Today's mobile phone technology troubles 4159
That's not how FAA regulations work. All RF devices are banned during flight unless there's a specific regulation or waiver allowing them, and the FAA has not done so.
The avionics in airliners have, for the most part, not been certified as being immune to cell phone emissions. That means, under current FAA regulations, the FAA cannot grant waivers allowing cell phones because they haven't been proven to be safe. Proving they're dangerous is unnecessary. That's the mentality at the FAA.
Several groups have done unofficial tests that appear to show there's no danger, but those tests did not meet the FAA's requirements for a variety of reasons. Nobody has ever done tests under the FAA's rules, so there are no official results to report and nothing for the FAA to act on.
I've never been able to uncover any FAR that specifically covers cell phones, but they're obviously covered under the general FAR against RF equipment. The FCC, however, has specifically banned airborne cell phone use due to the impact it has on towers, so there's no point in anyone bothering to make the planes cell-phone-safe because the FCC wouldn't play ball even if the FAA did.
-- Stephen Sprunk "God does not play dice." --Albert Einstein CCIE #3723 "God is an inveterate gambler, and He throws the K5SSS dice at every possible opportunity." --Stephen Hawking
Today's mobile phone technology troubles 4160
Not at all. Design criteria have changed. It used to be that robustness trumped efficiency; this has now been reversed, and cost trumps...