Patent ID: 7058300

Claim:
A method for arbitrating a data transmission rate between devices in an optical communication system before performing a data transmission between the devices via an optical transmission line, the method comprising: detecting a transmission band of the optical transmission line; detecting a slower one of maximum data transmission rates acceptable to the devices between which the data transmission is to be performed; and designating a data transmission rate as a data transmission rate for the data transmission, the data transmission rate being within the detected transmission band of the optical transmission line and equal to or less than the detected slower maximum data transmission rate, wherein the detecting of the transmission band of the optical transmission line comprises: transmitting a predetermined pilot signal comprising at least one cycle signal having a predetermined cycle from a first of the devices to a second of the devices; and detecting the transmission band of the optical transmission line based on a received state of the predetermined pilot signal as received by the second device, and wherein the detecting of the transmission band of the optical transmission line based on the received state of the predetermined pilot signal comprises: determining whether or not a frequency corresponding to the predetermined cycle of each of the at least one cycle signal is within the transmission band of the optical transmission line based on a waveform of the at least one cycle signal as received by the second device; and determining the transmission band of the optical transmission line based on a highest one among frequencies which are determined as being within the transmission band of the optical transmission line.