Cost effective transparent long-distance interconnection of metropolitan networks over ultra-long-haul optical links

In transparent optical networks, all data rates and formats can be transmitted simultaneously and the number of transponders, as the main driver of network costs, can be reduced significantly. High flexibility and an effective optical 1:N-protection can be implemented by configurable passive optical add-drop-multiplexers. We performed field experiments to interconnect metropolitan and long haul optical networks transparently.