BT, Alcatel-Lucent push 1.4 Tbps over existing fiber during trial

BT (NYSE: BT) and vendor partner Alcatel-Lucent (NYSE: ALU) pushed the boundaries of existing fiber by delivering speeds of 1.4 Tbps with spectral efficiency of 5.7 bits per second per Hertz during a recent trial.

Conducted over one of BT's existing core fiber connections between BT Tower in London and the telco's Adastral Park research center in Suffolk, the trial used a new "flexible grid" infrastructure (Flexgrid) to vary the gaps between transmission channels, usually set at 50 Gigahertz (GHz).

The two companies said that by increasing the density of channels on the fiber, they were able to achieve up to 42.5 percent greater data transmission efficiency.

One of the potential benefits of the trial is reduced costs. By using Flexgrid, BT could increase core network capacity using existing fiber, potentially forgoing the need to lay more fiber as bandwidth demands grow.

Leveraging Alcatel-Lucent's 1830 Photonic Service Switch (PSS), the trial was conducted through the overlaying of an "Alien Super Channel" comprised of seven 200 Gbps channels bundled together to provide a combined capacity of 1.4 Tbps.

Both companies claimed that "by reducing the spectral spacing between the channels from 50GHz to 35GHz using the 400Gb/s Photonic Services Engine (PSE) technology on the spectral efficiency is enhanced by almost 43 percent."

Service providers like BT can use the 1830 PSS as an optical extension shelf of the 7750 Service Router (SR) and the 7950 Extensible Routing System (XRS), the companies said.

BT and Alcatel-Lucent are hardly alone in their Tbps networking desires. Comcast (Nasdaq: CMCSA) and Telstra (ASX: TLS.AX) previously conducted separate Tbps trials on their live fiber networks last year.

For more:
- see the release

On the hot seat: Burger: BT Global Services focuses on what works for multinational customers

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