Instantaneous and average speed
Almost all of telematics devices transmit the instantaneous speed of the object. Calculation of the instantaneous speed is based on GPS data and may be a significant inaccuracy. Sometimes, there are reports of stationary objects with non-zero instantaneous speed.
Not at all clear what useful information carries the instantaneous speed in the telematic message. Control the exceeding of speed is not applicable due to a possible inaccurate value of speed.
One possible using an instantaneous speed in telematics systems - prediction of where the object can be in one (two) minute. In the picture below the green circle indicated the possible presence of the object in one minute (in the center of the circle was a message that the object has an instantaneous speed of 60 km/h).
This information can be useful if the data came in close to a real-time mode and displayed on the client with a slight delay.
Average speed is calculated by the two neighboring localization points. The average speed does not need to be stored in the history of messages. In certain situations, the average speed can also be with the error: GPS location data for a stationary object can be (and usually) different. In general, the average and instantaneous speed close enough:
The presence of non-zero average speed for fixed objects caused by inaccurate GPS locations in parking. But this is quite rare because time intervals in parking mode are large enough, and the distances are small.