Enhanced outdoor-to-indoor coverage estimation in microcells

Outdoor-to-Indoor propagation loss has been measured in four buildings in urban microcells. The results of the performed experiment as well as those of several other authors, are compared with COST231 model prediction and postulates are presented for improved coverage estimation in buildings with LOS illumination-an empirical equation for loss in the externally illuminated wall at perpendicular penetration is presented, heterogeneous building surface is fictitiously divided into multiple segments, and paths through NLOS surfaces are also considered for reception points located deep inside the building. It is shown that the proposed enhancements improve the COST231 model estimation error by approximately 3 dB.