Dissertations / Theses on the topic 'Optical telecommunication networks'
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Mbah, Afamefuna Maduka. "Hybrid fibre and free-space optical solutions in optical access networks." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/32572/.
Full textJabar, Sakena Abdul. "The efficient deployment of passive optical networks within the telecommunication access network." Thesis, University of Hertfordshire, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440171.
Full textYu, Wing Wa. "Routing and time-slot assignment in photonic circuit switching networks /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202002%20YUW.
Full textIncludes bibliographical references (leaves 68-70). Also available in electronic version. Access restricted to campus users.
Subramaniam, Suresh. "All-optical networks with sparse wavelength conversion /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/6032.
Full textAl-Fuqaha, Ala Isam Chaudhry Ghulam M. "Routing and wavelength assignment in all-optical DWDM networks with sparse wavelength conversion capabilities." Diss., UMK access, 2004.
Find full text"A dissertation in engineering and computer networking." Advisor: Ghulam Chaudhry. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Feb. 22, 2006. Includes bibliographical references (leaves 135-157). Online version of the print edition.
Ding, Zhemin. "Resource allocation and management in optical networks using the blocking island paradigm /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20DING.
Full textIncludes bibliographical references (leaves 123-127). Also available in electronic version. Access restricted to campus users.
Øverby, Harald. "Quality of service differentiation, teletraffic analysis and network layer packet redundancy in optical packet switched networks." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-563.
Full textOptical Packet Switching (OPS) has emerged as a promising candidate for the next-generation Wavelength Division Multiplexed (WDM) based alloptical network. By enabling packet switching in the optical domain, OPS networks can provide cost-efficient and transparent transport services to higher layers. However, a commercial deployment of OPS requires not only a maturation of several key enabling technologies, but also a thorough investigation of a number of networking challenges related to OPS, since OPS networks are fundamentally different from today’s store-and-forward networks. This thesis addresses the latter issue by considering the following three OPS networking issues:
· Quality of Service (QoS) differentiation at the WDM layer, with focus on packet loss rate (PLR) and delay-jitter differentiation.
· Teletraffic analysis of OPS networks.
· How to combat packet loss in OPS networks by using network layer packet redundancy.
First, a crucial issue in OPS networks is packet loss at the network layer due to contention. Contention occurs when a packet is destined for a wavelength currently occupied by another packet. Several approaches to combat such packet loss have been proposed in recent literature, e.g. by utilizing wavelength conversion, buffering, deflection routing or traffic shaping.
This thesis considers a novel approach to combat packet loss in OPS: The proposed Network Layer Packet Redundancy Scheme (NLPRS) allows redundancy packets to be injected into the OPS network, thus enabling reconstruction of lost data packets at the OPS egress node. Results show that the NLPRS is able to reduce the end-to-end data PLR several orders of magnitude in an asynchronous OPS ring network with and without wavelength conversion.
Another crucial issue in OPS networks is QoS differentiation at the WDM layer. Due to the lack of optical random access memory, existing QoS differentiation schemes suitable for today’s WDM point-to-point architecture are not feasible to use in OPS networks. Hence, new schemes that utilize the WDM layer to provide QoS differentiation are needed.
A preemption based QoS differentiation scheme, the Preemptive Drop Policy (PDP), has been proposed for asynchronous bufferless OPS. With the PDP, high priority arrivals are allowed to preempt and take over a busy wavelength currently occupied by a low priority packet in the case of contention. This results in a lower PLR for high priority traffic compared to low priority traffic. The PDP has been extended into the Adaptive PDP (APDP), which provides absolute guarantees to the PLR for high priority ivtraffic in OPS by using a measurement based preemption probability parameter adjustment.
An access-restriction based QoS differentiation scheme, the Wavelength Allocation algorithm (WA), has been studied. In the WA, which provides QoS differentiation in asynchronous bufferless OPS networks with full range output wavelength converters, a certain number of wavelengths at an output fibre are exclusively reserved for high priority traffic.
When QoS differentiation (with respect to the PLR) is introduced in asynchronous OPS, it has been shown that the average throughput decreases, often referred to as the throughput penalty of introducing QoS differentiation. The main cause for this throughput penalty is because network resources must be used in a non-optimal manner when employing QoS differentiation schemes that utilize the WDM layer to isolate the service classes. However, as shown in this thesis, the throughput penalty is only found in asynchronous OPS. For slotted OPS, the average throughput stays the same after the introduction of QoS differentiation.
