, nous avons proposé une solution de gestion de mobilité dans les réseaux sans fil dans le cadre du Information Centric Networking (ICN) en général et dans le contexte ne NetInf en particulier. NetInf est une architecture du Futur Internet basée sur le concept du ICN. Nous proposons un nœud mobile qui s’appelle NetInf Mobile Node (NetInf MN). L'architecture de ce nœud est compatible avec l'architecture d'Internet basée sur TCP/TP. Cette conception de l'architecture travaille en collaboration avec Central Control Unit (CCU) pour améliorer les performances en cas de handover dans les réseaux sans fil. La Virtual Node Layer (VNL) algorithme explique comment les différents modules de NetInf MN et des unités CCU travaillé ensemble. La modèle mathématique basé sur Théorie de Jeu et Renforcement Learning (CODIPAS-RL) montre comment handover et data relaying sont géré dans les réseaux sans fil. Les résultats des simulations montrent que le modèle proposé réalise à la fois de Nash et de Stackelberg équilibres alors que le CODIPAS-RL régime atteint un optimum global. Enfin, comme un exemple de cas d'utilisation de l'architecture NetInf, nous proposons le NetInf Email Service qui ne requiert pas des serveurs et ports dédiés contrairement au service e-mail existante. L'utilisation de clés asymétriques comme l'ID de l'utilisateur est la caractéristique unique proposée pour ce service. Le NetInf Email service architecture présenté, explique comment différents éléments architecturaux travail ensemble. Nous discuter des défis différents et des besoins relatifs à ce service. Le prototype développé pour NetInf sera utilisée pour la mise en œuvre de ce service / The contemporary Internet ecosystem today has gone through series of evolutionary changes during the last forty or fifty years. Though it was designed as a network with fixed nodes, it has scaled well enough with the development of new technologies both in fixed and wireless networks. Initially, the communication model of the Internet was based on the telephone network (and can be considered as the 1st Generation Internet). Later, its transition as a client-server model made it a network where communication systems exchange data over dedicated links. This 2nd Generation Internet, over the years, has been challenged by many problems and issues such as network congestion, path failure, DOS attacks, mobility issues for wireless networks, etc. The Internet users always look for some information, irrespectively where it is located or stored. This approach is the basic building block for a network architecture where information is considered as the premier entity. Such networks, in general, are termed as Information Centric Network (ICN), where information takes centric position superseding the node centric approach like in the current Internet. The problems faced by the current Internet architecture, mentioned above, can be handled with a unifying approach by putting the information at the centre of the network architecture. On a global scale, this network architecture design is termed as the Future Information Centric Internet. Similarly, Mobile Internet usage has increased overwhelmingly in the last decade. There has been an estimated 1.2 billion mobile broad-band subscriptions for 2.4 billion Internet users in 2011. Because of the increased spectrum efficiency and ubiquitous availability of cellular connectivity, the seamless mobility and connectivity is now considered as daily life commodity. However, in the case of the Internet, IP based mobility solutions cannot catch up in performance with the fast evolution of cellular networks. Therefore, one of the primary goals for the Future Internet is the design of mobility management schemes that overcome the issues in wireless networks such as handover and location management, multihoming, security, etc. In this thesis, we have proposed a mobility management solution in wireless networks in the context of ICN in general and in the context of Network of Information (NetInf) in particular. NetInf is ICN-based Future Internet architecture. We propose a NetInf Mobile Node (NetInf MN) architecture which is backward compatible with the current Internet architecture as well. This cross architecture design for mobility support works closely with Central Control Unit (CCU) (network entity) for improved performance in case of handover management in wireless networks. The Virtual Node Layer (VNL) algorithm explains how different modules of NetInf MN and CCU units work together. The game theoretical and Reinforcement Learning (CODIPAS-RL) scheme based mathematical model shows how handover management and data relaying in the wireless networks can increase the network coverage through cooperative diversity. Simulation results show that the proposed model achieves both Nash and Stackelberg equilibria where as the selected CODIPAS-RL scheme reaches global optimum. Finally, as a use case example of NetInf architecture, we propose the NetInf Email service that does not require dedicated servers or dedicated port unlike the current email service. The use of asymmetric keys as user's ID is the unique feature proposed for this service. The NetInf email service architecture framework presented, explains how different architectural components work together. We discuss different challenges and requirements related to this service. The prototype developed for the Network of Information will be used for the implementation of this service
