Measurements of the GSM signal strength by mobile phone

This paper presents results that are obtained by measuring the power of received GSM signal. The measurements are performed indoor, within hallways of the typical university building, containing offices and small labs. The identical measurement grid was used in different levels of the building and different heights above floor, in order to characterize the change of the signal strength with height. Although the received signal increases for higher levels, its strength is not uniformly increasing above floor. The measurements are performed for horizontally and vertically positioned mobile terminal, in order to distinguish between the vertical and horizontal components of the incoming signal. Additional measurements are used to evaluate impact of the body shadowing and antenna radiation pattern of the used mobile. It was found that random orientation of the mobile terminal and random position of the operator increase an average power level that is measured in the hallway for horizontal polarization. Comparison of measured results with COST231/Walfish-Ikegami propagation model shows mismatch of several dB.