Browsing by Issue Date, starting with "2001-02"
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- Capacity Analysis in a Multi-service Mobile Broadband SystemPublication . Velez, Fernando J.; Correia, Luis M.Multi-service traffic engineering will be a key aspect in cellular planning for Mobile Broadband Systems, the feasibility of the aggregate traffic model being crucial. An MMPP model is proposed for the modelling of the superimposition of data and video IPP sources. Given the correspondence between applications and their bearer service components, an algorithm for the Bernoulli case of the Bernoulli-Poisson-Pascal model is used to compute the blocking probability. The supported number of users is higher in scenarios with a lower maximum load per user. In a cell with 384 channels of 384 kb/s, it varies from 20 to 26 users/cell in urban scenarios, while with 288 channels/cell, although the number of channels is only 25 % lower, the supported number of users decreases 50 %. High terminal mobility strongly degrades the performance in the roads scenario.
- Teletraffic Engineering in UMTS FDD Mode NetworksPublication . Caramês Garcia, Miguel; Velez, Fernando J.; Correia, Luis M.This paper presents a tool for multi-service traffic engineering in UMTS FDD mode. For each of the WCDMA system scenarios, the power restrictions and a given mixture of symmetric applications are considered. The maximum number of supported codes was obtained by previous simulations, taking into account carrier-to-interference constraints, leading to a given available data rate per cell. Given the spread-factor, with the basic resource being considered of 15 kb/s, the various applications request a certain number of basic code channels. A standard algorithm was used to compute each application’s blocking probability, Pb, as a function of the fraction of active users in cells. In the urban1 scenario (20 % data at 40 kb/s plus 80% voice), using one carrier per cell, UMTS can support 26 speech users plus 7 data users for Pb = 2 %. If two carriers were used, it would support 60 speech users and 14 data users. In the urban2 scenario, as data at 320 kb/s is considered, system performance degrades, which can only be overcome by using three carriers per cells, which seems impracticable in an actual system. The consideration of terminal mobility leads to a slight decrease on the number of supported users.
- A antropologia em Timor Português: os constrangimentos do colonialismoPublication . Schouten, Maria Johanna ChristinaTexto sobre a prática etnográfica e antropológica em Timor-Leste, demonstrando a sua interligação com o poder colonial,