Andrasz
1G analogue mobile phones were a major problem. At that time I was involved in flight inspection (testing Navaids, including the ILS). I calibrated our kit every month, on the test bench. Looking at the Glideslope indicator I could get it to go full scale up or down as I walked up and down the workshop, about maximum distance of 20m, with my mobile in my pocket Our kit was installed and earthed to at least the same standards found in aircraft, and arguably to a far higher earthing standard. The cellphone was not making a call, it was communicating with the base station on an “overhead” channel or 2. I have no experience with 2, 3, 4 or 5g.