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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

Arquitetura OTN Switch Com Funcionalidades de Cross-conexão e Multiplexação Óptica e Digital em Redes OTN

DILEM, M. B. 21 August 2014 (has links)
Made available in DSpace on 2018-08-02T00:01:05Z (GMT). No. of bitstreams: 1 tese_6874_Dissertação - Matheus Brunoro Dilem.pdf: 3396145 bytes, checksum: 23d4b2f43ce73a4286b75baac4e3e12e (MD5) Previous issue date: 2014-08-21 / A demanda de novas tecnologias de transporte de dados cada vez mais velozes e com garantias de QoS (Quality of Service), ocasionadas pelo crescimento do tráfego da Internet, traz um grande desafio na área de redes de telecomunicação. As redes ópticas de transporte se apresentam como uma solução para as elevadas taxas de transmissão. No intuito de tornar as redes de núcleo mais flexíveis e ajustadas à dinamicidade e heterogeneidade das demandas, a ITU-T (International Telecommunication Union Telecommunication Standardization Sector) desenvolve uma série de recomendações abordando as mais diversas características das redes OTN (Optcial Transport Network), no contexto das redes de núcleo, determinando suas funcionalidades. Esta dissertação tem como objetivo desenvolver uma proposta de arquitetura OTN Switch, com o funcionamento da cross-conexão e da multiplexação de sinais ópticos e digitais presentes nas redes OTN. Para tal, sua arquitetura basea-se nas recomendações geradas pela ITU-T, tornando-a capaz de prover interoperabilidade com equipamentos já existentes.
2

Uma Proposta de Solução para Levantamento do Inventário dos Elementos de Rede em Redes Ópticas de Transporte

FAVORETO, R. C. 22 August 2014 (has links)
Made available in DSpace on 2018-08-02T00:01:06Z (GMT). No. of bitstreams: 1 tese_6875_Dissertação_Rafael_Campanharo_Favoreto_Versão_Final.pdf: 6258201 bytes, checksum: bed370fa569f7f0c60e71f03e2c28a5e (MD5) Previous issue date: 2014-08-22 / As demandas por serviços de telecomunicações multimídia, garantia de QoS (Quality of Service) e mecanismos de gerenciamento e controle direcionam a evolução da rede de núcleo para adoção da tecnologia OTN (Optical Transport Network) como solução de rede de transporte. Para conduzir a evolução da tecnologia OTN a ITU-T (International Telecommunication Union Telecommunications Standardization Sector) estabelece uma série de recomendações, dentre elas, as específicas para o plano de gerenciamento de redes. Essas, por sua vez, apresentam deficiências no que se referem ao levantamento do inventário dos objetos gerenciados definidos pelas normas da ITU-T. A ITU-T define a representação dos elementos de rede em caráter funcional, mais especificamente como módulos de Funções Atômicas. Contudo, a falta de clareza na implementação das Funções Atômicas e a carência de integração com as representações físicas dos elementos de rede implica na omissão, por parte dos diversos fabricantes, da implementação dos mecanismos recomendados em norma. Esta dissertação tem como objetivo geral apresentar uma proposta de solução para o levantamento do inventário dos elementos de rede em redes OTN abrangendo de forma integrada as representações funcional e física do elemento de rede, além de possibilitar aos diversos fabricantes a aderência às normas da ITU-T bem como oferecer ao operador de rede a configuração dos componentes de uma forma mais intuitiva.
3

Monitoreo del mantenimiento preventivo del Sistema OTN en el Consorcio Tren Eléctrico de Lima

