Editing Automatic vehicle location (section)

{{short description|Means for automatically determining and transmitting the geographic location of a vehicle}}
'''Automatic vehicle location''' ('''AVL''' or ~'''locating'''; '''telelocating''' in EU) is a means for automatically determining and transmitting the [[Geographic coordinate system|geographic location]] of a [[vehicle]].  This [[vehicle location data]], from one or more vehicles, may then be collected by a [[vehicle tracking system]] to manage an overview of vehicle travel. 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.{{Citation needed|date=May 2017}} 

Most commonly, the location is determined using [[Global Positioning System|GPS]] and the transmission mechanism is [[SMS]], [[GPRS]], or a satellite or terrestrial radio from the vehicle to a radio receiver. A single antenna unit covering all the needed frequency bands can be employed. [[GSM]] and [[Evolution Data Optimized|EVDO]] are the most common services applied, because of the low data rate needed for AVL, and the low cost and near-ubiquitous nature of these public networks. 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.
Other options for determining actual location, for example in environments where GPS illumination is poor, are [[dead reckoning]], i.e. [[inertial navigation]], or active [[RFID]] systems or cooperative [[Real-time locating system|RTLS]] systems. These systems may be applied in combination in some cases. In addition, terrestrial [[radio positioning]] systems using a low frequency switched packet radio network have also been used as an alternative to GPS based systems.