We study the multi-user scheduling problem for minimizing the Age of Information (AoI) in cellular wireless networks under stationary and non-stationary regimes. We derive fundamental lower bounds for the scheduling problem and design efficient online policies with provable performance guarantees. In the stationary setting, we consider the AoI optimization problem for a set of mobile users travelling around multiple cells. In this setting, we propose a scheduling policy and show that it is $2$-optimal. Next, we propose a new adversarial channel model for studying the scheduling problem in non-stationary environments. For $N$ users, we show that the competitive ratio of any online scheduling policy in this setting is at least $\Omega(N)$. We then propose an online policy and show that it achieves a competitive ratio of $O(N^2)$. Finally, we introduce a relaxed adversarial model with channel state estimations for the immediate future. We propose a heuristic model predictive control policy that exploits this feature and compare its performance through numerical simulations.

中文翻译：

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固定和非固定环境中信息年龄的基本限制

我们研究了多用户调度问题，以在静止和非静止状态下最小化蜂窝无线网络中的信息时代 (AoI)。我们推导出调度问题的基本下界，并设计具有可证明性能保证的高效在线策略。在固定设置中，我们考虑一组移动用户在多个小区周围移动的 AoI 优化问题。在这种情况下，我们提出了一个调度策略并表明它是 $2$-最优的。接下来，我们提出了一种新的对抗性信道模型，用于研究非平稳环境中的调度问题。对于 $N$ 用户，我们表明在此设置中任何在线调度策略的竞争比率至少为 $\Omega(N)$。然后我们提出了一个在线策略，并表明它实现了 $O(N^2)$ 的竞争比率。最后，我们引入了一个轻松的对抗模型，对不久的将来进行信道状态估计。我们提出了一种启发式模型预测控制策略，该策略利用此功能并通过数值模拟比较其性能。