Cerdeña Barreda, Luis Arturo January 2018 (has links)
En el presente documento de suficiencia profesional se explican algunas de las funciones que tiene el sistema OTN, donde se demuestra las ventajas que ofrece para los sistemas de comunicaciones en el ámbito civil e industrial. En este caso se tratará el de transporte masivo urbano, para ello se utiliza como ejemplo el caso del Tren Eléctrico de Lima, la Línea 1, ya que es donde se encuentra implementado este sistema. Por otro lado, para el caso del campo industrial, solo se menciona algunos ejemplos reales de comunicación actual (ver Figura 9, Figura 10 y Figura 11). Con la presentación de este documento, lo que se desea es que se haga de conocimiento al personal técnico de los futuros Metros de Lima, que la modernización y expansión de este tipo de comunicación en los campos de Transporte masivo urbano, industrial y minero se logra mediante la implementación del sistema modular OTN. Se presenta todas las interfaces que permite y que posee el módulo OTN en la Línea 1, sin embargo, se hace énfasis en la tarjeta BORA que es el corazón del OTN y en la tarjeta NMS que es la tarjeta que da soporte al módulo OTN. En este documento se compila la mayor cantidad de información relevante al sistema de comunicación OTN, específicamente el hardware, ya que es el elemento principal en el que he intervenido. Inicialmente se necesita al OMS para configurar la red OTN y sus componentes individuales y para establecer las conexiones de datos. Posteriormente se descargan las configuraciones de red en la tarjeta de red y finalmente la red puede operar de manera completamente autónoma. No obstante, es preferible mantener en línea el OMS para poder supervisar el estado de la red y de los procesos, Resumiré toda la información que logre obtener físicamente y digitalmente en este documento en lo que sea posible, ya que muchos de ellos son hojas técnicas de cada tarjeta y módulo.
4

Custos: algumas aplicações gerenciais: um caso prático

Pedrinola, Pietro 12 June 1990 (has links)
Made available in DSpace on 2010-04-20T20:14:36Z (GMT). No. of bitstreams: 0 Previous issue date: 1990-06-12T00:00:00Z / E um estudo de caso com o objetivo de mostrar em praticamente as distorções causadas pela inflação na Demonstração de Resultados feita pelos métodos contábeis tradicionais e sugerir uma metodologia que as minimize. O custeio direto e atualizações monetárias pela OTN fiscal via microcomputador foram as ferramentas utilizadas para tanto. Os resultados obtidos são válidos para o caso analisado restringindo-se portanto, as possibilidades de generalização.
5

Estudo experimental do tempo de recuperação de falhas em comutadores de caminhos óticos

Arnar, Claudecir Lopes January 2012 (has links)
Orientador: Gustavo Souza Pavani. / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Engenharia da Informação.
6

Aprovisionamento dinâmico de caminhos óticos em redes de transporte ótica G.709 controladas por GMPLS e com restrições de camada física

Jatoba Neto, Alaelson de Castro January 2011 (has links)
Orientador: Gelio Mendes Ferreira / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2011
7

Adaptive router bypass techniques to enhance core network efficiency

Ghonaim, Fahad A. 30 April 2018 (has links)
Internet traffic is increasing exponentially, driven by new technologies such as Internet of Things (IoT) and rich streaming media. The traditional IP router becomes a bottleneck for further Internet expansion due to its high power consumption and inefficiency in processing the growing traffic. Router bypass has been introduced to overcome capacity limitations and the processing costs of IP routers. With router bypass, a portion of traffic is provisioned to bypass the router and is switched by the transport layer. Router bypass has shown to provide significant savings in network costs. These advantages are limited by a reduction in the statistical multiplexing associated with the subdivision of the available bandwidth typically into bypass and traditional portions thus limiting the interest in bypass techniques. This thesis will explore multiple techniques to enhance the efficiency of router bypass. The main goals are to address the issue of the reduction in statistical multiplexing and to add a dynamic approach to the router bypass mechanism. The recent advancements in the Optical Transport Network (OTN) play a major role in the transport network. This proposal takes full advantage of OTN in the router-bypassing context by applying recent developments such as Hitless Adjustments ODUflex (HAO), which allow the provisioned channels to be adjusted without re-establishing the connections. In addition, it will allow the bypassing mechanism to be flexible enough to meet the traffic behaviour needs of the future. This thesis will study multiple approaches to enhance the router bypass mechanism including: an adaptive provisioning style using various degrees of provisioning granularities and controlling the provisioning based on traffic behaviour. In addition, this thesis will explore the impact of automation in Software-Defined Networking (SDN) on router bypass. The application-driven infrastructure in SDN is moving the network to be more adaptive, which paves the way for an enhanced implementation of router bypass. Many challenges still face the industry to fully integrate the three layers (3, 2, and 1) to transform the current infrastructure into an adaptive application driven network. The IP router (layer 3) provisions and restores the connection regardless of the underlying layers (layer 2 and 1) and the transport layer does the same regardless of the IP layer. Although allowing every layer to develop without being constrained by other layers offers a huge advantage, it renders the transport layer static and not fully aware of the traffic behaviour. It is my hope that this thesis is a step forward in transforming the current network into a dynamic, efficient and responsive network. A simulation has been built to imitate the router bypassing concept and then many measurements have been recorded. / Graduate
8

