Submitted in fulfilment of the academic requirements for the degree of Magister Technologiae: Department of Civil Engineering and Surveying, Faculty of Engineering and the Built Environment, Durban University of Technology, 2009. / The annual incidence of pedestrian casualties on South African roads is approximately 34 000. This includes 4 000 deaths, 10 000 serious injuries and 20 000 minor injuries, costing the country an estimated R2,55 billion. A large number of injuries involve children and this is distressing but preventing this is a challenge. Statistics indicate that pedestrians are most at risk. School children have been identified as forming a considerable percentage of pedestrians. Consequently it is important to understand factors that influence children's travel patterns as an initial step toward reducing the accident rate. This study examines children's travel patterns at primary and secondary schools in the eThekwini area. In the absence of statistics regarding journeys to transport children to school, a questionnaire survey was designed to determine demographics, mode of travel to school, travel cost and duration, factors influencing choices of alternate modes of travel and problems experienced during school travel in terms of road safety. In addition, an on-site investigation was undertaken to assess the relevant engineering aspects including geometric design, traffic calming, signage and other traffic management aspects. This study focuses on scholar transport and discusses the findings of pilot and focal surveys. On analyzing the data, various problems were identified, namely: the road environment favours drivers over pedestrians, an absence of a formal travel plan, poor driver behaviour and an absence of dedicated school buses. A range of possible solutions is recommended. The recommendations focus on the Engineering, Enforcement and Evaluation aspects.

L'objectif de ce travail de thèse dans un premier temps est l'évaluation de performances des modèles de routage multi-chemins pour l'ingénierie de trafic et l'équilibrage de charge sur un réseau de type IP/MPLS (MPLS-TE). Nous comparons la capacité de ces modèles à équilibrer la charge du réseau tout en faisant de la différentiation de trafic. Nous les appliquons sur des grandes topologies générées par le générateur automatique des topologies BRITE, qui s'approchent en forme et en complexité du réseau réel. Nous mesurons ainsi l'impact de leur complexité respective et donc la capacité à les déployer sur des réseaux de grande taille (scalabilité). Dans un second temps, l'objectif est de proposer un concept de modélisation générale d'un réseau à commutations par paquets. Ce modèle est établi sur la base de la théorie différentielle de trafic et la théorie des files d'attente, tout en utilisant des approches graphiques. Le but est d'estimer l'état de charge du réseau et de ses composants (routeurs, liens, chemins). Ensuite, en fonction de ça, nous développons des approches de contrôle de congestion et commande sur l'entrée améliorant les techniques de routage adaptatif et l'équilibrage de charge dans les réseaux IP/MPLS / In This work, firstly we present and evaluate the behavior of multipath routing models for the DS-TE (DiffSev aware MPLS traffic Engineering) called PEMS and LBWDP. To clarify network topologies and routing models that are suitable for MPLS Traffic Engineering, we evaluate them from the viewpoint of network scalability and end-to-end quality. Using a network topology generated by BRITE, that has many alternative paths, we applied these models on a huge topology that correspond to real network. This can provide a real simulation for the internet and gives a good evaluation for the end-to-end quality and the network use.Secondly, the aim of this work is to propose a general model for Packet switching networks. This model is established on the traffic differential theory and the Queuing theory, while using graphic approaches. The aim of this model is to calculate the network use state and its components (router, link, path...). Then, we develop control and command approaches in the entry of network to improve an adaptive routing plan and load balancing in IP/MPLS networks

