In this thesis a comparison between a predictive site survey and two passive site surveys is performed, to see if only a predictive survey is enough to estimate a well-functioning wireless network. Some fundamental facts and techniques that are involved in wireless networks are presented and also the method of how the site surveys were planned and performed. The outcome is compiled in diagrams. The difference between a predictive and a passive site survey is analyzed, and shows if the prediction is trustworthy or needs to be verified.