Spelling suggestions: "subject:"[een] SERVICE DISCIPLINE"" "subject:"[enn] SERVICE DISCIPLINE""
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[en] SERVICE DISCIPLINES IN COMUNICATION NETWORKS / [pt] DISCIPLINAS DE SERVIÇO EM REDES DE COMUNICAÇÕESANDRE FELIPE VIEIRA MACEDO 12 March 2002 (has links)
[pt] Este trabalho enfoca os efeitos provocados pelas
características auto-similares do tráfego agregado na
gerência de redes de serviços integrados. Para isso,
disciplinas de serviço,mecanismos essenciais para o
controle de congestionamento em uma rede, foram
implementadas, fontes de tráfego, elementos a serem
gerenciados, foram utilizadas e análises de desempenho
realizadas quando estas fontes compartilham uma rede.
Adicionalmente, este trabalho mostra por meio de simulações
as garantias e propriedades fornecidas por tais
disciplinas. / [en] This work concerns on the effects caused by the traffic
self-similar characteristics aggregated in the management
of the networks´ services. With this objective, service
disciplines, which are essential mechanisms used to control
networks` congestion, were implemented; traffic sources,
which are elements to be managed, were used; and performance
analysis were developed when all the sources shared the
network. Furthermore, this work shows through simulations
the guarantees and properties provided by the disciplines.
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Energy Efficiency and Differentiated QoS in Next Generation PONsChen, Shen 03 February 2012 (has links)
Energy conservation in next generation Passive Optical Network system (NG-PON) has gained more and more attention. NG-PON system can not only deliver best-effort data traffic, but also real-time data traffic, e.g. voice and video, that have strict bandwidth, delay, and jitter requirements. To meet the energy and service requirements, a NG-PON system must have energy efficiency and differentiated QoS mechanism built in.
Few research efforts have been reported on maximizing energy efficiency while maintaining QoS in the fairly new PON system design. We have extended the Upstream Centric Scheme (UCS-based) scheduling scheme idea into a novel QoS-differentiated energy-efficient PON system consisting of two main modules: firstly, the proposed differentiated QoS analytical model is described in detail to reduce the packet delay in the upstream traffic scheduling. The simulations further demonstrate the QoS metrics of the system: packet delay, bandwidth utilization, dropped packet rate, and queue length.
Secondly, a novel analysis is proposed for downstream traffic scheduling with limited service discipline at Optical Line Terminal (OLT) side under the UCS-based Green Bandwidth Allocation (GBA) framework. We, first, derive the mean packet delay expression of this model. Then, the sleep time for each Optical Network Unit (ONU) is derived by setting identical upstream/downstream transmission cycle time. Based on the analytical model, an approach is developed to save the maximum energy in a dynamic PON system while without violating the delay requirement.
Moreover, simulation is conducted to verify the developed analytical model and the proposed approach. In the end, considering the differentiated QoS and downstream traffic scheduling, an algorithm of the energy efficient scheduling scheme is proposed as well under the UCS-based GBA.
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Energy Efficiency and Differentiated QoS in Next Generation PONsChen, Shen 03 February 2012 (has links)
Energy conservation in next generation Passive Optical Network system (NG-PON) has gained more and more attention. NG-PON system can not only deliver best-effort data traffic, but also real-time data traffic, e.g. voice and video, that have strict bandwidth, delay, and jitter requirements. To meet the energy and service requirements, a NG-PON system must have energy efficiency and differentiated QoS mechanism built in.
Few research efforts have been reported on maximizing energy efficiency while maintaining QoS in the fairly new PON system design. We have extended the Upstream Centric Scheme (UCS-based) scheduling scheme idea into a novel QoS-differentiated energy-efficient PON system consisting of two main modules: firstly, the proposed differentiated QoS analytical model is described in detail to reduce the packet delay in the upstream traffic scheduling. The simulations further demonstrate the QoS metrics of the system: packet delay, bandwidth utilization, dropped packet rate, and queue length.
Secondly, a novel analysis is proposed for downstream traffic scheduling with limited service discipline at Optical Line Terminal (OLT) side under the UCS-based Green Bandwidth Allocation (GBA) framework. We, first, derive the mean packet delay expression of this model. Then, the sleep time for each Optical Network Unit (ONU) is derived by setting identical upstream/downstream transmission cycle time. Based on the analytical model, an approach is developed to save the maximum energy in a dynamic PON system while without violating the delay requirement.
Moreover, simulation is conducted to verify the developed analytical model and the proposed approach. In the end, considering the differentiated QoS and downstream traffic scheduling, an algorithm of the energy efficient scheduling scheme is proposed as well under the UCS-based GBA.
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[en] QUEUING SCHEDULING DISCIPLINE BASED ON USER’S SATISFACTION MEASURED BY QOS METRICS / [pt] DISCIPLINA DE SERVIÇO BASEADA NA SATISFAÇÃO MEDIDA POR MÉTRICAS DE QOSRAUL WAGNER DOS REIS VELLOSO FILHO 21 October 2009 (has links)
[pt] Redes de comutação em pacotes vêm substituindo gradativamente as redes
de comutação em circuitos, unificando assim, a forma como voz e dados são
trafegados. Devido a esse novo conceito de redes comutadas por pacotes, novos
desafios referentes ao surgimento de novas aplicações necessitando requisitos de
qualidade cada vez mais estritos, vêm recentemente atraindo a atenção de
pesquisadores da área de redes de computação. Entre os mecanismos existentes
para determinar a qualidade de serviço oferecida por tais redes, o mecanismochave
considerado, dos roteadores que desempenham tal função, é o escalonador
de pacotes. O conceito que dita à operação de tais escalonadores é o conceito de
disciplinas de serviço. No presente trabalho, é proposta uma nova disciplina de
serviço onde os pacotes são escalonados de acordo com um indicador de
desempenho que mede a satisfação dos usuários baseado no serviço recebido em
relação ao serviço contratado. Esse indicador é trazido da economia e se chama
Função Utilidade. O sistema considerado no trabalho leva em consideração o
funcionamento do roteador de borda de uma provedora de serviços de
telecomunicações onde os usuários requerem serviços de VoIP, FTP e HTTP. Os
resultados de simulação do sistema mostram que o desempenho da disciplina
proposta é comparável, sendo em alguns casos levemente insatisfatória, quando
comparada a outras disciplinas existentes na literatura. A lista de trabalhos futuros
sugere possibilidades de melhoria deste desempenho, mas que não foram testadas
por falta de tempo. / [en] Packet-switched networks have recently replaced circuit-switched networks
unifying the way voice and data are carried through those networks. Due to such a
new switching concept, challenges related to new applications with different
quality requirements have arisen and attracted much attention of computer
network researchers. Among the mechanisms used to provide quality of service in
those networks, the one chosen in this research is the router’s packet scheduler.
The concept that governs packet schedulers is queuing scheduling discipline. In
this research, a new queuing scheduling discipline is proposed where packets are
scheduled based on a performance indicator that evaluates the user’s satisfaction
with the service contracted. That performance indicator is a well-known economic
function called utility function. The system considered on this research is
focused on the operation of a telecommunications service provider network’s
border router where users request FTP, VoIP and HTTP services. Simulation
results show that the performance of the proposed service discipline is
comparable, but not always to a satisfactory degree, when compared with other
service disciplines found in the literature. Some suggestions for future research
are added in this dissertation, in order to improve the performance of the proposed
service discipline, but they have not been tested due to space and time limitations.
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