Performance Modeling of Scheduling Algorithms in a Multi-Source Status Update System.

Age of Information (AoI) is a widely used metric of information freshness in a status update communication system. In this paper, we study the AoI performance in a multi-source system in which multiple sources generate updates, but only one can be transmitted to a monitor at a time. Scheduling, or selecting the source update to transmit, is an important problem in such a system. We consider a time-slotted system with Bernoulli sources with no buffer. An update selected for transmission in a slot is delivered at the end of the slot. The AoI is analyzed for four different scheduling policies - random scheduling, round robin scheduling, age-greedy scheduling, and the Whittle index-based policy proposed in [1], [2]. Our analytical results are validated with simulation results, and a numerical performance comparison of the scheduling policies is presented.