Este trabalho insere-se na área de pesquisa de sistemas de transporte inteligente e mobilidade urbana buscando um cenário onde a infraestrutura rodoviária é capaz de monitorar um tráfego exclusivo de veículos inteligentes que não dependem de motoristas para serem guiados. A principal contribuição do trabalho é o desenvolvimento de uma solução matemática para otimizar o gerenciamento microscópico centralizado do tráfego de veículos inteligentes em trechos (segmentos) de rodovia. Para isto é apresentado um modelo de otimização baseado em Programação Linear Inteira Mista (MILP), que determina um plano ótimo de trajetórias individuais dos veículos em uma evolução de tráfego. O objetivo é reduzir o tempo de viagem individualmente e assegurar fluidez do tráfego. O modelo considera componentes essenciais do sistema dinâmico viário como topografia da pista, regras de trânsito e a curva de aceleração máxima de cada veículo. São contempladas várias situações de tráfego, tais como ultrapassagens, inclinação na pista, obstáculos e redutores de velocidade. Os resultados indicaram uma média de 20,5 segundos para o cálculo de um cenário com 6 veículos e 11 intervalos de tempo. Como o modelo MILP não tem solução em tempo computacional aceitável para aplicação real, também é proposto um algoritmo de simulação baseado em heurísticas o qual busca reduzir esse tempo de cálculo em detrimento da otimalidade da solução. O algoritmo reproduz o comportamento de um motorista que tenta manter sempre um valor de velocidade escolhido previamente, e por isso é forçado a ultrapassar outros veículos quando obstruído ao longo do trajeto. O resultado do algoritmo tem importância adicional, pois serve de referência para resolver o problema da prioridade nas ultrapassagens. Também são propostos novos indicadores para a avaliação microscópica de qualidade de tráfego. Finalmente, são apresentados resultados de testes em simulações a fim de avaliar e validar o modelo e o algoritmo. / This work focus on the research area of intelligent transportation systems and urban mobility. It considers a scenario where the roadside infrastructure is capable of monitoring traffic composed by 100% of intelligent vehicles that do not rely on drivers to be guided. The main contribution of this work is the development of a mathematical solution to optimize the centralized management of intelligent microscopic vehicular traffic in parts (segments) of highway. Therefore an optimization model based on Mixed Integer Linear Programming (MILP) is presented. The model determines individual trajectories plans of vehicles in a traffic evolution. The objective is to reduce the travel time individually and ensure traffic flow. The model considers essential components of the dynamic highway system, such as, topography of the lane, traffic rules and acceleration curve for each vehicle. Many traffic situations are considered, such as, overtaking, slopes, obstacles and speed reducers. The results indicated an average of 20.5 seconds to calculate a scenario with 6 vehicles and 11 time intervals. As the MILP model has no solution in acceptable computational time for real application, it is proposed an algorithm based on heuristic simulation which seeks to reduce the computation time at the expense of optimality of the solution. The algorithm reproduces the behavior of a driver who always tries to maintain a preselected velocity value, and is therefore forced to overtake other vehicles when blocked along the path. The result of the algorithm has additional importance because it serves as a reference for solving the problem of priority when overtaking. New indicators for microscopic evaluation of quality traffic are also proposed. Finally, test results are presented on simulations to evaluate and validate the model and algorithm.

