Multi-channel transmissions system could make fibre terabit capable to cope with expected growth in network traffic
Researchers at University College London (UCL) have achieved a record transmission rate of 1.125Tbps on a fibre connection in a development that could dramatically increase the capacity of optical infrastructure.
A team at UCL’s Optical Networks Group used techniques commonly used to boost the capacity of wireless transmissions to create a multiple channel, single receiver system capable of coping with the anticipated growth in network traffic, fuelled by cloud services, online video and the Internet of Things (IoT).
Record fibre transmission
“This result is a milestone as it shows that terabit per second optical communications systems are possible in the quest to reach ever higher transmission capacities in optical fibres that carry the vast majority of all data generated or received,” explained Professor Polina Bayvel, the principal investigator of the UNLOC programme at UCL.
“A high-capacity digital communications infrastructure underpins the internet and is essential to all aspects of the digital economy and everyday lives.”
The system created splits signals into 15 channels, allowing transmissions to adjust for distortions in system electronics. The channels are modulated using the 256QAM format used in cable modems and combined into a ‘super channel’ that is interpreted by the receiver.
The lab tests were designed to achieve the maximum data rates possible with the system and the researchers’ attention will now turn to see what realistic rates are possible in real world scenarios involving thousands of kilometres of fibre.
Future data demand
“Using high-bandwidth super-receivers enables us to receive an entire super-channel in one go,” added Lead researcher, Dr Robert Maher, UCL Electronic & Electrical Engineering. “Super-channels are becoming increasingly important for core optical communications systems, which transfer bulk data flows between large cities, countries or even continents.
“However, using a single receiver varies the levels of performance of each optical sub-channel so we had to finely optimise both the modulation format and code rate for each optical channel individually to maximise the net information data rate. This ultimately resulted in us achieving the greatest information rate ever recorded using a single receiver.”
Increasing the capacity of mobile and fixed networks to cope with growing demand for data has become a priority for the communications industry. Fujitsu and the Tokyo Institute of Technology recently achieved a record wireless transmission of 56Gbps, while BT has been able to reach 5Gbps on a copper cable using G.Fast.