This paper presents a study on cost/benefit analysis regarding WiMAX in Europe. The first step is the engineering process (the cellular planning to be more accurately) in which the number of base stations needed to provide coverage and to ensure the quality of service in a given environment (rural, suburban or urban) is calculated through mathematical models. Following the engineering process, and with the appropriate financial variables (ARPU - Average Revenue Per User, desired return, OPEX, etc.) defined, the NPV (Net Present Value) is computed for a maximum of seven years and for four scenarios, thus providing the cost/benefit result of the study. To conclude, the economic feasibility of the telecommunication systems is compared for all the different spectrum possibilities.