BT, Alcatel-Lucent show 1.4Tbps fibre speeds


Blue and red fibre optical cables

news British telco BT and French networking equipment supplier Alcatel-Lucent have teamed up for a trial which has demonstrated speeds of up to 1.4Tbps over BT’s core fibre network, in what is believed to be the fastest data speeds ever achieved using commercial-grade hardware in a real-world telco environment.

The field trial, conducted over an existing fibre link between the BT Tower in London and BT’s Adastral Park research campus in Suffolk, used a new ‘flexible grid’ infrastructure (Flexgrid) to vary the gaps between transmission channels over the fibre network, usually set at 50Gigahertz (GHz). By increasing the density of channels on the fibre, this approach achieved up to 42.5 percent greater data transmission efficiency compared to today’s standard networks.

The trial demonstrated that use of the Flexgrid approach can increase BT’s core network capacity using existing optical fibres, potentially reducing the expense of laying more fibre as bandwidth demands grow. This could allow BT to more easily scale its core network capacity to meet consumer and business demands for more bandwidth-hungry services such as streaming video, whilst more efficiently using its existing core fibre infrastructure.

The trial was conducted through the overlaying of an “Alien Super Channel” comprised of seven 200 Gigabits per second (Gbps) channels bundled together to provide a combined capacity of 1.4Tbps. By reducing the spectral spacing between the channels from 50GHz to 35GHz using the 400Gbps Photonic Services Engine (PSE) technology on the 1830 Photonic Service Switch (PSS), spectral efficiency is enhanced by almost 43 percent.

The 1830 PSS can be used as an optical extension shelf of the 7750 Service Router (SR) and the 7950 Extensible Routing System (XRS). Flexgrid is the key to creating high-capacity, spectrally efficient super channels. The super channel is “alien” because it operates transparently on top of BT’s existing optical network.

The speeds were achieved on a 410km fiber link between BT’s Adastral Park research campus in Ipswich and the BT Tower in London. Alien Wavelengths allow telecom operators like BT to introduce new features and technology without the need to update the existing optical transport infrastructure.

Neil J. McRae, Chief Network Architect at BT said: “Investing for the future is core to BT’s strategy and this outstanding achievement demonstrates that BT can easily introduce new features and technologies across our core network maximizing the efficiency of our existing infrastructure. Working with Alcatel-Lucent on this trial has been highly productive in demonstrating the viability of an alien wavelength approach.”

Dr Tim Whitley, BT’s MD of Research and Innovation said: “BT has alonghistory of leading innovation in telecommunications, from the earliest days of the electric telegraph to today’s global fiber networks.These trials continue that tradition,as weworkwithAlcatel-Lucentto push the boundaries of fiber technology,allowing us tosupport the ever increasing bandwidth required by our customers, and deliver new and exciting services which rely on fast, data-hungry applications”.

I published this article on Delimiter today because I received quite a few reader requests to highlight it.

What it strongly demonstrates is that fibre networks, once laid, offer almost limitless upgrade capacity for upgrade in future. Sure, the core network being used for these trials by BT and Alcatel-Lucent in the UK is very different from the Fibre to the Premises infrastructure being deployed in Australia under Labor’s National Broadband Network project, and I consider it very unlikely that any consumer access network would ever need terabit per second speeds — these are the kind of speeds used by backhaul networks. However, the principle is still being demonstrated here — fibre is a future-proof network distribution technology.

We’ve seen this kind of phenomenon before, with copper. Copper telephony networks were never intended to be used for data transmission — they were built for analogue telephone calls, initially directed by (gasp!) manual switching — polite people in telephone exchanges unplugging cables when people placed calls. Fast forward a few decades, however, and we better understand the capabilities of the medium and wham, bam! We’ve got ADSL2+ speeds up to 24Mbps — speeds which would be considered astronomical by the standards of previous decades.

Image credit: Clix, royalty free


  1. I don’t know why they bothered, did they not hear Tony Abbott proclaim 25mbps was enuf for everyone?

  2. Last paragraph before your opinion/analysis has a lot of missing spaces in it (personally i would be firing your editor and finding a more competent one :)).

    One of the things that has been known about fibre for a long time now, is that once the cable is laid, unless some sort of disaster causes it to have to be repaired, the only thing you need to do is upgrade the endpoints.

    At the primary school i work at, we’ve had fibre optic between buildings since the late 90’s, and we’ve never had to touch the cable itself ever again.

    Shame the powers that be are too up themselves to realise what a good idea ubiquitous fibre would have been.

  3. But lucky we have FTTN which will help us now, rather than provide for us in the future.. right??

    Right guys?????


  4. i love my adsl 2 …. you know, when a game lags because my wife is uploading a photo to facebook ..

    it’s awesome!

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