{"title":"Análise da Evolução de Características de Tráfego VoIP","authors":"Carlos Pedroso, K. Fonseca, J. Caldeira","doi":"10.14209/sbrt.2008.42649","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42649","url":null,"abstract":"The growing number of users of Voice over IP (VoIP) systems compared to the traditional telephony systems attracts the attention of large telecommunication carriers. In order to provide VoIP services, system designers and implementors should characterize and model VoIP traffic, which may not be the same of the conventional telephony. This step is essential for the correct sizing of network facilities and also for scientific research. Based on the analysis of data collected over two years in a telecommunication carrier operator, this paper presents a VoIP traffic characterization. The analysis points out changes in traffic characteristics over two consecutive years, discusses their possible causes and trends. Keywords— VoIP, traffic models.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128100257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paulo Carvalho, R. M. Lemos, T. Bento, G. A. Rosa, Priscila Barreto
{"title":"Uma Ferramenta de Simulação de Redes Multimídia Baseada no Modelo Fluido","authors":"Paulo Carvalho, R. M. Lemos, T. Bento, G. A. Rosa, Priscila Barreto","doi":"10.14209/sbrt.2008.42770","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42770","url":null,"abstract":"Resumo— Este trabalho apresenta os conceitos e a implementação de uma ferramenta para a simulação de redes multimídia com base no modelo fluido. O simulador desenvolvido propõe a utilização da modelagem de fl uxos fluidos contínuos em lugar da simulação individual dos paco tes de uma rede. O objetivo da modelagem de fluxos fluidos é p roduzir um número menor de eventos para diminuir custos comput acionais para a simulação de redes complexas. Foram feitos e xp rimentos para comparação o desempenho da ferramenta proposta com outros simuladores existentes e verificou-se que os resultados obtidos são coerentes, o que permite considerar a f erramenta como promissória na simulação de redes complexas. Palavras chave— Simulador de redes ( network simulator), Simulação de eventos discretos ( discrete events simulation ), Simulação Fluida (fluid simulation), Modelo de tráfego fluido (fluid traffic model).","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124869642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Implementação de um Equalizador Adaptativo em FPGA Utilizando o Algoritmo CORDIC","authors":"Bruno Chang, F. J. Aquino, C. Rocha","doi":"10.14209/sbrt.2008.42769","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42769","url":null,"abstract":"—In this paper we present a FPGA implementation of an adaptive equalizer using the trigonometric LMS algorithm. The trigonometric functions needed for filtering and coefficient adaptation are evaluated with CORDIC rotations. This algorithm needs a hypercube definition, in which the minima of the objective function must be contained. This paper proposes the adoption of the multisplit procedure to ease the hypercube definition. Simulations show that, when using this procedure, the algorithm converges without the need for an exaustive search for the hypercube coordinates.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130395399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Wavelets Cíclicas de Shannon e Aplicações em Processamento de Imagem","authors":"G. D. Silva Jr., R. Souza","doi":"10.14209/sbrt.2008.42840","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42840","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123317724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Helvecio Moreira de Almeida, Eduardo Queiroz, A. César
{"title":"Análise de Rede Brasileira de Comunicação Óptica Integrada com Rede de Satélites LEO","authors":"Helvecio Moreira de Almeida, Eduardo Queiroz, A. César","doi":"10.14209/sbrt.2008.42557","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42557","url":null,"abstract":"— The simulation of an optical WDM network integrated with a LEO satellite network covering the Brazilian territory is described in this article. The optical network is composed of 44 nodes and 56 links and the satellite network of 14 terrestrial stations, which 5 have interconnection with the optical network, covering the territory by 3 orbital paths. There are links between satellites and terrestrial stations and inter-satellites. Degradation factors of signal quality are considered in the networks, such as rain, PMD and ASE. The performance of the integrated network is evaluated by means of blocking probability of connection request and throughput.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132675315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Estimação Semicega de Canais com Correlação Usando Filtro de Kalman e Códigos Espaço-Temporais","authors":"M. Loiola, R. Lopes","doi":"10.14209/sbrt.2008.42849","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42849","url":null,"abstract":"In this paper we propose a semiblind algorithm for estimation of flat, time-varying and spatially correlated MIMO channels. The proposed estimator employs a Kalman filter to track the channel in orthogonal space-time block coded systems. After developing a state-space model to spatially correlated MIMO channels we show that the proposed estimator can be simplified by using the orthogonality inherent to space-time block codewords. Simulation results indicate that the proposed algorithm is robust to antennas spatial correlations. Keywords— MIMO channel estimation, Kalman filter, orthogonal space-time block codes, spatial correlation.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114840410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joaquim Celestino Júnior, A. B. D. Souza, A. Vieira, Jessyca Silva, A. L. Barros, G. Campos, Laure W. N. Mendouga
{"title":"GAFUPA: Uma Proposta para Proteção em Redes Ópticas","authors":"Joaquim Celestino Júnior, A. B. D. Souza, A. Vieira, Jessyca Silva, A. L. Barros, G. Campos, Laure W. N. Mendouga","doi":"10.14209/sbrt.2008.42845","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42845","url":null,"abstract":"- One way of offering QoS in optical networks, inside a policy based environment, is to use route protection policies. For each established contract, the network administrator defines the type of protection for each class of service ( Gold, Silver, Bronze ). However, the pre-planned backup routes can be inadequate to guarantee the SLA (Service Level Agreement). In case of failure, there is no way to guarantee that the selected protection route will deal with client requirements. In this paper, we propose a method for choosing best backup routes, using Genetic Algorithms, Fuzzy Logic and PBM, called GAFUPA.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114984721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nakagami High-Order Statistics from a Different Perspective","authors":"J. S. Santos Filho, M. Yacoub","doi":"10.14209/sbrt.2008.42723","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42723","url":null,"abstract":"— The Nakagami fading signal has been traditionally modeled as a sum of multipath Rayleigh components. Recently, an alternative Nakagami model, particularly attractive for simulation, has been proposed in the literature: a single Rayleigh signal propagating over a nonlinear path. Here, we derive many important high-order statistics associated to this model (second-order distribution, autocorrelation, joint distribution of the envelope and its time derivative, average outage rate, and average outage duration) and compare these statistics to those of the traditional model, widely assigned to Nakagami fading. We show that the two models lead to very different high-order statistics, except for the autocorrelations, which are indeed similar.","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128429052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Batalheiro, Mariane R. Petraglia, Diego B. Haddad
{"title":"Separação Cega de Fontes para Misturas Convolutivas Usando um Banco de Filtros Não-Uniforme","authors":"P. Batalheiro, Mariane R. Petraglia, Diego B. Haddad","doi":"10.14209/sbrt.2008.42397","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42397","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125409819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Antena em F-Invertido Planar com Fenda em Formato de L-Deitado Otimizada por Algoritmo Genético","authors":"M. Kawakatsu, V. Dmitriev, D. Melo","doi":"10.14209/sbrt.2008.42859","DOIUrl":"https://doi.org/10.14209/sbrt.2008.42859","url":null,"abstract":"","PeriodicalId":340055,"journal":{"name":"Anais do XXVI Simpósio Brasileiro de Telecomunicações","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127134162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}