NEC Achieves Long-distance Wireless Optical Communication Transmission over 10 Kilometers in Japan

NEC Corporation has successfully achieved Japan’s longest ground wireless optical communication, or free space optical communication (FSO), with a distance of over 10 kilometers. In addition, NEC has successfully built the tallest building in Japan, TOKYO SKYTREE ® FSO communication was conducted between the observation deck and a ground location approximately 3 kilometers away, representing a significant change in altitude.

  

FSO is a wireless communication method that can achieve high-speed and high-capacity communication compared to radio waves. It does not use physical paths such as optical fibers to transmit and receive light beams. In addition, it has high directionality and does not propagate beams, so the risk of interception by third parties is low, reducing interference and congestion in communication, and does not require a radio wave usage license.

These newly developed technologies are expected to be used for communication in locations and regions where it is difficult to install fiber optics, as well as communication between sea and land vessels. In addition, it is expected that in the event of disasters such as damage to wired communication networks and communication difficulties, these technologies will be used as alternative communication or emergency communication methods, as well as for highly confidential short-range communication related to national security.

Traditionally, one of the challenges faced by FSO communication is overcoming the negative impact of atmospheric flow on stable communication, such as thermal haze, which increases with distance and is difficult to grasp the different atmospheric flows between different heights.

At present, NEC has successfully achieved communication over distances of more than 10 kilometers and FSO communication at different altitudes using capture and tracking technology developed for its communication system and long-distance optical communication technology for satellites.

Based on this successful demonstration, NEC plans to promote technological development, improve communication quality, and reduce equipment size from the current 2 cubic meters to about 1% that can be carried by one person, achieving commercialization by 2028. In addition, by combining quantum encryption communication technology (expected to be applied to national level critical infrastructure systems) with FSO communication technology, NEC aims to develop free space quantum key distribution technology in the future to achieve more secure communication. NEC also aims to apply this technology to communication between the ground and satellites, while continuing to advance its efforts to provide networks that meet the different needs of its customers.