Investigation of indoor radio channels from 2.4 GHz to 24 GHz

This paper provides the results of indoor radio propagation measurements at current and potential wireless LAN frequency bands, 2.4, 5.2 10, 17 and 24 GHz in the Moore laboratory at Caltech. Three scenarios (floor to floor in the hall, a line-of-sight path down the hall, and a non line-of-sight path from office to hall) were considered. The loss in going from floor to floor increased with frequency from 15 dB at 2.4 GHz to 50 dB at 24 GHz. In addition, for the line-of- sight path, we found a path loss exponent n less than 2, indicating a guiding effect of the hall. The non line-of-sight path shows a loss exponent n that is larger than 2, indicating scattering. We found that the rms delay spread decreased with frequency inside a room, but increased with frequency along a non-line-of-sight path.