I'm working on an IoT project and i want to simulate ZigBee and Bluetooth networks for the same system in order to evaluate each protocol and then choosing the best one.
I would recommend you to work in ns2 as it provides models for both zigbee (wan, IEEE 802.15.4) and bluetooth. I have been using ns2 for my work in ieee 802,15.4 and results have been good. all the best