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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.
1

Mobility management across converged IP-based heterogeneous access networks

Mussabbir, Qazi Bouland January 2010 (has links)
In order to satisfy customer demand for a high performance “global” mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged “all-IP” centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme.
2

Improve Handover Performance Using Multicast Technology in Mobile IPv6 Environment

Chou, Kai-pei 24 August 2006 (has links)
With the flourishing development of the Internet and progress of science and technology, the wireless network technology is growing up rapidly at present. People can make connections through the Internet whenever and wherever possible. Mobile IPv6 is proposed in order to support mobility in IPv6 network, offers safer and more efficient mobile communication service to users than Mobile IPv4. However, it still suffers long delays and high packet losses. In order to enable smooth handovers, many researches in which use buffering and forwarding methods have been proposed. Although these proposals significantly improve handover performances, they suffer from the out-of-order delivery problem. This paper proposes a scheme which integrates multicast technologies with FMIPv6 for improving the handover performance. By switching between unicast addressing mode and multicast addressing mode, and letting the access router of the new network (NAR) join the multicast group in anticipation during handover, correspondent nodes (CNs) can transmit data packets to the new and old networks of mobile nodes (MNs) directly at the same time. It not only averts the out-of-order delivery problem, but also reduces the effect of the Duplicated Address Detection (DAD) time on the service disruption time.
3

Design of a Cross-Layer Handover Scheme for Data Transmission

Hsia, Ming-chun 14 September 2007 (has links)
IEEE 802.11-based wireless local area networks (WLANs) have been set up in many public places in last few years. It provides convenient network connectivity to mobile nodes (MNs) and allows users moving from one wireless network to another. With mobility protocol support, such as Mobile IPv6 (MIPv6), people can roam across wireless IP subnets without loss of network-layer connectivity. However, the handover latency may make users feel uncomfortable in MIPv6. To support seamless handover, an enhanced MIPv6 scheme, Fast Handovers for Mobile IPv6 (FMIPv6)[13], was been proposed. In order to further reduce the handover latency, integrating the lower layer procedure with the upper layer procedure is necessary. Unfortunately, when integrating the IEEE 802.11-based standard with FMIPv6, FMIPv6 always fails to perform predictive handover procedure. This may make the handover procedure result in reactive handover. It is because of the protocol nature of IEEE 802.11 and the weak relation between IEEE 802.11 and FMIPv6. Furthermore, a MN can¡¦t receive packets destined to it when it sends the Fast Binding Update (FBU) to the original access router (OAR). This would cause unnecessary packet loss and make the redictive handover have more packet loss then reactive. Those issues will cause quality of services degradation and make real-time applications unreachable. In this dissertation, a low-latency MIPv6 handover scheme will be proposed. It is a FMIPv6-based scheme which is assisted by an active-scan link layer scheme. It has the advantage of FMIPv6 and can reduce unnecessary packet loss when the handover occurs. Also, with the assistance of the active scheme, it can avoid the longest phase that IEEE 802.11 will enter, and can lower the handover latency.
4

Mobile IPv6 v prostředí OPNET Modeler / Mobile IPv6 in OPNET Modeler

Žáček, Martin January 2010 (has links)
Master’s thesis includes knowledges about mobility support in IPv4 networks and studies abilities for mobility support in IPv6 networks. Describes protocols for mobility support, their functions and topologies like MIPv6 (RFC 3775), FMIPv6 (RFC 5568), HMIPv6 (RFC 5380) and F-HMIPv6. The thesis contains a design of the simulation MIPv6 in the OPNET Modeler program and the measured results are explained. There are analysis of source code for mobility support in MIPv6 too, which were used for design a new protocol according to FMIPv6 in the OPNET. The following parts of the proposal have been successfully resolved. The link-layer events detection, which triggers FMIPv6 protocol and implementation of two new types of messages, RtSolPr and PrRtAdv. Knowledges from this thesis could be used for next development of FMIPv6 in the OPNET. But could be used for generaly development new protocols working at network-layer too.
5

Estudo e classificação de propostas e protocolos para provimento de mobilidade sobre IPv6

