Improvement of indoor to outdoor propagation model at GSM900/GSM 1800/CDMA-2100

Mobile communication has becoming more popular with the help of rapidly growing new wireless technologies. Due to the increasing the number of the speech and data users, the wireless network operators tends to increase the number of their indoor base stations and femtocells instead of macro base stations. On the other hand, in the city centers, increasing the number of indoor base stations leads to increase indoor to outdoor interference as well as EMG problems which must be taken into consideration when designing wireless network, especially in hotspot areas. In literature, there are studies about indoor propagation, outdoor to indoor propagation loss calculations, but there are a few studies considering about indoor to outdoor propagation.In this study, test microcell with one indoor omni antenna was installed in the first floor of a building, and indoor to outdoor propagation loss was measured along the outer periphery of a building at GSM900, GSM1800 and CDMA 2100, respectively. A new indoor to outdoor empirical penetration formula has been derived from outdoor to indoor propagation model.