Another fibre-optic bandwidth record tumbles
Send 400 DVDs per second over 7000km? - now that's what I call filesharing
Parent company Alcatel-Lucent claims this is ten times more capacity than rivals have yet achieved.
The company uses a compound measure of performance, multiplying transmission rate by distance carried, to give a figure of 100 Petabits per second kilometre, which can also be expressed as 100 million Gigabits per second kilometre. In real-world terms, this is equivalent to sending the contents of 400 DVDs per second over 7,000 kilometres, roughly the distance between Paris and Chicago.
Researchers from the Bell Labs facility in Villarceaux, France, used 155 lasers, each operating at a different wavelength and transmitting 100 Gigabits of data per second, to drive their signals over an optical network that included repeaters every 90 kilometres. This spacing distance is 20% greater than that commonly used in transoceanic networks.
The researchers used a couple of other techniques to increase the fibre's capacity. The first was to apply coherent detection techniques, which make it possible to acquire details for a greater number of properties of light than the direct detection method used in today’s systems. This helps because it makes it possible to run more wavelengths of light in a fibre at once while still being able to separate them out at the other end. The other technique was to use more advanced digital signal processors to extract the signal from the noise introduced during transmission over such long distances.
Details of the breakthrough were presented in a research paper that was reviewed in a post-deadline session of ECOC 2009, the European optical communications conference.