Indoor Coverage Prediction and Optimization for UMTS Macro Cells

As most of the time mobile devices are used inside buildings, it is of particular interest for mobile network operators to cover indoor areas with their services. In order to reach satisfying indoor coverage without having too much extra costs for e.g. additional cell sites, optimum network planning has to be performed with the aid of coverage prediction by using propagation models. In this work we compare eight empirical and one deterministic model (ray tracing) by their usability and general validity for predicting the indoor coverage in UMTS macro cells. Furthermore, the accuracy of the models is shown via a comparison to measurements inside an office building in a live UMTS network in the city center of Vienna, Austria. It was found that despite the high effort for the usage, the deterministic model could not reach higher accuracy than the empirical models. Additionally, in this work we investigate improvements of the indoor coverage in UMTS macro cells by optimizing various base station antenna parameters.