In this project, we constructed a cable of 12-coupled-core fiber, in which signal coupling occurs between 12 cores, while significantly reducing propagation delay dispersion, and installed it in a tunnel or aerial section emulating a terrestrial field environment. NEC, as one of the top three enterprises in the submarine cable market, succeeded in prototyping the world's first four-core optical fiber submarine cable in July 2022. In this press release, we announce the success of our transoceanic long-distance transmission experiment over 7,280 km using. Tokyo, Japan, March 21, 2024 – NEC Corporation (NEC; TSE: 6701) and NTT Corporation (NTT) today announced that they have successfully conducted a first-of-its-kind transoceanic-class 7,280km transmission experiment using a coupled 12-core multicore fiber (*1), which consists of 12 optical signal. NEC, NTT conduct a groundbreaking 7,280km transmission using a 12-core optical fiber, setting the stage for large-capacity optical networks and undersea cables. By using a connected 12-core multicore fiber - a standard outer diameter optical fiber (0. 125 mm) with 12 optical signal transmission. Japanese tech titans NTT and NEC reckon they've proven the performance of a novel fiber optic technology that could increase capacity of submarine cables by a factor of 12. This accomplishment opens new possibilities for increasing the.