As far as I know and use it, the Packet Tracer 7.2 (from Cisco) is a reliable tool for all kind of networks. To have a quick view of using smartphones over 3G/4G :
https://youtu.be/XJSJzX5AVbo
Obviously, this kind of simulated networks can be analyzed with Wireshark and slightly calibrated and/or adjusted to your main purpose. Servers, IoT sensors and actuators, all types of cables, computers, VoIP phones, etc. can be added.
Let me know if it (packet Tracer) seems to be promising for your purpose.