POLLING

The Polling signal can come from anywhere in the world and transmits the current position of the Vehicle or Asset. It obtains it from the Global Positioning System Satellites (GPS) usually through the GPRS network or less commonly through the Satellite Communication System and transmits it back to Vehicle Tracking Systems' Servers. The GPS position, along with the time and any other information such as panic alarms, security alarms and door switches then is logged in the tracker and is available to clients through a Web Interface.

The limitation of using the GPRS system is that if there is no GPRS signal then the Polling signal will not be transmitted until the Vehicle or Asset next enters into a GPRS coverage area. However, because the DCM has a memory buffer all position signals along with the time will be transmitted to Vehicle Tracking Systems' Servers.

If clients want their data to be transmitted all the time irrespective as to if there is GPRS coverage or not then the Satellite Communication System is used, this is extremely expensive and usually reserved for the Military and Government purposes or in areas such as Afghanistan, Bosnia etc and where there is no GPRS coverage, or for Search and Rescue beacons.

The Cost of all GPRS Polling signals, (each is a separate GPRS call) are included in the Service Cost. The more frequent the Polling Signal interval is, the more accurate the Vehicles or Assets Trips are, which is why we use a one minute polling interval.

Changing the Polling Signal Interval

The Polling Signal Interval is determined by the programming of the DCM. This can be changed remotely by Vehicle Tracking Systems Limited. Changes to a Polling Interval may incur extra service costs.