Loureiro, Cesar Augusto Hass January 2012 (has links)
A iminente implantação do IPv6, pode ser uma solução para o crescente uso de dispositivos móveis, para ensejar a mobilidade e para solucionar problemas derivados do esgotamento de endereços IPv4. Contudo, para o provimento de mobilidade é necessário garantir conectividade ao usuário, permitindo uma utilização continuada de seus dispositivos quando em movimento, sem que ocorra a perda de conexão, de forma segura e transparente. Isto não é possível com a arquitetura TCP/IP atualmente implementada nas redes que estão operacionais, mesmo que utilizem o protocolo IPv6. Neste sentido, este trabalho visa estudar as propostas mais expressivas no provimento de mobilidade sobre IPv6, com vistas a evidenciar suas características e funcionalidades. Apresenta como resultado, uma análise desses protocolos, em especial no que tange ao tempo de troca de rede (handover) e facilidade de implementação. / The imminent deployment of IPv6, may be a solution to the growing use of mobile devices, to bring mobility and to solve problems arising from the exhaustion of IPv4 addresses. However, to provide mobility is necessary ensure connectivity for the user, allowing continued use of their devices while on the move, without loss of connection, securely and transparently. This is not possible with the TCP/IP architecture currently deployed in networks that are operating, even if used the IPv6 protocol. Thus, this work aims to study the most significant proposals in the provision of mobile IPv6, in order to contrast their features and functionalities. Presents as result, an analysis of these protocols, especially with respect to time network exchange (handover) and ease of implementation.
6

Mécanismes de handover inter système 3G-WiMAX. Etude des performances comparées d'une approche basée sur IP et d'une approche utilisant des protocoles radio de niveau 2

Liu, Bin 04 May 2009 (has links) (PDF)
Résumé Dans les futurs réseaux mobiles, différentes technologies d'accès radio, telles que GSM, UMTS, WiMAX, WIFI coexisteront. Pour réaliser un handover vertical sans couture (handover inter-RAT) entre ces technologies, des architectures d'interconnexion et des moyens pour gérer le handover inter-RAT sont proposés. Afin de proposer une solution efficace, nous allons d'abord analyser la solution " Fast MIPv6 (FMIPv6) ". Les analyses numériques démontrent les défauts de FMIPv6 et les exigences de handover inter-RAT. En considérant une architecture de couplage intégré (integrated coupling), nous proposons une nouvelle sous-couche commune d'interconnexion (IW sublayer) au niveau 2 sur le RNC (Radio Network Controller) et le MS (Mobile Station) pour offrir un handover inter-RAT sans couture entre les systèmes UMTS et WiMAX. Cette sous-couche IW permet d'éliminer la perte des paquets et de réduire la latence de handover. Ces paramètres sont des éléments importants communs à la plupart des scénarios de handover inter-RAT. Cette sous-couche IW est également étendue à l'architecture de couplage serré (tight coupling). En outre, deux types de solution basées sur TCP Proxy, qui utilisent la sous-couche IW, sont également introduites sur le RNC pour résoudre deux problèmes rencontrés avec l'utilisation du trafic TCP dans un handover inter-RAT: le " BDP mismatch " et le " spurious RTO (Retransmission TimeOut) ". Le premier type de solution basé sur TCP Proxy est adapté aux scénarios où le handover est fréquent, tandis que le deuxième type de solution basé sur TCP Proxy est conçu pour les scénarios où le handover est occasionnel. Par rapport aux autres solutions de handover vertical, les résultats de simulation montrent que notre deuxième type de solution a le mérite de maintenir la pile de protocole TCP existante inchangée. Les solutions classiques de handover inter-RAT sont généralement réalisées au niveau 2 ou au-dessus, parce qu'il n'y a pas de module commun à la couche physique pour les deux systèmes, ou en raison de la distance géographique des systèmes. Mais pour les futurs systèmes LTE et WiMAX dans à l'architecture " integrated coupling ", ce n'est pas le cas, parce qu'ils ont un certain nombre de techniques physiques communes, telles que MIMO et OFDM. Deux modules nommés " precoder " et " combiner " sont proposés respectivement sur les BSs (stations de base) et sur le MS au niveau physique afin d'exploiter au maximum la diversité des deux réseaux d'accès radio et de réaliser un " soft " handover inter-RAT. Ce " soft " handover inter-RAT au niveau physique est entièrement nouveau à notre connaissance.
7

Estudo e classificação de propostas e protocolos para provimento de mobilidade sobre IPv6

