5 research outputs found

    MOBILITY SUPPORT ARCHITECTURES FOR NEXT-GENERATION WIRELESS NETWORKS

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    With the convergence of the wireless networks and the Internet and the booming demand for multimedia applications, the next-generation (beyond the third generation, or B3G) wireless systems are expected to be all IP-based and provide real-time and non-real-time mobile services anywhere and anytime. Powerful and efficient mobility support is thus the key enabler to fulfil such an attractive vision by supporting various mobility scenarios. This thesis contributes to this interesting while challenging topic. After a literature review on mobility support architectures and protocols, the thesis starts presenting our contributions with a generic multi-layer mobility support framework, which provides a general approach to meet the challenges of handling comprehensive mobility issues. The cross-layer design methodology is introduced to coordinate the protocol layers for optimised system design. Particularly, a flexible and efficient cross-layer signalling scheme is proposed for interlayer interactions. The proposed generic framework is then narrowed down with several fundamental building blocks identified to be focused on as follows. As widely adopted, we assume that the IP-based access networks are organised into administrative domains, which are inter-connected through a global IP-based wired core network. For a mobile user who roams from one domain to another, macro (inter-domain) mobility management should be in place for global location tracking and effective handoff support for both real-time and non-real-lime applications. Mobile IP (MIP) and the Session Initiation Protocol (SIP) are being adopted as the two dominant standard-based macro-mobility architectures, each of which has mobility entities and messages in its own right. The work explores the joint optimisations and interactions of MIP and SIP when utilising the complementary power of both protocols. Two distinctive integrated MIP-SIP architectures are designed and evaluated, compared with their hybrid alternatives and other approaches. The overall analytical and simulation results shown significant performance improvements in terms of cost-efficiency, among other metrics. Subsequently, for the micro (intra-domain) mobility scenario where a mobile user moves across IP subnets within a domain, a micro mobility management architecture is needed to support fast handoffs and constrain signalling messaging loads incurred by intra-domain movements within the domain. The Hierarchical MIPv6 (HMIPv6) and the Fast Handovers for MIPv6 (FMIPv6) protocols are selected to fulfil the design requirements. The work proposes enhancements to these protocols and combines them in an optimised way. resulting in notably improved performances in contrast to a number of alternative approaches

