I determined the change in the signal strength of the network due to metal interference. I used the same setup as the previous experiment. Received Signal Strength Indicator (RSSI) was used as a metric to measure signal strength.
ESP32 WIFI (2.4 GHz)
A point to point connection was established using 2 ESP32 modules.
I have noticed that the ESP modules get significantly warm when used on WIFI for a few minutes.
NRF24l01 Modules (2.4 GHz)
A point to point connection was created using NRF24l01 modules. NRF24l01 module do not give a numeric RSSI value. It only displays whether the signal strength is above or below -64 dBm.
LoRa Modules (433 MHz)
A point to point connection was created using LoRa modules.