Increasing the transmission distance by dispersion scheme optimization for terrestrial ultra-high-bitrate long-haul transmission systems

The increasing demand for higher transmission capacity originated by upcoming Triple-Play services forces the network operators to increase the transmission capacity and drive down the costs per bit/s. Therefore the line rates of installed networks, operating at 2.5 and 10 Gbit/s/λ, must be upgraded. In current optical networks first implementations of WDM Systems with line rates of 40 Gbit/s/λ are already accomplished. First results with electronically multiplexed transmitters and receivers at 80 Gbit/s/λ have already been published and higher channel data rates e.g. 100 or 160 Gbit/s/λ attract more and more attention in the R&D community. With increasing data rates unfortunately new circumstances and physical impairments have to be considered, which are negligible at lower data rates. For data rates above 40 Gbit/s chromatic dispersion causes pulses to broaden extremely rapidly, so that transmission behaviour can be regarded as "quasi-linear". Due to the broad signal spectra and massive pulse overlap the signal quality is mainly degraded by the intra-channel effects intra-channel-cross-phase modulation (IXPM) and Intra-channel four wave mixing (IFWM). In this paper we present an analytic engineering rule to extend the system reach limits for 160 Gbit/s/λ data rates by optimizing the dispersion compensation schemes for different parameters such as fiber types and modulation formats. With minimizing the effect of non-linear intra-channel crosstalk, by able system design the maximum system reach can be extended by more than 40%.