I saw a TV ad for the OnStar (sp?) system the other day. The one where this guy locks himself out of his GM car in the middle of nowhere. Fortunately (for him) he has his cell phone so he calls somebody and from some control room somewhere (it looks like Mission Control in Houston) they push a button and his car doors magically unlock. Neat trick.
But my question is this. I know how GPS works but how does someone remotely unlock his doors? Does the Satellite send a signal to his car? Does his car have a dish hidden somewhere.
And what would happen if he was stick in the middle of a tunnel? At first I thought it had something to do with cellular phone cells but that doesn’t work in the middle of nowhere…
So how does this trick work?