Minimizing Age of Information under Arbitrary Arrival Model with Arbitrary Packet Size

In networked systems such as internet-of-things, cyber-physical systems, etc., information timeliness is a critical requirement. Timely updates ensure that the information available at the subsystems (nodes) are accurate, and actions are well-coordinated. One popular metric to capture information timeliness is the age of information (AoI) 1. At any time, for a source-destination pair, AoI is equal to the time elapsed since the generation time of the latest update of the source that has been completely transmitted to the destination. Thus, at time t, the AoI Δ(t) = t - λ(t), where λ (t) denotes the generation time of the latest update of the source that has been completely transmitted until time t.