How to block bluetooth signals

[Børre]

How do I block Bluetooth signals ? (I want the signals to be transmitted 180 degrees, not 360 degrees)

I have read it could be done with aluminium foil, but I have not tried it.

[MartinBL]

Yes I guess some sort of shielding is the only way to do it. I think it might work very well in open air (in theory), but if you plan to do this inside with walls, furniture, etc, you will have lots reflections that might ruin your plans.