OREANDA-NEWS. Alcatel-Lucent (Euronext Paris and NYSE: ALU) has achieved a technological record for subsea communications by extending the reach of unrepeatered cable systems at 100 gigabits-per-second to more than 610 kilometers using the same fiber for both signal and amplifier transmission.

By freeing up individual fibers normally combined in a cable system, the breakthrough - enabled by engineers from Alcatel-Lucent Submarine Networks - will lead to significant improvements to cable system efficiency, creating benefits for operators in terms of total cost of network ownership. Mainly driven by connectivity needs, unrepeatered undersea cable projects consist in the construction of cable systems for distances currently up to 500km without using repeaters to amplify the signal. Built to offer additional capacity and/or complement terrestrial networks to gain resiliency, they can offer a design capacity of 25 Tbit/s depending on the system configuration.

When offered commercially, this technology could extend the reach of current unrepeatered systems without affecting the signal transmission (low-loss) and offers an optimized trade-off which significantly exceeds the capabilities of other transmission technologies. The state-of-the-art solution used for the laboratory demonstration was based on a 100 Gbit/s channel over a single second-generation coherent submarine fiber using advanced modulation schemes and Raman amplification.  

Leveraging Alcatel-Lucent Submarine Networks’ long-standing expertise in high-performance, field-proven innovation in ultra long-distance transmission, the flexible new technology will enable deployment in multiple configurations that could further extend reach over unrepeatered distances, while ensuring ultra low-loss signal attenuation.

By seamlessly supporting channel rates of up to 100 Gbit/s, ASN’s unrepeatered systems offer a homogeneous solution for systems with a variety of segment lengths, providing cable protection and armoring options for any installation environment or sea floor conditions.

Olivier Gautheron, Chief Technology Officer of Alcatel-Lucent Submarine Networks said: “Operators’ infrastructures continue to be challenged by the demands of traffic arising from  broadband services and content delivery. ASN’s breakthrough further demonstrates the application of our own innovation to extend the reach of unrepeatered submarine cable systems in order to enhance their performance to help operators get the most out of their networks and build new revenue streams.”

ASN has so far deployed more than 20,000 km of unrepeatered cable systems in more than 40 projects for major telecom operators worldwide.  Leveraging best-in-class research and development capabilities, ASN has also achieved several experiments in this domain setting world records for unrepeatered transmission distances, the latest showcasing 8 Tbit/s unrepeatered transmission of 200 Gbit/s 16 QAM channels over 363 km and 16 Tbit/s transmission of 200 Gbit/s 16 QAM channels over 321 km with third order Raman amplification in late 2014.

About Alcatel-Lucent Submarine Networks

Alcatel-Lucent Submarine Networks leads the industry in terms of capacity and installed based with more than 575,000 km of optical submarine cables/systems deployed worldwide. From traditional telecom to new Oil & Gas applications, ASN provides every part of a global undersea transmission network, all tailored to the customer’s needs. An extensive service portfolio completes its comprehensive offering for the submarine business, including project management, installation and commissioning and marine operations and maintenance performed by its fleet of seven cable ships.