A data transmission rate 50,000 times faster than the UK’s superfast broadband has been achieved by British researchers, setting a new digital data rate record.
A team from University College London’s Optical Network Group has built an optical transmission system capable of transmitting 1.125 terabits of data per second. For comparison, state-of-the-art commercial optical transmission systems are currently capable of a maximum of 100 gigabits per second, while the average speed of a superfast broadband connection in the UK is only 24 megabits per second.
“The data rate we have achieved would allow the entire HD Game of Thrones series to be downloaded within one second,” said Robert Maher, who led the team.
The experiment, described in today’s issue of the journal Scientific Reports, is part of efforts aimed at increasing the capacity limits of optical transmissions systems, which is required to address the growing demand for fast data rates stemming from the development of the Internet of Things, as well as cloud-connected e-health services.
“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 custom-built optical communications system built for the experiment consists of fifteen channels and a single receiver. Each channel carries an optical signal of a different wavelength. The channels were modulated using the 256QAM format typically used in cable modems, combined and sent to a single optical receiver for detection.
By grouping the channels together, the team created a ‘super-channel’ which although not yet commercially available is widely believed to be a way forward for the next generation of high-capacity communication systems.
“Using high-bandwidth super-receivers enables us to receive an entire super-channel in one go,” said Maher. “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.”
In this study, the researchers connected the transmitter directly to the receiver to achieve the maximum data rate. They will now test the system and measure the achievable data rates in a long distance transmission scenario where optical signals can become distorted as they travel through thousands of kilometres of optical fibres.
In the quest for providing higher data rates, Japanese researchers have recently unveiled a new wireless transmitter that could give Wi-Fi the speed of fibre-optics.
The transmitter, developed jointly by Hiroshima University and Panasonic, could transmit up to 100 gigabits of data per second. The transmitter uses the as-yet under-utilised terahertz band and transmits via multiple channels at 300 GHz.
The researchers believe that the system, implemented as a silicon CMOS integrated circuit, could be easily commercialised,
“Today, we usually talk about wireless data-rates in megabits per second or gigabits per second,” said Hiroshima University Professor Minoru Fujishima. “I foresee we’ll soon be talking about terabits per second. That’s what THz wireless technology offers. Such extreme speeds are currently confined in optical fibres. I want to bring fibre-optic speeds out into the air and we have taken an important step toward that goal.”
The THz band is a new and vast frequency resource not currently exploited for wireless communications. Its frequencies are even higher than those used by the millimetre-wave wireless local area network (from 57GHz to 66GHz) and the available bandwidths are much wider. Since the speed of a wireless link is proportional to the bandwidth in use, THz is ideally suited to ultra-high-speed communications.