It would be child's play for the NSA to accomplish this from orbit.....hmmmmm I wonder what they call it?
On the other hand, with enough directionality . . . . nah, the antenna would be a monster.
Actually, no it wouldn't. A yagi antenna at 800 Mhz is not very large at all. A 16 element at that frequency would probably be less than 5 feet long. Beans for a satellite to carry into orbit today. Of course the problem then is the beam will provide a fairly wide "spot" on the surface of the Earth that will still cover several cell sites. Although come to think of it, narrowed to area to adjacent sites you'll not have to contend with hearing two sites on the same frequency due to coordination. -- Pat Hykkonen, N5NPL Texas State Technical College at Waco Internet: {pat,postmaster,root}@tstc.edu Instructional Network Services Packet: N5NPL@WD5KAL.#CENTX.TX.USA.NA 3801 Campus Dr. Waco, Tx 76705 V:(817) 867-4830 F:(817) 799-2843