Common GPS vehicle tracking systems use “cellular” GSM/GPRS based transponders. Once the device calculates position from the GPS satellites the transponder transmits the position to the cellular GSM/GPRS network of receivers (cell towers) in the area. At this point the GSM/GPRS system operator transports the data to your output device. Obviously the network operator charges a fee for this service, and is in control of your data as well.
Radio-based solutions are different in that the radio transponders transmit position over a mobile radio frequency, typically designated by a government administrative agency for your exclusive use. A GSM/GPRS system is not used; instead the operator of the radio system installs one or more receivers in position(s) around the area to be tracked. One receiver – or more exact: the connected RF antenna – is capable of covering an area of typically 10-25 mile radius from its own position, although this range might vary depending upon how high in elevation the receiving antenna is, and what the local terrain is like.
As the radio operator owns both the GPS position transmitters as well as the receiver(s), the fleet may transmit positions very frequently without concern for any fees, and with extremely fast delivery of data; allowing for true real-time position updates which common cellular solutions do not provide (or charge high fees for).
Often radio users install just one receiver, and mount it high atop a building, antenna tower, or point of elevation to cover the tracking area. This area might be a city, an open pit mine or other remote area, or a fleet of boats where the group can be tracked by other boats in the fleet. Since the entire system operates independently from any GSM/GPRS network, radio modems can work anywhere GPS satellite lock can be acquired. In fact, the entire system can be mobile and – in case of Raveon’s M7-GX series radios – any fleet member can receive GPS reports from other fleet members in radio range, even while all are moving at high speeds.
If a larger area of coverage is needed, or the tracking headquarter is not at a good location for area reception, a single radio repeater may be established at a preferred location where the repeater then wirelessly relays the transmissions it receives to the central tracking location. If the area of coverage is very large, then multiple receivers may be installed and connected together as well as to a central location via an IP backbone, which can include either a private network or the public internet. The determination of the proper receiver layout is based principally upon the area the system must cover for effective fleet tracking, as well as the local terrain.
Primarily the decision to install a radio-based tracking solution versus a common cellular system comes down to the area of tracking coverage required and the size of the fleet involved. Even the area of coverage required is vast, requiring a large number of receivers, and the fleet itself is small, and the cost per vehicle may become prohibitive. In these cases the operator must rely on a pre-installed network of GSM/GPRS system receivers owned and operated by another entity and pay their monthly fees. If GSM/GPRS service coverage is poor then an expensive communications satellite relay may be a considered alternative.