BT and Alcatel-Lucent Record Real-World Fibre Optic Speed of 1.4Tbps In the UK 70
Mark.JUK writes "The United Kingdom's national telecoms operator, BT, has successfully teamed up with Alcatel-Lucent to conduct a field trial that delivered real-world data speeds of 1.4 Terabits per second over an existing commercial-grade 410km fiber optic link. The trial used a 'record spectral efficiency' of 5.7 bits per second per Hertz and Flexgrid technology to vary the gaps between transmission channels for 42.5% greater data transmission efficiency than today's standard networks. The speed was achieved by overlaying an 'Alien Super Channel' (i.e. it operates transparently on top of BT's existing optical network), which bundled together 7 x 200Gbps (Gigabits per second) channels and then reduced 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). It's hoped that this could help boost capacity to those who need it without needing to lay expensive new fiber cables."
Re:DSL.. (Score:5, Informative)
The difference is that DSL is running data over old Cat 3 voice grade lines, and there is a clear technological benefit to moving to an alternative media for distribution. The reason is noise: Cat 3 was never designed to reject it. Coax, Cat 5, and other wire types were specifically engineered to help reject noise at different frequencies. And the better the category of wire, the better the throughput.
Fiber doesn't generally have that same kind of problems (unless you foolishly installed cheap plastic optical fibers.) There isn't a special "greased lightning fiber" people can turn to that carries more data. Instead, advances in lasers, optics, and encoding technologies are used to increase throughput by replacing the transmitters and receivers.
In general, if you need more throughput in a fiber environment than commercially available transmitters can produce, your only choice is to pull more fibers. Whereas in DSL-land if you need more throughput, the rational choice is to abandon the technology completely and move to a different media.