I am doing a project where I have to design a communication network which should be the combination of RF wireless and fiber optical wired/optical wireless communication network, does Omnet++ support such networks?
Yes, it does. For more help, go to this website and contact one of the organizers of this conference. They are experts in omnet++ and researchers in Fiber optic networks.
I would say yes. In OMNET++ you are able to model the channel according to your requirements. There you can set the delay and the data, probability of error and bit error rates.