Age-of-Information in Networks with Periodic Workflow

We derive a description for the Age-of-Information distribution in a system whose activities are strictly limited to periodic instances on a global time grid. In particular, one agent periodically generates updates while the other agent periodically uses the most recently received of those updates. Likewise, transmission of those updates over a network can only occur periodically. All periods may differ. We use a network model which, among others, accounts for stochastic transmission failure, making the results applicable to instances with wireless communication. A suitable approximation for the expected Age-of-Information and an upper bound for its largest occurring value are developed. Additionally, we present numerical results on the approximation error based on extensive evaluations over a tight parameter space.