Minimizing Age of Information via Scheduling over Heterogeneous Channels
Minimizing Age of Information via Scheduling over Heterogeneous Channels
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DOI：
10.1145/3466772.3467040
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发表时间：
2020-12
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影响因子：
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通讯作者：
Jiayu Pan;A. Bedewy;Yin Sun;N. Shroff
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文献类型：
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作者：
Jiayu Pan;A. Bedewy;Yin Sun;N. Shroff
本文研究了当源可以通过两个异构通道传输状态更新时最小化信息年龄的问题。我们的工作受到5G毫米波技术的最新发展的推动，其中传输可能发生在不可靠但快速的（例如，毫米波）信道或慢可靠（例如，sub-6 GHz）信道。不可靠信道被建模为时间相关的Gilbert-Elliot信道，其中当信道处于“ON”状态时，信息可以以高速率传输。可靠信道提供确定性但较低的数据速率。调度策略确定用于传输的信道，目的是最小化信息的时间平均年龄（AoI）。最优调度问题被公式化为马尔可夫决策过程（MDP），这在我们的设置中提出了一些重大挑战，因为例如，超模块性不适用于状态空间的一部分。我们发现，存在一个多维的基于阈值的调度策略，是最佳的年龄最小化。进一步设计了一种低复杂度的二分法来计算最优阈值。数值模拟比较不同的调度策略。
In this paper, we study the problem of minimizing the age of information when a source can transmit status updates over two heterogeneous channels. Our work is motivated by recent developments in 5G mmWave technology, where transmissions may occur over an unreliable but fast (e.g., mmWave) channel or a slow reliable (e.g., sub-6GHz) channel. The unreliable channel is modeled as a time-correlated Gilbert-Elliot channel, where information can be transmitted at a high rate when the channel is in the "ON" state. The reliable channel provides a deterministic but lower data rate. The scheduling strategy determines the channel to be used for transmission with the aim to minimize the time-average age of information (AoI). The optimal scheduling problem is formulated as a Markov Decision Process (MDP), which in our setting poses some significant challenges because e.g., supermodularity does not hold for part of the state space. We show that there exists a multi-dimensional threshold-based scheduling policy that is optimal for minimizing the age. A low-complexity bisection algorithm is further devised to compute the optimal thresholds. Numerical simulations are provided to compare different scheduling policies.