Loureiro, Cesar Augusto Hass January 2012 (has links)
A iminente implantação do IPv6, pode ser uma solução para o crescente uso de dispositivos móveis, para ensejar a mobilidade e para solucionar problemas derivados do esgotamento de endereços IPv4. Contudo, para o provimento de mobilidade é necessário garantir conectividade ao usuário, permitindo uma utilização continuada de seus dispositivos quando em movimento, sem que ocorra a perda de conexão, de forma segura e transparente. Isto não é possível com a arquitetura TCP/IP atualmente implementada nas redes que estão operacionais, mesmo que utilizem o protocolo IPv6. Neste sentido, este trabalho visa estudar as propostas mais expressivas no provimento de mobilidade sobre IPv6, com vistas a evidenciar suas características e funcionalidades. Apresenta como resultado, uma análise desses protocolos, em especial no que tange ao tempo de troca de rede (handover) e facilidade de implementação. / The imminent deployment of IPv6, may be a solution to the growing use of mobile devices, to bring mobility and to solve problems arising from the exhaustion of IPv4 addresses. However, to provide mobility is necessary ensure connectivity for the user, allowing continued use of their devices while on the move, without loss of connection, securely and transparently. This is not possible with the TCP/IP architecture currently deployed in networks that are operating, even if used the IPv6 protocol. Thus, this work aims to study the most significant proposals in the provision of mobile IPv6, in order to contrast their features and functionalities. Presents as result, an analysis of these protocols, especially with respect to time network exchange (handover) and ease of implementation.
8

Estudo e classificação de propostas e protocolos para provimento de mobilidade sobre IPv6

Loureiro, Cesar Augusto Hass January 2012 (has links)
A iminente implantação do IPv6, pode ser uma solução para o crescente uso de dispositivos móveis, para ensejar a mobilidade e para solucionar problemas derivados do esgotamento de endereços IPv4. Contudo, para o provimento de mobilidade é necessário garantir conectividade ao usuário, permitindo uma utilização continuada de seus dispositivos quando em movimento, sem que ocorra a perda de conexão, de forma segura e transparente. Isto não é possível com a arquitetura TCP/IP atualmente implementada nas redes que estão operacionais, mesmo que utilizem o protocolo IPv6. Neste sentido, este trabalho visa estudar as propostas mais expressivas no provimento de mobilidade sobre IPv6, com vistas a evidenciar suas características e funcionalidades. Apresenta como resultado, uma análise desses protocolos, em especial no que tange ao tempo de troca de rede (handover) e facilidade de implementação. / The imminent deployment of IPv6, may be a solution to the growing use of mobile devices, to bring mobility and to solve problems arising from the exhaustion of IPv4 addresses. However, to provide mobility is necessary ensure connectivity for the user, allowing continued use of their devices while on the move, without loss of connection, securely and transparently. This is not possible with the TCP/IP architecture currently deployed in networks that are operating, even if used the IPv6 protocol. Thus, this work aims to study the most significant proposals in the provision of mobile IPv6, in order to contrast their features and functionalities. Presents as result, an analysis of these protocols, especially with respect to time network exchange (handover) and ease of implementation.
9

Analýza handoveru v Mobile IPv6 / Mobile IPv6 handover analysis

Klügl, Richard January 2010 (has links)
This master’s thesis is focused on IP mobility support for mobile users and their devices in IPv6-based wireless networks. Then the Mobile IPv6 (MIPv6) protocol was proposed for this purpose and that is also the main objective of the thesis. This consists of several basic sections and is organized as follows: The first one deals with the overview of the function of Mobile IP, which enables the mobility of nodes around the Internet, without a change of their original IP address. Moreover there are introduced the primary differences between MIPv6 and its previous version – i.e., MIPv4, proposed for IPv4-based environment. The second chapter of the master’s thesis thereafter describes detailed information about all the most important mechanisms and features of Mobile IPv6 and this way tries to explain principles of its functioning. Further the thesis analyses some of proposed MIPv6 extensions – i.e., Hierarchical Mobile IPv6 (HMIPv6), Mobile IPv6 Fast Handover (FMIPv6) a Fast Handover for HMIPv6 (F-HMIPv6) protocols, and mainly aim at signaling process during the handover of a mobile node. In the last main section of the master’s thesis an analytical method to evaluate the performance of IPv6-based mobility management protocols was proposed. Subsequently, this method is applied on the protocols which were mentioned above and are studied the effects of various network parameters on the performance of these protocols.

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