New Delhi, April 9 -- Ever found your mobile phone's signal to be patchy while waiting for a flight? That's because telecom operators can't provide stronger signals near airports, as these can interfere with a small cockpit tool-a radio altimeter.

The electronic gauge, which measures the altitude of an airborne plane, feeds data to multiple automated systems on board. A wrong reading can be a safety risk, especially during poor visibility. But the restrictions have sparked concerns as telecom operators expand 5G coverage and prepare for even stronger 6G networks.

Now, the civil aviation regulator has asked all airlines to modify the altimeters so that they are tolerant to 3,300-3,670MHz C-band-a key range of spectrum to provide 5G servi...