Este trabalho insere-se na área de pesquisa de sistemas de transporte inteligente e mobilidade urbana buscando um cenário onde a infraestrutura rodoviária é capaz de monitorar um tráfego exclusivo de veículos inteligentes que não dependem de motoristas para serem guiados. A principal contribuição do trabalho é o desenvolvimento de uma solução matemática para otimizar o gerenciamento microscópico centralizado do tráfego de veículos inteligentes em trechos (segmentos) de rodovia. Para isto é apresentado um modelo de otimização baseado em Programação Linear Inteira Mista (MILP), que determina um plano ótimo de trajetórias individuais dos veículos em uma evolução de tráfego. O objetivo é reduzir o tempo de viagem individualmente e assegurar fluidez do tráfego. O modelo considera componentes essenciais do sistema dinâmico viário como topografia da pista, regras de trânsito e a curva de aceleração máxima de cada veículo. São contempladas várias situações de tráfego, tais como ultrapassagens, inclinação na pista, obstáculos e redutores de velocidade. Os resultados indicaram uma média de 20,5 segundos para o cálculo de um cenário com 6 veículos e 11 intervalos de tempo. Como o modelo MILP não tem solução em tempo computacional aceitável para aplicação real, também é proposto um algoritmo de simulação baseado em heurísticas o qual busca reduzir esse tempo de cálculo em detrimento da otimalidade da solução. O algoritmo reproduz o comportamento de um motorista que tenta manter sempre um valor de velocidade escolhido previamente, e por isso é forçado a ultrapassar outros veículos quando obstruído ao longo do trajeto. O resultado do algoritmo tem importância adicional, pois serve de referência para resolver o problema da prioridade nas ultrapassagens. Também são propostos novos indicadores para a avaliação microscópica de qualidade de tráfego. Finalmente, são apresentados resultados de testes em simulações a fim de avaliar e validar o modelo e o algoritmo. / This work focus on the research area of intelligent transportation systems and urban mobility. It considers a scenario where the roadside infrastructure is capable of monitoring traffic composed by 100% of intelligent vehicles that do not rely on drivers to be guided. The main contribution of this work is the development of a mathematical solution to optimize the centralized management of intelligent microscopic vehicular traffic in parts (segments) of highway. Therefore an optimization model based on Mixed Integer Linear Programming (MILP) is presented. The model determines individual trajectories plans of vehicles in a traffic evolution. The objective is to reduce the travel time individually and ensure traffic flow. The model considers essential components of the dynamic highway system, such as, topography of the lane, traffic rules and acceleration curve for each vehicle. Many traffic situations are considered, such as, overtaking, slopes, obstacles and speed reducers. The results indicated an average of 20.5 seconds to calculate a scenario with 6 vehicles and 11 time intervals. As the MILP model has no solution in acceptable computational time for real application, it is proposed an algorithm based on heuristic simulation which seeks to reduce the computation time at the expense of optimality of the solution. The algorithm reproduces the behavior of a driver who always tries to maintain a preselected velocity value, and is therefore forced to overtake other vehicles when blocked along the path. The result of the algorithm has additional importance because it serves as a reference for solving the problem of priority when overtaking. New indicators for microscopic evaluation of quality traffic are also proposed. Finally, test results are presented on simulations to evaluate and validate the model and algorithm.

Orientador: Mauricio Ferreira Magalhães / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-04T17:32:51Z (GMT). No. of bitstreams: 1 Sazima_Ricardo_M.pdf: 1107563 bytes, checksum: a1179beaec699c0dcd87b45284e4a99c (MD5) Previous issue date: 2004 / Resumo: Dados a banda de transmissão atualmente disponível, o protocolo (IP) utilizado para transmitir a maior parte de tráfego e a quantidade de tráfego e seus requisitos de aos, a Engenharia de Tráfego (TE, de Traffic Engineering) tomou-se um componente cada vez mais importante nas redes de comunicações. O padrão do IETF para enncaminhamento roteamento entitulado Multi-Protocol Label Switching (MPLS) preenche lacunas importantes neste cenário e é peça chave das metodologias de TE mais sofisticadas. Nesta dissertação é apresentado um modelo genérico de TE e uma proposta para uma Plataforma para Experimentos com MPLS (PLEX MPLS) que