| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce a transmission restriction due to wavelength dispersion in a high-speed passive optical network (PON) system with a large transmission distance difference. <P>SOLUTION: Uplink optical burst signals from optical network units (ONUs) (18-1 to 18-n) are inputted to a variable dispersion compensator (34) via a WDM optical coupler (32). The variable dispersion compensator (34) comprises two dispersion compensation elements (36-1, 36-2) with different dispersion amounts, and an input-side switch (38) and an output-side switch (40) for selecting these elements. In response to input timing of the uplink optical burst signals, a switch control device (56) of an OLT control apparatus (52) changes over the switches (38, 40) to apply suitable dispersion compensation to the relevant uplink optical burst signals. A dispersion compensation value of the dispersion compensation elements (36-1, 36-2) is determined, while taking into account the difference of cumulative wavelength dispersion of the uplink optical burst signals from the ONUs, (18-1 to 18-n), such that a cumulative wavelength dispersion value is settled within an allowable range. <P>COPYRIGHT: (C)2009,JPO&INPIT |
