In Wideband DS-CDMA system, increasing the utilization of Orthogonal Variable Spreading Factor (OVSF) code tree can serve more users. As Dynamic Code Assignment (DCA) does, the allocated codes will be reassigned when a new call can¡¦t be served even if the capacity is enough. However, reassigning occupied codes is expensive. In this thesis, we have proposed a state classification code assignment principle and a proportional reservation policy. In the proposed algorithm, the OVSF code tree is classified into four states. Then, the system will decide whether to reassign codes or not by checking the current state of the tree. In other words, the occupied codes will be reallocated in an appropriate occasion. Besides, we reserve vacant and available codes corresponding to the probability of requests for each supported rate when reassignment occurs. Therefore, the reassignment is reduced. It is also proved on the basis of the property of Markov Chain. Taking advantage of the proposed states classification code assignment and the policy of proportional code reservation, the call blocking rate and the number of reassignment can be reduced.

Made available in DSpace on 2015-10-19T11:50:24Z (GMT). No. of bitstreams: 1 mendes2012.pdf: 1111419 bytes, checksum: 8f829b2b1ca8244f5f9bf9f380c76641 (MD5) Previous issue date: 2012-03-30 / The objective of the present work is to analyse the Fiocruz document classification code in archive (CCDA-Fiocruz) as an instrument of organization and as a representation of archival information in a public health foundation. Presents Fiocruz institutional environment in the context of history, mission, functions and in the setting National Archives National Policy. The analyses CCDA-Fiocruz are developed by an exploratory qualitative approach through the colletion of bibliographic and empirical data. Searches theoretical contributions of Classification Theory principles, document management, and archival classificatory principles classification. Investigates about characteristics of use and training of CCDA-Fiocruz. Finally points out the demands for changes in the CCDA-Fiocruz aiming to improve Its performnce acording to Oswaldo Cruz Foundation users demands / O presente trabalho tem como objetivo analisar o código de classificação de documentos de arquivo da Fiocruz (CCDA-Fiocruz) enquanto instrumento de organização e representação da informação arquivística em uma instituição pública com a missão de produzir, disseminar e compartilhar conhecimentos e tecnologias voltadas para o fortalecimento do Sistema Único de Saúde (SUS). A análise é feita a partir dos princípios teóricos da classificação, da gestão de documentos, e dos princípios arquivísticos de classificação. Investiga o treinamento para aplicação do CCDA-Fiocruz e identifica demandas por alterações entre a comunidade de prática visando a adequação do código às demandas de informação da Fundação Oswaldo Cruz