First-generation, line-of-sight (LOS) fixed broadband wireless access techniques have been around for several years. However, services based on this technology have been limited in scope to service areas where transceivers can communicate with their base stations, unimpeded by trees, buildings and other obstructions. This limitation has serious consequences in that the system can deliver only 50% to 70% coverage within a given cell radius, thus affecting earned revenue. Next generation broadband fixed wireless access techniques are aimed at achieving a coverage area greater than 90%. To achieve this target, these techniques must be based on a point-to-multipoint (PMP) cellular architecture with low base station antennas, thus possessing the ability to operate in true non-line-of-sight (NLOS) conditions. A possible limiting factor for these systems is link degradation due to interference. This thesis presents a new model to estimate the levels of co-channel interference for such systems operating within the 3.5 GHz multichannel multipoint distribution service (MMDS) band. The model is site-specific in that it uses statistical building/roof height distribution parameters obtained from practically modeling several metropolitan cities in the U.S. using geographic information system (GIS) tools. This helps to obtain a realistic estimate and helps analyze the tradeoff between cell radius and modulation complexity. Together, these allow the system designer to decide on an optimal location for placement of customer premises equipment (CPE) within a given cell area. / Master of Science

Yes / Unmanned Aerial Vehicles (UAVs) are considered, nowadays, as a futuristic and robust paradigm for 5G wireless networks, in terms of providing Internet connectivity services onto infrastructure cellular networks. In this paper, the interference regime caused by multiple downlink aerial wireless transmission beams has been highlighted. This has been introduced by estimating the UAVs coverage area that is analytically derived in a tractable closed-form expression. The rationale of the analysed coverage approach relies on observing and adapting the joint aerial distance between the aerial base stations. This can minimize the intra-overlapped coverage and ultimately maximize the overall coverage performance for a better quality of service demands. The novelty of our approach brings useful design insights for UAVs system-level performance that technically helps in aerial coverage computations without the need of performing an aerial deployment setup. To the end, the performance effectiveness of our methodology has been tested under an urban propagation environment conditions, in which the original probabilistic channel model approximation has been taken into account. Moreover, this paper identifies the interference issue of such an aerial network as a shrinkage or distortion phenomenon.

Fires, with their sudden appearance and destructive character, cause property losses beside much more death and injury especially in cities. Providing fire safety is a multi-faceted context that is related with staff, vehicle, equipment, function, organization, technology, education and consciousness. These are related, indirectly, with spatial organization that is the other side of the issue: they affect space or they are affected from space. In research context, the fire stations are evaluated as a unit of emergency and land use element of urban space. By associating the concepts related to emergency management and to urban scale, the space-time relation is examined in urban areas. This research bases on the spatial deficiencies of fire stations in urban areas which are reasons of the fire losses. Level of laws and regulations in Turkey for spatial requirements are examined. Site selection and design criteria of fire stations are evaluated with available information about implications in Ankara case study. As a result of the interviews that have been made to top executive of fire station, it is found that process of site selection and design of fire stations is going on with subjective experiences in urban space. In conclusion of the research, it is displayed that the decisions about the site selection and design of the fire stations are related to not only population criterion, but also many issues in macro-meso-micro scales. It is considered that the set of multi-criteria that are reached in this regard will provide contribution in legal organization and developing the standards.