I would doubt very much if they jam any presidential or secret service
communications; or any public safety communications system since they would
also be extensively involved in presidential security. Then there are the
multitude of frequencies used by the various media involved in covering the
event.

So there has to be large holes in the jamming spectrum - I would suspect the
jamming is quite selective and devoted to those frequencies determined to
pose a threat, just as military jamming is designed to deny useage of
specific frequencies or bands while permitting use of their own equipment.
It is a quite complex, and possibly dynamic, problem.

Dave

"Jim Douglas" wrote in message
...
Wondering how they jam stuff around the President when he's speaking
inside
and outside, I would imagine the cell phones are dead, but wonder what
else?

"Jim" wrote in message
m...
I want to create "no RF zone" for a size of 2 football fields. Would
satellite
jamming be the only option? Any thoughts?