As of 2017, GPS technology has reached the point of having the transmitting device be smaller than the size of a human thumb (thus easier to conceal), able to run 6 months or more between battery charges, easy to communicate with smartphones (merely requiring a duplicate SIM card from one's mobile phone carrier in most cases) — all for less than $20 USD.
The low bandwidth requirements also allow for satellite technology to receive telemetry data at a moderately higher cost, but across a global coverage area and into very remote locations not covered well by terrestrial radio or public carriers.
AVL is often utilized by government agencies, such as Public Safety and Parks and Recreation, to track the movement of patrol units, emergency responders, and field workers.
Another purpose of tracking is to provide graded service or to manage a large driver and crewing staff effectively.
For example, suppose an ambulance fleet has an objective of arriving at the location of a call for service within six minutes of receiving the request.
[1] Amateur radio and some cellular or PCS wireless systems use direction finding or triangulation of transmitter signals radiated by the mobile.
The LORAN system was intended for ships but signal levels on the US east- and west-coast areas were adequate for use with receivers in automobiles.
Because of the limited resolution, this type of system was impractical for small communities or operational areas such as a pit mine or port.
In the simplest systems, data from the GPS receiver is displayed on a map allowing humans to determine the location of each vehicle.
For example, the computer assisted dispatch system may check the location of a call for service and then pick a list of the four closest ambulances.
In centers with computer-aided dispatch, the system may assign an address to the call based on these coordinates or may project an icon depicting the caller's location onto a map of the area.
With an open bus system the users can send invoices based on goods delivered with exact location, time and date data where if connected to scale, RFID or barcode readers, can make a fairly good automated system to avoid human errors.
Later by analyzing log-file it is possible to get reports on any kind of events, like stops, visited streets, speed limits violations, etc.
If, for example a thief breaks into your car and attempts to steal it, the tracking system can be triggered by the immobiliser unit or motion sensor being activated.
Without needing to call each driver to check his location the dispatcher can pinpoint the nearest recovery vehicle and assign it to the new job.
An example of this distinction is given in the following scenario; A construction company owns some pieces of plant machinery that are regularly left unattended, at weekends, on building sites.
Thieves break onto one site and a piece equipment, such as a digger, is loaded on the back of a flat bed truck and then driven away.