Patent ID: 7236701

Claim:
An optical transmitting device for transmitting an optical signal via an optical transmission path to a receiving device connected via prescribed communication lines to first to n'th terminal devices (where n is an integer of 2 or more), the optical transmitting device comprising: a modulating section for generating first to n'th modulated signals based on first to n'th data signals to be transmitted to the first to n'th terminal devices, respectively, the first to n'th modulated signals being obtained by modulation with individual modulation parameters; an optical transmitting section for converting the first to n'th modulated signals generated by the modulating section into an optical signal and for transmitting the optical signal to the receiving device via the optical transmission path; a data amount estimating section for estimating an amount of data for each of the first to n'th data signals; and a parameter control section for setting the individual modulation parameters used in the modulating section based on amounts of data for the first to n'th data signals estimated by the data amount estimating section, wherein the data amount estimating section previously holds information about each of the first to n'th terminal devices with respect to use of a corresponding one of the prescribed communication lines, and estimates the amount of data for each of the first to n'th data signals based on the information and a current time.