Homing-Architekturen für Multi-Layer Netze: Netzkosten-Optimierung und Leistungsbewertung / Homing Architectures in Multi-Layer Networks: Cost Optimization and Performance Analysis

Palkopoulou, Eleni 21 December 2012 (has links) (PDF)
Die schichtenübergreifende Steuerung von Multi-Layer Netzen ermöglicht die Realisierung fortgeschrittener Netzarchitekturen sowie neuartiger Konzepte zur Steigerung der Ausfallsicherheit. Gegenstand dieser Arbeit ist ein neues ressourcensparendes Konzept zur Kompensation von Core-Router-Ausfallen in IP-Netzen. Core-Router-Ausfälle führen zur Abkopplung der an Ihnen angeschlossenen Zugangsrouter vom Netz. Daher werden die Zugangsrouter üblicherweise mit jeweils zwei oder mehreren verschiedenen Core-Routern verbunden (engl.: dual homing) was jedoch eine Verdoppelung der Anschlusskapazität im IP Netz bedingt. Bei dem neuen Verfahren - Dual Homing mit gemeinsam genutzten Router-Ersatzressourcen (engl.: dual homing with shared backup router resources, DH-SBRR) - erfolgt die Zugangsrouter-Anbindung zum einen zu einem Core-Router des IP-Netzes und zum anderen zu einem Netzelement der darunterliegenden Transportschicht. Damit lassen sich Router-Ersatzressourcen, die im IP-Netz an beliebigen Stellen vorgehalten werden können, uber das Transportnetz an die Stelle eines ausgefallenen Core-Routers schalten. Die Steuerung dieser Ersatzschaltung geschieht über eine schichten übergreifende, d.h. das Transportnetz- und IP-Netz umfassende Control-Plane - beispielsweise auf Basis von GMPLS. Da beim Umschalten der Routerressourcen auch aktuelle Zustände (bspw. Routing-Tabellen) auf die Router-Ersatzressourcen mit übertragen werden müssen, beinhaltet das neue Verfahren auch Konzepte zur Router-Virtualisierung. Zum Vergleich und zur Bewertung der Leistungsfähigkeit des neuen DH-SBRR Verfahrens werden in der Arbeit verschiedene Zugangsrouter-Homing-Varianten hinsichtlich Netz-Kosten, Netz-Verfügbarkeit, Recovery-Zeit und Netz-Energieverbrauch gegenübergestellt. Als Multi-Layer Netzszenarien werden zum einen IP über WDM und zum anderen IP über OTN (ODU) betrachtet. Zur Bestimmung der minimalen Netz-Kosten ist ein generisches Multi-Layer Netzoptimierungsmodell entwickelt worden, welches bei unterschiedlichen Homing-Architekturen angewendet werden kann. Neben dem Optimierungsmodell zur Netzkostenminimierung wird auch eine Modellvariante zur Minimierung des Energieverbrauchs vorgestellt. Um die Rechenzeit für die Lösung der Optimierungsprobleme zu verringern und damit auch größere Netzszenarien untersuchen zu können bedarf es heuristischer Lösungsverfahren. Im Rahmen der Arbeit ist daher eine neue speziell auf die Multilayer-Optimierungsprobleme zugeschnittene Lösungsheuristik entwickelt worden. Aus der Netzkosten-Optimierung ergibt sich, dass durch den Einsatz von DH-SBBR signifikante Kosteneinsparungen im Vergleich zu herkömmlichen Homing-Architekturen