An evaluation framework suitable for quantifying the throughput penalty when introducing QoS differentiation has been proposed. Using this framework, three fundamental different QoS differentiation schemes for asynchronous OPS, including the PDP and the WA, have been evaluated. It has been shown that preemptive techniques result in the lowest throughput penalty, followed by access-restriction and dropping based techniques. This is because, when using preemption, packets are dropped only when the output port is congested. With access-restriction, packets are dropped when the output port is highly strained, and with statistically packet dropping, packets are dropped independently of the state of the output port.
A QoS differentiation scheme for slotted OPS has been proposed and evaluated. The scheme isolates the service classes by ensuring that a certain number of high priority packets can be transmitted at an output port in a time-slot in the case of contention. Using the proposed scheme does not result in a reduced throughput when the service classes are isolated.
QoS differentiation schemes for asynchronous OPS with a share pernode (SPN) contention resolution pool architecture consisting of Tunable Wavelength Converters (TWCs) and Fibre Delay Lines (FDLs) have been proposed. In particular, it has been shown that the PLR and delay-jitter may be independently differentiated in this switch architecture.
Analytical models of some of the proposed QoS differentiation schemes have been derived, providing explicit results of the PLR. In addition, an analytical framework regarding packet arrivals to an output port in an optical packet switch has been derived for both asynchronous and slotted OPS. This framework is particularly useful for studying the effects of nonuniform traffic. Furthermore, it has been shown that both the Erlang and Engset traffic models are suitable to model packet arrivals to an output port in an asynchronous optical packet switch. Regarding the Engset traffic model, it has been shown how the blocking probability can be evaluated vusing either the Engset lost calls cleared (LCC) traffic model or the Engset overflow (OFL) traffic model. For all Engset based traffic models, the time-, call- and traffic congestion have been derived. A numerical evaluation of the presented traffic models reveals that there is a small, but non-negligible, deviation between the observed blocking probabilities, which depends on the number of input/output fibres and the system load.
Mustafa, Haithem A. "Opto-VLSI-based adaptive optical power splitter/combiner for next generation dynamic optical telecommunication networks." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/923.
Full textDa, Rosa Marcelo Zannin. "Optical gain clamping in erbium doped fibre amplifier : investigation in optical burst switching networks." Thesis, Swansea University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678524.
Full textChowdhury, Arshad M. "Optical Label Switching Technologies for Optical Packet Switched Networks." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14047.
Full textLim, Wee Shoong. "An evaluation of management techniques for SONET/SDH Telecommunication networks." Thesis, Monterey California. Naval Postgraduate School, 2004. http://hdl.handle.net/10945/1389.
Full textA study of SONET network management applications and the load they impart to the network is conducted to provide a better understanding of the capability of various management approaches. In this study, a SONET network is set up in the Advanced Networking Laboratory of the Naval Postgraduate School using four Cisco ONS 15454s. Next, two Element Management Systems, the Cisco Transport Controller and the Cisco Transport Manager, are deployed onto the SONET network. Subsequently, the network traffic of the Element Management Systems is captured and analyzed using a packet analyzer. Link utilization of the two tools is computed using the first-order statistics of the captured traffic distributions. In addition, the Hurst parameter is estimated using the variance-index plot technique (which uses higher-orders statistics of the modeled distributions) to determine the captured traffic's degree of self-similarity. Finally, the calculated utilization is extrapolated to obtain the link utilization for 2500 network elements (the maximum number supported by the Cisco Transport Manager). The result obtained is useful in determining the maximum number of network elements (Cisco ONS 15454s) that the Cisco Transport Manager can support from a network loading point of view.
Civilian, Ministry of Defense, Singapore
Li, Jonathan Chi Fai. "Eye closure penalty based signal quality metric for intelligent all-optical networks /." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/7047.
Full textPaul, Harald. "Passive optical network planning in the local access network - an optimisation based approach utilising genetic algorithms." Thesis, University of Sunderland, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310010.
