More info... (Score 1)

Thanks for all the feedback so far. Allow me to provide some more info as it seems my original question was a little ambiguous.

First, I am not really transmitting much info. A simple "signal is on" is ok... perhaps a bitmap, but that's it. I'm not transmitting audio/video/data at all. In terms of the broadcast stations, they must be mobile.

There can be no line of site.

I don't care who picks up the signal or what they do with it... the data is unimportant.

I just want to make sure no one can broadcast (or at least make it as hard as possible) the same signal.