Submitted by Hellen Luz (hellencrisluz@gmail.com) on 2017-10-02T17:05:11Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_TechniquesDownstreamRate.pdf: 1238526 bytes, checksum: 6b7ca82987aca1343ace4357e45edf39 (MD5) / Rejected by Irvana Coutinho (irvana@ufpa.br), reason: Devolvendo... on 2017-10-03T14:13:39Z (GMT) / Submitted by Hellen Luz (hellencrisluz@gmail.com) on 2017-10-03T14:15:04Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_TechniquesDownstreamRate.pdf: 1238526 bytes, checksum: 6b7ca82987aca1343ace4357e45edf39 (MD5) / Rejected by Edisangela Bastos (edisangela@ufpa.br), reason: on 2017-10-10T17:03:03Z (GMT) / Submitted by Hellen Luz (hellencrisluz@gmail.com) on 2017-10-16T14:12:59Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_TechniquesDownstreamRate.pdf: 1238526 bytes, checksum: 6b7ca82987aca1343ace4357e45edf39 (MD5) / Approved for entry into archive by Edisangela Bastos (edisangela@ufpa.br) on 2017-11-13T15:44:03Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_TechniquesDownstreamRate.pdf: 1238526 bytes, checksum: 6b7ca82987aca1343ace4357e45edf39 (MD5) / Made available in DSpace on 2017-11-13T15:44:04Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_TechniquesDownstreamRate.pdf: 1238526 bytes, checksum: 6b7ca82987aca1343ace4357e45edf39 (MD5) Previous issue date: 2015-03-10 / FADESP - Fundação de Amparo e Desenvolvimento da Pesquisa / Conforme a tecnologia DSL (Digital Subscriber Line) atinge o seu limite de largura de banda física e o modelo Fiber-to-the-Home (FTTH) se torna um substituto em potencial, novas técnicas são desenvolvidas para lidar com as exigências da indústria de acesso à Internet. Nesse contexto, o padrão recém acordado do International Telecommunication Union (ITU), o G.9700 (G.fast) traz para a rede de cobre uma renovação de sua vida útil, com o uso de técnicas como o Vectoring. Esta, apesar de ser uma ferramenta poderosa para que DSL se torne uma tecnologia competitiva para a fibra óptica, ainda deve lidar com o problema de que os assinantes podem obter taxas diferentes em seus CPEs (Customer Premises Equipments), causado principalmente por aspectos físicos do canal. Com isso em mente, este trabalho propõe métodos para balancear as taxas entregues às linhas dos usuários no downstream. Isso é feito por meio de diferentes ordenações das colunas da matriz do canal, em cenários que utilizam o Precoder Tomlinson-Harashima (THP) até 200 MHz. Simulações foram feitas usando cada método de balanceamento de taxas em seis cabos medidos, a fim de demonstrar os progressos de cada método. Estas simulações são estendidas para o ainda não validado cenário Near-Far, que tenta representar as situações em que algumas linhas têm comprimento maior do que outras, e serve apenas como referência. Os métodos propostos produziram resultados promissores de balanceamento, com reduções de até 95,79% do desvio padrão para o cabo Swisscom I51, quando se comparando resultados de um método de algoritmo genético com aqueles do THP. / As the DSL (Digital Subscriber Line) technology reaches its physical bandwidth limit and the Fiber-to-the-Home (FTTH) model becomes a potential substitute, new techniques and standards are developed to cope with the requirements from the Internet access industry. In this context, the newly agreed G.9700 (G.fast) standard, from the International Telecommunication Union (ITU), brings to the copper plant a renewal of its lifespan with the use of techniques such as Vectoring. Although Vectoring is a powerful tool for DSL to become a competitive technology for optical fiber, it must deal with the problem that subscribers still may get differing rates at their CPEs (Customer Premises Equipment), caused mainly by physical aspects of the channel. With that in mind, this work proposes methods of balancing the achievable rates delivered to user lines at Downstream. This is done by using different column sortings of the channel matrix, in scenarios that utilize the Tomlinson-Harashima Precoder (THP) up to 200 MHz. Simulations using each rate balancing method on six measured cables are made in order to show each method’s progress. These simulations are extended to the Near-Far Scenario, which tries to resemble the situations where some lines have greater length than others, that is, differing distances between the CPE and the DSLAM (Digital Subscriber Line Access Multiplexer). The proposed methods yielded promising balancing result, with reductions of up to 95.79% of the standard deviation for the Swisscom I51 cable, when comparing results of a genetic algorithm method with those of the THP.