Smart/Globe locator just simply uses SMS transmission of specific location of ur car. I think these cellular company uses a triangulization method of detecting a specific car. Its more accurate now depending on the density of the location and the number of cellsites around the tracked car. Basically sa MMla talagang accurate na sya and Luzon areas. Sa bandang Visayas and Mindanao mukhang ok nadin esp these 2 cos compete when it comes to the volume of their cellsites. So kahit di naka GPS medyo ok na din.