Measurements of the Outdoor-To-Indoor Attenuation of Mobile Phone Signal

This work reports a series of measurements of the attenuation of UMTS and GSM mobile phone signal by buildings structures in the city of Rome. The context of the research is the concern about the exposure of the population resident in the buildings to electromagnetic fields emitted by the radio base stations of the mobile phone radio access network. The aim of the research is to analyze a conservative method of measurement for the outdoor-to-indoor attenuation. The measurement method takes intrinsically into account the presence of apertures like doors and windows on the wall of the buildings, the materials around the apertures and within the buildings. The measurements of attenuation are carried out by instrumentations able to demodulate the radio base station antennas RF carriers. Four different topologies of urban buildings are considered: reinforced concrete buildings, buildings between late 1800 and early 1900th century, historical buildings in the inner Rome and steel and glass buildings structures. Measurements of electromagnetic attenuation are in the range 6 - 27 dB. A numerical analysis of the attenuation of apertures like door/windows has been computed and the results discussed. The results show that the attenuation depends on the material of the walls and by the objects indoor located.