125

Mobility management and vertical handover decision making in heterogeneous wireless networks / Prise de décision de handover vertical pour la gestion de mobilité dans les réseaux hétérogènes sans fil

Zekri, Mariem 23 January 2012 (has links)
L’évolution des technologies réseaux sans fil, des terminaux mobiles ainsi que des contenus et des services créent des environnements hétérogènes de plus en plus complexes. Dans ce contexte, un compromis entre la mobilité, la transparence et la performance apparaît. Des utilisateurs mobiles, ayant différents profils et préférences, voudraient être toujours connectés au meilleur réseau à tout moment, sans avoir à se soucier des différentes transitions entre réseaux hétérogènes. Face à cette complexité, il parait nécessaire de proposer de nouvelles approches afin de rendre ces systèmes plus autonomes et de rendre les décisions de handover vertical plus efficaces. Cette thèse se concentre sur la gestion de mobilité verticale, plus précisément sur la prise de décision de handover vertical dans un environnement de réseaux hétérogènes sans fil. Après l’identification des différents paramètres de prise de décision et l’analyse de l’état de l’art relié à la gestion de la mobilité verticale, nous avons proposé un système de réputation qui permet de réduire les délais de prise de décision. La réputation d’un réseau est introduite comme une nouvelle métrique de prise de décision qui peut être recueillie à partir des expériences précédentes des utilisateurs sur ce réseau. Nous montrons que la réputation est une métrique efficace qui permet l’anticipation du handover et accélère la prise de décision. Bien que l’objectif principal soit de garantir la meilleure qualité de service et l’utilisation optimale des ressources radios, les aspects économiques doivent également être considérés, y compris la minimisation des coûts pour les utilisateurs et la maximisation des revenus pour les fournisseurs de services ou les opérateurs. Nous proposons alors, dans la deuxième partie de la thèse, un mécanisme de prise de décision basé sur la théorie des jeux. Ce dernier permet la maximisation des utilités des réseaux et des utilisateurs. Dans cette solution, chaque réseau disponible joue un jeu de Stackelberg avec un ensemble d’utilisateurs, tandis que les utilisateurs jouent un jeu de Nash entre eux pour partager les ressources radios limitées. Un point d’équilibre de Nash, qui maximise l’utilité de l’utilisateur et les revenus des fournisseurs de services, est trouvé et utilisé pour le contrôle d’admission et la prise de décision de handover vertical. Dans la troisième partie de cette thèse, nous proposons et discutons deux différentes solutions architecturales sur lesquelles nos mécanismes de prise de décision proposés peuvent être intégrés. La première architecture proposée est basée sur la norme IEEE 802.21 à laquelle nous proposons certaines extensions. La seconde architecture proposée est basée sur un niveau de contrôle composé de deux couches de virtualisation. La virtualisation est assurée via des agents capables de faire un raisonnement et de prendre des décisions pour le compte d’entités physiques qu’ils représentent au sein du système. Cette architecture permet une plus grande flexibilité / Mobility management over heterogeneous wireless networks is becoming a major interest area as new technologies and services continue to proliferate within the wireless networking market. In this context, seamless mobility is considered to be crucial for ubiquitous computing. Service providers aim to increase the revenue and to improve users’ satisfaction. However there are still many technical and architectural challenges to overcome before achieving the required interoperability and coexistence of heterogeneous wireless access networks. Indeed, the context of wireless networks is offering multiple and heterogeneous technologies (e.g. 2G to 4G, WiFi, Wimax, TETRA,...). On the one hand, this rich environment allows users to take profit from different capacities and coverage characteristics. Indeed, this diversity can provide users with high flexibility and allow them to seamlessly connect at any time and any where to the access technology that best fits their requirements. Additionally, cooperation between these different technologies