permite que o usuário defina, execute, e analise configurações de Engenharia de Tráfego com MPLS em uma rede IP. Os principais objetivos da PLEX MPLS são: . Estudo da tecnologia MPLS e suporte a outros trabalhos em andamento no contexto do grupo de estudos em MPLS do DCA . Experimentos com engenharia de tráfego com MPLS: validação das tecnologias e conceitos relacionados . Experimentos didáticos em disciplinas de laboratório de redes. Os principais conceitos de TE e MPLS são apresentados como referência, bem como uma descrição do NIST Switch, a plataforma MPLS escolhida para este trabalho. A análise, projeto e implementação da PLEX MPLS são apresentados, pois formam parte significativa do trabalho desenvolvido. A PLEX não só utiliza, como também estende as funcionalidades oferecidas pelo NIST Switch a fim de oferecer um esquema de TE mais completo e eficiente. Na fase de análise, vemos quais os principais requisitos para a implementação desta plataforma, seguindo uma metodologia de Engenharia de Software. Na fase de projeto, vemos as soluções propostas para os problemas identificados na fase de análise e temos uma especificação dos componentes a serem implementados. Na fase seguinte, discutimos a implementação das principais características dos componentes da PLEX, justificando as decisões tomadas. Para validar a implementação da PLEX de acordo com sua proposta, foram realizados alguns experimentos em uma rede de testes com tráfego real. A execução destes experimentos é descrita e seus resultados analisados. Os resultados obtidos assinalam claramente a importância e utilidade de esquemas de TE baseada em MPLS. Uma interessante metodologia para TE, compilada a partir de várias propostas, é apresentada. Finalmente, apontam-se caminhos a seguir em um trabalho futuro de refinamento da PLEX / Abstract: Given the bandwidth currently available, the protocol (IP) used to transmit most Internet traffic, the quantity of traffic produced and its QoS requirements, Traffic Engineering (TE) has become an increasingly important component of communications networks. IETF's standard for forwarding/routing, which is entitled Multi-Protocol Label Switching (MPLS), presents important solutions in this scenario playing a major role in more sophisticated TE methodologies. This work presents a generic methodology for TE and a proposal for a Platform for Experiments with MPLS (PLEX MPLS) which allows the user to define, execute and analyze Traffic Engineering configurations with MPLS in an IP network. The main goals of PLEX MPLS are: . Study of the M PLS technology and support of other ongoing works with M PLS in the DCA . Traffic Engineering experiments with MPLS: validation of the related concepts and technologies . Support of didactic experiments in academic disciplines. The main concepts of MPLS and TE are presented as reference, as well as a brief description of NIST Switch, the MPLS software chosen for the PLEX MPLS implementation. The analysis, project and implementation of PLEX MPLS are presented, since are significant part of the developed work. PLEX not only uses, but also extends NIST Switch functionalities to offer a more complete and efficient TE scheme. In the analysis phase the main requirements for the PLEX implementation are specified, following a well-known Software Engineering methodology. The solutions found for the problems identified in the analysis phase are presented in the project phase alongside with a specification of the components that will be implemented. In the next phase, the implementation of PLEX is discussed focusing on the most important characteristics of PLEX components and justifying the implementation ecisions. In order to validate PLEX implementation and its proposal, some experiments were made in a test network with reallive traffic. These experiments are described and its results analyzed. The results obtained clearly indicate the importance and utility of TE schemes based on MPLS. Also an interesting TE methodology compiled from several proposals is presented. Finally, possible improvements and future work on PLEX MPLS are indicated. / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T09:49:57Z (GMT). No. of bitstreams: 1 Silveira_LorenoMenezesda_M.pdf: 2626161 bytes, checksum: b80454b10dc90baf554cb0f37c6ba67e (MD5) Previous issue date: 2015 / Resumo: Esta dissertação apresenta uma visão da evolução das redes de telecomunicações objetivando o atendimento dos parâmetros da Qualidade de Serviço de redes IP aos requisitos de qualidade de voz das redes telefônicas de circuitos comutados. Gera também uma série de resultados úteis para planejar a introdução de novas tecnologias e de Redes de Nova Geração (NGN) para