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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.
61

Handover Algorithms For Mobile Ipv6

Gungor, Vehbi Cagri 01 December 2003 (has links) (PDF)
With recent technological advances in wireless communication networks, the need for an efficient architecture for IP mobility is becoming more apparent. Enabling IP mobility architecture is a significant issue for making use of various portable devices appearing on the Internet. Mobile IP, the current standard for IP based mobility management, is capable of providing wireless Internet access to mobile users. The most important feature of Mobile IP is its ability to support the changing point of attachment of the mobile user by an algorithm known as handover. A handover algorithm is needed to maintain connectivity to the Internet whenever the mobile users move from one subnet to another, while simultaneously providing minimum disruption to ongoing sessions. This thesis gives an overview of Mobile IP, its open issues, some of the subsequent enhancements and extensions related to the handover management problem of the mobile user. Description and evaluation of various handover algorithms for Mobile IP which have been proposed to reduce packet loss and delay during handover constitute the core of the thesis. In this thesis, a comparative performance evaluation of the proposed protocols and the combination of them is also presented through simulations.
62

Planering för ett hållbart resande : En kvalitativ studie om hur en exploatör kan planera för ett hållbart resande

Kroik, Matilda January 2022 (has links)
This study has aimed to investigate how a developer builds for sustainable travel. To answer the question, sustainable travel in urban planning has been reviewed regarding Umeå municipality's intentions and what strategy documents there are to relate to as a developer. The study has used a qualitative study method and to answer the study's questions, four planning documents have been studied: Umeå Municipality's Overview Plan, Mobilitetsbokslut which is a program for sustainable modes of transport, Strategy Documents for Umeå Municipality's districts and Detailed Plan for Östra Station, Umeå 2:1. To strengthen the planning documents and to gain a better understanding of sustainable travel from the municipal and developer level, two interviews were conducted. A representative from Umeå municipality and a representative from the developer, Balticgruppen, to find out how the communication between them regarding the purpose of the study. The representatives were interviewed as officials regarding their competence within the planning area's establishment, Östra Station.  The results of the study show that the developer, Balticgruppen, does not have much to say about a new establishment in Umeå municipality. The communicative planning is carried out with dialogue efforts and consultations, but where Umeå municipality has strong goals and strategies for building for sustainable travel that Umeå municipality believes Balticgruppen should relate to. This means that the dialogue efforts usually lead back to Umeå municipality's planning documents and intentions, which generates in that it is the municipality that decides the developer's construction for sustainable travel in the event of a new establishment and not the developer himself. This indicates that there are strict regulations at a new establishment in Umeå municipality, which creates, according to Pacione, power structures.
63

IP mobile multicast over next generation satellite networks : design and evaluation of a seamless mobility framework for IP multicast communications over a multi-beam geostationary satellite network

Jaff, Esua Kinyuy January 2016 (has links)
The inherent broadcast nature of satellites, their global coverage and direct access to a large number of subscribers give satellites unrivalled advantages in supporting IP multicast applications. A new generation of satellite systems that support regenerative on-board processors and multiple spot beam technology have opened new possibilities of implementing IP multicast communication over satellites. These new features enable satellites to make efficient use of their allocated bandwidth resources and provide cost effective network services but equally, create new challenges for mobile satellite terminals. IP mobility support in general and IP mobile multicast support in particular on mobile satellite terminals like the ones mounted on continental flights, maritime vessels, etc., still remain big challenges that have received very little attention from the research community. Up till now, there are no proposed mechanisms to support IP multicast for mobile receivers/sources in multi-beam satellite networks in open literature. This study explores the suitability of IP multicast mobility support schemes defined for terrestrial networks in a satellite environment and proposes novel schemes based on the concepts of Home and Remote subscription-based approaches, multiple interface and PMIPv6 protocol. Detailed analysis and comparison of results obtained from the proposed schemes, Mobile IP (MIP) Home and Remote subscription-based approaches (for terrestrial networks) when implemented on a reference multi-beam satellite network are presented. From these results, the proposed schemes outperform the MIP Home and Remote subscription-based approaches in terms of gateway handover latency, number of multicast packets lost and signalling cost over the satellite air interface.
64

Impactos da implantação de medidas de gerenciamento da mobilidade em uma área urbana com múltiplos pólos atratores de viagens

