Cache-aided wireless device-to-device (D2D) networks have demonstrated more promising performance improvement for video distribution than conventional distribution methods; thus, understanding the fundamental scaling behavior of such networks is highly important. However, the existing scaling laws for multi-hop networks are not optimal even in the case of Zipf popularity distributions (gaps between upper and lower bounds are not constants); furthermore, there are no scaling law results for such networks for the more practical case of a Mandelbrot-Zipf (MZipf) popularity distribution. We thus in this work investigate the throughput-outage performance for cache-aided wireless D2D networks adopting multi-hop communications, with the MZipf popularity distribution for file requests and users distributed according to Poisson point process. We propose an achievable content caching and delivery scheme, and then analyze its performance. We obtain the optimal scaling law by showing that the achievable performance is tight to the proposed outer bound. Since the Zipf distribution is a special case of the MZipf distribution, the optimal scaling law for the networks considering the Zipf popularity distribution is also obtained, which closes the gap in literature.

中文翻译：

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缓存辅助无线多跳 D2D 网络的最优吞吐量-中断分析


缓存辅助无线设备到设备 (D2D) 网络已证明比传统分发方法更有希望提高视频分发性能；因此，了解此类网络的基本扩展行为非常重要。然而，即使在 Zipf 流行度分布的情况下（上限和下限之间的差距不是常数），多跳网络的现有缩放法则也不是最优的；此外，对于 Mandelbrot-Zipf (MZipf) 流行度分布的更实际情况，此类网络没有缩放定律结果。因此，我们在这项工作中研究了采用多跳通信的缓存辅助无线 D2D 网络的吞吐量中断性能，文件请求的 MZipf 流行度分布和根据泊松点过程分布的用户。我们提出了一种可实现的内容缓存和交付方案，然后分析其性能。我们通过证明可实现的性能紧邻所提出的外界来获得最佳缩放定律。由于Zipf分布是MZipf分布的特例，因此还获得了考虑Zipf流行度分布的网络的最优缩放法则，这弥补了文献中的空白。