serviços de voz. Entre os resultados, introduz uma metodologia de planejamento de rede com base na experiência do autor na área. A aplicação desta metodologia é descrita em um caso de estudo sobre a introdução do serviço de voz através de uma rede IP existente. Analisa parâmetros de qualidade de serviço, requisitos de qualidade de voz e, finalmente, calcula a taxa de transferência de fluxo de dados adicional devido ao tráfego de voz. Os cálculos são baseados em um modelo de dimensionamento implementado em uma planilha do Excel. Apesar de não mostrado neste trabalho, os resultados provaram sua efetividade e consistência com a implantação de uma prestadora específica e com o comportamento subsequente da rede em cidades relevantes, como São Paulo, Rio de Janeiro e Belo Horizontes. A dissertação também apresenta modelos de dimensionamento para o tráfego de sinalização: Sistema de Sinalização Nº 7 (ISUP - Rede Digital de Serviços Integrados e BICC - Portador de Controle de chamada Independent) para uso em redes TDM (Time Division Multiplex), ATM (Asynchronous Transfer Mode) ou NGN, explorando estes modelos de aplicação para o protocolo H.248 com possível extensão a SIP, ambos usados no contexto NGN / Abstract: This dissertation provides an overview of telecommunication networks evolution in the light of compliance of IP networks Quality of Service¿s parameters with Public Switched Telephone Networks (PSTN) voice quality requirements. It also delivers a number of new results useful for planning and designing the introduction of new technologies as well as Next Generation Networks (NGN), to provide voice services. Among the results, it introduces a network planning methodology based on the author's experience in this area. The application of such methodology is depicted in a study case concerning the introduction of the voice service over an existing IP network. It analyzes Quality of Service parameters, voice quality requirements and, finally, it calculates the additional data flow throughput due to the voice traffic. The calculations are based on a dimensioning model implemented in an excel spreadsheet. Although not being shown here, the results have been proved effective and consistent with a specific carrier deployment and subsequent network behavior in relevant cities like São, Paulo, Rio de Janeiro and Belo Horizonte. This work also presents a dimensioning model for signaling traffic: Signalling System Nº 7 (ISUP ¿ Integrated Services Digital Networks and BICC - Bearer Independent Call Control) for use in TDM (Time Division Multiplex), ATM (Asynchronous Transfer Mode) or NGN networks. Furthermore, it exploits the application of the dimensioning model to H.248 protocol, suggesting how to extend it to SIP, both used in the NGN context / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

In recent years, IP based end-to-end services have grown in popularity. Efficiently meeting the user demand for such services, different techniques for traffic engineering transport networks have been developed. One such technique, currently being developed for multilayered networks, is Generalized Multi-Protocol Label Switching (GMPLS). GMPLS is a necessary networking technique because provisioning end-to-end services will today, and in the foreseeable future, very likely require the co-operation of multiple network layers. Here, the readiness of GMPLS for optical networks is investigated by reviewing the current support for optical networking components in the GMPLS standard documents. Based on this investigation, a candidate solution for routing and constraint-based path computation in optical network segments has been derived. This candidate solution is shown to efficiently handle the additional attributes and constraints inherent in optical networking components. / De senaste åren har IP-baserade tjänster ökat i popularitet. För att effektivt möta de användarkrav som ställs på sådana tjänster har olika tekniker för att styra transportnätverk utvecklats. En sådan teknik, nu under utveckling för multi-lagrade nätverk, är GMPLS. GMPLS är en nödvändig nätverksteknik eftersom tillhandahållandet av sluttjänster mellan olika användare idag, och inom en överskådlig framtid, mycket sannolikt kommer att kräva samarbete mellan flera nätverkslager. Här undersöks GMPLS färdighet i optiska nätverk genom att se över det nuvarande stödet för optiska nätverkskomponenter i GMPLS standarddokument. Baserat på denna undersökning har en kandidatlösning för routing och begränsad vägberäkning i optiska nätverkssegment tagits fram. Denna kandidatlösning visas effektivt hantera de ytterligare attribut och restriktioner som existerar i optiska nätverkskomponenter.

