Evaluation on outdoor to indoor propagation characteristics for 0.8/2.2/4.7 GHz bands

Recently, the next generation (5G) mobile communication system has been actively investigated all over the world, in order to satisfy the strong demand for the faster and larger data communication. not only UHF band but also SHF/EHF bands have been much attracted much attention. Therefore, frequency characteristic of radio propagation loss must be studied. We previously investigated the outdoor to indoor (O2I) propagation characteristics in the 2.2 GHz band, and have proposed a modified path loss model instead of 3 GPP model. In this paper, in order to develop more advanced model, we show measurement results of 0.8, 2.2 and 4.7 GHz bands. Moreover, we consider an indoor penetration loss factor which is calculated by the least square approximation.