Patent ID: 7274878

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 of 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 span counts in the node segment and in the node-to-node segment, respectively, to a total span count between the transmitting-end and receiving-end terminal nodes, each add drop multiplexing (OADM) node has dispersion compensators disposed at its transmitting-end and receiving end, respectively, and the amount of compensation of the transmitting-end dispersion compensator is determined from an average span distance of spans following an associated add drop multiplexing (OADM) node or from an average transmission line dispersion value.