Interferrence??
I put it to you that if the max signal strength of 600mW from a mobile phone interferes with aircraft systems, then they must get a real belting from approach radar sweeps.
Haven't heard of any serious incidents caused by flying through a radar lobe on approach anywhere.
If the systems are so susceptible from internal EMF sources, I suggest the systems are in a serious state. My mobile phone can ring while sitting on my laptop and neither interferes with the other.