Case Study of Legacy Communication Migration to IP Networks in Japan

This paper presents a case study on the phased migration of analog communication lines (Ear and Mouth (E&M), Foreign Exchange Station (FXS), and Foreign Exchange Office (FXO)) used in monitoring and control networks operated by Japanese electric power companies to existing IP-based infrastructures. Although several analog lines remain in service, the production of Time Division Multiplexing (TDM) systems such as Plesiochronous Digital