KPN, TNO and TU/e started their cooperation years ago, in the area of radio channel measurement and modeling. Specifically in urban areas mobile networks are more difficult to plan because of shadowing, over-rooftop-diffraction, reflections on rough building surfaces and in-building penetration of the radio waves. The cooperation resulted in a novel measurement system using a three-dimensional antenna array with 31 small dipoles. Combined with an advanced signal processing scheme the antenna is capable of making high-resolution measurements of radio waves coming from literally all directions. The antenna has provided a detailed analysis of coverage problems of the UMTS network close the Arena (Amsterdam) and Rotterdam Central Station.