Microwave path-loss characteristics in urban LOS and NLOS environments

To model the path-loss characteristics of microwave propagation in urban environments, we performed measurements at frequencies of 3.35, 8.45, and 15.75 GHz in metropolitan Tokyo. The actual breakpoint (BP) distance was shorter than the theoretical one because of the influence of vehicles, pedestrians, and other objects on the road. This effect can be characterized in terms-of the effective road height. We also found that the BP disappeared when the mobile-antenna height approached the effective road height. In non-line-of-sight (NLOS) areas, the corner losses and attenuation coefficients were greater than those of the UHF band. The attenuation coefficients increased with LOS distance between the base station and the corner into NLOS area.