A few questions:
1. What kind of environment?
2. What kind of Tx-Rx scenario? Number of Tx and Rx?
3. What kind of channel parameters do you want to analyze?
NS-3 is capable of modeling the channel in all these frequency bands and provides you with the channel parameters like throughput, delay, SINR, etc.
Kindly look at other people's answers to get a good grasp of your problem.
Thank You,
Rahul Singh Gulia