Patent ID: 8295703

Claim:
An optical transmission apparatus for performing optical transmission while dropping and adding optical signals, comprising: an optical switching unit including an N×M wavelength selective switch with N input ports and M output ports; an add controller configured to perform add control, wherein provided that add optical signals, which are optical signals to be added, have k different bit rates, the add controller is connected to k (<N) inputs ports, out of the N input ports, and sends the add optical signals to the k input ports; and a drop controller connected to m (<M) output ports, out of the M output ports, for performing drop control on optical signals sent from the m output ports, wherein k links connecting the k input ports of the N×M wavelength selective switch with the add controller have introduced therein dispersion compensators for compensating chromatic dispersions of the add optical signals with the respective bit rates, and wherein the add controller selects one of the links through which the add optical signal is to be passed for dispersion compensation, and sends the add optical signal to the N×M wavelength selective switch via the selected link.