Joint and Competitive Caching Designs in Large-Scale Multi-Tier Wireless Multicasting Networks
Joint and Competitive Caching Designs in Large-Scale Multi-Tier Wireless Multicasting Networks
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DOI：
10.1109/tcomm.2018.2807445
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发表时间：
2018-02
影响因子：
8.3
通讯作者：
Ying Cui;Zitian Wang;Yang Yang-Yang;Feng Yang;Lianghui Ding;Liang Qian
中科院分区：
文献类型：
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作者：
Ying Cui;Zitian Wang;Yang Yang-Yang;Feng Yang;Lianghui Ding;Liang Qian
缓存和组播是支持多层无线网络中大量内容传递的两种有前途的方法。在本文中，我们考虑了一种随机缓存和组播方案，以两层的缓存分布为设计参数，以实现在两层大规模支持缓存的无线组播网络中高效的内容传播。首先，我们利用随机几何的工具分别推导出一般区域、高信噪比（SNR）区域和高用户密度区域的成功传输概率的易于处理的表达式。然后，对于两层只有一个操作符的情况，我们给出了在一般非凸的渐近区域内成功传输概率最大化的最优联合缓存设计问题。利用分块逐次逼近优化技术，提出了一种迭代算法，该算法收敛于一个平稳点。其次，对于两种不同的运营商，每层一个运营商，我们制定了竞争缓存设计博弈，其中每层在渐近区域内最大限度地提高其成功传输概率。我们证明了该博弈具有唯一的纳什均衡（NE），并采用迭代算法，该算法在温和条件下收敛于NE。最后，通过数值模拟，我们表明所提出的设计比现有方案取得了显著的进步。
Caching and multicasting are two promising methods to support massive content delivery in multi-tier wireless networks. In this paper, we consider a random caching and multicasting scheme with caching distributions in the two tiers as design parameters, to achieve efficient content dissemination in a two-tier large-scale cache-enabled wireless multicasting network. First, we derive tractable expressions for the successful transmission probabilities in the general region as well as the high signal-to-noise ratio (SNR) and high user density region, respectively, utilizing tools from stochastic geometry. Then, for the case of a single operator for the two tiers, we formulate the optimal joint caching design problem to maximize the successful transmission probability in the asymptotic region, which is nonconvex in general. By using the block successive approximate optimization technique, we develop an iterative algorithm, which is shown to converge to a stationary point. Next, for the case of two different operators, one for each tier, we formulate the competitive caching design game where each tier maximizes its successful transmission probability in the asymptotic region. We show that the game has a unique Nash equilibrium (NE) and adopt an iterative algorithm, which is shown to converge to the NE under a mild condition. Finally, by numerical simulations, we show that the proposed designs achieve significant gains over existing schemes.