Comparison and verification of urban propagation models

The classical empirical field-strength prediction models like the model of Hata (1980) are used widely in mobile radio. However there is no experience in the building height distribution and land usage factor for most European cities. The Technical University of Budapest started a study to characterise the mobile propagation path in Budapest. The paper introduces the first results, showing the building height distribution and the measured results for the chosen test area and a comparison of the mostly used propagation models. The article compares the model of Hata, Ibrahim and Parsons (1983) and the COST 231 model (Low, 1992). The authors introduce the diffraction of plane waves by an array of absorbing half-screens (Xia and Bertoni, 1992) and the influences of different building heights are investigated in detail. The calculations show that building height differences of 2-5 m cause 1-2 dB difference in field strength compared with equal height screens. Measurements in the 900 MHz band were performed in the smooth part of Budapest and are compared with the models above.