SoftBank Corp. has partnered with Cisco Systems G.K. to begin deployment of its all-optical network in Japan’s metro networks. Using Cisco's latest routers that support 400GbE (Gigabit Ethernet) and adopting a simplified architecture optimized for metro networks, the system eliminates the need for optical-electrical conversion, reducing energy consumption by approximately 90% compared with conventional configurations. SoftBank completed the deployment of its all-optical network nationwide in core networks in October 2023. This initiative is now being expanded to metro networks across Japan, connecting base stations, AI services, and other user-proximate points to the core network. The first phase was completed in the initial area of Osaka Prefecture in September. Comparison of the conventional network and the all-optical network. Courtesy of SoftBank. While long-distance optical signal transmission, such as in core networks, has traditionally required the installation of rack-mounted optical amplifiers, the all-optical network for metro networks, which is not intended for long-distance transmission, introduces Cisco's newly developed quad small form-factor pluggable – double density (QSFP-DD) pluggable open line system (OLS), a palm-sized optical amplifier module that can be directly installed on routers. Cisco is combining this module with SoftBank's optical multiplexer — which requires no external power supply and supports up to 6.4 Tbps. SoftBank plans to complete the deployment of its all-optical network in metro networks nationwide by 2027. With the rapid increase in data traffic due to generative AI and cloud services, even greater traffic demand is expected in the Beyond 5G/6G era. Meanwhile, communication providers are required to reduce environmental impact and build more sustainable communication infrastructure.