Schmitt, Rafael da Silva January 2006 (has links)
Nesta dissertação são analisados os impactos da implantação de medidas de gerenciamento da mobilidade (GM) em uma área urbana localizada na cidade de Porto Alegre com vários pólos atratores de viagens. O GM – abordagem européia do gerenciamento da demanda de viagens – busca uma mobilidade urbana mais sustentável, tentando influir no comportamento de viagem das pessoas. São discutidos seu conceito, suas ferramentas, medidas e serviços de transporte, incluindo exemplos de implantação no mundo. Foram escolhidas duas medidas de GM, dentro de um pacote de medidas a serem implantadas pelo projeto Moviman na área de estudo, localizada na zona leste de Porto Alegre, onde atualmente há uma universidade (PUCRS), hospitais, um shopping center, hipermercados, entre outros estabelecimentos. A primeira medida analisada foi a carona programada, uso compartilhado de um automóvel com divisão de custos. Foi feita uma pesquisa com alunos da PUCRS para verificar sua receptividade em relação a esta medida. A partir dos resultados desta pesquisa, foi avaliado o possível impacto da implantação desta medida no tráfego da área de estudo. Também foi feita pesquisa com trabalhadores de uma empresa local para comparar a receptividade a esta medida por usuários diferentes. A segunda medida foi a implantação de um Sistema de Informação ao Usuário (SIU) de transporte coletivo em duas paradas de ônibus, através da realização de pesquisas de importância e satisfação, para priorizar as informações e de uma pesquisa final de satisfação e análise de intenção de mudança modal causada pelo SIU. Os resultados demonstram que a carona programada é uma medida com boa receptividade entre os grupos-alvo pesquisados, que causa uma melhora das condições de tráfego locais. E um novo SIU nas paradas de ônibus é uma medida de qualificação do transporte coletivo com um bom potencial de atração de novos usuários e de fidelização dos atuais. Portanto, comprovouse o impacto positivo da implantação destas medidas de GM em uma cidade brasileira, pois ambas atenderam aos objetivos de uma mobilidade urbana sustentável sem a limitação da mobilidade das pessoas. / This dissertation presents the evaluation of the impacts produced by mobility management (MM) measures introduced in an urban area, with many trip production centers, located in Porto Alegre city, southern Brazil. The MM, European approach of travel demand management, aims a more sustainable urban mobility, trying to influence in the travel behavior of people. Their concepts, tools, measures and transport services are discussed, including other implantation examples worldwide. Two MM measures were chosen within a package of measures that would be implemented by the Moviman project in the studied area. The selected area, situated in the east zone of Porto Alegre, holds a university (PUCRS), hospitals, a shopping center, among others commercial establishments. The first analyzed measure was carpooling, shared use of an automobile with division of costs, using the application of a survey with university students, from PUCRS, to verify their receptivity in relation to this alternative transportation mode. The survey results were used for the analysis of possible impacts of this measure in the traffic of the study area. A survey with workers of a local company was done to compare the receptivity with these measures in distinct users. The second measure was the installation of a public transport user information system (UIS) in two bus stops, using importance and satisfaction surveys in order to define information priorities, and a final survey of satisfaction and analysis of modal change intention caused by UIS. The results demonstrate that carpooling is a transport measure with good receptivity among the target groups, and improves the local traffic conditions. Moreover the installation of new UIS in bus stops is a measure of qualification of the public transportation with good potential for attraction of new users and consolidation of actual users. Therefore, the impacts of MM measures in a Brazilian city were positive, considering that both measures reach the goal of sustainable mobility without limiting people mobility.
65

Impactos da implantação de medidas de gerenciamento da mobilidade em uma área urbana com múltiplos pólos atratores de viagens

