For future wireless networks, applications such as Industrial Internet of Things are strictly delay-sensitive. Meanwhile, millimeter-wave (mmWave) communication is a promising means to provide ultra-high data rate and ultra-low latency services to massive number of devices. In order to minimize uplink end-to-end delay in such machine-to-machine (M2M) mmWave communications, we investigate buffer-aided multi-hop relaying networks and formulate the problem as a multi-tier queueing system. We propose a Minimum-Delay relaying scheme, and by leveraging stochastic geometry, we present a tractable analytical framework to investigate the signal-to-interference-plus-noise-ratio (SINR) distribution of devices at each-tier, thereby computing the expected delay and delay outage probabilities using Lagrange optimization. A state-of-art max-SINR relaying scheme is analyzed for comparison, and the performance of Minimum-Delay relaying in 3-tier architecture is further analyzed. The derived average delay and delay outage probability are validated through simulations based on multiple cells in a dense urban scenario. Numerical results show that the proposed Minimum-Delay relaying scheme achieves significant lower average end-to-end delay than direct association or the max-SINR relaying scheme. Furthermore, results for Jain’s fairness and spectral efficiency reveal that the Minimum-Delay relaying scheme has even greater performance improvement under high traffic loads.

中文翻译：

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毫米波 M2M 网络：提高中继的延迟性能

对于未来的无线网络，工业物联网等应用对延迟非常敏感。同时，毫米波（mmWave）通信是一种向海量设备提供超高数据速率和超低延迟服务的有前途的手段。为了最大限度地减少此类机器对机器 (M2M) 毫米波通信中的上行链路端到端延迟，我们研究了缓冲辅助多跳中继网络，并将问题表述为多层排队系统。我们提出了一个最小延迟中继方案，并通过利用随机几何，我们提出了一个易于处理的分析框架来研究每一层设备的信号干扰加噪声比 (SINR) 分布，从而计算预期的延迟和延迟中断概率使用拉格朗日优化。分析了最先进的最大 SINR 中继方案以进行比较，并进一步分析了 3 层架构中最小延迟中继的性能。派生的平均延迟和延迟中断概率通过基于密集城市场景中多个小区的模拟进行验证。数值结果表明，所提出的最小延迟中继方案比直接关联或最大 SINR 中继方案实现了显着更低的平均端到端延迟。此外，Jain 的公平性和频谱效率的结果表明，最小延迟中继方案在高流量负载下具有更大的性能改进。派生的平均延迟和延迟中断概率通过基于密集城市场景中多个小区的模拟进行验证。数值结果表明，所提出的最小延迟中继方案比直接关联或最大 SINR 中继方案实现了显着更低的平均端到端延迟。此外，Jain 的公平性和频谱效率的结果表明，最小延迟中继方案在高流量负载下具有更大的性能改进。派生的平均延迟和延迟中断概率通过基于密集城市场景中多个小区的模拟进行验证。数值结果表明，所提出的最小延迟中继方案比直接关联或最大 SINR 中继方案实现了显着更低的平均端到端延迟。此外，Jain 的公平性和频谱效率的结果表明，最小延迟中继方案在高流量负载下具有更大的性能改进。