Why?
Two reasons:
1. OSNR Monitoring Method
2. Operation & Maintenance (O&M)
OSNR Monitoring Method
Normal monitoring using Optical Spectrum Analyzer(OSA) which can directly detect OSNR. In 10G system single wavelength have a narrow spectrum.
Figure .1: ONSR value calculated from noise power floor to signal power.
For 40 and 100Gbit/s system, spectrum become wider. OSA cannot accurately monitor the OSNR.
Figure.2: The spectrum have 2 diffrent floor.
Operation & Maintenance (O&M)
Network become meshed and WDM become more flexible. Frequent service creation and deletion operation. This will make commissioning & maintenance more complex.
i. Complex performance monitoring configuration: As the link travel long distance and pass through numerous NE.
ii. Failure to discover deterioration in advanced: Traditional service interupted happen without warning and base on alarms or performance which need to check manually.
iii. Manual Optimization: Wide network required large data needs to analyzed which it is time consuming and costly.
Using Optical Doctor function, 40 & 100Gbit/s network can be efficently handle which can save CAPEX & OPEX.
