Validation of empirical radiowave propagation models for diagnostics of intrasystem EMC and electromagnetic safety of microcellular radio networks

Abstract

At mass coverage of populous urban areas by wireless communications services the microcellular structure of cellular radio networks and tendency of further reduction of its sites are occur. However, the widely used empirical radio wave propagation models (Okumura-Hata, COST231-Hata, COST231-Walfish-Ikegami, Lee, etc.), as a rule, are defined for propagation on distances between mobile and base stations not less than 1 km. Under these conditions at few hundred meters of microcells' dimensions specific for such urban-area networks, the use of these models for intrasystem EMC diagnostics and electromagnetic safety analysis of microcellular radio networks must be extra validated. In this paper the analysis of applicability of empirical models for diagnostics of intrasystem EMC and electromagnetic safety of microcell's structure of urban area cellular networks at cell radius less than 1 km is performed. This analysis is executed with the use of three-dimensional multibeam radio wave propagation model (X3D model) and 3D model of typical urban area covered by 2–6 floors buildings of 6–20 m height. As a criterion of estimation of compliance of models parameters the “Mean difference”, “Mean error”, “Standard deviation” and “Root mean square error” are used. As a result the conclusion concerned the applicability of the known empirical models of UHF radio wave propagation in urban area of the considered type at diagnostics of intrasystem EMC and electromagnetic safety of microcellular radio networks is given. For these models the range of values of base stations antenna height over terrestrial surface is defined, at which the smallest differences between estimations of radio wave attenuation in microcells at usage of empirical models and X3D model at specified conditions, is observed, and also possibilities of its usage at distances less than 1 km and at extended frequency ranges are discussed.