In-line dispersion compensation free WDM transmission with low-slope non-zero dispersion-shifted fibre for introduction of 40-Gbit/s

A transmission line with 240 km of low-slope non-zero dispersion-shifted fibre is proved to enable cost effective upgrade from a completely dispersion compensation free 10-Gbit/s WDM system to an in-line dispersion compensation free 40-Gbit/s WDM system.