    I-Centric Communications

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    Diese Arbeit beschreibt die Vision I-centric Communications ein neues Paradigma fĂŒr zukĂŒnftige Telekommunikationssysteme. Das Hauptziel dieses Ansatzes ist es das menschliche Kommunikationsverhalten und nicht die Technologien die typischerweise zur Kommunikation eingesetzt werden, als Ausgangsbasis fĂŒr den Entwurf von Telekommunikationssystemen zu benutzen. Daher konzentriert sich diese Arbeit auf die konzeptionelle Integration aller fĂŒr I-centric Communications notwendigen Aspekte. Untersucht man das Kommunikationsverhalten von Menschen nĂ€her, wird klar, dass Menschen regelmĂ€ĂŸig mit einer bestimmten Menge von Objekten in ihrer Umgebung interagieren um ihre tĂ€glichen Probleme zu lösen. Diese Erkenntnis kann als Grundlage fĂŒr den Entwurf von Telekommunikationssystemen dienen. Der Entwurf stĂŒtzt sich dabei nicht auf spezifische Telekommunikationstechnologien sondern auf die Analyse individueller KommunikationsrĂ€ume. Das Resultat eines solchen Entwurfs ist ein Telekommunikationssystem, dass sich an die individuellen Anforderungen eines jeden Menschen anpasst (I-centric). Das Kommunikationssystem agiert im Sinne des Benutzers, protokolliert wiederkehrende Aktionen, um sich selbst den BedĂŒrfnissen des Benutzers weiter anzupassen. Die beschriebene FunktionalitĂ€t erfordert eine intelligente Diensterbringung im Hinblick auf die Personalisierung von Diensten, der Adaption an situationsbedingte oder umgebungsabhĂ€ngige EinflĂŒsse, und der Überwachung bzw. Steuerung von individuellen KommunikationsrĂ€umen. Kommunikationssysteme die dieser Idee folgen mĂŒssen individuelle KommunikationsrĂ€ume modellieren und verwalten um sich an die persönlichen Interessen, Umgebungen und PrĂ€ferenzen anpassen zu können. Diese Arbeit beginnt mit der Vorstellung der Vision I-centric Communications , gefolgt von der Entwicklung eines entsprechenden Referenzmodells. Im Anschluss wird auf der Basis des Referenzmodells eine Architektur zur Implementierung von I-centric Kommunikationssystemen entwickelt. Die Vorstellung einer der Architektur folgenden Implementierung schließt diese Arbeit ab. Die Forschungsarbeit im Bereich I-centric Communications wurde in Kooperation zwischen dem Lehrstuhl fĂŒr Offene Kommunikationssysteme (OKS) der Technischen UniversitĂ€t Berlin (TUB) und dem Fraunhofer Institut FOKUS durchgefĂŒhrt. Die Vision sowie das Referenzmodell fĂŒr I-centric Communications , die in der vorliegenden Arbeit vorgestellt werden, sind Ergebnisse dieser Kooperation. Die Forschungsschwerpunkte der Kooperation zwischen TUB und FOKUS waren das Generelle Modell fĂŒr I-centric Dienste , die Dienstplattform fĂŒr I-centric Dienste sowie die Interaktion zwischen Nutzern und I-centric Diensten . Die vorliegende Arbeit konzentriert sich auf das generische Model fĂŒr I-centric Dienste und entsprechende Dienstplattformen. Aspekte der individuellen Benutzerinteraktion werden nicht betrachtet. Diese Aspekte wurden in einer zweiten Dissertation von Stephan Steglich, TUB, analysiert und ausgearbeitet. Die Ergebnisse dieser Dissertation wurden in verschiedenen nationalen und internationalen Forschungsprojekten (BMBF: LiveFutura, VHE-UD, PI-AVIda, IST: WSI, WWRI), Standardisierungsgremien (OMG, WWRF), Konferenzpapieren sowie Zeitschriften eingebracht, um die Vision von I-centric Communications einem grĂ¶ĂŸeren Auditorium vorzustellen.This thesis describes the vision of I-centric communications a new paradigm for future telecommunication systems. The main objective of this approach is to consider the human communication behavior, not the technologies that support communication, as the starting point for the design of telecommunication systems. The focus of this thesis is on the conceptual integration of all aspects of I-centric communications. Looking at the communication behavior of human, it is obvious, that human beings frequently interact with a set of objects in their environment. Following this view, a new approach is not to build communication systems based on specific technologies, but on the analysis of the individual communication space. The result is a communication system that adapts to the demands of each individual (I-centric). The communication system will act on behalf of human s demands, reflecting recent actions to enable self-adaptation. I-centric Services adapt to individual communication spaces and situations. In this context I means I, or individual, Centric means adaptable to I requirements and the individual s environment. The rationales above require intelligence in service provisioning in order to personalize, adapt to situational and environmental conditions, to monitor and to control the individual communication space. An I-centric communications system will provide the intelligence required for modeling the communication space of each individual adapting to its interests, environment, and preferences. The thesis introduces the vision of I-centric communications, followed by the development of a reference model for I-centric communications. Since both, the vision and the reference model, are general, an architectural framework for I-centric communications is introduced later on. This framework is used to design and implement an I-centric communications system. The work in the area of I-centric communications was carried out in cooperation of the Department for Open Communication Systems (OKS) at the Technical University Berlin (TUB) and the Fraunhofer Institute FOKUS. The vision and the reference model, introduced in this thesis, are the results of this cooperation. The main research directions for the cooperation between TUB and FOKUS have been a general model for I-centric Services, the service platform for I-centric Services, and an approach for the interaction of users with I-centric Services. This thesis focuses on I-centric Services and according communication system. The aspects of user interaction are out of scope of this thesis. Nevertheless, these aspects have been analyzed by Stephan Steglich, researcher at the TUB, in a second PhD thesis in parallel. The results of this thesis have been contributed to different national and international projects (BMBF: LiveFutura, VHE, PI-AVIda, IST: WSI, WWRI), standardization bodies (OMG, WWRF), conference papers, and journals by introducing the vision of I-centric communications to a larger auditorium, and by exploiting parts of the developed I-centric systems
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