NEC Corporation, along with its subsidiary OCC Corporation and Sumitomo Electric Industries, has stated that they have conducted the first testing of an uncoupled 4-core underwater fiber cable and confirmed its transmission performance to fulfill the stringent requirements of global telecommunications networks.
International data usage is anticipated to increase by 30-40% by 2026, owing to reasons such as the expansion of 5G mobile data and the necessity to exchange ever more content between data centers located around the world. Submarine networks are using space division multiplexing (SDM) technology to fulfill this need, which increases the number of separate spatial channels to maximize the overall capacity of the system, decrease energy usage and minimize the cost per bit transferred. Multicore fiber is projected to increase the number of parallel optical fiber cores without changing the size and structure of underwater cables, allowing the introduction of second generation of submarine SDM systems.
Each individual fiber in a conventional single mode fiber contains a single core. Each multicore fiber, on the other hand, has several cores, four in this case. This translates to a four-fold increase in the number of spatial channels for the same number of optical fibers, keeping the same fiber structure without altering the width of the cable.
NEC and OCC have proven that the optical transmission performance of the cable in water completely fulfills the stringent criteria demanded of current long-haul underwater cables. They also demonstrated that the cabling procedure has no influence on the optical characteristics of Sumitomo Electric’s multicore fiber, resulting in outstanding attenuation qualities.
The Ministry of Internal Affairs and Communications (MIC) of Japan funded this study via the project “Research and Development of Innovative Optical Network Technology for a Novel Social Infrastructure” (JPMI00316).