Browsing by Author "Marcos, Rui P."
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- Aspects of Cellular Planning for Emergency and Safety Services in Mobile WiMax NetworksPublication . Velez, Fernando J.; Carvalho, Vitor; Santos, Dany; Marcos, Rui P.; Costa, Rui; Sebastião, Pedro; Rodrigues, AntónioThis work addresses cellular planning aspects for a WiMax (worldwide interoperability for microwave access) point-to-multipoint wireless network to be developed in the region of Beira Interior. It is concentrated in more detail in the district of Covilha, and, particularly, in the urban area of the city, in order to guarantee communications from the Health Science Faculty of University of Beira Interior (HSF/UBI)/ Hospital Pero da Covilha to all central urban area of the city. By having aspects related with the carrier-to-noise and carrier-to-interference ratios into account, one concluded that it is necessary to consider a cellular structure with sectorisation, and cell coverage distances around 3 km. Because this zone is very hilly, the optimization of the choice of the location for base stations is essential; the potentialities of the GIS (geographic information systems) tools were explored to optimise the existence of line of sight coverage in coverage. Future research directions regarding architectures for interoperability and mobile IP, security, and the impact of multimedia applications are also addressed.
- Cellular Planning of an IEEE 802.16 Wireless Metropolitan Area NetworkPublication . Velez, Fernando José; Carvalho, Vitor; Santos, Dany; Marcos, Rui P.; Costa, Rui; Sebastião, Pedro; Tomé, Ricardo; Rodrigues, AntónioThis work intends to develop a WiMax (Worldwide Interoperability for Microwave Access) point-to-multipoint wireless network that includes all the district of Covilhã, and particularly the urban area of the city in detail, with the objective to guarantee a point-to-multipoint connection from the Health Science Faculty of the University of Beira Interior (HSF/UBI) / Hospital Pêro da Covilhã to all urban area of the centre of the city. The cellular planning of this WiMax mobile network was done having in account aspects related with the carrier-to-noise ratio and carrier-to-interference ratio, concluding that is necessary to consider a cellular structure with coverage distances of 3 km and sectorisation is needed to create a high capacity wireless network in the urban area of Covilhã. Because this zone is very hilly, the choice of the location for base stations is essential; one used the potentialities of the GIS (Geographic Information Systems) tools to optimize the line of sight coverage and, simultaneously, reduce the propagation exponent. A new mobile IP architecture for Wi-Fi/WiMax interoperability is being conceived, developed and implemented based in Media Independent Handover.
- Planning of an IEEE 802.16e Network for Emergency and Safety ServicesPublication . Velez, Fernando José; Caravalho, Vitor; Santos, Dany; Marcos, Rui P.; Costa, Rui; Sebastião, Pedro; Rodrigues, AntónioAn overlaid Wimax cellular structure is proposed for emergency and safety services, with micro-cells covering urban hotspots over a macro-cellular structure. In the region of Beira Interior the process of cellular planning has to account for carrier-to-noise-interference ratio. Sectorisation is used in order to reduce reuse patterns and increase system capacity, while cell overlay is proposed to overcome coverage problems in large towns and cities. Geographic Information Systems tools are considered for Line-of-Sight discovery, and ~75% of LoS coverage is guaranteed in the city of Covilhã. The point-to-point component is also being incorporated in the planning tool. By comparing the 3.5GHz and the 5.8GHz bands one concludes that it is possible to use lower values of the antenna gains in the first case.