The test follows Nokia Siemens Networks' recent announcement* of its 400G wavelength multiplexing (DWDM) equipment.

"Nokia Siemens Networks has repeatedly demonstrated its leadership capabilities in optical networks**. The latest study shows that repurposing existing fiber and achieving double the speed per wavelength of 200G is now possible," said Oliver Jahreis, head of product management for WDM networks at Nokia Siemens Networks. "This development is a significant milestone and shows that we are on the right track toward a cost-effective approach to 400G networks and beyond."

As demand for higher-capacity transport networks continues to grow, network operators need to increase the speed per wavelength on existing networks. This will help operators get the most out of their investments, as deploying additional fiber lines to meet capacity demand is a costly option.

The move to 400G is the next step in the deployment of optical transport, following the current 10/40/100G networks. Reusing existing fibers for the evolution to higher-capacity networks will protect operators' investments, as well as provide high data speeds for end users.

Nokia Siemens Networks conducted the test at its research and development center in Munich with its prototype equipment.