Transmission limitations in the all-optical network

All-optical networks are of considerable interest as flexible, high-capacity communication networks, but generally they do have transmission limitations due to the non-idealities of their building blocks. Some transmission limitations are typical for networks, or more complicated in networks than in point-to-point links, e.g. crosstalk and channel power equalisation, whereas others are common to networks and point-to-point links, e.g. dispersion. Because of the accumulation of impairments in all-optical networks, it will probably be difficult to implement networks with a large number of optical nodes and full end-to-end transparency for all connections; instead, there might be need for electrical "isolation" between different parts or levels of the optical network. The optimum placement of this border between all-optical and OEO networks remains to be determined.