论文标题
物联网中信息变化的平均年龄
Average Age of Changed Information in the Internet of Things
论文作者
论文摘要
在关键任务的物联网（IoT）应用程序中，必须进行状态更新的新鲜感。最近，已经提出了信息时代（AOI）来衡量接收器更新的新鲜度。但是，AOI只会随着时间的流逝而表征新鲜感，但忽略了内容的新鲜感。在本文中，我们介绍了一个新的性能指标，更改信息的年龄（AOCI），该指标既捕获时间的流逝又捕获了信息内容的变化。另外，我们在时间宣传的状态更新系统中检查了AOCI，其中传感器采样物理过程并以成本传输更新数据包。我们制定了马尔可夫决策过程（MDP），以找到最大程度地减少AOCI加权和更新成本的最佳更新策略。特别是，在特殊情况下，物理过程是由具有均等过渡概率的两态离散时间马尔可夫链建模的，我们表明，最佳策略是相对于AOCI的阈值类型，并得出了阈值的封闭形式。最后，进行模拟以表现出阈值政策的性能及其优越性比零等基线政策。
The freshness of status updates is imperative in mission-critical Internet of things (IoT) applications. Recently, Age of Information (AoI) has been proposed to measure the freshness of updates at the receiver. However, AoI only characterizes the freshness over time, but ignores the freshness in the content. In this paper, we introduce a new performance metric, Age of Changed Information (AoCI), which captures both the passage of time and the change of information content. Also, we examine the AoCI in a time-slotted status update system, where a sensor samples the physical process and transmits the update packets with a cost. We formulate a Markov Decision Process (MDP) to find the optimal updating policy that minimizes the weighted sum of the AoCI and the update cost. Particularly, in a special case that the physical process is modeled by a two-state discrete time Markov chain with equal transition probability, we show that the optimal policy is of threshold type with respect to the AoCI and derive the closed-form of the threshold. Finally, simulations are conducted to exhibit the performance of the threshold policy and its superiority over the zero-wait baseline policy.
