Propagation loss prediction: A comparative study with application to the mobile radio channel

A number of statistical models are available in the literature for the prediction and the calculation of transmission loss, but the main differences between them as well as their usefulness in a particular situation is not easy to assess. In this article, the experimental results of Okumura, as seen through the empirical expression derived by Hata, are compared with the models of Egli, Edwards and Durkin, Blomquist and Ladell, and Allsebrook and Parsons. Comparisons are made for the case of an open region and flat terrain, first without and then with inclusion of a statistical estimation of diffraction losses due to terrain in the models of Blomquist and Ladell, Edwards and Durkin, and Allsebrook and Parsons. The study is also extended to cover the case of irregular terrain and urban areas. The method proposed by Hata, based on Okumura´s results, and Allsebrook and Parsons´ model, which provides an easy way to take into account the influence of buildings are the most complete and it is suggested to use them with the inclusion, as required, of an estimation of diffraction losses due to terrain. As a conclusion, experimental propagation loss measurements taken in the Ottawa region at 910 MHz are presented and are found to fall very nicely in the range predicted by the above-mentioned methods.