This month's number of Popular Science magazine in US has a small article on some test work NASA did on one or more United 737s on the ramp with broadband radio emissions. Apparantly the broadband radio uses all kinds of frequenci4es and hops all over the place putting fundamental emissions and harmonics as well as whatever leaky IF gets out in frequencies used for transponders, ACAS/TCAS, and other supposidly protected bands.
US Federal Communications Commission appears to have approved the comemrcial broadband for 3GEN cell phones etc and must see visions of spectrum auctions dancing in it's head but does not appear concerned with effects on safety. The industry pooh poohs any concern also (big suprise).