CHARACTERISTICS PREDICTION IN URBAN AND SUBURBAN ENVIRONMENTS

In this paper, the character of the propagation in the microcellular u rban and suburban environments in the 902-928-MHz frequency band in li ne-of-sight (LOS) conditions is investigated both theoretically and ex perimentally for the purpose of wireless radio local loop (WRLL) predi ction, The path-loss characteristics and the range of a break point, a t which the polynomial character of field intensity decay along the st reet level is changed, are analyzed for various parameters of street w idths, for different average building heights, and for the actual elec trical impedance properties of building walls, A multislit waveguide w ith randomly distributed gaps between the sides of buildings is consid ered as a model of straight streets, Results of experiments for VHF/UH F wave propagation along the straight streets in urban environment in the conditions of direct visibility between receiver and transmitter a re compared with theoretical analysis of field intensity decay, path-l oss distribution, and dependence of the break point on street topograp hy in LOS conditions.