A propagation model for the prediction of indoor radio channel characteristics at millimetre-wave frequencies, based on geometrical optics is described. This model has been shown to agree well with wide-band measurements carried out at Eindhoven University of Technology . Simulation results for 4th and 6th order reflection are compared with corresponding measured data obtained in small and medium size rooms. The influence of objects located inside the room superstructure, on the indoor radio channel characteristics, is analysed. The agreement between measured and simulated results, confirms the validity of the proposed simulation method.