Most industry standard GPS receivers do a very good job of calculating where you are , but additional methods are required for transmitting this information to another location — so that other people also know where you are. Generally this is accomplished using an existing Cellular network (such as AT&T). The GPS information from the receiver is transmitted to the Operations Center via the cellular provider — were the data is then collected from multiple GPS receivers — and deciphered such that it can be displayed on a graphical track plan on a central office system workstation.