realisiert werden können. Änderungen der Verkehrslast, der Kosten der IP-Netzelemente oder der Netztopologie haben keinen signifikanten Einfluss auf dieses Ergebnis. Neben dem Kosten- und Energieeinsparungspotential sind auch die Auswirkungen auf die Netz-Verfügbarkeit und die Recovery-Zeit untersucht worden. Für die Ende-zu-Ende Verfügbarkeit bei Anwendung der verschiedenen Homing-Architekturen Können untere Grenzwerte angegeben werden. Zur Bestimmung der Recovery-Zeit bei Einsatz von DH-SBRR ist ein eigenes analytisches Berechnungsmodell entwickelt und evaluiert worden. Damit kann das DH-SBRR Verfahren zur Einhaltung vorgegebener Recovery-Zeiten (wie sie für bspw. Für bestimmte Dienste gefordert werden) entsprechend parametriert werden. / The emergence of multi-layer networking capabilities opens the path for the development of advanced network architectures and resilience concepts. In this dissertation we propose a novel resource-efficient homing scheme: dual homing with shared backup router resources. The proposed scheme realizes shared router-level redundancy, enabled by the emergence of control plane architectures such as generalized multi-protocol label switching. Additionally, virtualization schemes complement the proposed architecture. Different homing architectures are examined and compared under the prism of cost, availability, recovery time and energy efficiency. Multiple network layers are considered in Internet protocol over wavelength division multiplexing as well as Internet protocol over optical data unit settings - leading to the development of multi-layer optimization techniques. A generic multi-layer network design mathematical model, which can be applied to different homing architecture considerations, is developed. The optimization objective can be adapted to either minimizing the cost for network equipment or the power consumption of the network. In order to address potential issues with regard to computational complexity, we develop a novel heuristic approach specifically targeting the proposed architecture. It is shown that significant cost savings can be achieved - even under extreme changes in the traffic demand volume, in the cost for different types of network equipment, as well as in the network topology characteristics. In order to evaluate occurring tradeoffs in terms of performance, we study the effects on availability and recovery time. We proceed to derive lower bounds on end-to-end availability for the different homing architectures. Additionally, an analytical recovery time model is developed and evaluated. We investigate how service-imposed maximum outage requirements have a direct effect on the setting of the proposed architecture.
9

Homing-Architekturen für Multi-Layer Netze: Netzkosten-Optimierung und Leistungsbewertung / Homing Architectures in Multi-Layer Networks: Cost Optimization and Performance Analysis

