Opportunistic Spectrum Access: Does Maximizing Throughput Minimize File Transfer Time?
Opportunistic Spectrum Access: Does Maximizing Throughput Minimize File Transfer Time?
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DOI：
10.23919/wiopt52861.2021.9589243
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
Jie Hu;Vishwaraj Doshi;Do Young Eun
中科院分区：
文献类型：
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作者：
Jie Hu;Vishwaraj Doshi;Do Young Eun
为了利用授权信道的随机动态特性以机会主义的方式进行文件传输，已经为二级用户开发了随机频谱接入（OSA）模型。为面向吞吐量的应用程序设计信道感测策略的常见方法往往会最大化长期吞吐量，并希望它也能减少文件传输时间。在本文中，我们表明，这是不正确的，特别是对于小文件。与以前的延迟相关的作品，很少考虑异构信道速率和突发传入数据包，我们的工作明确考虑最小化的文件传输时间的一个单一的文件组成的多个数据包在一组异构信道。我们制定了一个数学框架的静态政策，并扩展到动态政策，我们的文件传输问题映射到随机最短路径问题。我们分析了我们提出的静态最优和动态最优的政策，最大限度地提高长期吞吐量的政策的性能。然后，我们提出了一个启发式的政策，考虑到性能复杂性的权衡和扩展到未知的信道参数的在线实现，也提出了我们的在线算法的遗憾界。我们还提出了数值模拟，反映我们的分析结果。
The Opportunistic Spectrum Access (OSA) model has been developed for the secondary users (SUs) to exploit the stochastic dynamics of licensed channels for file transfer in an opportunistic manner. Common approaches to design channel sensing strategies for throughput-oriented applications tend to maximize the long-term throughput, with the hope that it provides reduced file transfer time as well. In this paper, we show that this is not correct in general, especially for small files. Unlike prior delay-related works that seldom consider the heterogeneous channel rate and bursty incoming packets, our work explicitly considers minimizing the file transfer time of a single file consisting of multiple packets in a set of heterogeneous channels. We formulate a mathematical framework for the static policy, and extend to dynamic policy by mapping our file transfer problem to the stochastic shortest path problem. We analyze the performance of our proposed static optimal and dynamic optimal policies over the policy that maximizes long-term throughput. We then propose a heuristic policy that takes into account the performance-complexity tradeoff and an extension to online implementation with unknown channel parameters, and also present the regret bound for our online algorithm. We also present numerical simulations that reflect our analytical results.