Trees shouldn't block a signal, but a concrete and steel parking garage most certainly will absorb any radio / satellite signal.
I run a small fleet down in Texas and I've been looking at tracking options. I came across these guys. Has anyone used them? GPS Fleet Tracking...
We've done some oil field contracts in my fleet and the feedback is variable. I issue satellite phones as a back-up for going into cell-dead...
Jimmy Hoffa ... I keep a secondary "tool kit" that's a trauma / bug-out kit. I've seen some rough accidents that the kit came in handy for ......