Palkopoulou, Eleni 13 December 2012 (has links)
Die schichtenübergreifende Steuerung von Multi-Layer Netzen ermöglicht die Realisierung fortgeschrittener Netzarchitekturen sowie neuartiger Konzepte zur Steigerung der Ausfallsicherheit. Gegenstand dieser Arbeit ist ein neues ressourcensparendes Konzept zur Kompensation von Core-Router-Ausfallen in IP-Netzen. Core-Router-Ausfälle führen zur Abkopplung der an Ihnen angeschlossenen Zugangsrouter vom Netz. Daher werden die Zugangsrouter üblicherweise mit jeweils zwei oder mehreren verschiedenen Core-Routern verbunden (engl.: dual homing) was jedoch eine Verdoppelung der Anschlusskapazität im IP Netz bedingt. Bei dem neuen Verfahren - Dual Homing mit gemeinsam genutzten Router-Ersatzressourcen (engl.: dual homing with shared backup router resources, DH-SBRR) - erfolgt die Zugangsrouter-Anbindung zum einen zu einem Core-Router des IP-Netzes und zum anderen zu einem Netzelement der darunterliegenden Transportschicht. Damit lassen sich Router-Ersatzressourcen, die im IP-Netz an beliebigen Stellen vorgehalten werden können, uber das Transportnetz an die Stelle eines ausgefallenen Core-Routers schalten. Die Steuerung dieser Ersatzschaltung geschieht über eine schichten übergreifende, d.h. das Transportnetz- und IP-Netz umfassende Control-Plane - beispielsweise auf Basis von GMPLS. Da beim Umschalten der Routerressourcen auch aktuelle Zustände (bspw. Routing-Tabellen) auf die Router-Ersatzressourcen mit übertragen werden müssen, beinhaltet das neue Verfahren auch Konzepte zur Router-Virtualisierung. Zum Vergleich und zur Bewertung der Leistungsfähigkeit des neuen DH-SBRR Verfahrens werden in der Arbeit verschiedene Zugangsrouter-Homing-Varianten hinsichtlich Netz-Kosten, Netz-Verfügbarkeit, Recovery-Zeit und Netz-Energieverbrauch gegenübergestellt. Als Multi-Layer Netzszenarien werden zum einen IP über WDM und zum anderen IP über OTN (ODU) betrachtet. Zur Bestimmung der minimalen Netz-Kosten ist ein generisches Multi-Layer Netzoptimierungsmodell entwickelt worden, welches bei unterschiedlichen Homing-Architekturen angewendet werden kann. Neben dem Optimierungsmodell zur Netzkostenminimierung wird auch eine Modellvariante zur Minimierung des Energieverbrauchs vorgestellt. Um die Rechenzeit für die Lösung der Optimierungsprobleme zu verringern und damit auch größere Netzszenarien untersuchen zu können bedarf es heuristischer Lösungsverfahren. Im Rahmen der Arbeit ist daher eine neue speziell auf die Multilayer-Optimierungsprobleme zugeschnittene Lösungsheuristik entwickelt worden. Aus der Netzkosten-Optimierung ergibt sich, dass durch den Einsatz von DH-SBBR signifikante Kosteneinsparungen im Vergleich zu herkömmlichen Homing-Architekturen realisiert werden können. Änderungen der Verkehrslast, der Kosten der IP-Netzelemente oder der Netztopologie haben keinen signifikanten Einfluss auf dieses Ergebnis. Neben dem Kosten- und Energieeinsparungspotential sind auch die Auswirkungen auf die Netz-Verfügbarkeit und die Recovery-Zeit untersucht worden. Für die Ende-zu-Ende Verfügbarkeit bei Anwendung der verschiedenen Homing-Architekturen Können untere Grenzwerte angegeben werden. Zur Bestimmung der Recovery-Zeit bei Einsatz von DH-SBRR ist ein eigenes analytisches Berechnungsmodell entwickelt und evaluiert worden. Damit kann das DH-SBRR Verfahren zur Einhaltung vorgegebener Recovery-Zeiten (wie sie für bspw. Für bestimmte Dienste gefordert werden) entsprechend parametriert werden. / The emergence of multi-layer networking capabilities opens the path for the development of advanced network architectures and resilience concepts. In this dissertation we propose a novel resource-efficient homing scheme: dual homing with shared backup router resources. The proposed scheme realizes shared router-level redundancy, enabled by the emergence of control plane architectures such as generalized multi-protocol label switching. Additionally, virtualization schemes complement the proposed architecture. Different homing architectures are examined and compared under the prism of cost, availability, recovery time and energy efficiency. Multiple network layers are considered in Internet protocol over wavelength division multiplexing as well as Internet protocol over optical data unit settings - leading to the development of multi-layer optimization techniques. A generic multi-layer network design mathematical model, which can be applied to different homing architecture considerations, is developed. The optimization objective can be adapted to either minimizing the cost for network equipment or the power consumption of the network. In order to address potential issues with regard to computational complexity, we develop a novel heuristic approach specifically targeting the proposed architecture. It is shown that significant cost savings can be achieved - even under extreme changes in the traffic demand volume, in the cost for different types of network equipment, as well as in the network topology characteristics. In order to evaluate occurring tradeoffs in terms of performance, we study the effects on availability and recovery time. We proceed to derive lower bounds on end-to-end availability for the different homing architectures. Additionally, an analytical recovery time model is developed and evaluated. We investigate how service-imposed maximum outage requirements have a direct effect on the setting of the proposed architecture.
10

