Hi Burhaan
In non ROADM networks, if not already pre-assigned, adding new services requires redesign or major network change which takes time, resources and poses risks of traffic disruptions.The Reconfigurable Optical Add Drop Multiplexer (ROADM) adds the required flexibility so that adding WaveLengths or changing the Wavelngth destination becomes easy and remotely managed process providing full control and monitoring over the entire high capacity infrastructure.
If your system design ignores the above difference.
Then you can posssibily use the COADM in your project.
Regards.