In this paper path loss, delay and angular spread predictions of a 3D ray tracing propagation tool are compared to spatially resolved wideband radio channel measurements performed in a modern office building. Measurements were carried out in the 5 GHz band by using a wideband radio channel sounder, which gives out complex channel impulse responses. Reference rms delay spread and angular spreads at transmitter and receiver were obtained from SAGE processed super-resolution data, and path losses were available from sounder matched filter outputs after appropriate calibrations. Comparisons between propagation predictions and measurements were made in different indoor scenarios including office, lobby and cafeteria environments. For propagation modelling a full 3D ray optical model was used.