FlexTDMA for Delay-Stable Communications in Asynchronous Industrial Control Networks

To support closed industrial control networks the authors consider constant end-to-end delay with minimal delay-jitter support in an asynchronous network. The Rate Constrained Static Priority Rate-Jitter (RCSP-RJ) minimizes jitter while not providing full restoration of traffic at each switch. RCSP-DelayJitter (-DJ) provides jitter free network communication but requires a means of time coordination between switches. They introduce FlexTDMA that allows nearly constant delay bounds with minimal delay-jitter in an asynchronous network. FlexTDMA uses a token bucket to restore the arrival envelope of each flow. This eliminates delay-jitter, simplifies analysis of the network and avoids cyclic dependent issues in network analysis.