Alcatel will up the fibre optics data transmission ante with a 17 petabit-per-second demo over 2 700km at the upcoming Optical Fibre Communications expo.
Seventeen petabits translates to 17 000Tb, or 17-trillion kilobits, a monstrous amount of Internet information sent at once over one fibre, an optical technology which enables colour-based transmission over 256 channels.
This transmission was made possible by introducing two adaptations to current technology, after the previous record of 6Tbps. They are bandwidth-limited phase-shaped binary transmission (BL- PSBT) and an adjustment of dispersion map and signal power (to 43Gbps), transmitted at 50GHz spacing, the company says.
Cristophe Savey, Alcatel research and development communications director, says the company`s technologists discovered that the good properties of BL-PSBT reside in its low signal-to-noise ratio, chromatic dispersion tolerance and its resistance to cross-talk with 50GHz channel spacing.
Low signal-to-noise ratios are achieved, Savey says, with the introduction of narrow filters at transmitting and receiving ends. The chromatic dispersion of BL-PSBT after 2 100km (the length of the 6Tb transmission) shows large tolerance with the use of 43Gbps systems, compared to other modulation formats, he adds.
The choice of modulation formats is also affected by testing for robustness against non-linear and linear effects. The impact of cross-non-linear effects is a crucial factor in high-density systems, but it remains constant in testing, whatever the power, meaning most of the penalty is from cross-talk.
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