The technology that uses a constellation of satellites to provide accurate location information to mobile devices is commonly referred to by its initials, which stand for Global Positioning System. This service uses the timing of signals from multiple satellites to calculate the receiver's position on Earth. The other options listed refer to different wireless technologies or services. Cellular triangulation uses the signal from phone towers to determine a less accurate position, while the remaining options, are used for short-range wireless communication and data transmission, not for pinpointing geographic location.