Full textYuen, Siu Yu. "Routing and time-slot assignment algorithms and connection management in photonic circuit switched networks /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202005%20YUEN.
Full textSau, Ignasi. "Optimization in Graphs under Degree Constraints. Application to Telecommunication Networks." Phd thesis, Université de Nice Sophia-Antipolis, 2009. http://tel.archives-ouvertes.fr/tel-00429092.
Full textBozek, Matthew Peter. "Express lanes modification to the data vortex photonic all-optical path interconnection network." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24680.
Full textCommittee Chair: Wills, D. Scott; Committee Member: Keezer, David; Committee Member: Yalamanchili, Sudhakar
Puris, Dmitriy [Verfasser], and Klaus [Akademischer Betreuer] Petermann. "Modeling of Quantum Dot Semiconductor Optical Amplifiers for Telecommunication Networks / Dmitriy Puris. Betreuer: Klaus Petermann." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2013. http://d-nb.info/1035276380/34.
Full textJordan, Wayne George. "New zirconium fluoride-based halide glasses for 1.3 #mu#m optical fibre amplifiers in telecommunication networks." Thesis, Brunel University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239091.
Full textNg, Hwee Ping. "Performance analysis of management techniques for SONET/SDH telecommunications networks." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Mar%5FNg.pdf.
Full textSharma, Ameeth. "Performance comparison of two dynamic shared-path protection algorithms for WDM optical mesh networks." Diss., Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-01262009-141918/.
Full textJia, Zhensheng. "Optical millimeter-wave signal generation, transmission and processing for symmetric super-broadband optical-wireless access networks." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24640.
Full textCommittee Chair: Gee-Kung Chang; Committee Co-Chair: Jianjun Yu; Committee Member: John A. Buck; Committee Member: Joy Laskar; Committee Member: Umakishore Ramachandran; Committee Member: Ye Li
Chen, Jiajia. "Design, analysis and simultion for optical access and wide-area networks." Doctoral thesis, KTH, Mikroelektronik och tillämpad fysik, MAP, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10348.
Full textQC 20100707
Hawkins, William Cory. "Evaluation of the data vortex photonic all-optical path interconnection network for next-generation supercomputers." Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-12182006-155304/.
Full textDr. Henry L. Owen III, Committee Member ; Dr. David Keezer, Committee Member ; Dr. D. Scott Wills, Committee Chair.
Woeste, Christian C. "Passive-optical-network planning based on Tabu Search : an investigation of zero-base Brownfield planning for passive optical telecommunication networks based on the modern heuristic optimisation method Tabu Search." Thesis, University of Sunderland, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267750.
Full textSavasini, Marcio Saenz. "Esquemas de proteção e conversão de comprimento de onda em redes opticas WDM." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261764.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Este trabalho tem como objetivo analisar a redução na probabilidade de bloqueio com o uso de conversores de comprimento de onda e esquemas de proteção em redes ópticas. É apresentada a proteção por roteamento em sub-grafos, um método de criar caminhos de proteção dependentes a falha para cada conexão. Alguns esquemas para eliminar realocações desnecessárias de conexões no caso de falha, sem penalizar fortemente a aceitação de novas conexões, foram sugeridos e comparados. Outro tema abordado no trabalho foi o ganho do uso de conversores de comprimento de onda em redes em malha em um ambiente dinâmico de tráfego. Foi utilizado nas simulações um número limitado de conversores plenos espalhados pela rede. Foi analisada a quantidade suficiente de conversores para se ter uma probabilidade de bloqueio satisfatória, pensando em minimizar os investimentos a serem feitos no momento de uma expansão da rede. Para um melhor entendimento dos problemas estudados há uma descrição do funcionamento da rede óptica e seus elementos principais e dos algoritmos de roteamento e alocação de comprimento de onda utilizados e descritos na literatura
Abstract: This work examines the blocking reduction with the use of wavelength converters and some protection schemes in optical networks. Sub-Graph Routing Protection, a protection method that creates different failure-dependent protection paths for each connection is presented. Some schemes were proposed and compared, aiming at eliminating unnecessary connection reallocations on a failure occurrence, without compromising the acceptance of new connections. Another topic studied for this work is the conversion gain, when wavelength converters are used in mesh topology networks under dynamic traffic. A limited number of total converters were used in the simulations. The sufficient amount of converters for a satisfactory blocking probability was analyzed, for minimizing investments in a network upgrade. For a better problem formulation understanding the optical network and its elements were explained. The routing and wavelength allocation algorithms proposed in the literature are also detailed.
