I'll certainly look at the report when my issue of IEEE Spectrum arrives, but according to the USA Today article, no attempt was made to see if RF emissions from cellphones had any effect on avionics or radionavigation. A study published in the IEEE Journal of Electromagnetic Compatibility a year or two ago specifically studied cellphone emissions from the passenger compartment on a commercial airliner (not in the air), and found that they were not on frequencies that could affect avionics or radionavigation.