Аннотация:3D finite integration technique (FIT) has been applied to radio propagation calculations over areas up to 400 m2 with computing time of less than 3 hours on a single-processor computer and frequency range of up to 1 GHz. Numerical effort of FIT Maxwell's equations solver in time domain increases at a slower rate with the problem size than other commonly employed methods, thus larger and more complex structures may be analyzed. Measurements have shown a high accuracy of the method for field level prediction: error was in the range 2-3.7 dB with spatial detailing of prediction at wavelength scales, for a complex indoor environment, various transmitter locations and frequencies. The method also demonstrated quite accurate prediction of wideband channel characteristics (power delay profile envelope).