Several experiments were done, culminating in the log haul transmission from Lyngby to Aalborg in Denmark, a distance of 525km. This used only optical amplification and dispersion compensating fibres.

A section of this was also used for a GRID computing experiment – 250km was used as a data-feed “backbone” simulating a 10G Ethernet computing GRID connecting several clusters together.

Taking part in this experiment were the following partners:

• ESTA project; CERN and COM
• Global Connect Denmark
• Danish Research Network (DAREnet)
• Uni-C
• DIKU (Dept. of Computer Science, University of Copenhagen)
• NBI (Niels Bohr Institute)
• AAU (Aalborg University)
• SDU (University of Southern Denmark)

XENPAK modules rated at 40km were used, with span lengths from 38 to 121km; a total of nine optical amplifiers were used (one at each end and seven intermediate stages). Half duplex data transmission was run and a BER (Bit Error Rate) of 10^-14 was achieved or better, which is acceptable.

For the dispersion compensation, we found it necessary to use under compensation of approximately 800 ps/nm due to the non-linearities generated by the high launch powers.

For the GRID computing experiment, details can be found at www.10ge-grid.uni-c.dk/