Alcatel-Lucent redefining capacity limits of optical networks to meet future 5G and IoT demands


Bell Labs, the research arm of Alcatel-Lucent has made a breakthrough in its ambition to shatter the capacity limits of optical networks as they strive to meet the explosion in traffic expected from 5G and the Internet of Things.

According to a study by Bell Labs, telecommunications operators and enterprises are witnessing rapid network data traffic growth at cumulative annual rates of up to 100 percent. With the promise of 5G wireless technology on the horizon, Bell Labs estimates that, within about a decade there will be an acute need for commercial optical transport systems capable of handling Petabit-per-second capacities.

With this demand threatening to outstrip the capacity limits of current optical fiber networks, at the 2015 IEEE Photonics conference Bell Labs revealed an optical networking technology that could potentially help operators address this expansion: a real-time space-division multiplexed optical multiple-input-multiple-output (MIMO-SDM) system.

This world’s first demonstration of the Bell Labs’ pioneered MIMO-SDM technique has the potential to increase today’s 10 to 20 Terabit-per-second fiber capacities to Petabit-per-second capacity – the equivalent of 1,000 Terabits/s. The successful 6×6 MIMO-SDM real-time experiment using six transmitters and six receivers in combination with real- time digital signal processing was conducted over a 60-km-long coupled-mode fiber in Bell Labs’ global headquarters in New Jersey.

Using the MIMO-SDM technique, Bell Labs aims to overcome the capacity limitations imposed by the non-linear ‘Shannon limit’ on current optical fiber. This sets a fundamental threshold for the maximum information transfer rate on a single optical fiber used in today’s metro and long-haul transport networks.

Commenting on this breakthrough, Marcus Weldon, CTO of Alcatel-Lucent and President of Bell Labs said: “This experiment represents a major breakthrough in the development of future optical transport. We are at the crossroads of a huge change in communications networks, with the advent of 5G Wireless and cloud networking underway. Operators and enterprises alike will see their networks challenged by massive increases in traffic. At Bell Labs we are continuously innovating to shape the future of communications networks to meet those demands.”

Bell Labs has demonstrated a world’s first prototype technology – a 6×6 real-time optical MIMO transmission system – that will push the limits of optical transport network capacity to meet future traffic demands.

Using the MIMO-SDM technique, Bell Labs aims to overcome the non-linear Shannon limit of currently deployed optical fiber. During the 6×6 real-time MIMO transmission technology experiment, crosstalk from multiple signals on a special fiber supporting six parallel optical signal paths was removed for the first time using real-time processing. This breakthrough brings the technology a step closer to reality compared to previous experiments using off-line processing.