Here I describe my experience with building a smart home using:
- KNX (mostly from MDT) for basic control: only needs power
- Home Assistant for Automations: only needs LAN.
- KNX Integration for, well, writing/reading KNX commands
- ZHA Integration for controlling Philips Hue lights
- Alexa for voice commands: needs WAN (Internet)
In addition, I have the following devices
- A weather station on the roof: needs WLAN
- Philip Hue smart lights: need ZigBee dongle/hub
- Reolink Cameras: need PoE cables