NETWORKS

New 'flexible grid' infrastructure allows more efficient bundling of channels, (42.5% increase in spectral efficiency) and data speeds of up to 1.4 Terabits per second (Tb/s) achieved without deployment of more fiber

Alcatel-Lucent and BT have today announced trial speeds of up to 1.4Tb/s with a record spectral efficiency of 5.7 bits per second per Hertz (b/s/Hz)  on an existing core fiber connection. This is believed to be the fastest speed ever achieved in commercial grade hardware in a real-world environment and is equivalent to transmitting 44 uncompressed HD films in a single second.

The field trial, conducted over an existing fiber 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, usually set at 50 Gigahertz (GHz). By increasing the density of channels on the fiber, 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 fibers, potentially reducing the expense of laying more fiber 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 fiber infrastructure.

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

Key Facts:

    --  During October and November of 2013, BT and Alcatel-Lucent successfully
        demonstrated a number of world-leading high-speed alien wavelength
        technical achievements, including a record spectral efficiency of
        5.7b/s/Hz which is equivalent to fitting a 1Tb super channel in less
        than 200GHz spectrum.
    --  The speeds were achieved on a 410km fiber link between BT's Adastral
        Park research campus in Ipswich and the BT Tower in London
    --  The trials were performed using production equipment that was software
        reconfigurable between 200Gb/s using 16 QAM modulation and 100Gb/s using
        QPSK modulation
    --  Alien Wavelengths allow telecom operators like BT to introduce new
        features and technology without the need to update the existing optical
        transport infrastructure
    --  Flexgrid maximizes the spectral efficiency of the installed fiber
        infrastructure, deferring the need to deploy costly new fiber
        infrastructure
    --  Trial and evaluation of the 1.4Tb/s alien super channel showed stable,
        error-free operation, when being transmitted with a mix of 40Gb/s and
        100Gb/s native wavelengths. This was achieved for standard 50GHz
        sub-channel spacing and for flexgrid with sub-channel spacing down to
        35GHz
    --  Working with BT to efficiently and cost effectively increase high-speed
        network capacity is aligned with the The Shift Plan, the industrial
        strategy to reposition Alcatel-Lucent as a specialist vendor of IP
        Networking and Ultra-Broadband Access

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 a long history 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 we work with Alcatel-Lucent to push the boundaries of fiber technology, allowing us to support the ever increasing bandwidth required by our customers, and deliver new and exciting services which rely on fast, data-hungry applications"

Cormac Whelan, CEO, Alcatel-Lucent UK & Ireland said: "As part of our long-standing relationship, BT and Alcatel-Lucent continue to work together to use innovation from Bell Labs, Alcatel-Lucent and BT Research and Development to move the industry forward and meet the ever evolving needs of the marketplace. These trials represent another step forwards by BT and Alcatel-Lucent in this continual evolution"