The problem with that approach is that the French are only allowing the blocking of cell phones under the caveat that "emergency" calls not be inhibited. Moreover, I am not at all convinced that you can get solid call blocking in the entirety of a given room without some fringe fields producing undesired effects outside of the room.

I see similar problems with the mini-cell site inside the room. What if you are right outside the room. There needs to be some way to definitively put the active cell phone in the room in order to charge the "nuisance fee."

What kind of timing resolution would one need in order to use triangulation down to, say six inches? Are there any '51 derivatives that can measure time that closely?