Path Loss Model from 922 MHz to 28 GHz in Office Environment

To build a stable wireless communication system in an indoor environment, it is necessary to perform highly accurate simulations of radio wave propagation characteristics. The ITU-R Recommendation P series, especially ITU-R P.1238, lists estimation models for propagation loss in indoor environments under various conditions. However, there are a few cases in which propagation loss has been measured at various frequencies in the same building and under the same conditions. In these cases, necessary parameters may not be described, meaning that simulation cannot be easily performed. In this paper, we measure the radio wave propagation characteristics on the same floor and across floors for the 922 MHz to 28 GHz frequency band, which is often used in office spaces. We then apply a path loss model to each frequency and calculate the coefficient of office environment (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$N$</tex>) and inter-floor attenuation <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(L_{f}(n))$</tex>.