| 摘要 |
<P>PROBLEM TO BE SOLVED: To measure correctly a span loss of a signal wavelength range without using an optical signal arranged in the signal wavelength range in a WDM transmission system. <P>SOLUTION: At the time of initial start-up of an optical communication system, an ASE standard span loss is calculated based on transmission power and reception power of ASE light generated by an optical amplifier 11 and further an OSC standard span loss is calculated based on transmission power and reception power of monitoring control light. In an operation of the optical communication system, the span loss is calculated using the monitoring control light and then a span loss variation amount is calculated which represents a difference between the span loss calculated using the monitoring control light and the OSC standard span loss. The span loss variation amount is added to the ASE standard span loss and thereby the present span loss can be calculated between a transmission station 10 and a reception station 20. <P>COPYRIGHT: (C)2007,JPO&INPIT |
