Non-regular update packet transmission
The source host can model the prediction algorithm being used by the remote 
  host.
The host only needs to transmit updates when there is a significant divergence 
  between the object’s actual position and the remote host’s predicted 
  position.
Only transmit an update when an error threshold is reached or after a timeout 
  period (heartbeat).
Entities must have a “heartbeat” otherwise cannot distinguish 
  between live entities and ones that have left the system.
U.S. Army’s SIMNET, the DIS standard, NPSNET, PARADISE.