The period following NTTPC's initial foundational phase witnessed a series of breakthroughs that dramatically reshaped Japan's telecommunications landscape, transforming the corporation into a significant market player. The unprecedented economic growth Japan experienced from the 1960s through the 1980s, often referred to as the "Japanese economic miracle," served as a powerful catalyst for the expansion and modernization of NTTPC's services. This era of rapid industrialization saw Japan emerge as a global leader in manufacturing, finance, and technology, generating immense demand for sophisticated communication infrastructure. As industries grew and urban populations swelled, the demand for more advanced and reliable communication solutions surged, providing NTTPC with a clear mandate for sustained investment and innovation to support the nation's burgeoning economy. This symbiotic relationship between national economic growth and telecommunications development became a hallmark of NTTPC's strategy.
Key to this era of growth was the relentless pursuit of technological advancement, often driven by a strategic national vision. NTTPC's research laboratories, notably the Musashino Electrical Communication Laboratory (ECL) and later the Yokosuka Electrical Communication Laboratory, played a pivotal role in this. These state-of-the-art facilities were instrumental in developing and deploying cutting-edge technologies that moved Japan's telecommunications network beyond basic telephony. One of the most significant innovations was the widespread adoption of crossbar switches, such as the domestically developed C460 and C400 systems, which automated and streamlined call routing, substantially increasing network capacity and reliability compared to older step-by-step electromechanical systems. By the late 1960s, crossbar exchanges were being rapidly deployed across the country, significantly reducing the manual intervention previously required for connections. This was followed by the introduction of electronic switching systems (ESS), notably the D10 ESS, which brought computer control, higher speed, and greater flexibility to the network. The D10, first put into commercial service in 1971, was a landmark achievement, enabling new services and features like push-button dialing, call waiting, and call forwarding, thus modernizing the user experience and improving network efficiency. These advancements paralleled global trends in telecommunications but often saw NTTPC taking a leading role in their large-scale, high-quality implementation.
Market expansion during this period was characterized by both deepening penetration of existing services and the introduction of entirely new communication modalities. While fixed-line telephone service continued its robust growth, NTTPC embarked on ambitious programs to address the significant waiting lists for telephone lines that characterized the earlier part of the era. By the mid-1970s, household telephone penetration in major urban centers neared universality, with national penetration rising dramatically. For instance, the number of subscribers soared from approximately 5 million in the early 1960s to over 30 million by the early 1980s. Beyond traditional voice communication, the early 1970s saw the development and launch of Japan's first public data network, DDX (Dendenkosha Digital Data Exchange). This strategic move towards accommodating the nascent demands of computer communication was prescient, anticipating the future digital transformation of commerce and industry. The DDX network initially offered circuit-switched (DDX-C) and later packet-switched (DDX-P) services, enabling businesses, financial institutions, and government agencies to transmit data efficiently and reliably, laying essential groundwork for future internet services.
Competitive positioning for NTTPC was unique during this phase due to its status as a government-owned monopoly. While it did not face direct market competition for core services, its competitive imperative was internal – to efficiently meet national demand, drive technological progress, and maintain exceptionally high service standards. Industry reports from the time, including those from international bodies like the CCITT (now ITU-T), indicate that NTTPC's extensive R&D capabilities positioned it at the forefront of global telecommunications innovation, particularly in areas like fiber optics, digital transmission, and early mobile communications research. For example, research into optical fiber communication at Musashino ECL led to early commercial deployments, such as the world's first large-capacity optical fiber transmission system for commercial use in 1981, linking central Tokyo. These internal drivers fostered a culture of continuous improvement, pushing the boundaries of what was technologically possible and setting high benchmarks for service quality, network resilience, and cost-efficiency in a controlled environment. The corporation's massive capital expenditure, often exceeding several hundred billion yen annually, was strategically directed towards long-term network modernization and expansion, a scale of investment that would have been challenging for a fragmented private market.
The business impact of these key innovations was profound. The automation of exchanges through crossbar technology and the subsequent transition to electronic switching dramatically reduced operational costs per call, minimized personnel requirements for manual switching, and simultaneously improved call quality and reduced connection times. These efficiencies directly contributed to the productivity gains seen across the Japanese economy. The development of digital transmission technologies, initially over microwave links and later through early optical fiber deployments, laid the groundwork for high-speed data communication, which would become critical for the information age. These advancements not only supported Japan's economic growth but also enhanced the daily lives of citizens, making communication faster, easier, and more reliable. The introduction of push-button phones, widespread facsimile (FAX) services – which gained significant popularity in Japan due to its written language – and even public videophone trials further diversified NTTPC's offerings, demonstrating its commitment to leveraging technology for broader societal benefit.
Leadership evolution and organizational scaling were continuous processes within NTTPC. Managing a vast, rapidly expanding national infrastructure required sophisticated organizational structures and skilled leadership. The corporation grew into one of the largest employers in Japan, with an estimated workforce exceeding 300,000 employees by the early 1980s, dedicated to technical operations, network maintenance, customer service, and R&D. Extensive training programs were established to ensure a highly competent workforce capable of managing increasingly complex digital networks. As the network grew in complexity and scale, so did the internal management systems designed to oversee its maintenance, expansion, and technological upgrades. The centralized nature of the public corporation model allowed for strategic, long-term investments that might have been difficult for a fragmented private market to achieve, ensuring a unified and consistent national telecommunications policy.
By the late 1970s and early 1980s, NTTPC had undeniably established itself as a dominant and technologically advanced force in Japanese telecommunications. It had achieved remarkable success in building a comprehensive national network and pioneering a range of communication services, from basic telephony to early data transmission. The corporation played an indispensable role in Japan's economic prosperity and societal development, delivering on its mandate of universal service and technological leadership. However, this very success, coupled with growing international pressure for market liberalization and domestic calls for increased efficiency and innovation beyond a monopoly structure, began to generate serious discussions about the future structure of the corporation. As a large public entity, it faced increasing scrutiny regarding its operational efficiency and the potential benefits of introducing competition into the telecommunications market. The technological breakthroughs had provided a robust foundation, but the very scale and scope of NTTPC's operations now prompted consideration of a new organizational paradigm, setting the stage for a period of significant structural reform and strategic reorientation.