# When to Preempt in a Status Update System?

arXiv: https://arxiv.org/abs/2402.00845 · HTML: https://mlsanity.com/paper/2402.00845/

## Key facts

- Cited by 1 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 1 Feb 2024.

## Built on by (most cited first, 1 of 1)

- [Policy Gradient Algorithms for Age-of-Information Cost Minimization](https://mlsanity.com/paper/2512.11990/) (2025)

## Abstract (arXiv)

We consider a time-slotted status update system with an error-free preemptive queue. The goal of the sampler-scheduler pair is to minimize the age of information at the monitor by sampling and transmitting the freshly sampled update packets to the monitor. The sampler-scheduler pair also has a choice to preempt an old update packet from the server and transmit a new update packet to the server. We formulate this problem as a Markov decision process (MDP) and find the optimal sampling policy. We find a sufficient, and also separately a necessary, condition for the always preemption policy to be an optimal policy. We show that it is optimal for the sampler-scheduler pair to sample a new packet immediately upon the reception of an update packet at the monitor. We propose a double-threshold sampling policy which we show to be an optimal policy under some assumptions on the queue statistic.