etween voice services and data services. The United States should have made more efforts on developing mobile data services. If subscribers are only led to use more voice services, there might be less room for data services as we have seen in the United States. References 1. RNCOS, 3G market outlook, 2007 (2007-2010). http://www.rncos.com/Report/ IM506.htm 2. Kuo, Y.F. and C.W. Yu, 3G telecommunication operators' challenges and roles: A per- spective of mobile commerce value chain. Technovation, 26(12), 1347-1356, 2006. 3. Tilson, D. and K. Lyytinen, The 3G transition: Changes in the US wireless industry. Telecommunications Policy, 30, 569-586, 2006. Comparative Study on the Mobile Data Service Development 4. FCC, Annual report and analysis of competitive market conditions with respect to commercial mobile services (12th report), February 2008, Federal Communications Commission: Washington, DC. 5. China Mobile Limited Annual Report 2001-2007. 6. China Unicom Limited Annual Report 2001-2007. 7. Choi, B.-S., The competition of (value-added services) in Mobile Telecommunication Industry (Economy Focus report no. 24), 2005. Samsung Economy Research Institute. South Korea. 8. iResearch, Mobile VAS Market Development in China 2007-2008. 2008, iResearch Consulting Group. China. 9. CNNIC, WAP Development in China. May 2007, China Internet Network Information Center. China. 10. MII, The Development Report of the Communications Industry 2007 (in Chinese). 2008, Ministry of Information Industry of People's Republic of China: Beijing. 11. NIDA, Survey for wireless internet usage of wireless service type. September 2007. 12. Ko, J.-m., Contents Business in Mobile Era 2003, Samsung Economy Research Institute. 13. Zhang, J. and X.J. Liang, 3G in China: Environment and Prospect, in Portland International Conference on Management of Engineering and Technology (PICMET). 2007: Portland, OR. 14. Xu, Y., Mobile data communications in China. Communications of the ACM, 46(12), 81-85, 2003. 15. Preez, G.T.d. and C.W.I. Pistorius, Analyz