Diffusion of 3G cellular technology varies widely across countries and regions. Past studies have shown that lower levels of diffusion of previous technologies and higher levels of income are significant factors in accelerating the take up of 1st and 2nd generation of mobile telephony. In addition, spectrum management policy plays a significant role in shaping 3G diffusion. Regulatory policies regarding spectrum management include mandating band and technology and decisions to hold spectrum auctions. An econometric analysis over a multi-country panel dataset shows that these spectrum management policies do have significant influence on the take-up of 3G. Findings suggest that the presence of multiple technologies for the previous generation is associated with rollout delay. The estimations indicate that countries that mandated a specific frequency band for 3G saw faster roll out, but in the long run those countries experienced a slower growth rate. Also estimations find that 3G diffusion is not significantly affected by the choice of auctions vs. alternative license award processes. Insights gained from this study of the 2G to 3G transition can provide guidance to regulators now contemplating the transition to newer generations.