The introduction of Motorola Type II SmartZone introduced the IntelliRepeater.
It is simply sophisticated software running on a Quantar repeater.
IR sites are generally used for a small geographic area or to fill in holes.
For sites that are used to fill in coverage traffic is very limited.
Once this happens radios resort to their programmed information which contains timing values that determine what to do once the timer runs out and there is still no control channel (Signal "Out of Range," switch sites, etc.)