can provide higher efficiency in the usage of the scarce wireless resources offering more economic systems for network providers. On the other hand, the heterogeneity of technologies and architectures and the multiplication of networks and service providers creates a complex environment where cooperation becomes challenging at different levels including and not limited to mobility management, radio resource provisioning, Quality of Service and security guarantees. This thesis is focusing on mobility management and mainly on decision making for Vertical handover within heterogeneous wireless network environments. After the analysis of the related state of the art, we first propose a reputation based approach that allows fast vertical handover decision making. A decision making scheme is then built on that approach. Network’s reputation, is a new metric that can be gathered from previous users’ experiences in the networks. We show that it is an efficient construct to speed up the vertical handover decision making thanks to anticipation functionalities. While the main objective remains guaranteeing the best Quality of Service and optimal radio resource utilization, economical aspects have also to be considered including cost minimization for users and revenue maximization for network providers. For this aim, we propose, in the second part of the thesis, a game theoretic based scheme that allows maximizing benefits for both networks and users. In this solution, each available network plays a Stackelberg game with a finite set of users, while users are playing a Nash game among themselves to share the limited radio resources. A Nash equilibrium point, that maximizes the user’s utility and the service provider revenue, is found and used for admission control and vertical handover decision making. The analyses of the optimal bandwidth/prices and the revenue at the equilibrium point show that there are some possible policies to use according to user’s requirements in terms of QoS and to network capacities. For instance, we pointed out that networks having same capacities and different reputation values should charge users with different prices which makes reputation management very important to attract users and maximize networks’ revenue. In the third part of this thesis, we provide and discuss two different architectural and implementation solutions on which our proposed vertical handover decision mechanisms can be integrated. The first proposed architecture is a centralized one. It is based on the IEEE 802.21 standard to which some extensions are proposed. The second proposed architecture is distributed. It is based on an overlay control level composed of two virtualization layers able to make reasoning on behalf of physical entities within the system. This architecture allows higher flexibility especially for loosely coupled interconnected networks
126

IP mobility enhancements for heterogeneous wireless networks / Améliorations de la prise en charge de la mobilité des réseaux sans fil hétérogènes

Gurkas Aydin, Gulsum Zeynep 30 January 2014 (has links)
Au cours des dernières décennies, le besoin pour des communications multimédia en mobilité est devenu indéniable dans les réseaux de type IP, ainsi la gestion de la mobilité et la continuité de session est depuis plusieurs années un problème de recherche très important aussi bien pour le milieu académique qu’industriel. Comme l'hétérogénéité des réseaux d’accès est en perpétuelle évolution, l'intégration des différents types de réseaux sans fil au niveau de la couche IP est devenue un domaine de recherche difficile et inévitable. L'un des problèmes les plus importants liés à l'exécution de la gestion de la mobilité concerne le fait que la couche d'application souffre de la modification d'adresses IP au cours du mouvement du nœud mobile alors que celle-ci construit sa session sur la base de l’adresse IP de connexion au réseau. Une nouvelle approche d'amélioration de la prise en charge de la mobilité propose de séparer l'identification de session et l'identification de l’emplacement ou l’attachement au réseau. Donc, par la séparation de ces deux concepts, les sessions ne sont pas identifiés par les adresses IP qui elles sont dynamiques puisque la mobilité dans le réseau impose le changement d’adresse IP, mais les nouveaux identificateurs uniques qui définissent un nœud et qui ne change pas à cause de la mobilité ce qui offrirait une stabilité pour le niveau applicatif. Selon ces concepts, Host Identity Protocol (HIP) est l'une des solutions dominantes en recherches qui est proposé par l'IETF et l’IRTF. Dans cette thèse, le protocole HIP est principalement examiné et de nouvelles améliorations de la mobilité sur la base de ce protocole ont été conçues et mises en place / Over the last decades, with rapid and tremendous growth of IP networks in mobile and wireless