Recently while new technologies have been rapidly changing the shape of the telecommunications industry, the growth of market demand has slowed. This case aims to discuss how to invest into new technology properly in a highly competitive industry considering the environmental factors such as technology policy and customers, competitors, and the competitiveness of firm. This case first describes SK Telecom's investment experience of CDMA network in Korea and then move on to the issue of whether to invest on wireless broadband service (WiBro). This case will be effectively used for discussing not only the difficulties of decision-making on choosing a certain technology which requires huge investment, but also complicated strategic decision making process in commercializing new mobile service based on new technology.