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica
De, Vega Rodrigo Miguel. "Modeling future all-optical networks without buffering capabilities." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210455.
Full textIn the first part we introduce the basic functionality and structure of OBS and OPS networks. We identify the blocking probability as the main performance parameter of interest.
In the second part we study the statistical properties of the traffic that will likely run through these networks. We use for this purpose a set of traffic traces obtained from the Universidad Politécnica de Catalunya. Our conclusion is that traffic entering the optical domain in future OBS/OPS networks will be long-range dependent (LRD).
In the third part we present the model for bufferless OBS/OPS networks. This model takes into account the results from the second part of the thesis concerning the LRD nature of traffic. It also takes into account specific issues concerning the functionality of a typical bufferless packet-switching network. The resulting model presents scalability problems, so we propose an approximative method to compute the blocking probability from it. We empirically evaluate the accuracy of this method, as well as its scalability.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Pereira, Flavio de Melo. "Modelagem, policiamento e escalonamento em redes Ethernet PON." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260703.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Resumo: Neste trabalho, apresentamos uma nova proposta de modelagem, policiamento e escalonamento de tráfego em redes Ethernet com elementos ápticos passivos. Esta proposta visa ao suporte a garantias de desempenho individuais para os fluxos. Propomos um processo envelope denominado Processo de Chegada com Limitante Fracionário para a representação de tráfego multimidia com características fractais. Com base neste modelo, propomos o uso do algoritmo do balde furado para o policiamento do tráfego. Para o escalonamento de tráfego, propomos uma nova política em que a rede reserva uma parcela minima de banda para cada fluxo, sendo que os fluxos com demanda reprimida recebem uma parcela justa dos recursos ociosos. Para esta política, denominada Compartilhamento Proporcional com Reserva de Carga, estabelecemos as condições de estabilidade da rede e apresentamos expressões limitantes para a justiça e para o atraso dos fluxos
Abstract: We propose new framework for traffic modelling, policing and scheduling in Ethernet Passive Optical Networks. This framework aims at providing performance guarantees to individual flows in access networks. We propose a new envelope process called Fractional Bounded Arrival Process for selfsimilar 'multimedia traffic representation. The policing of such a kind of traffic by using the leaky bucket algorithm is also proposed. We present a novel discipline for scheduling the upstream flows in EPON networks. In such a discipline, which is calle4 Proportional Sharing with Load Reservation, each flow is guaranteed a minimum share of bandwidth and the unused bandwidth is fairly distributed among them in proportion to their own demands and priorities. We analyze the performance of the proposed discipline and provide fairness and delay bounds on a per-flow basis
Doutorado
Telecomunicações e Telemática
Doutor em Engenharia Elétrica
Walker, Graham Richard. "Optical amplifiers for future telecommunications networks." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241118.
Full textEvans, T. "Active optical waveguide devices for telecommunications networks." Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598865.
Full textAMORIM, RAFAEL FREITAS DE. "INTEGER PROGRAMMING PROBLEMS ON TELECOMMUNICATIONS OPTICAL NETWORKS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2006. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8796@1.
Full textImpulsionadas pelo crescimento do mercado corporativo e pela prestação de serviços para grandes clientes, as operadoras de serviços de telecomunicação estão buscando processos automatizados e redução de custo no desenvolvimento de novos projetos de redes de telecomunicações. Nesse cenário, dois modelos de Programação Inteira são apresentados buscando uma minimização de custos. O primeiro para o problema de planejamento de novas redes. E segundo para o problema de configuração de trails nas redes SDH. Uma introdução sobre meios de transmissão, redes de telecomunicações, topologias mais utilizadas e sistemas de proteção são apresentados. Por fim, em ambos problemas, são apresentados estudos comparativos com situações reais, com o intuito de validar os modelos.