Schmitt, Rafael da Silva January 2006 (has links)
Nesta dissertação são analisados os impactos da implantação de medidas de gerenciamento da mobilidade (GM) em uma área urbana localizada na cidade de Porto Alegre com vários pólos atratores de viagens. O GM – abordagem européia do gerenciamento da demanda de viagens – busca uma mobilidade urbana mais sustentável, tentando influir no comportamento de viagem das pessoas. São discutidos seu conceito, suas ferramentas, medidas e serviços de transporte, incluindo exemplos de implantação no mundo. Foram escolhidas duas medidas de GM, dentro de um pacote de medidas a serem implantadas pelo projeto Moviman na área de estudo, localizada na zona leste de Porto Alegre, onde atualmente há uma universidade (PUCRS), hospitais, um shopping center, hipermercados, entre outros estabelecimentos. A primeira medida analisada foi a carona programada, uso compartilhado de um automóvel com divisão de custos. Foi feita uma pesquisa com alunos da PUCRS para verificar sua receptividade em relação a esta medida. A partir dos resultados desta pesquisa, foi avaliado o possível impacto da implantação desta medida no tráfego da área de estudo. Também foi feita pesquisa com trabalhadores de uma empresa local para comparar a receptividade a esta medida por usuários diferentes. A segunda medida foi a implantação de um Sistema de Informação ao Usuário (SIU) de transporte coletivo em duas paradas de ônibus, através da realização de pesquisas de importância e satisfação, para priorizar as informações e de uma pesquisa final de satisfação e análise de intenção de mudança modal causada pelo SIU. Os resultados demonstram que a carona programada é uma medida com boa receptividade entre os grupos-alvo pesquisados, que causa uma melhora das condições de tráfego locais. E um novo SIU nas paradas de ônibus é uma medida de qualificação do transporte coletivo com um bom potencial de atração de novos usuários e de fidelização dos atuais. Portanto, comprovouse o impacto positivo da implantação destas medidas de GM em uma cidade brasileira, pois ambas atenderam aos objetivos de uma mobilidade urbana sustentável sem a limitação da mobilidade das pessoas. / This dissertation presents the evaluation of the impacts produced by mobility management (MM) measures introduced in an urban area, with many trip production centers, located in Porto Alegre city, southern Brazil. The MM, European approach of travel demand management, aims a more sustainable urban mobility, trying to influence in the travel behavior of people. Their concepts, tools, measures and transport services are discussed, including other implantation examples worldwide. Two MM measures were chosen within a package of measures that would be implemented by the Moviman project in the studied area. The selected area, situated in the east zone of Porto Alegre, holds a university (PUCRS), hospitals, a shopping center, among others commercial establishments. The first analyzed measure was carpooling, shared use of an automobile with division of costs, using the application of a survey with university students, from PUCRS, to verify their receptivity in relation to this alternative transportation mode. The survey results were used for the analysis of possible impacts of this measure in the traffic of the study area. A survey with workers of a local company was done to compare the receptivity with these measures in distinct users. The second measure was the installation of a public transport user information system (UIS) in two bus stops, using importance and satisfaction surveys in order to define information priorities, and a final survey of satisfaction and analysis of modal change intention caused by UIS. The results demonstrate that carpooling is a transport measure with good receptivity among the target groups, and improves the local traffic conditions. Moreover the installation of new UIS in bus stops is a measure of qualification of the public transportation with good potential for attraction of new users and consolidation of actual users. Therefore, the impacts of MM measures in a Brazilian city were positive, considering that both measures reach the goal of sustainable mobility without limiting people mobility.
66

Heterogeneous networking for beyond 3G system in a high-speed train environment : investigation of handover procedures in a high-speed train environment and adoption of a pattern classification neural-networks approach for handover management

Ong, Felicia Li Chin January 2016 (has links)
Based on the targets outlined by the EU Horizon 2020 (H2020) framework, it is expected that heterogeneous networking will play a crucial role in delivering seamless end-to-end ubiquitous Internet access for users. In due course, the current GSM-Railway (GSM-R) will be deemed unsustainable, as the demand for packet-oriented services continues to increase. Therefore, the opportunity to identify a plausible replacement system conducted in this research study is timely and appropriate. In this research study, a hybrid satellite and terrestrial network for enabling ubiquitous Internet access in a high-speed train environment is investigated. The study focuses on the mobility management aspect of the system, primarily related to the handover management. A proposed handover strategy, employing the RACE II MONET and ITU-T Q.65 design methodology, will be addressed. This includes identifying the functional model (FM) which is then mapped to the functional architecture (FUA), based on the Q.1711 IMT-2000 FM. In addition, the signalling protocols, information flows and message format based on the adopted design methodology will also be specified. The approach is then simulated in OPNET and the findings are then presented and discussed. The opportunity of exploring the prospect of employing neural networks (NN) for handover is also undertaken. This study focuses specifically on the use of pattern classification neural networks to aid in the handover process, which is then simulated in MATLAB. The simulation outcomes demonstrated the effectiveness and appropriateness of the NN algorithm and the competence of the algorithm in facilitating the handover process.
67

Transporte e exclusão social: a mobilidade da população de baixa renda da Região Metropolitana de São Paulo e trem metropolitano / Transportation and social exclusion: the mobility of low income population of São Paulo metropolitan region and metropolitan train.