Transit travel time is affected by many factors including traffic signals and traffic condition. Transit agencies have implemented strategies such as transit signal priority (TSP) to reduce transit travel time and improve service reliability. However, due to the lack of empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level. This study utilizes and integrates three databases available along an urban arterial corridor in Portland, Oregon. Data sources include stop-level bus automatic vehicle location (AVL) and automatic passenger count (APC) data provided by the Tri-County Metropolitan Transportation District of Oregon (TriMet), the Sydney Coordinated Adaptive Traffic System (SCATS) signal phase log data, and intersection vehicle count data provided by the City of Portland. Based on the unique collection and integration of these fine granularity empirical data, this research utilizes multiple linear regression models to understand and quantify the joint impact of intersection signal delay, traffic conditions and bus stop location on bus travel time and its variability at stop-to-stop segments. Results indicate that intersection signal delay is the key factor that affects bus travel time variability. The amount of signal delay is nearly linearly associated with intersection red phase duration. Results show that the effect of traffic conditions (volumes) on bus travel time varies significantly by intersection and time of day. This study also proposed new and useful performance measures for evaluating the effectiveness of TSP systems. Relationships between TSP requests (when buses are late) and TSP phases were studied by comparing TSP phase start and end times with bus arrival times at intersections. Results show that green extension phases were rarely used by buses that requested TSP and that most green extension phases were granted too late. Early green effectiveness (percent of effective early green phases) is much higher than green extension effectiveness. The estimated average bus and passenger time savings from an early green phase are also greater compared to the average time savings from a green extension phase. On average, the estimated delay for vehicles on the side street due to a TSP phase is less than the time saved for buses and automobiles on the major street. Results from this study can be used to inform cities and transit agencies on how to improve transit operations. Developing appropriate strategies, such as adjusting bus stop consolidation near intersections and optimizing bus operating schedules according to intersection signal timing characteristics, can further reduce bus travel time delay and improve TSP effectiveness.

Multi-Protocol Label Switching (MPLS) makes use of traffic engineering (TE) techniques and a variety of protocols to establish pre-determined highly efficient routes in Wide Area Network (WAN). Unlike IP networks in which routing decision has to be made through header analysis on a hop-by-hop basis, MPLS makes use of a short bit sequence that indicates the forwarding equivalence class (FEC) of a packet and utilises a predefined routing table to handle packets of a specific FEC type. Thus header analysis of packets is not required, resulting in lower latency. In addition, packets of similar characteristics can be routed in a consistent manner. For example, packets carrying real-time information can be routed to low latency paths across the networks. Thus the key success to MPLS is to efficiently control and distribute the bandwidth available between applications across the networks. A lot of research effort on bandwidth management in MPLS networks has already been devoted in the past. However, with the imminent roll out of 5G, MPLS is seen as a key technology for mobile backhaul. To cope with the 5G demands of rich, context aware and multimedia-based user applications, more efficient bandwidth management solutions need to be derived. This thesis focuses on the design of bandwidth management algorithms, more specifically QoS scheduling, in MPLS network for 5G mobile backhaul. The aim is to ensure the reliability and the speed of packet transfer across the network. As 5G is expected to greatly improve the user experience with innovative and high quality services, users’ perceived quality of service (QoS) needs to be taken into account when deriving such bandwidth management solutions. QoS expectation from users are often subjective and vague. Thus this thesis proposes the use of fuzzy logic based solution to provide service aware and user-centric bandwidth management in order to satisfy requirements imposed by the network and users. Unfortunately, the disadvantage of fuzzy logic is scalability since dependable fuzzy rules and membership functions increase when the complexity of being modelled increases. To resolve this issue, this thesis proposes the use of neuro-fuzzy to solicit interpretable IF-THEN rules.The algorithms are implemented and tested through NS2 and Matlab simulations. The performance of the algorithms are evaluated and compared with other conventional algorithms in terms of average throughput, delay, reliability, cost, packet loss ratio, and utilization rate. Simulation results show that the neuro-fuzzy based algorithm perform better than fuzzy and other conventional packet scheduling algorithms using IP and IP over MPLS technologies. / Tertiary Education Trust Fund (TETFUND)

No description available.