Torres
GSM (digital) mobiles are generally in the 900Mhz band (860 to 920Mhz) with some small cells in the 1800Mhz band to fill holes in the concrete jungles.
I can see where some of the aruments are coming from and suspect the interference may come from sideband and digital slew products
BUT
if the aircraft systems are effected by the miniscule power levels involved they should be subjected to a very serious EMF susceptabliity check and have the faults rectified PDQ.
I for one would not be happy flying in an electronically controlled box so easily interrupted by stray pulses.