Traffic shaping to reduce jitter in controller area network (CAN)

When a message is transferred from one CAN bus to another via a gateway, variability in the response time of the message on the source network typically translates into queuing jitter on the destination network. This jitter inheritance accumulates across each gateway and can significantly impact the schedulability of lower priority messages. In this paper, we show that the real-time performance of the network can be enhanced by a simple method of traffic shaping that eliminates this inherited queuing jitter. This method does not require access to global time, nor does it require precise time-stamping of when messages are received at the gateway or blocking read calls. It can also be extended to account for clock drifts between networks.