Early GSM networks are getting older than a decade. First generation mobile systems cannot fully satisfy actual user expectations. New services like WAP, mobile internet, video streaming, etc. require higher capacity and more efficient networks. In this paper we present the results of a nationwide GSM network upgrade for EDGE (Enhanced Data rates for GSM Evolution). A Hungarian operator decided to improve its mobile network performance by replacing old transceivers to EDGE capable equipments in order to meet the subscriber requirements better. More than 800 base stations were involved in the project that started in the capital and continued in the countryside. Technical details and the performance of the EDGE upgraded network are discussed.