environments, mobility management and session continuity has become a more important issue. As the heterogeneity increases in network environments and gradual spread of Internet of Things wave, the integration of different types of wireless networks in the IP layer became a challenging and inevitable research area. One of the most important issues related to mobility management is related to the fact that the application layer suffers from the changing of IP addresses during the movement of the mobile node. It is expected the network layer and above layers to be aware of movement of mobile nodes. New wave in the improvement ideas on this concept is separating the session identification and the location identification. This avoids the applications to suffer when the IP address changes during the mobility. This new approach needs to introduce a new layer in the TCP/IP protocol stack, on top of the IP layer that will handle the new identifiers correspondent with the current IP address or new complete architecture designs which are inheriting locator/identifier separation idea. According to these concepts, Host Identity Protocol (HIP) is one of the dominant and prominent researches that is proposed by IETF and IRTF. This protocol proposes to solve the locator/identifier split problem by also including the security support. In this thesis, predominantly HIP protocol is examined and new mobility enhancements based on this protocol have been designed and introduced
127

”Visst ska man tänka på miljö, men…” : En studie av synen på den egna parkeringsplatsen i flerbostadshus med sänkt parkeringstal / “Sure, the environment is important, but...” : a study of residents’ attitudes relating to personal parking spaces in blocks of flats affected by lowered minimum parking requirements

Sundbom, Henrick January 2022 (has links)
I detta kandidatexamensarbete undersöker jag den demokratiska hållbarheten i kommunpolitiska beslut om sänkta krav på parkering (så kallade ”flexibla parkeringsnormer”). Den tidigare forskningen på ämnet har fokuserat på huruvida den önskade beteendeförändringen kan uppnås, varför användarnas uppfattningar kring beslutet inte studerats. Jag undersöker dessa med en kvantitativ fallstudie, där jag samtidigt diskuterar de politiska konsekvenser som uppfattningarna skulle kunna leda till och om beslutet uppfattas som demokratiskt legitimt. Fallstudien är baserad på en enkätundersökning i två flerbostadshus i Malmö som fått ett parkeringstal på ungefär 0,5 parkeringsplatser per lägenhet som följd av ett beslut om flexibel parkeringsnorm. Resultatet visar att många av de boende upplever det som svårt att få en egen parkeringsplats i bostadshuset och att månadsavgifterna upplevs som dyra. Få av de boende uppger att de känner till det politiska beslutet, och när de får veta om det uppger två tredjedelar att de är negativt inställda till det. Fyra femtedelar uttrycker dock att frågan inte är viktig nog för att få dem att rösta på ett annat parti i lokalpolitiken. En slutsats av detta är att inget omedelbart tryck på partierna för att ändra sin syn på frågan finns. Den andra slutsatsen är att ifall kommuner önskar fortsätta med denna typ av parkeringsnorm på ett hållbart sätt, eller ifall de önskar hitta politiskt stöd för att utöka sänkningen ytterligare, kommer de att behöva hitta sätt att utöka acceptansen hos de som påverkas av beslutet. / In this bachelor’s degree thesis, I explore the democratic sustainability of Swedish municipal policies reducing minimum parking requirements (so called “flexible parking requirements”). Past research into such policies has focused on their effectiveness in achieving behavioural change, while leaving the attitudes of the affected users unexamined. I examine these attitudes using a quantitative case study, while discussing the political consequences they might lead to and whether the users might find the policies democratically legitimate or not. The case study is based on a survey of residents in two blocks of flats in Malmö affected by a flexible parking requirement policy requiring about 0.5 parking spaces per flat.  The results show that many residents experience difficulty in getting a lease for a parking space within their own building and find the monthly fees to be expensive. Few of the residents report being aware of the municipal policy and two thirds state that they dislike its content when told about it. However, four fifths of the residents state that the matter is not important enough to them to affect which political party they would vote for. I conclude first that there is no imminent pressure upon the local political parties to change their stances. Secondly, if the municipalities wish to sustainably continue using such policies or to find political support for increasing the reduction further, they need to find measures to improve the acceptance among the affected users.