[pt] ANÁLISE DO IMPACTO DO AUMENTO DAS TAXAS DE TRANSMISSÃO NO DESEMPENHO E NA CONFIABILIDADE SISTEMAS DE COMUNICAÇÕES ÓPTICAS / [en] IMPACT OF ULTRA HIGH BIT RATE IN THE PERFORMANCE AND CONFIABILITY IN OPTICAL SYSTEMS

MARCOS BOMFIM DO NASCIMENTO 25 June 2015 (has links)
[pt] O objetivo desta Dissertação é apresentar a análise do comportamento de protocolos e dos métodos de proteção em sistemas ópticos para as futuras redes de altas taxas de transmissão. A demanda por banda de transmissão em redes ópticas vem aumentando sobremaneira nas últimas décadas, principalmente, devido à disseminação do acesso e da utilização da Internet e aos novos tipos de aplicações que ela utiliza, com compartilhamento de vídeos e aplicações em nuvem. Esse aumento de tráfego tem impulsionado fortemente o desenvolvimento de tecnologias de sistemas ópticos que procuram garantir o atendimento a essa demanda. Várias frentes de estudos buscam obter taxas de transmissão de bits mais altas por canais (100Gbps, 400Gbps e 1Tbps), utilizando-se de tecnologias avançadas como o formato de modulação multinível, fibras com baixa perda e área de transmissão efetiva mais larga, amplificação híbrida EDFA/Raman e tecnologias de detecção digital coerente. A taxa máxima de transmissão em sistemas ópticos está saindo do atual 10Gbps e indo na direção dos 40Gbps e 100Gbps, já comercialmente oferecidos, e dos 400Gbps e 1Tbps ainda em desenvolvimento. E esse aumento na taxa de transmissão gera uma necessidade de avaliação do comportamento dos protocolos e métodos de proteção atuais quando aplicados a essas novas redes ultra-rápidas. A mudança para taxas de transmissão tão altas pode requerer diferentes estratégias de operação, e a razão é que os efeitos de retardo de propagação alteram significantemente o controle de fluxo do tráfego. / [en] The aim of this Dissertation is to present an analysis of the behavior of protocols and protection methods in optical communication systems for the ultra high bit rate networks. The demand for optical networking transmission bandwidth is increasing greatly in recent decades, mainly due to the spread of access to and the use of the Internet and new types of services, with video sharing and cloud applications. This increase in traffic has driven strongly the development of optical systems technologies that seek to ensure compliance with this demand. Several fronts of studies seeking to obtain rates from higher bits per channel (100Gbps, 400Gbps and 1Tbps), using advanced technologies such as multilevel modulation format, fibers with low loss and wider effective transmission area, hybrid EDFA/Raman amplification and digital coherent detection technologies. The maximum transmission rate in optical systems is coming out of the current 10Gbps and 40Gbps and going towards the 100Gbps, already commercially offered, and still developing 400Gbps and 1Tbps. This increase in transmission rate generates a need for evaluation of the behavior of current protection protocols and methods when applied to these new ultra-fast networks. The change to so high transmission rates may require different operating strategies, and the reason is that the effects of propagation delay alter significantly the control traffic flow.

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