Managing the Transition from PSTN to IP Networks

This study tries to evaluate problems surrounding the transition from public switched telephone networks (PSTNs) to IP networks that affect both the current users of PSTN and competitive carriers. For this purpose, this study surveys discussions on the transition based on four perspectives: (1) consumer-oriented, (2) forward-looking, (3) competitive neutrality and (4) proportionality of regulation. It is organised in the following manner. First, it clarifies the background of the transition, especially the impact of the diffusion of broadband Internet and mobile technologies. Second, it surveys a series of the Nippon Telegraph and Telephone Corporation’s (NTT) migration proposals published since 2010. Third, the Ministry of Internal Affairs and Communications’ (MIC) investigation responding to NTT’s proposals is summarised. Fourth, problems regarding the transition are evaluated by contrasting NTT’s proposals and MIC’s reports. Finally, the study infers five important remarks based on the above analysis. It must be acknowledged that the evaluations and remarks are premature because discussions on the transition are still in progress and the details of the transition have not yet been officially published.