Anyone IoT?

Thank you all for the feedback and suggestions.
It is not that I am trying to find the best, but the most practical one for the model rail.
Regarding the interference, that's a bottleneck, right.
I have only two devices to run. The experiences of many told me one good thing for going forward.
Necessary to have a master controller on a station and proprietary protocol for the slaves on the trains.
I will come back with more ideas.

Real rail networks are coming to the same solution (hub to internal network). Till now it is GSM-R (which is hard enough to apply for modelling, placing antennas and TR/TX for every locomotive).

Till 2030 GMS-R is going to be abandoned and new networks with complex hierarchy built: Satellites/5G 'orchestration' installed on sites with acceptable coverage, then distributed through the hybrid satellite and 5G terrestrial network.

My vision is that my space engineering company 'satellite' will be Wi-Fi to the station and '5G' - signaling through power/DCC.

Suzie said:

2.4GHz Wi-Fi is too crowded for exhibition use, if you are going to use Wi-Fi it has to be a 802.11ac or newer 5GHz router with beam-forming (the type that has at least three aerials). Fortunately the new Pis have 5GHz Wi-Fi so can be used, but otherwise you will be best using a more resilient wireless solution such as Zigbee with a gateway to Wi-Fi.

Click to expand...

I've attended automation exhibition. But it was more stuffed with LoRa and more expensive analogues, including operator class Wi-Fi (which was used during Olympic games in London).
ZigBEE really is a leader for a budget friendly choice.
Thank you.