Patent ID: 7542677

Claim:
A wavelength division multiplexing optical communication system comprising: a transmitting-end terminal node and a receiving-end terminal node; a wavelength division multiplexing optical communication transmission line including a plurality of spans each having an optical fiber, the plurality of spans joining the transmitting-end terminal node and the receiving-end terminal node; and a plurality of add drop multiplexing (OADM) nodes disposed on the wavelength division multiplexing optical communication transmission line; wherein when taking as a reference a residual dispersion target value between the transmitting-end terminal node and the receiving-end terminal node, a residual dispersion target value for a node segment between one of the terminal nodes and one of the add drop multiplexing (OADM) nodes and a residual dispersion target value for a node-to-node segment between two of the add drop multiplexing (OADM) nodes are set so as to be proportional to ratios of the dispersion in the node segment and in the node-to-node segment, respectively, to the total dispersion between the transmitting-end and receiving-end terminal nodes.