Stimulated by the growth of the corporate market and by the services dedicated to big customers, providers are searching for, even more nowadays, automated process and cost reduction on the development of new telecommunications networks projects. In that setting, two models of Integer Programming will be presented, seeking a minimization of costs. At first, for the problem of planning of new networks, and second for the problem of configuration of trails in the SDH networks. Beyond that, an introduction about transmission lines, networks of communication, topology more utilized and systems of protection will be presented. In both problems, comparing real situations, with the purpose of validate the models.
Gilfedder, Timothy Hugh. "Physical layer modelling of optical telecommunications architecutures." Thesis, University of Strathclyde, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366806.
Full textRotich, Enoch Kirwa. "Fibre optic network supporting high speed transmission in the square kilometre array, South Africa." Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/6552.
Full textStanojević, Daliborka. "Optimization of contemporary telecommunications networks : generalized spanning trees and WDM optical networks." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/3194.
Full textThesis research directed by: Business and Management. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Brown, Deborah Robyn. "Optimal design, dimensioning and tariffing of telecommunications networks /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phb8774.pdf.
Full textLowe, Ewart D. "Performance and dimensioning of optical transport networks." Thesis, University of Essex, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295647.
Full textAntoniu, Nikolaos H. "Optimal admission policies for small star networks." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5665/.
Full textAgarwal, Shweta S. "Search for an optimal network reporting threshold." Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1091451063.
Full textSampson, David Douglas. "High bandwidth temporal correlators using optical fibre networks." Thesis, University of Kent, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293712.
Full textStark, Andrew Joseph. "16QAM for next-generation optical transport networks." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47732.
Full textBoldrini, Leonardo. "Camera Based Localization for Indoor Optical Wireless Networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20240/.
Full textO'Farrell, Timothy. "Code-division multiple-access (CDMA) techniques in optical fibre local area networks." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257164.
Full textWosinska, Lena. "A study of the reliability of optical switching nodes for high capacity telecommunications networks /." Stockholm, 1999. http://www.lib.kth.se/abs99/wosi0617.pdf.
Full textZhang, Jihui. "On the optimal formulation of resource management in wireless networks /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?COMP%202005%20ZHANG.
Full textRhee, Seung Hyong. "Optimal flow control and bandwidth allocation in multiservice networks : decentralized approaches /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
Full textDiab, Wassim. "Converging Fronthaul and Backhaul Traffic in Edge Optical Networks." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
Find full textThiessen, Christian. "Resilient routing and spectrum assignment in Elastic Optical Networks under Dynamic Traffic." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-155684.
Full textTransparenta Elastiska Optiska Nätverk (EON) ses som en lovande lösning för framtida optiska transportnät för att hänga med Internettrafikens tillväxt, eftersom de möjliggör att tillhandahålla förbindelser med olika krav på bandbredd på ett effektivt sätt. För att uppnå hög spektrumeffektivitet i dessa nätverk är det viktigt att fatta bra beslut vad avser routing, modulering och spektrumtilldelning (Routing, Modulation Level and Spectrum Assignment, RMLSA). Eftersom fiberavbrott är vanliga, så är tåligheten mot enstaka länkfel et annat viktigt ämne. Detta kan ske effektivt genom att skydda gemensamma reservvägar (Shared Path Protection, SPP), vilket dock försvårar RMLSA-problemet. Befintliga routing, modulering och spektrumtilldelningsalgoritmer för SPP fokuserar på strategier i två steg, där först de primära vägarna väljs oberoende av deras backupalternativ. Att välja en annan primär väg, kan dock möjliggöra en bättre reservväg med bättre delning av backupresurser om i stället par av primära och sekundära vägar bedöms tillsammans. Tidigare studier på SPP i EONs anser främst statiska trafikscenarier. I ett dynamiskt trafikscenario, där oförutsägbara anslutningsbegäranden inkommer och avslutas över tiden, så kommer fragmenteringen av spektrala resurser ha en betydande inverkan på nätverkets prestanda. I denna avhandling föreslås en ny algoritm för SPP i EONs för hantering av enskilda länkfel, där par av primära och sekundära vägar väljs gemensamt, vilket minimerar fragmentering och maximerar delning vilket leder till bättre nätverksprestanda i form av minskat blockering. Till skillnad från befintliga algoritmer beslutas den primära och sekundära vägen och spektrum samtidigt från en uppsättning av par av kandidatvägar och spektrumtilldelningen görs med en hybrid-kostnadsfunktion. Funktionen är en viktad kombination av befintliga mått som integrerar fragmentering och delning till en multi-objektiv målfunktion. Med användning av nätverkstrafiksimuleringar i två referensnätverk studeras effekten av olika kostnadsfunktioner på algoritmens beteende och en optimal uppsättning av vikter bestäms. Med dessa parametrar, trafiksimuleringar i en reducerad US-nätverkstopologi med belastningsvärden på 190-240 Erlang, motsvarande blockeringssannolikheter på 0,1 - 1%, visar en genomsnittlig förbättring under referensalgoritmen på 79% i blockeringens sannolikhet, 6.9% i delning och 5,9% i fragmentering. Det visas också att det mesta av denna förbättring beror på det samtidiga tilldelning av primära och reservlänkar. Hybridkostnadsfunktionen minskar blockeringen med ytterligare 10%.
