Researchers from the Optical Network Group in University College London have set a new record for the fastest data rate for digital information. The team managed to achieve a rate of 1.25 Tb/s. This is part of their research to optimize the growing demands of data rates. In short, they managed to stretch the capacity limits of optical transmission systems.
Their study has been published in Scientific Reports last February 11th.
Leading the research team is Dr. Robert Maher from the UCL Electronic and Electrical Engineering department. He clarifies the research, asserting, "While current state-of-the-art commercial optical transmission systems are capable of receiving single channel data rates of up to 100 gigabits per second (Gb/s), we are working with sophisticated equipment in our lab to design the next generation core networking and communications systems that can handle data signals at rates in excess of 1 terabit per second (Tb/s)."
"For comparison this is almost 50,000 times greater than the average speed of a UK broadband connection of 24 megabits per second (Mb/s), which is the current speed defining "superfast" broadband. To give an example, the data rate we have achieved would allow the entire HD Games of Thrones series to be downloaded within one second."
How did they achieve this record?
The team credits techniques from information theory and digital signal processing to set this new record.
They custom-built an optical communication systems that has multiple channeling system and a single receiver. Initially, the team wanted to check if there are ways to improve the current optical network infrastructure so that it can better accommodate digital content, cloud, and e-health services. Smart devices are also on the list of what they call "Internet of Things" or "IoT".
"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. A high-capacity digital communications infrastructure underpins the internet and is essential to all aspects of the digital economy and everyday lives.", said Professor Polina Bayvel, the principal investigator of the UNLOC programme at UCL.
Even though there were limitations on the transmitter and receiver, the team was able to find the best way of encoding information in optical signals. They then used coding techniques that are not widely used in optical communications so that they can be sure that the transmitted signals to distortions. UNLOC has state-of-the-art lab facilities that was utilized to build a new optical system. They measured the performance of fifteen channels that each carried an optical signal of different wavelengths. The channels were modulated using the 256QAM format that is often used in cable modems. These were combined and sent to a single optical receiver. The result of this channel combination led to what they call a "super-channel" which they believe is the next step in high-capacity communication systems.
"Using high-bandwidth super-receivers enables us to receive an entire super-channel in one go. 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," said Dr Robert Maher.
According to these researchers, the work is not done. They still plan to test the system in order to find out the best achievable data rates for long distance communication systems. This will prove to be a real challenge knowing that there are plenty of distortions stretched out in thousands of kilometers of optical fibers. It is definitely fascinating to see how fast our communication systems can really go.