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Location based authenticated multi-services group key management for cyber security in high speed broadband wireless multicast communications. Multi-service group key management scheme with location based handover authentication for multi-handoffs participating in multi-group service subscriptions, its performance evaluation and security correctness in high speed broadband wireless multicast communications

Mapoka, Trust Tshepo January 2015 (has links)
Secure information exchanges over cyberspace is on the increase due to the convergence of wireless and mobile access technologies in all businesses. Accordingly, with the proliferation of diverse multicast group service subscriptions that are possible to co-exist within a single broadband network, there is also huge demand by the mobile subscribers to ubiquitously access these services over high speed broadband using their portable devices. Likewise, the Network Providers (NPs) invest hugely in infrastructure deployment to disseminate these services efficiently and concomitantly. Therefore, cyber security in any business is obligatory to restrict access of disseminated services to only authorised personnel. This becomes a vital requirement for a successful commercialisation of exchanged group services. The standard way to achieve cyber security in a wireless mobile multicast communication environment is through confidentiality using Group Key Management (GKM).The existing GKM schemes for secure wireless multicast from literature only target single group service confidentiality; however, the adoption of multiple group service confidentiality in them involve inefficient management of keys that induce huge performance overheads unbearable for real time computing. Therefore, a novel authenticated GKM scheme for multiple multicast group subscriptions known as slot based multiple group key management (SMGKM) is proposed. In the SMGKM, the handovers move across diverse decentralised clusters of homogeneous or heterogeneous wireless access network technologies while participating in multiple group service subscriptions. Unlike the conventional art, the SMGKM advances its security by integrating location based authentication and GKM functions. Both functions are securely offloaded from the Domain Key Distributor (DKD) to the intermediate cluster controllers, Area Key Distributors (AKDs), in a distributed fashion, using the proposed location based authenticated membership list (SKDL). A significant upgrade of fast handoff performance with reduced performance overheads of the SMGKM scheme is achieved. The developed numerical analysis and the simulation results display significant resource economy in terms of reduced rekeying transmission, communication bandwidth and storage overheads while providing enhanced security. The performance of the SMGKM in a high speed environment is also evaluated and has demonstrated that SMGKM outperforms the previous work. Finally, the SMGKM correctness against various attacks is verified using BAN logic, the eminent tool for analysing the widely deployed security protocols. The security analysis demonstrates that SMGKM can counteract the security flaws and redundancies identified in the chosen related art.
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Charting a Path to Sustainable Student Housing for International Students : Case Study of Språkskrapan / Kartläggning av vägen till hållbara studentbostäder för internationella studenter : Fallstudie om Språkskrapan

Melpomeni, Petrou January 2024 (has links)
In an era of increasing emphasis on sustainability across industries, the housing sector faces unique challenges in providing sustainable accommodations, particularly for international students. Efficient facility management in this context necessitates collaborative stakeholder efforts to achieve ecological, economic, and social sustainability goals amid cultural diversity that impacts occupant satisfaction. Akademiska Hus, a prominent Swedish company, leads sustainable housing initiatives for international students, leveraging digital innovations to enhance stakeholder satisfaction.This master's thesis aims to explore efficient and sustainable facility management approaches in student housing using a smartphone app. It culminates in the development of a prototype roadmap for delivering sustainable student accommodations. The roadmap is informed by a case study of Språkskrapan, a student accommodation facility owned by Akademiska Hus and managed by the University of Gothenburg.The study engages stakeholders, including housing providers and students, to identify needs and goals, assesses the performance of a smartphone app for facility management, and explores strategies for sustainable building management tailored to student requirements. The research follows the structured approach of the double- diamond design process: identifying student needs through interviews, defining challenges based on feedback, proposing solutions, and testing potential solutions.The findings will yield a comprehensive roadmap for offering sustainable student housing, providing insights into sustainable facility management aligned with digital innovation for student accommodation. This study serves as a blueprint for future community development projects, offering guidance on achieving sustainability objectives in resource-constrained environments. / I en tid då hållbarhet betonas allt mer i alla branscher står bostadssektorn inför unika utmaningar när det gäller att tillhandahålla hållbara boenden, särskilt för internationella studenter. Effektiv fastighetsförvaltning i detta sammanhang kräver samarbete mellan intressenter för att uppnå ekologiska, ekonomiska och sociala hållbarhetsmål mitt i kulturell mångfald som påverkar hyresgästernas tillfredsställelse. Akademiska Hus, ett framstående svenskt företag, leder hållbara bostadsinitiativ för internationella studenter och utnyttjar digitala innovationer för att öka intressenternas tillfredsställelse.Denna masteruppsats syftar till att utforska effektiva och hållbara metoder för fastighetsförvaltning i studentbostäder med hjälp av en smartphone-app. Det kulminerar i utvecklingen av en prototyp för en färdplan för att leverera hållbara studentbostäder. Färdplanen baseras på en fallstudie av Språkskrapan, ett studentboende som ägs av Akademiska Hus och förvaltas av Göteborgs universitet.Studien engagerar intressenter, inklusive bostadsleverantörer och studenter, för att identifiera behov och mål, utvärderar prestandan hos en smartphone-app för fastighetsförvaltning och utforskar strategier för hållbar fastighetsförvaltning som är skräddarsydd för studenternas krav. Forskningen följer det strukturerade tillvägagångssättet i designprocessen med dubbla diamanter: identifiera studenternas behov genom intervjuer, definiera utmaningar baserat på återkoppling, föreslå lösningar och testa potentiella lösningar.Resultaten kommer att leda till en omfattande färdplan för att erbjuda hållbara studentbostäder och ge insikter i hållbar fastighetsförvaltning i linje med digital innovation för studentbostäder. Denna studie fungerar som en plan för framtida samhällsutvecklingsprojekt och ger vägledning för att uppnå hållbarhetsmål i resursbegränsade miljöer.
