Type T-12s-Tr transistorized short-haul carrier system

The toll network in Japan has been expanded and improved through long-term projects, utilizing various types of new equipments. The main long-distance network has been built up of coaxial cable and microwave systems, which are used to connect offices larger than primary outlets. To connect offices smaller than primary outlets, a more economical system had to be considered, and with recent acceleration in conversion to the toll dialing system, it became imperative to increase rapidly the number of toll circuits between large cities and their surrounding satellites, as well as between the principal large cities.