GPS satellites broadcast location data

How does VLS work?  

Diplomat incorporates Global Positioning Systems (GPS) (1), two-way wireless communication (such as GPRS or iDEN) (2 and 3), a communications server (4) and the Internet (5) as part of DCS’s Vehicle Location Service.  

In-vehicle GPS receiver transmits location data, via wireless network to server Communication server interprets data, displays it on maps, and creates reports

Users access data on PCs, via Internet connection