We have a customer, a 3G mobile network provider, 
who wants to implement a vehicle tracking service.  
We need a reliable GPS vehicle tracking device that can send 
updates back to the base station on a 3G WCDMA SIM card.  
We prefer a device that sends only when car electrical system is on, 
so signals can be powered by car battery with only programming 
and memory on internal battery.  We also prefer a device that is 
able to log position in some kind of memory storage for uploading 
when cell phone signal is lost.