Indoor radio path loss comparison between the 1.7 GHz and 37 GHz bands

Third generation indoor wireless systems providing broadband communications will make use of higher frequency millimeter wave bands. In the planning of these networks it would be useful to estimate coverage based on the many studies of indoor propagation at L-band coupled with knowledge of the building structure. This paper presents results of a comparison between path loss at 1.75 GHz and 37.2 GHz from 100 locations throughout four buildings. The authors analyze the large scale path loss in line of sight and obstructed paths, compare this with building layout and construction and then estimate transmission loss through walls. Results indicate that at 1.75 GHz the non line of sight signals decayed with distance to the exponent N=2.7 while for 37.2 GHz on average N=3.5. The propagation loss through walls at 37.2 GHz showed a much higher dependence on construction type than at 1.7 GHz.