When joining Siemens in 2001, I also extended my research interest towards radio net work planning methodologies. This area of research brought together my personal interest in mobile communications and in the design of efficient algorithms and data structures. Between 2001 and 2003, I participated in the EU project Momentum, which was target ing the performance evaluation and optimization of UMTS radio networks. In this project my main focus was on Monte Carlo snapshot techniques, shortly after I broadened my research scope towards network optimization techniques. Both constitute the basis of this thesis. Later I got the chance to bring in the ideas and methods of my thesis into a Siemens internal planning and optimization tool, the development of which I guided over the last two years. First of all I would like to thank Professor Dr. Carmelita Görg for supervising this thesis, for her guidance, and her encouragement. I very much appreciate that she although I, as an external Ph. D. student, was not part of her department at the University of Bremen was always very open for discussions and provided me with a large amount of useful suggestions over the past years. I without a doubt greatly benefited from this, both in my scientific work and personally. I am also deeply grateful for the comments and suggestions by Professor Dr. Thomas Kürner, who is also the second examiner of this thesis.