August 26, 2020
At the Electronic & Electrical Engineering department of University College London (UCL), Dr. Lidia Galdino and her research team worked with Xtera and KDDI Research to achieve an Internet transmission rate of 178 terabits per second (178,000,000 megabits per second). This speed represents double the capacity of any other system operating today and would enable a user to download the entire Netflix library in less than one second. UCL and its partners achieved this by transmitting data through a much wider range of wavelengths than typically used in optical fiber.
According to UCL, “current infrastructure uses a limited spectrum bandwidth of 4.5THz, with 9THz commercial bandwidth systems entering the market, whereas the researchers used a bandwidth of 16.8THz.”
The researchers used “different amplifier technologies” to increase the signal power over the wider bandwidth. They also developed “new Geometric Shaping (GS) constellations (patterns of signal combinations that make best use of the phase, brightness and polarization properties of the light), manipulating the properties of each individual wavelength.”
By simply upgrading amplifiers on optical fiber routes at 40km to 100km intervals, this newly developed technique can be “deployed on already existing infrastructure cost-effectively.” It notes that, “upgrading an amplifier would cost £16,000, while installing new optical fibers can, in urban areas, cost up to £450,000 a kilometre.” This record-breaking speed is “close to the theoretical limit of data transmission set out by American mathematician Claude Shannon in 1949.”
Galdino, a UCL lecturer and Royal Academy of Engineering Research Fellow, noted that, “while current state-of-the-art cloud data center interconnections are capable of transporting up to 35 terabits a second, we are working with new technologies that utilize more efficiently the existing infrastructure, making better use of optical fiber bandwidth and enabling a world record transmission rate of 178 terabits a second.”
During the COVID-19 pandemic, some broadband operators have experienced up to a 60 percent increase in Internet traffic, stressing the capacity of networks.
“But, independent of the COVID-19 crisis, Internet traffic has increased exponentially over the last 10 years and this whole growth in data demand is related to the cost per bit going down,” said Galdino. “The development of new technologies is crucial to maintaining this trend towards lower costs while meeting future data rate demands that will continue to increase, with as yet unthought-of applications that will transform people’s lives.”