NEC achieves Japan’s longest terrestrial wireless optical communication over 10 km

On Friday, April 25, 2025, at 16:50 HKT/SGT, NEC accomplished the longest terrestrial wireless optical communication in Japan spanning over 10 km. The achievement involved conducting free-space optical (FSO) communication, including a connection between the observation deck at TOKYO SKYTREE®, Japan’s tallest structure, and a ground location approximately 3 km away, showcasing a significant elevation change.
FSO technology facilitates high-speed, high-capacity communication by transmitting and receiving light beams without the need for physical paths like optical fibers. Its high directionality prevents beam dispersion, lowering the risk of interception, reducing communication congestion, and eliminating the necessity for radio wave permits.
These advancements are anticipated to benefit communication setups in areas where optical fiber installation is challenging, enhance ship-to-shore communications, and serve as a backup communication method during disasters when wired networks are compromised. NEC aims to enhance communication quality, reduce device size, and commercialize the technology by 2028, enabling secure communications through the integration of quantum cryptography and FSO technologies.