Silvio José Rosa 12 September 2006 (has links)
A Região Metropolitana de São Paulo (RMSP) com mais de 18 milhões de habitantes realizando por dia 39 milhões de viagens, sendo 25 milhões motorizadas e 14 milhões a pé, convive com problemas diários que dificultam os deslocamentos necessários da sua população. O crescimento desordenado da região exigiu mais e maiores deslocamentos, contribuindo para deteriorar a qualidade do transporte coletivo. Os indivíduos, insatisfeitos com essa condição, buscaram suprir suas necessidades de transporte, invariavelmente, com o uso do automóvel (os que podem), o que aumenta a dependência por esse modo e contribui para a inviabilidade do transporte público segregando espacialmente os mais pobres. Assim, temos a caracterização de uma forma de exclusão social proporcionada pela insuficiência dos meios de transportes na RMSP, que pode se agravar à medida que o custo financeiro crescente do deslocamento em função da distância, transbordos tarifados etc., atinja diretamente os usuários de menores rendas. Há uma associação muito estreita entre mobilidade urbana e renda, ou seja, a renda familiar é um fator determinante da mobilidade. Diante disto, este trabalho tem como objetivo analisar a mobilidade da população de baixa renda da Região Metropolitana de São Paulo (RMSP), usuária do Trem Metropolitano. Esta analise se dará pela comparação dos dados das pesquisas Origem e Destino de 1997, realizada pela Companhia do Metropolitano de São Paulo (CMSP), e a de Acesso e Difusão de 2005, realizada pela Companhia Paulista de Trens Metropolitanos (CPTM). Desta forma, busca-se entender os padrões de viagens da população de baixa renda estudada, em face das suas limitações de renda e da eventual segregação espacial e, posteriormente, diante dos resultados obtidos, propor programas de Gerenciamento da Mobilidade, que potencializem a sua mobilidade. / The São Paulo Metropolitan Region (RMSP) with more than 18 million inhabitants carrying through per day 39 millions trips, shared in 25 millions motorized and 14 millions walking, coexists daily problems that make it difficult the necessary displacements of its population. The disordered growth of the region demanded more and bigger displacements contributing to decrease the quality of the collective transport. The individuals, unsatisfied with this condition, had searched to supply its transportation necessities, invariably, with the use of the automobile (the ones that can), what it increases the dependence for this way and contributes for the unfeasibility of the public transport, propelling the poorer to a spatial segregation. Thus, we have the characterization of a form of proportionate social exclusion for the insufficience of the transports modes in the RMSP that can be aggravated to the measure that the increasing financial cost of the displacement in function of the distance, cost modes transferences etc., and directly reaches the users of lesser incomes. It has a very narrow association between urban mobility and income, that is, the familiar income is a determinative factor of mobility. Ahead of this, this work has as objective to analyze the mobility of the low income population of the São Paulo Metropolitan Region (RMSP), user of the Metropolitan Train. This analyzes will give for the comparison of the data of the research Origin and Destination of 1997, carried through for the Company of the Metropolitan of São Paulo (CMSP), and of Access and the Diffusion of 2005, carried through for the São Paulo Company of Metropolitan Trains (CPTM). In such a way, one searchs to understand the standards of trips of the studied low income population, in face of its limitations of income and eventual spatial segregation e, later, ahead of the overcome, to consider programs of Management of Mobility, that improve its mobility.
68

Impactos da implantação de medidas de gerenciamento da mobilidade em uma área urbana com múltiplos pólos atratores de viagens

