New transoceanic optical transmission record

New transoceanic optical transmission record

Researchers at Nokia Bell Labs have established two new world records in submarine optical communications, using higher-baud-rate technologies

Nokia Bell Labs: new 800 Gb/s world record for transoceanic optical transmission

The new optical speed record for transoceanic distances is now 800 Gbps on a single optical wavelength at 7865 km - twice as much as what current state-of-the-art equipment can transmit at the same capacity. A second record, achieved with subsidiary Alcatel Submarine Networks, established 41 Tb/s net throughput over 291 km via a C-band unrepeated transmission system.

C-band unrepeated systems are commonly used to connect islands and offshore platforms to each other and the mainland. The previous record for such systems over the same distance is 35 Tb/s. According to Nokia, the research behind these records will have “significant impact on the next generation of submarine optical transmission systems”.

Both world records could be achieved through the innovation of higher-baud-rate technologies Baud rate refers to the number of signal changes (symbols) per second, and each symbol can carry multiple bits of information, especially with advanced modulation formats. A higher baud rate effectively increases the amount of data that can be transmitted over an optical fiber in a given period of time.

High baud rates can significantly increase optical transmission data capacity but can also introduce challenges related to signal quality. They may require more complex modulation techniques and electronics and can increase overall cost and power consumption. Advances in technology are critical to mitigating these challenges and fully leveraging the benefits of high baud rates in optical communication systems.

“With these higher baud rates, we can directly link most of the world’s continents with 800 Gb/s of capacity over individual wavelengths. Previously, these distances were inconceivable for that capacity. This world record is the next step toward next-generation Terabit-per-second submarine transmissions over individual wavelengths.”

Sylvain Almonacil

Research Engineer at Nokia Bell Labs

In transoceanic systems, the increased baud rates can double the distance at which a certain capacity can be transmitted. In the case of C-band unrepeated systems, higher baud would allow service providers connecting islands or off-shore platforms to achieve higher capacities with fewer transceivers and without adding new frequency bands.

“These research advances show that that we can achieve better performance over the existing fiber infrastructure,” adds Hans Bissessur, Unrepeated Systems Group leader at ASN. “Whether these optical systems are crisscrossing the world or linking the islands of an archipelago, we can extend their lifespans.”

Nokia Bell Labs and ASN presented the scientific findings behind both records on the 4th and 5th of October at the European Conference on Optical Communications (ECOC), in Glasgow, Scotland. Both milestones were reached at the companies’ optical research testbeds in Paris-Saclay, France.