Research & Development in the Telecommunication Industry in Prewar Japan -Automatic Telephone Switchboard-

The telephone system was not sufficiently developed in prewar Japan. This study examines the technological development of automatic telephone switchboard (ATS) to clarify the problems of telephone system in prewar Japan. Ministry of Communication(MOC) introduced automatic telephone system in 1923. From the standpoint of the telephone exchange service, it was a very opportune decision; however, it was technologically premature. Although they had conducted research on the system before WW1, their only choice was the primitive S ~ S system. Further, the dependence on import technology caused different A-type and H-type ATS to coexist. Each local telephone exchange district independently introduced a different type. The MOC had to prepare the specifications and parts for repair for two different systems. These factors hampered the improvement of the telecommunication quality. Standardizing the system by using independent technology became the biggest issue for the MOC in the 1930s. In the 1930s, some joint researches were organized with private enterprises. They tried to develop a gT-type h or gElectronic Tube-type h ATS. However, the T-type ATS was merely an improvement over the outdated S ~ S system with respect to the circuit design. On the other hand, Matsumae aimed at a novel technology, an electronic common control system. However, a suitable electronic tube was not invented. As a result, the telecommunication industry was unable to resolve the coexistence problem in the prewar period. However, the engineers of MOC and ATS suppliers recognized their technological backwardness and shared an awareness of the importance of standardization by independent technology. This was the starting point for the research and development system of the telecommunication industry in gPostwar Japan. h