PASSIVE OPTICAL NETWORK SYSTEM, AND RANGING METHOD

• Main Authors: KAZAWA TORU, YAJIMA YUSUKE, OHIRA MASATERU
• Format: Patent
• Language: English
• Published: 09.04.2009
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; MULTIPLEX COMMUNICATION; TRANSMISSION

PROBLEM TO BE SOLVED: To prevent decrease in utilization bands caused by a ranging procedure as further as possible in a WDM-PON system in which a plurality of optical network units (ONUs) share a wavelength to perform transmission. SOLUTION: One wavelength dedicated to ranging is provided, ranging is performed only with the dedicated wavelength, and a reciprocation delay time is measured. Regarding other wavelengths, on the basis of the resultant reciprocation delay time, transmission signals from the plurality of ONUs are transmitted in time-division multiplexing. Furthermore, an optical line terminal (OLT) includes a burst receiving circuit only for the wavelength dedicated for the ranging, controls to adjust a transmission amplitude and a transmission phase for each ONU continuously to a ranging procedure, and aligns a reception amplitude and a reception phase to be equal for the OLT. Therefore, the OLT includes, as the burst receiving circuit, a means for measuring an amplitude and a phase of a reception signal and has a table for controlling the reception amplitude and the reception phase for each ONU. COPYRIGHT: (C)2009,JPO&INPIT