Patent ID: 6404523
Filing Date: 2002-06-11
Classification: H04B,H04J

Abstract:
A wavelength division multiplexing system in which a plurality of terminal stations are connected by a network, comprising:a first terminal station comprising a control means for terminating a transmission path and for controlling a pre-emphasis process to be performed in a terminal station among respective terminal stations which are included in the wavelength division multiplexing system; branching and inserting means for branching and inserting an optical signal of a predetermined wavelength among wavelength-multiplexed optical signals which propagate through the transmission path; and a second terminal station connected to the branching and inserting means, for receiving the optical signal of a predetermined wavelength from the transmission path, and for transmitting an optical signal of a predetermined wavelength to be inserted to the transmission path, wherein when a pre-emphasis process is performed for a wavelength-multiplexed optical signal to be transmitted in the wavelength division multiplexing system in a direction where the first terminal station is a receiving station, the control means obtains spectrum information of an optical signal received by the first terminal station, causes the second terminal station to transmit spectrum information of an optical signal to be received by the first terminal station, obtains spectrum information received from the second terminal station, and instructs a terminal station for transmitting optical signals about how great a pre-emphasis process should be performed, using spectrum information received from the first and the second terminal stations.