This letter investigates ultra-reliable low-latency communications (URLLC) operating over millimeter-wave (mmWave) frequencies, exploiting the multi-connectivity to enhance the robustness of URLLC. A user association problem is first formulated to maximize the throughput of enhanced mobile broadband (eMBB) users while guaranteeing the reliability constraint of URLLC users. We first utilize queueing theory and matrix geometric method to analyze the queueing system of the URLLC users, where the characteristics of multi-connectivity and channel blockage are both considered. Based on the results, we introduce an efficient algorithm to obtain the optimal solution to the user association problem. Simulation results validate the effectiveness of our analysis and algorithm.

中文翻译：

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毫米波超可靠低延迟通信用户协会

这封信调查了在毫米波（mmWave）频率上运行的超可靠的低延迟通信（URLLC），并利用多连接性来增强URLLC的鲁棒性。首先制定用户关联问题，以最大程度地提高增强型移动宽带（eMBB）用户的吞吐量，同时保证URLLC用户的可靠性约束。我们首先利用排队论和矩阵几何方法来分析考虑了多连接性和信道阻塞特性的URLLC用户的排队系统。基于结果，我们引入了一种有效的算法来获得用户关联问题的最佳解决方案。仿真结果验证了我们的分析和算法的有效性。