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Previous issue date: 2015-11-13 / The wavelength division multiplexing (WDM) optical network accommodates traffic load in 100, 50 and 25 GHz fixed-grid channel. This fixed-grid condition limits the number of lightpath for each optical fiber (80 channels in c-band) and doesn t allow bit rates with bandwidth over 50 GHz. To improve these factors, the flexibly grid elastic optical network (EON) was proposed, aiming accommodate adequately bit rates demand by customers. This proposal allows efficiency bandwidth and also expands bit rates supported by network. The EON bandwidth efficiency is obtained by routing and spectrum assignment (RSA) algorithm which acts to maximize the bandwidth utilization. Even with RSA, EON still show fragmentation rates substantial. In this context, this work proposes a new elastic optical network defragmentation strategy. This defragmentation strategy selects the lightpaths from the most fragmented link. The defragmentation process is based on RSA (DF-RSA). The DF-RSA determines the new position to reallocate the connection selected and performs. Using computer simulation of EON operation, were submitted several bit rates demands with different modulations format and traffic load between 45 and 100 erlang. Two simulation scenarios were proposed. The first one, compare the performance of RSA algorithm first-fit (FF) with and without defragmentation. It was considered as defragmentation process beginning point (trigger), the number of release connections. This scenario had until 48% of relative gain on minimizing blocking probability. The second scenario compared the performance of the follows RSA algorithms: FF, Maximize Path Spectrum Consecutiveness (MPSC) and Fragmentation Aware (FA). The FF was evaluated with and without defragmentation process and the others just with defragmentation process. The trigger employed was eventual connection blocked. The second scenario reached over the 80% blocking probability relative gain in 50 erlang traffic load. We conclude that the new elastic optical network defragmentation offers substantial gain bandwidth utilization and consequently blocking probability reduction. / As redes ?pticas de multiplexa??o por divis?o de comprimento de onda (WDM) acomodam o tr?fego em canais fixos de 100, 50 e 25 GHz. Esta condi??o de grade fixa limita o n?mero de conex?es por fibra ?ptica (80 canais na banda C), e n?o permite taxas de transmiss?o com ocupa??o espectral acima de 50 GHz. Para melhorar estes fatores, foram propostas as redes ?pticas el?sticas (EON) com canais flex?veis, visando acomodar adequadamente as taxas de transmiss?o demandas pelos usu?rios. Esta proposta possibilita maior efici?ncia espectral e tamb?m amplia as taxas de transmiss?o suportadas pela rede. A efici?ncia espectral nas EONs ? obtida com os algoritmos de roteamento e atribui??o espectral (Routing and Spectrum Assignment, RSA), que atuam para maximizar seu uso espectral. Mesmo com o uso de RSAs, as EONs ainda apresentam ?ndices de fragmenta??o consider?veis. Neste contexto, este trabalho prop?e uma nova estrat?gia de desfragmenta??o espectral para EONs. Esta proposta de desfragmenta??o seleciona as conex?es do enlace mais fragmentado, para o processo de desfragmenta??o. A desfragmenta??o baseia seu processo de realoca??o de conex?es por RSA, denominado DF-RSA. O DF-RSA determina a nova posi??o e realiza a realoca??o das conex?es. Com o uso de simula??o computacional da opera??o de funcionamento da EON, foram submetidas v?rias demandas de taxas de transmiss?o com diferentes modula??es e cargas de tr?fego entre 45 e 100 erlang. Foram propostos dois cen?rios de simula??o. No primeiro, foi comparado o desempenho do algoritmo RSA First-Fit (FF) com e sem o processo de desfragmenta??o. Considerou-se como ponto de inicio das desfragmenta??es (gatilho), o n?mero de conex?es liberadas da rede. Neste cen?rio obteve-se at? 48% de ganho relativo na minimiza??o da probabilidade de bloqueio. No segundo cen?rio, foram comparados os desempenhos dos seguintes algoritmos RSAs: FF, Maximize Path Spectrum Consecutiveness (MPSC) e Fragmentation Aware (FA). O FF foi avaliado com e sem desfragmenta??o e os demais somente com desfragmenta??o. Empregou-se como gatilho o eventual bloqueio de conex?o. O segundo cen?rio alcan?ou mais de 80% de ganho relativo de probabilidade de bloqueio para carga de tr?fego de 50 erlang. Conclui-se que a nova estrat?gia de desfragmenta??o para EONs oferece ganhos consider?veis na utiliza??o espectral e, consequentemente, redu??o na probabilidade de bloqueio.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede.bibliotecadigital.puc-campinas.edu.br:tede/559 |
| Date | 13 November 2015 |
| Creators | F?vero, Ricardo Vicente |
| Contributors | Demanboro, Antonio Carlos, Fagotto, Eric Alberto de Mello, Nascimento, Luiz Henrique Bonani do |
| Publisher | Pontif?cia Universidade Cat?lica de Campinas, Programa de P?s-Gradua??o em Engenharia El?trica, PUC-Campinas, BR, CEATEC ? Centro de Ci?ncias Exatas, Ambientais e de Tecnologias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_CAMPINAS, instname:Pontifícia Universidade Católica de Campinas, instacron:PUC_CAMP |
| Rights | info:eu-repo/semantics/openAccess |
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