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"Syns det inte, finns det inte" : En kvalitativ fallstudie av hinder och möjligheter för resepolicy i Svalövs kommun / "Out of sight, out of mind" : A qualitative case study of barriers and opportunities for travel policy in Svalöv Municipality

Karlsson, Alexandra, Bekteshi Krasniqi, Albulena January 2024 (has links)
Klimatförändringar medför förhöjda temperaturer vilket kan leda till höjda havsnivåer och översvämningar med förödande konsekvenser för djur och människors hälsa, tillgång till mat, ekonomi och miljön. De globala klimatmålen riktas mot nationella regeringar. År 2045 ska Sverige inte ha några nettoutsläpp av växthusgaser. Detta innebär att kommuner i Sverige,däribland Svalövs kommun, måste arbeta utifrån sina lokala förutsättningar för att nå dessa mål. Transportsektorn står för den största energianvändningen och utsläppen av växthusgaser. Svalövs kommun har med sin nya klimat- och energiplan sikte på att minska kommunens transportbehov. En uppdaterad resepolicy kan vara ett verktyg att uppnå dessa mål. Studiens syftar till att undersöka de faktorer som möjliggör och hindrar en implementering av en uppdaterad resepolicy i Svalövs kommun. Därför är studiens frågeställningar: Vilka hinder och möjligheter upplevs av tjänstepersoner i Svalövs kommuns för att följa en resepolicy? Samt vilka åtgärder kan Svalövs kommun vidta för att öka medvetenheten och efterlevnaden av den nya resepolicyn bland sina medarbetare?En kvalitativ fallstudie genomfördes i Svalövs kommun och empiri inhämtades genom semistrukturerade intervjuer med tjänstepersoner i Svalövs kommun samt expertintervjuer med Malmö stad och Lunds kommun. En tematisk analys genomfördes på de transkriberade intervjuerna. Resultatet visade att det största hindret för efterlevnaden av resepolicyn är att de flesta inte känner till dess existens vilket gör kommunikation om resepolicyn till den främsta möjligheten att förbättra rådande förutsättningar. Resultaten indikerar att implementeringsprocessen är det viktigaste steget för en väl förankrad resepolicy / Climate change results in elevated temperatures, which can lead to rising sea levels and floods with devastating consequences for animals and human health, food availability, the economy, and the environment. The global climate targets are directed at national governments. By 2045, Sweden should have no net emissions of greenhouse gases. This means that municipalities in Sweden, such as Svalöv Municipality, must work based on their local conditions to achieve these goals. The transport sector accounts for the largest energy use and greenhouse gas emissions. With its new climate and energy plan, Svalöv Municipality aims to reduce the municipality's transport needs. An updated travel policy can be a tool to achieve these goals. The study aims to examine the factors that enable and hinder the implementation of an updated travel policy in Svalöv Municipality. Therefore, the study's research questions are: What obstacles and opportunities are perceived by officials in Svalöv Municipality to comply with a travel policy? And what measures can Svalöv Municipality take to increase awareness and compliance with the new travel policy among its employees?A qualitative case study was conducted in Svalöv Municipality, and empirical data was collected through semi-structured interviews with officials in Svalöv Municipality as well as expert interviews with Malmö Municipality and Lund Municipality. A thematic analysis was conducted on the transcribed interviews. The results showed that the biggest obstacle to compliance with the travel policy is that most people are unaware of its existence, making communication about the travel policy the primary opportunity to improve the current conditions. The results indicate that the implementation process is the most crucial step for a well-anchored travel policy.

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