Schmitt, Rafael da Silva January 2006 (has links)
Nesta dissertação são analisados os impactos da implantação de medidas de gerenciamento da mobilidade (GM) em uma área urbana localizada na cidade de Porto Alegre com vários pólos atratores de viagens. O GM – abordagem européia do gerenciamento da demanda de viagens – busca uma mobilidade urbana mais sustentável, tentando influir no comportamento de viagem das pessoas. São discutidos seu conceito, suas ferramentas, medidas e serviços de transporte, incluindo exemplos de implantação no mundo. Foram escolhidas duas medidas de GM, dentro de um pacote de medidas a serem implantadas pelo projeto Moviman na área de estudo, localizada na zona leste de Porto Alegre, onde atualmente há uma universidade (PUCRS), hospitais, um shopping center, hipermercados, entre outros estabelecimentos. A primeira medida analisada foi a carona programada, uso compartilhado de um automóvel com divisão de custos. Foi feita uma pesquisa com alunos da PUCRS para verificar sua receptividade em relação a esta medida. A partir dos resultados desta pesquisa, foi avaliado o possível impacto da implantação desta medida no tráfego da área de estudo. Também foi feita pesquisa com trabalhadores de uma empresa local para comparar a receptividade a esta medida por usuários diferentes. A segunda medida foi a implantação de um Sistema de Informação ao Usuário (SIU) de transporte coletivo em duas paradas de ônibus, através da realização de pesquisas de importância e satisfação, para priorizar as informações e de uma pesquisa final de satisfação e análise de intenção de mudança modal causada pelo SIU. Os resultados demonstram que a carona programada é uma medida com boa receptividade entre os grupos-alvo pesquisados, que causa uma melhora das condições de tráfego locais. E um novo SIU nas paradas de ônibus é uma medida de qualificação do transporte coletivo com um bom potencial de atração de novos usuários e de fidelização dos atuais. Portanto, comprovouse o impacto positivo da implantação destas medidas de GM em uma cidade brasileira, pois ambas atenderam aos objetivos de uma mobilidade urbana sustentável sem a limitação da mobilidade das pessoas. / This dissertation presents the evaluation of the impacts produced by mobility management (MM) measures introduced in an urban area, with many trip production centers, located in Porto Alegre city, southern Brazil. The MM, European approach of travel demand management, aims a more sustainable urban mobility, trying to influence in the travel behavior of people. Their concepts, tools, measures and transport services are discussed, including other implantation examples worldwide. Two MM measures were chosen within a package of measures that would be implemented by the Moviman project in the studied area. The selected area, situated in the east zone of Porto Alegre, holds a university (PUCRS), hospitals, a shopping center, among others commercial establishments. The first analyzed measure was carpooling, shared use of an automobile with division of costs, using the application of a survey with university students, from PUCRS, to verify their receptivity in relation to this alternative transportation mode. The survey results were used for the analysis of possible impacts of this measure in the traffic of the study area. A survey with workers of a local company was done to compare the receptivity with these measures in distinct users. The second measure was the installation of a public transport user information system (UIS) in two bus stops, using importance and satisfaction surveys in order to define information priorities, and a final survey of satisfaction and analysis of modal change intention caused by UIS. The results demonstrate that carpooling is a transport measure with good receptivity among the target groups, and improves the local traffic conditions. Moreover the installation of new UIS in bus stops is a measure of qualification of the public transportation with good potential for attraction of new users and consolidation of actual users. Therefore, the impacts of MM measures in a Brazilian city were positive, considering that both measures reach the goal of sustainable mobility without limiting people mobility.
69

Integration of heterogeneous wireless access networks with IP multimedia subsystem

Peyman, Talebifard 05 1900 (has links)
Next generation heterogeneous wireless networks are expected to interwork with Internet Protocol (IP)-based infrastructures. Conventional network services operate like silos in that a specific set of services are offered over a specific type of access network. As access networks evolve to provide IP-based packet access, it becomes attractive to break these “service silos” by offering a converged set of IP-based services to users who may access these services using a number of alternative access networks. This trend has started with third generation cellular mobile networks, which have standardized on the use of the IP Multimedia Subsystem (IMS) to manage user access to a wide variety of multimedia services over the mobile Internet, while facilitating interworking of heterogeneous wireless and landline access networks. The future users of communication systems will subscribe to both IP-based and Circuit Switched (CS) based services and in the foreseeable future a single database that handles user profiles across all domains will be required. Home Subscriber Server (HSS) as an evolved version of Home Location Register (HLR) is one of the key components of IMS. In deploying HSS as a central repository database, in a fully overlapped heterogeneous network setting, changes of access mode are very frequent and conveying this information to HSS imposes excessive signaling load and delay. In our proposed scheme we introduce an Interface Agent (IA) for each location area that caches the location and information about the access mode through which a user can be reached. This method results in significant amount of savings in signaling cost and better delay performance. The existing call delivery approaches in cellular networks may not be well suited for future communication systems because they suffer from unnecessary usage of network resources for call attempts that may fail which adds to excessive signaling delays and queuing costs. Reducing the number of queries and retrievals from the database will have a significant impact on the network performance. We present a new scheme based on Reverse Virtual Call setup (RVC) as a solution to the call delivery problem in heterogeneous wireless networks and evaluate the performance of this framework. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
70

Predictive Mobile IP Handover for Vehicular Networks

Magnano, Alexander January 2016 (has links)
Vehicular networks are an emerging technology that offer potential for providing a variety of new services. However, extending vehicular networks to include IP connections is still problematic, due in part to the incompatibility of mobile IP handovers with the increased mobility of vehicles. The handover process, consisting of discovery, registration, and packet forwarding, has a large overhead and disrupts connectivity. With increased handover frequency and smaller access point dwell times in vehicular networks, the handover causes a large degradation in performance. This thesis proposes a predictive handover solution, using a combination of a Kalman filter and an online hidden Markov model, to minimize the effects of prediction errors and to capitalize on advanced handover registration. Extensive simulated experiments were carried out in NS-2 to study the performance of the proposed solution within a variety of traffic and network topology scenarios. Results show a significant improvement to both prediction accuracy and network performance when compared to recent proposed approaches.

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