Optimal Link Scheduling for Age Minimization in Wireless Systems
Optimal Link Scheduling for Age Minimization in Wireless Systems
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DOI：
10.1109/tit.2017.2746751
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发表时间：
2018-07-01
影响因子：
2.5
通讯作者：
Ephremides, Anthony
中科院分区：
文献类型：
--
作者：
He, Qing;Yuan, Di;Ephremides, Anthony
信息时代是最近引入的一个度量，用来表示通信系统中信息的新鲜度。我们研究了无线网络中的年龄最小化问题，并提出了一种优化调度策略的新方法，以尽可能地传递所有最新的消息。具体来说，我们考虑一组共享公共通道的链接。每个链路上的发送器包含给定数量的数据包，这些数据包带有来自生成它们的信息源的时间戳。我们以最小的总时间为目标来解决链路传输调度问题。这个最小时间调度问题（MASP）不同于最小化发送数据包的时间或延迟。我们对MASP进行了数学建模，并证明了它在一般情况下是np困难的。我们还确定了可处理的情况以及最优性条件。给出了一个用于性能基准测试的整数线性规划公式。在此基础上，提出了一种具有较好可扩展性的最速年龄下降算法。数值研究表明，与其他调度策略相比，采用最优调度策略可以显著降低总年龄。
Information age is a recently introduced metric to represent the freshness of information in communication systems. We investigate age minimization in a wireless network and propose a novel approach of optimizing the scheduling strategy to deliver all messages as fresh as possible. Specifically, we consider a set of links that share a common channel. The transmitter at each link contains a given number of packets with time stamps from an information source that generated them. We address the link transmission scheduling problem with the objective of minimizing the overall age. This minimum age scheduling problem (MASP) is different from minimizing the time or the delay for delivering the packets in question. We model the MASP mathematically and prove it is NP-hard in general. We also identify tractable cases as well as optimality conditions. An integer linear programming formulation is provided for performance benchmarking. Moreover, a steepest age descent algorithm with better scalability is developed. Numerical study shows that, by employing the optimal schedule, the overall age is significantly reduced in comparison to other scheduling strategies.