2012-05-042012-05-042011-02-03BALIEIRO, Andson Marreiros. Handoff de espectro em redes baseadas em rádio cognitivo utilizando redes neurais artificiais. Orientador: Carlos Tavares da Costa Júnior. 2011. 106 f. Dissertação (Mestrado em Engenharia Elétrica) - Instituto de Tecnologia, Universidade Federal do Pará, Belém, 2011. Disponível em: http://repositorio.ufpa.br/jspui/handle/2011/2691. Acesso em:.https://repositorio.ufpa.br/handle/2011/2691Nowadays, the radio spectrum is one of the most important natural resources in the world. According to the FCC (Federal Communications Commission) report, the licensed bands are abundant but poorly utilized. The Cognitive Radio (CR) technology aims improving the spectral efficiency through the opportunistic access to the electromagnetic spectrum. It enables that new applications based on wireless communications are supported, without causing interference at the licensed communication and trying to ensure the quality of service to the applications. Thus, the efficient spectrum handoff is a critical requirement to be taken into account for the success of CR systems. This work outlines concepts about the cognitive radio technology. It proposes and evaluates a proactive strategy based on Artificial Neural Networks for spectrum handoff in CR networks. The performance of the proposal regarding the inference level to the primary user, spectrum handoff number triggered by secondary user and spectral utilization is compared with that one obtained by a reactive scheme. Differently from previous works, this study considers measured traces made available by IEEE Dyspan 2008 in order to evaluate our proposal. Numerical results show the superiority of the proposed scheme.porAcesso AbertoRádio cognitivoEstratégia proativaRedes neurais artificiaisHandoff de espectroProactive strategySpectrum handoffCognitive radioArtificial neural networksDissertaçãoCNPQ::ENGENHARIAS::ENGENHARIA ELETRICA::TELECOMUNICACOES