Implementation of a propagation model for indoor environments for GSM

This paper describes the implementation of an indoor propagation model based on a ray launching method. Rays are launched according to a cubic spatial structure, and their subdivision is done in a way that the spatial resolution is kept to a maximum value, specified by the user. Special care is taken for each ray´s subdivision, so that aspects of reflection and obstruction by objects are taken into account. In order to validate the approximations performed and the model obtained, a comparison with measurements is made. These measurements were made in an underground car park where a GSM900 operator had installed one repeater and two indoor antennas. Results show a standard deviation error and a mean error of around 4 dB. Additionally, one concludes that an increase in resolution does not improve errors after a certain value