Ni, Wenlong. "Optimal call admission control policies in wireless cellular networks using Semi Markov Decision Process /." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1227028023.
Full textOzcelik, Fatih Mehmet. "Optimal And Implementable Transmission Schemes For Energy Harvesting Networks." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614636/index.pdf.
Full textDantas, Joana Sócrates. "Priority realloc: um mecanismo para alocação de rotas e recursos em redes EON." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-12072016-080408/.
Full textRedes backbone s~ao responsáveis pelo transporte de dados à longa distância que atendem a uma grande quantidade de clientes com um grande volume de dados. Como redes backbone devem basear-se em uma rede robusta e de alta capacidade, a tecnologia atual amplamente adotada pela indústria é Wavelength Division Multiplexing (WDM). Redes WDM permitem que uma única fibra opere com múltiplos canais de alta largura de banda, aumentando drasticamente a capacidade da fibra. Em redes WDMcada canal está associado a um comprimento de onda particular. Por conseguinte, toda capacidade do comprimento de onda é atribuída a uma única conexão, fazendo com que parte da largura de banda seja desperdiçada no caso em que a requisição de largura de banda da conexão seja menor do que a capacidade total do canal. A partir da metade da última década, as Redes Ópticas Elásticas (Elastic Optical Networks - EON) têm sido propostas e desenvolvidas com base no uso flexível do espectro óptico conhecido como flexigrid. EONs s~ao adaptáveis às requisições por banda dos clientes e podem, portanto, melhorar o desempenho das redes ópticas. Por estas razões, EONs têm recebido cada vez mais interesse dos meios de pesquisa e provedores de serviço e provavelmente substituirão WDM como a tecnologia universalmente adotada pela indústria em redes backbone. EONs têm duas características que podem limitar a utilização eficiente de recursos. A fragmentação do espectro, inerente à operação dinâmica das EONs, pode diminuir a capacidade da rede em distribuir recursos ao atender às solicitações por conexões aumentando a probabilidade de bloqueio na rede. A fragmentação do espectro também intensifica a negação de serviço a solicitações por taxa de transmissão mais elevada, gerando injustiça no serviço prestado. Como EONs foram desenvolvidas recentemente, respostas às questões acima mencionadas ainda estão sob estudo e soluções continuam sendo propostas na literatura. Além disso, EONs ainda não fornecem funções específicas como um mecanismo que proveja diferenciação de serviço. Estratégias de diferenciação de serviço são importantes em redes backbone para garantir os diversos requisitos dos clientes em caso de uma falha na rede ou do congestionamento e disputa por recursos que podem ocorrer em alguns períodos em uma rede. Impulsionada pelos fatos anteriormente mencionados, esta tese possui três objetivos. Através do desenvolvimento e proposta de um mecanismo de roteamento e atribuição de recursos para EONs, temos a intenção de disponibilizar diferenciação de serviço, diminuir o nível de fragmentação de espectro e aumentar a justiça na distribuição de serviços. O mecanismo proposto nesta tese foi testado em simulações de EONs. Resultados indicaram que o mecanismo proposto promove benefícios através do aprimoramento da performance de uma rede EON quando comparado com algoritmos de referência.
Liu, Cheng. "Advanced system design and signal processing techniques for converged high-speed optical and wireless applications." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49058.
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